Research Article
Adel Dezyani; Aman Mohammad Ziaiifar; Seyed Mahdi Jafari; Mohammad Ghorbani; Alireza Sadeghi Mahoonak
Abstract
Introduction: High sensitivity of fruit and vegetables juices to heat has been resulted to the development of spray drying method for drying this category of products. Spray drying is a well-established and widely used method for transforming a wide range of liquid food products into powder form. The ...
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Introduction: High sensitivity of fruit and vegetables juices to heat has been resulted to the development of spray drying method for drying this category of products. Spray drying is a well-established and widely used method for transforming a wide range of liquid food products into powder form. The process involves spraying finely atomized solutions into a chamber where hot dry air rapidly evaporates the solution leaving the spray-dried particles. Spray-dried powders can be stored at room temperature for prolonged periods without compromising the powder's stability. Powders are cheaper to transport and easier to handle in manufacturing plants. Spray-dried powders are economical to produce compared to other processes, such as freeze-drying. Spray drying has many applications, particularly in the food, pharmaceutical and agrochemical industries. The conversion of high value food materials, such as fruit and vegetable extracts, into particulate form is not easy due to the presence of a high proportion of low molecular weight sugars in their composition which lead to the problem of stickiness. The particles stick to one another, to the dryer and to cyclone walls and remain there, forming thick wall deposits, while very little product comes out at the dryer's exit. This might lead to low product yield and operating problems. In general, the stickiness causes considerable economic loss and limits the application of spray drying on foods as well as on pharmaceutical materials. In order to reduce stickiness, different solutes have been used as carriers and coating agents for the spray drying. Some examples of these are Arabic gum, maltodextrins, starches, gelatin, methyl cellulose, gum tragacanth, alginates, pectin, silicon dioxide, tricalcium phosphate, glycerol monostearate and mixtures of some of them. Of these additives, maltodextrin offers a good compromise between cost and effectiveness. It has been found that it contributes to the retention of some food properties, such as nutrients, color and flavor, during spray drying and storage. On the other hand, the feed flow rate, the inlet and outlet air temperatures, atomizer speed, feed concentration, feed temperature and inlet air flow rate are important factors that have to be controlled in a spray drying process. Tomato paste is a typical example of a product that is very difficult to be spray dried due to the low glass transition temperature of the low molecular weight sugars present.
Materials and methods: This study was carried out to evaluate the effect of inlet air temperature of dryer (120, 150 and 180 °C) and concentration of drying aid or carrier agent of maltodexterin along with whey protein concenterate ratio of 4 to 1 (25, 37.5 and 50% w/w) on the quantitative and qualitative properties of tomato paste powder including moisture content, bulk density, solubility, powder morphology, amount of lycopene, and production efficiency. Response surface methodology was used to choose optimum conditions of the powder production process.
Results and Discussion:the results revealed that the production efficiency (not significant) and solubility (significant) were increased with increased higher inlet air temperatures of dryer; however, at these conditions moisture content (significant), bulk density (not significant) and amount of lycopene (significant) in the powder were decreased also higher concentrations of carrier agent increased the production efficiency, solubility and amount of lycopene in the powder; however, moisture content and bulk density of powder were decreased.
Conclusion: Optimal conditions in order to achieve maximum production efficiency, solubility, the amount of lycopene and the lowest moisture content of powder, bulk density were achieved at inlet temperature of 150°C and carrier agent concentration of (w/w) 50%.
Research Article
Amir Pourfarzad; Mahdi Karimi; Zahra Ahmadian; Sudiyeh Hejri-Zarifi; Siamak Gheibi
Abstract
Introduction: Flat breads are the main dietary staple in many Middle Eastern and North African countries. In today’s demanding world, the use of bread improvers has become an indispensable part of enhancing the quality of bakery products. Bread improvers are technically sophisticated blends of functional ...
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Introduction: Flat breads are the main dietary staple in many Middle Eastern and North African countries. In today’s demanding world, the use of bread improvers has become an indispensable part of enhancing the quality of bakery products. Bread improvers are technically sophisticated blends of functional ingredients, which if formulated correctly, will enhance the development of dough structure, facilitate trouble-free production, and provide the desired result of consistent products having optimal quality at the lowest possible cost. Among the functional food additives, polyols have been increasingly used to improve the quality and shelf life of bread. Polyols have been used successfully to extend the shelf life of ready to eat bread used by the military, Barbari bread fortified with soy flour, as well as flour tortillas. Emulsifiers, a subset of surfactants, have been widely used by the baking industry. The function of surfactants, as crumb softening agents, is closely related to their interaction or complex formation with starch, particularly the linear amylose fraction, to retard bread staling. Surfactants, such as SSL and DATEM that are the most efficient in breadmaking are able to form lamellar mesophases or gel structures in water. It has been shown that for polar lipids the lamellar liquid-crystalline phase is the most effective form in which this component can be added to bread dough in order to improve loaf volume. Mechanical properties of dough play an important role in baking industries. In a few cases, it can be desirable, for example, to fix some ingredients on bakery products. The dough is expected not to stick to metal surfaces and to show a good resistance to vibration and mechanical shock to minimize detrimental effects such as process breakdown, production loss and contamination of the equipment. Thus, the present study was designed: (a) to examine the effects of different emulsifiers (sodium stearoyl-2-lactylate and diacetyl tartaric acid esters of monoglycerides) and polyol (propylene glycol) on Barbari flat bread performance when used singly and in combination at different levels; (b) to obtain the relationship between mechanical and rheological properties of dough and quality, shelf life, sensory and image parameters of bread using the asymmetric methods (response surface methodology and partial least squares regression) and symmetric methods (coefficients of determination and Principal components analysis) and (c) to determine the optimum formulations for Barbari flat bread improver.
Materials and methods: Commercial Triticum aestivum wheat flour (locally named Setareh) was procured from the AceeArd Co., Khorasan, Iran. Propylene glycol (PG) was purchased from J.T. Baker Chemical Company (Phillipsburg, NJ). Sodium stearoyl-2-lactylate (SSL) and diacetyl tartaric acid esters of monoglycerides (DATEMs) were provided by Vista Tejarat Company (Tehran, Iran). Moisture, ash, fat, protein, wet gluten and falling number were determined according to standard AACC methods. Three replications were taken for each characteristic. Gel samples were prepared using sodium stearoyl-2-lactylate (SSL), diacetyl tartaric acid esters of monoglyceride (DATEM) and propylene glycol (PG) in the range of 0-0.5 g/100g. Bread making was carried out according to the method of Maleki et al. (1981). Quality analysis of fresh bread samples was carried out by measuring specific volume. Sensory attributes of bread were selected according to the Iranian flat bread evaluation method, including bread form and shape; upper surface property; bottom surface property; cavity and porosity; firmness and softness of texture; chewiness; odor, flavor and taste and overall quality score. Staling phenomenon and its changes were evaluated by penetration test after 1 hour, 3, 5 and 7 days. The average values of L*, a*and b* colors describing the outer crust regions were obtained. The crumb grain features were the mean cell area, porosity, and cell density. A central composite design was constructed using the software Design Expert Version and was used for sampling of different combination of gel constituents. In addition, Lack of fit, coefficients of determination (R2), adj-R2, coefficient of variation (CV) and significant probabilities were calculated to check the model adequacy. Multivariate correlation matrix, coefficients of determination and principal components analysis were performed by using Minitab 15 software.
Results and Discussion: The characteristics of the flour are in the range of typical values of medium strong flour, suitable for Iranian Barbari flat bread. The results showed dough adhesiveness was increased by SSL addition but it was decreased by quadratic effect of SSL like as resilience. All of three components to the gel formula caused decrement in the hardness, gumminess and chewiness. But the interaction of them influenced on them. On the other hand, although cohesiveness increased by addition of all components but influenced significantly by interaction of them. Dough mechanical properties were furthermore correlated with dough farinographic aspects, quality, sensory parameters, image processing and shelf life of bread. It was proved that principal components analysis (PCA) is able to extract relevant information and offer an easy and promising approach for the interpretation of dough mechanical properties and its correlation with other properties and dough and bread. Partial least squares regression (PLSR) models were applied to determine the relationships between dough mechanical properties and dough farinographic properties, bread quality, sensory, image processing and shelf life aspects. Results from statistical analysis suggest that the mechanical parameters of dough are capable in predicting more than 50% of dough and bread properties
Research Article
Elham Sadati gol afshani; Seyed Mahdi Jafari; Mahdi Kashani-Nejad; Shahram Beiraghi-Toosi; Mohammad Ganjeh
Abstract
Introduction: Osmotic dehydration involves the partial removal of water by direct contact of a product with a hypertonic medium such as high concentration of sugar, salt or sugar-salt solutions. In this process, food pieces are immersed in a hypertonic solution. The natural membrane of food cells acts ...
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Introduction: Osmotic dehydration involves the partial removal of water by direct contact of a product with a hypertonic medium such as high concentration of sugar, salt or sugar-salt solutions. In this process, food pieces are immersed in a hypertonic solution. The natural membrane of food cells acts as a semipermeable layer so the water moves across the membrane from an area of high water potential (low solute concentration) to an area of low water potential (high solute concentration), meaning the driving force for water removal is the concentration gradient between the solution and the intracellular fluid. During osmotic dehydration, osmotic solute is absorbed by food materials and has undesirable effects on water removal, nutritional and organoleptic properties. Use of coating improves the osmotic processing. Best factor for evaluation of coating material is performance ratio (WL/SG). So a coating should reduce solid uptake without negative effects on water removal.
Materials and methods: The apples (Golden delicious) used in this study were purchased from a local market in Mashhad (Iran) and stored at 4-6°C before processing. The sucrose (99.9%, Fariman sugar company, Iran), carrageenan (kappa type, Negin Khorak Pars Company, Iran), carboxy methyl cellulose (sandros, Japan) and calcium chloride (Dr. Mojallali Lab., Iran) were also used. In this work, apple cubes were single and double coated in three concentrations (0.5, 1 and 1.5% w/w) of carboxy methyl cellulose (CMC) and carrageenan solution and dehydrated osmotically in different concentrations (30, 45 and 60˚ BX) of sucrose solutions.
Results and Discussion: The results of this study indicated that increasing coating solution concentration from 0.5% to 1.5% decreased water loss. Also the water loss increased when the number of coating layers and the concentration of osmotic solution increased (from 30 to 60 ˚ BX). Generally, water loss and solids uptake in the samples coated with carrageenan was higher and lower than their CMC counterparts, respectively. The solids uptake in the samples coated with CMC increased by increasing the number of layers, osmotic solution concentration (from 30 to 60˚BX) and coating solution concentration (from 0.5 to 1.5%). The solids uptake increased and decreased with increase in layer number and coating solution concentration (from 0.5% to 1.5%), respectively. Increasing the osmotic solution concentration up to 45 ˚ BX increased solids uptake but, more increasingly did not have a significant effect on it. Finally, it cannot be said strictly that one coating type would facilitate osmotic process or not. It depends on various process factors. Among the 36 treatments studied in this research, the single coated samples with 1% carrageenan treated in 60 ˚ BX sucrose solution and the single and double coated samples with 0.5% CMC treated in 45 ˚ BX sucrose solution were the best, as they had 50% higher performance ratio than control (uncoated) sample.
Research Article
Hamed Beyki; Nasser Hamdami; Jalal Pourtaghi
Abstract
Introduction: Heat treatment of potato tissue involves chemical, physical and structural changes. The magnitude of these changes will depend on the extent of thermal processing in terms of time and temperature. Blanching is a heating process that used to inactivate enzymes, de-aeration and modification ...
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Introduction: Heat treatment of potato tissue involves chemical, physical and structural changes. The magnitude of these changes will depend on the extent of thermal processing in terms of time and temperature. Blanching is a heating process that used to inactivate enzymes, de-aeration and modification of texture, preserving color, flavor and nutritional value of fruits and vegetables prior to freezing, canning, drying and frying. Temperature and time of blanching is largely determined by the amount of reducing sugars and textural characteristics of the species. In the previous studies performed on the changes of reducing sugars content in potatoes during blanching, some researchers found evidence that besides the mass transfer to the bath there exists an internal generation of reducing sugars, probably due to an enzymatic hydrolysis of starch. Therefore when predicting the concentration of reducing sugars changes, both mechanisms should be considered. Considering that no study has been done on the effect of internal generation of reducing sugars on their effective diffusivity during blanching and so far there is no comprehensive study on the kinetic of texture changes during blanching of potato at different temperatures and also direct relationship of reducing sugars with Maillard reaction and acrylamide formation in potato, therefore the aims of this study are: 1) determination of effective diffusivity of reducing sugars with and without consideration of them generation and 2) investigation of kinetic of texture changes during blanching of potato strips at the temperature range of 50-90 ºC and modeling of these phenomena.
Materials and methods: Potatoes (variety Agria, ~23 g/100g (dry basis)) was the raw material used in this study. Potatoes stored in a dark room at 20 ºC for 2 weeks were washed and peeled. Then, were striped into dimensions of 0.8×0.8×8 cm using an electric striping machine (Halldeh, model RG-100). Raw potato strips were rinsed immediately after cutting for 1 min in distilled water to eliminate the starch material adhering to the surface prior to blanching. Then, blanching was accomplished by immersing the potato strips in hot distilled water (ratio of mass of potato to water of 1:20) at 50, 60, 70, 80 and 90 ºC. To investigate the kinetic of generation of reducing sugars, strips packaged in duplex in the polyethylene (HDPE with 10 micron thickness) film were immersed in hot distilled water to blanching at the temperatures. Samples were withdrawn after 5, 10, 15, 20, 40, 60, 80, 100 and 120 minutes to measure the reducing sugars content and texture firmness. All experiments were done in triplicate. Maximum stress caused by penetrating of the probe (diameter of 2 mm) into strip texture was the texture evaluation index. To describe the mass transfer (extraction of reducing sugar) during blanching, a three dimensional numerical model based on finite difference method of solving Fick's Second Law has been developed in MATLAB software. The first order kinetic with production rate limiting effect was used to describe the potato strips texture changes during blanching. All experiments were done in triplicate as factorial based on completely randomized design. Data analysis and plotting of figures were performed in SAS and Excel software respectively.
Results and Discussion: The results showed that increasing of blanching temperature increase the reducing sugars effective diffusion coefficient significantly (P
Research Article
Mina Kargozari; Morteza Jamshid EIni
Abstract
Introduction: The osmotically dehydrated carrots can be added directly into soups, stews or can be used in a broad range of food formulations including instant soups, snack seasoning and etc. Osmotic dehydration is a suitable way to produce the shelf-stable products or partially dehydrated foods ready ...
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Introduction: The osmotically dehydrated carrots can be added directly into soups, stews or can be used in a broad range of food formulations including instant soups, snack seasoning and etc. Osmotic dehydration is a suitable way to produce the shelf-stable products or partially dehydrated foods ready to place in other complementary processes such as air-drying, freezing and others. Modeling can certainly make differences in the food industry, leading to reduced costs and increased profitability. In food technology, at the simplest level, there are equations that determine the relationship between two or more variable. Simulation models in operation units and food preservation systems have attracted much attention in the past four decades. The mathematical equations describing mass transfer during osmotic dehydration, allow a better understanding of the composition of the material and operating parameters during dewatering. In this regard, many experimental and theoretical models have been reported in the literature but experimental models have more popularity because of easier applications. Regarding the classification of modeling in food processes, kinetic models are classified among theoretical models. It was ideal if we could use kinetic models based on fundamental scientific theories for the purposes of prediction and controlling the changes that occur in real food systems. But the complexity of the food makes the direct application of basic models impossible. The alternative is the direct study of kinetics on real food. As a result, the obtained models would be experimental or semi-experimental. Kinetics has developed as a powerful tool in modeling food quality features and in other words the modeling of food quality estimation is almost equivalent to the modeling of reaction kinetics in foods. The present study aimed to evaluate kinetics of osmotic dehydration of carrot cubes in terms of solid gain and water loss, which was studied at three glucose syrup concentration levels (30, 40 and 50% w/w), three salt concentration levels (5, 10 and 15% w/w) and three temperature levels of osmotic solution (30, 40 and 50°C) for 240 min. The experimental data were fitted to different semi-empirical kinetic models including Magee, Peleg and Page.
Materials and methods: Fresh well graded carrots were washed and peeled manually. A vegetable dicer was used to prepare carrot cubes of dimensions 1 cm× 1cm× 1 cm. The cubes were washed with fresh water to remove the carrot fines adhered to the surface of the fruit. The initial moisture content of the fresh carrot cubes varied from 86% to 90% (wet basis). Considering the greater effectiveness of a mixture of solutes over a single solute, a binary solution of salt and glucose syrup was used as the osmotic solution. The samples were excluded from the osmotic solution after 15, 30, 60, 120, 180 and 240 minutes. Carrot cubes were then washed with deionized distilled water, and were dried using a paper towel. Evaluation of mass exchange between the solution and sample during osmotic dehydration were made by using water loss and solid gain parameters. The experimental data were then fitted to different semi-empirical kinetic models including Magee, Peleg and Page which are widely used in biologic fields and the parameters of the models were determined. Data fitting was conducted using Microsoft Excel spreadsheet (Microsoft Office, 2010) using SOLVER add-in. Coefficient of determination (R2), chi-squared (χ2) and root mean square error (RMSE) were used to determine the best suitable model. An analysis of variance was conducted to determine the significant effects of process variables on solid gain and water loss.
Results and Discussion: At the beginning of the osmotic dehydration process, because of the high osmotic driving force between the concentrated solution and the fresh sample, the rate of water removal and solid gain was relatively high. Although water loss reached nearly the equilibrium conditions towards the late processing times, solid gain kept increasing. This increase in solid gain blocks the surface layers of the product, which reduces the concentration gradient between the product and osmotic solution, posing an additional resistance to mass exchange and lowering the rates of water loss at further processing times. It was also observed that while increasing the salt concentration, the solid gain in most of the samples significantly (p
Research Article
Meysam Mohammadi; Mehdi Saidi; Orang Khademi
Abstract
Introduction: Bell pepper (Capsicum annuum L.) from Solanaceae family is one of the most important vegetables which are fruit pods on the capsicum plant grown for their sweet fruits and delicate peppery flavor they extend to the recipes. Sweet pepper contains an impressive list of plant nutrients that ...
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Introduction: Bell pepper (Capsicum annuum L.) from Solanaceae family is one of the most important vegetables which are fruit pods on the capsicum plant grown for their sweet fruits and delicate peppery flavor they extend to the recipes. Sweet pepper contains an impressive list of plant nutrients that found to have disease preventing and health promoting properties. Unlike in other fellow chili peppers, it has very less calories and fats. 100 g provides just 31 calories. Because of their versatility, low calories, intense flavor and high concentration of vitamins, sweet peppers are a great snack raw and an easy addition to many different recipes.In recent years extending shelf-life of this perishable vegetable has been accomplished (Banaras et al., 2005). The losses in vegetable quality and quantity between harvest and consumption affect the crop productivity. It is estimated that the magnitude of the postharvest losses of fresh horticultural crops is from 5 to 25% in developed countries and of 20 to 50% in developing countries. Fresh peppers are often eaten raw and supplied pre-cut to manufacturers as ready-to-use ingredients. However, the main problems limiting their shelf life occur by shriveling, decay development on the cut surface, as well as degreening of the vegetable among different degraded quality characteristics (Sakaldas and Kaynas, 2010). Those problems are correlated to an undesirable loss of water during metabolism or diffusion through the skin and respiration. Temperature management is the most effective tool for extending the shelf life of fresh horticultural commodities. Nowadays, to reduce high losses and keeping product’s quality, in addition to lowering temperature, coating and packing must be noticed. Therefore, in this study, dipping in chitosan solution and coatings by edible Chitosan was assayed to improve quality of sweet peppers storability during cold storage.
Materials and methods: Plant material and sample preparation: Green peppers obtained from a Research farm, College of Agriculture, Ilam University, Ilam, Iran were used in the present study. The fruits were sanitized with hyperchlorinated water (1 mL/L) and rinsed with tap water. Peppers were divided in random into different group for chitosan treatments. Treatments and storage condition: The green peppers were dipped for 2 min into a solution either 0% (control) or 1% (w/v) chitosan (Chitosan, 80-95% deacetylation degree, medium molecular weight). The coating solution was prepared by dispersing 0 and 10 g of chitosan powder into 1L of distilled water containing 1% (v/v) glacial acetic acid (Kyu Kyu Win et al., 2007) and final pH of the solution adjusted to pH 5.0. After being air dried for 2 hrs. at room Temperature, ten similar sizes fruits were placed in each plastic crate, tightly closed by cellophane films and stored at 10°C, 85-90% relative humidity to be later assessed for further analyses intended for 14 and 28 days. The control samples of ten untreated fruits per crate were kept unsealed under similar environmental conditions of temperature and relative humidity separately. The current study carried out as a factorial assay on the basis of a RCBD with three replications during 2013-2014 at Ilam University. The main factor was included of four treatments (control, Chitosan coating, Cellophane sealing and Chitosan coating + Cellophane sealing) and the sub factor was included of storage period duration (14 and 28 days). Data were subjected to ANOVA using SAS software version 9.2. Verification of significant differences was done using Duncan's Test at 5% probability level.
Results and Discussion: Results showed that fruits quality declines with long storage, but treatments with Cellophane and Chitosan decreased weight loss and kept firmness, TSS, titratable acidity, sugar/acid ratio, ascorbic acid, antioxidant activity, total phenol, and catalase and peroxidase enzymes better than control. Furthermore, for most of the traits no significant difference was observed between treatments, although cellophane coating recorded more fungal infection and lower marketability. Shelf life enhancement by Chitosan has been already reported on carrot, orange and Japanese Medlar (Rashidi et al., 2009, Ahmad et al., 1989 & Ding et al., 2002) through its antimicrobial activity (Xing et al., 2011) and suppressing respiration by blocking stomata. It has been reported that both edible and nonedible coverage (such as chitosan and cellophane) of fruits can provide a modified atmosphere surround them which results in decreasing the rate of their maturity and senesces. Taking overall quality into consideration, the best treatment was joint application of cellophane and chitosan. That treatment appears to be an effective method for improving the postharvest quality of peppers which could more effectively preserved quality and biochemical characteristics. These fruits remained hydrated, green and had good visual appearance after storage. The low rate of respiration of these fruits may also account for the retention of pepper quality.
Research Article
Maryam Soltani Kazemi; Saman Abdanan; Mokhtar Heidari; Seyed Mojtaba Faregh
Abstract
Introduction: Blackberry is a perennial woody plant native to warm, temperate, and subtropical regions of Asia, Africa, North America, and southern Europe. Blackberry fruit (Morus Alba Varnigra L.) is a rich source of anthocyanins. Furthermore, it has great many medicinal properties such as an antidiabetic ...
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Introduction: Blackberry is a perennial woody plant native to warm, temperate, and subtropical regions of Asia, Africa, North America, and southern Europe. Blackberry fruit (Morus Alba Varnigra L.) is a rich source of anthocyanins. Furthermore, it has great many medicinal properties such as an antidiabetic (Asano et al., 2001), antihyperglycemic (Andallu &Varadacharyulu, 2003), antiviral (Du et al., 2003), antioxidative (Kim et al., 1998), hypolipidemic (El-Beshbishy et al., 2006), and neuroprotective (Kang et al., 2006). However, measuring some qualitative and nutrient parameters in this fruit such as anthocyanins, vitamin C and phenol directly has become a major issue (Pace et al, 2013). Therefore, researchers try to predict aforementioned parameters by mathematical models. One of these models is the fractal model which is widely used to study the properties of the images/objects (Welstead, 1999; Zhang, 2007). Recently, many researchers try to develop different methods to classify or predict the agricultural products quality (Langner, 2001). In a research Seng and Mirisaee (2009) designed a machine vision algorithm for classification of fruits (apple, lemon, strawberry and banana) based on color, shape and size. Li and He investigated the application of visible/near infrared spectroscopy (Vis/NIRS) for measuring the acidity of Chinese bayberry. The model for prediction the acidity (r=0.963), standard error of prediction (SEP) 0.21 with a bias of 0.138 showed an excellent prediction performance. Therefore, the aim of this study was to predict biochemical parameters (TSS, anthocyanins, browning compounds, total phenols, Ascorbic Acid, pH) of blackberry juice, nondestructively, during maturity process using machine vision and fractal analysis. To develop predictive models and data classification, artificial neural networks (ANN) and k-nearest neighbor (k-NN) were used.
Materials and methods: Eighty blackberry fruits from four maturity stages were selected. The fruit samples were placed in airtight polyethylene bags, stored in an ice-filled cooler and transported to the laboratory to keep at cold temperature (4±1◦C).
Fresh fruits were squeezed by a household juicer, and immediately transported to the laboratory. Then, juice images were taken with a digital camera CASIO (Model Exilim EX-ZR700; 16 megapixels, Japan) and stored to the computer.
There are several ways to measure the fractal dimension. In this study, the proposed method by Addison (2005) was used to calculate the fractal dimension.
Feature selection is one of the issues that have been raised in the context of machine learning. In this study, floating search method feature selection was used (Pudil et al., 1994).
k-Nearest Neighbor (k-NN) is one of the simplest methods for information classification. In this study, the Euclidean distance between two points was used to determine the distance between the input data with the training patterns (Mucherino et al., 2009).
To train the neural network, Levenberg–Marquardt training algorithm was used. In this regard, the data were divided randomly into two parts (two-thirds for training (60) and one-third (20) for testing the network). Input parameters were Xa, Xb, X, Y and S and output parameters were TSS, ascorbic acide, acidity, polyphenols, anthocyanins, brown-causing substances and pH. Moreover, in this study, the number of neurons in the hidden layer was selected by trial and error method.
After selecting the best features extracted from the image processing with the highest correlation with chemical parameters (TSS, anthocyanins, total phenols, ascorbic acid, and pH), a machine vision system was designed and built to be able to determine the internal properties of black mulberry juice.
Total soluble solids (TSS) were determined by a hand refractometer device (model: MT03 Japan). The anthocyanin content was estimated following the procedure of Holecraft et al., (1998). Ascorbic acid of the juice was measured by titration with copper sulfate and potassium iodide based on the Barakat et al., (1973) procedure. Titratable acidity was measured according to the Eksi and Turkman, (2011) method. Waterhouse (2002) method was used for measuring the total phenol of juice.
Results and discussion: Artificial neural network (ANN) and (k-NN) models were used to predict the changes of anthocyanin (AC), browning compounds, ascorbic acid (AA), total phenols (TP), acidity, TSS and pH in mulberry juice during ripening based on fractal analysis. Two features namely: maximum fractal and fractal curve area were selected from five extracted features and used for training neural network and k-NN classifier
Research Article
Fatemeh Azarikia; Soleiman Abbasi
Abstract
Introduction: Maillard reaction is a well-known technique for covalent coupling of protein–polysaccharide which is usually used to improve the functional properties of proteins. Conjugation by the dry heating method is occurred during Amadori rearrangement step in the Maillard reaction where amine ...
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Introduction: Maillard reaction is a well-known technique for covalent coupling of protein–polysaccharide which is usually used to improve the functional properties of proteins. Conjugation by the dry heating method is occurred during Amadori rearrangement step in the Maillard reaction where amine groups of the proteins are linked to the reducing end of the polysaccharides. This glycation process leads to the improvement of solubility, foaming and emulsifying properties of proteins (Liu et al., 2012). Protein-based emulsions are sensitive to pH and ionic strength alterations as well as heating and freezing–thawing processes. While, joining proteins to high molecular weight polysaccharides protects them against environmental stresses. A wide range of carbohydrates were already utilized to enhance the emulsifying properties of proteins–polysaccharides namely whey protein isolate–dextran (Akhtar et al., 2003), β-lactoglobulin–dextran (Wooster et al., 2006), sodium caseinate–maltodextrin (O’Regan et al., 2009), deamidated wheat protein–maltodextrin or glucose (Wong et al., 2011), whey protein isolate–pectin (Xu et al., 2012), yolk phosvitin–dextran (Chen et al., 2014), β-lactoglobulin–six-carbon monosaccharides (Cheetangdee et al., 2014), soy protein isolate–soy soluble polysaccharides (Yang et al., 2015), lysozyme–tragacanth (Koshani et al., 2015), and β-lactoglobulin–Persian gum (Golkar et al., 2015). However, based on the existing literature, it seems that conjugation of Iranian native gums and proteins needs to be more attended to show their potential applications. Therefore, in this study, conjugate formation between milk proteins (sodium caseinate and whey protein isolate) and soluble fraction of Iranian native gums (gum tragacanth and Persian gum) was optimized using response surface methodology (RSM) and the resulting conjugates were used in emulsion formulation in order to compare protein capability before and after being attached to the gums.
Materials and methods: Iranian native gums were pulverized and sieved (mesh size < 60) after being prepared from local herbal stores. To obtain protein–polysaccharide conjugates, dry heat treatment was accomplished at 60oC and 79% relative humidity at different protein:polysaccharide ratios and heating times. Free amino group content was determined by the ninhydrin method described by Doi et al. (1981). To measure color changes before and after Maillard reaction, Hunter Lab was used. Besides, possibility of stabilizing oil-in-water emulsions using the conjugates was studied. Emulsions were formed by addition of oil phase (4% w/w) into protein–polysaccharide conjugates solution (0.4% w/w) following by ultrasound treatment (amplitude of 100%, for 4 min). Samples were kept at 4 oC for 30 days after adjusting the pH at 3, 5 and 7 to compare the effect of protein–polysaccharide conjugates on their stability at different protein charges. For optimization of Maillard reaction using RSM (central composite design), protein:polysaccharide ratio and heating time were selected as independent variable and were studied at 5 levels. The dependent variables were the substitution degree of free amino groups and color change.
Results & Discussion: Based on our findings, the decrease of free amino group indicated that NH2 group of amino acids in milk proteins was covalently linked to carbonyl group of the gums. Comparing free amino group reduction of the samples containing soluble fraction of gum tragacanth and Persian gum also showed that Persian gum was more capable of forming covalent linkage with milk proteins than gum tragacanth; probably, due to the lower side branches of Persian, its molecular weight as well as its structural flexibility. Moreover, we believe the higher side branches of attached-tragacanthin molecules might prevent further attachment of protein to the other polysaccharide molecules via steric repulsion. According to the results of color measurement before and after dry Maillard reaction, conjugation led to reduction of L* and increase of a* and b*. In addition, higher heating time and protein:polysaccharide ratio caused progress of Maillard reaction (especially in the case of milk proteins–soluble fraction of Persian gum). Based on our findings, in dry Maillard reaction, the optimum heating time and protein:polysaccharide ratio were 8 days and 1:1.59 for whey protein isolate–soluble fraction of Persian gum, 7 h and 1:2 for sodium caseinate–soluble fraction of Persian gum, 13.64 days and 1:3 for whey protein isolate–soluble fraction of gum tragacanth, and 7.82 h and 1:3 for sodium caseinate–soluble fraction of gum tragacanth, respectively. Besides, the obtained Maillard reaction products did not cause complete stability of emulsions at pHs 3, 5 and 7. Our findings also declared that attachment of polysaccharides to proteins might negatively affect the proteins functionality, as emulsifier, possibly by hindering adsorption of hydrophobic groups of proteins to oil droplets. Furthermore, homogenization process during emulsion preparation using ultrasound could break the formed covalent bonds and polysaccharide structure leading to lower steric repulsion and viscosity.
Research Article
Rohollah Pashaei Bahram; Sodeif Azadmard Damirchi; Javad Hesari; Seyed Hadi Peighambardoust; Samad Bodbodak; , Boukaga Farmani
Abstract
Introduction: Cornelian cherry is one of horticultural crops in Iran. There are about 1094.26 hectares of cornelian cherry orchards in Iran and 2329.36 ton cornelian cherry fruit are produced annually based on statistics of the Ministry of Agriculture-Jahad. Cornelian cherry fruit is usually consumed ...
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Introduction: Cornelian cherry is one of horticultural crops in Iran. There are about 1094.26 hectares of cornelian cherry orchards in Iran and 2329.36 ton cornelian cherry fruit are produced annually based on statistics of the Ministry of Agriculture-Jahad. Cornelian cherry fruit is usually consumed in fresh form, but it products are also used in form of dried fruit, jam, pickles, sauce, juice, jelly, marmalade, vinegar, fruit roll-ups (Golriz et al., 1996; Demir and Kalynoco, 2003; Gulcin et al., 2005) and syrup (Damir et al, 2003; Jayaprakasam et al., 2006). Cornelian cherry fruit is a rich source of antioxidant compounds and has different benefits such as nutritional, medicinal value, profitability and export values (Panatelidis et al., 2006).Total anthocyanins content of most varieties of Cornus are 15-10 times higher than other fruits more that are used as anthocyanins source (Vareed et al., 2007). Although it is obvious that bioactive compounds of cornelian cherry fruit are valuable, but there is little information about changes of their composition and activity during postharvest storage. Some parameters such as Storage temperature, light and exposure to oxygen have great influence on the stability of the composition during postharvest storage of the fruits (Kalt et al., 1999). Since cornelian cherry is a climacteric fruit, the aim of the research was studying the effect of storage and transport of cornelian cheery in ambient temperature on physicochemical properties and bioactive compounds. Two ways of cornelian cherry preservation are included storage of cornelian cherry at room temperature and storage in dried form.
Materials and methods: Cornelian cherry fruit is supplied from an orchard in the city Horand in east Azerbaijan Province from a high yielding tree. After picking, fruits were sorted and held in incubator (25 ˚C) for 9 days and were sampled at intervals of 24 hours up to 9 days and physico-chemical parameters of samples such as pH, acidity, dry matter, Total ash and loss of their bioactive compounds (total phenols, total flavonoids, total anthocyanin, vitamin C and antioxidant capacity) were evaluated. In this research, the effects of storage time on the physicochemical properties and bioactive compounds contents of cornelian cherry fruit during storage at room temperature (25 ˚C) were analyzed by means repeated measurements in time method in three replications. The results obtained were analyzed by using analysis of variance and mean comparison using the least squares (p≤0.05).
Results and discussion: The results showed that pH and acidity significantly increased and decreased during storage time respectively. It could be attributed to consumption of organic acids in the respiration pathways as a substrate and use of them by mold. It gradually led to an increase of pH and improved the condition for yeast growth. The results showed that after 9 days storage at 25 ˚C the amount of Vitamin C decreased from 1385 to 354 (mg/100 gd. b). It could be ascribed to oxidation of Vitamin C during storage in presence of air. Total anthocyanins decreased from 379 to 195 (mg/100 gd. b) which is the result of degradation of the compounds in presence of oxygen and condensation of them with tannin and protein compounds during storage at ambient condition) PiljacZegarac et al., 2011). The amount of total phenols increased from 1237 to 2067 (mg/100 gd. b) During 9 days of storage at ambient conditions. The increase of phenolics compounds could attributed to release of them from protein and carbohydrate complexes (Doshi & Adsule, 2008). Prior et al. (2005) concluded that increase of phenolic compounds during storage of fruits could be the result of moisture decrease and reducing sugar content increase and their interaction with folin ciocalteu reagent. Also flavonoid content of cornelian cherries increased from 491 to 943 (mg/100 gd. b) During storage which probably is due to release of flavonoid compound during ripening process in postharvest storage time. Also, the antioxidant activity was reduced to 33%. According to the results, it could be concluded that storage of cornelian cheery fruit in ambient condition significantly decreased the bioactive compounds. Therefore it was recommended that cornelian cheery should be stored in low temperature condition and consumed in fresh form in short time after harvesting in order to remain nutritional properties and bioactive compounds.
Research Article
Maryam Ghanadrezaee; Akram Arianfar; Zahra Sheikholeslami
Abstract
Introduction: Application of emulsifiers is important in production of good quality cake. Monoglycoside and its derivatives, sterol lactilat, propylene glycol, Mono stearate, Mono stearate sorbitan, polysorbate, lecithin are used as Emulsifiersin in cake industry. Emulsifier that is used as a gel form ...
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Introduction: Application of emulsifiers is important in production of good quality cake. Monoglycoside and its derivatives, sterol lactilat, propylene glycol, Mono stearate, Mono stearate sorbitan, polysorbate, lecithin are used as Emulsifiersin in cake industry. Emulsifier that is used as a gel form in production of cakes , called cake gel. The use of gel cake in the cake batter increases distribution of air bubbles and resulting viscosity was increased and form a better texture and volume of the cake.Today, crystalline alpha gel of glycerol ester with alpha gel monoglycerides and propylene glycol stearate gel was used in the production of cakes. The stable Alpha gel wiche made from a mixture of monoglycerides and polyglycerol ester glycerol have impact effect on cake quality. The purpose of this study was to investigated the effect of Datem emulsifiers in three levels (5, 10 and 15%) poly glycerol in two levels (10 and 15%) and monoglycoside (60%) in gel emulsifier formulation to improve physicochemical, rheological and sensory properties of oil cake. The color index (L *, a * and b *), specific volume, texture and moisture of the cake were evaluated. The results showed that Datm emulsifier in (10%) with polyglycerol at 15% concentrations in gel emulsifier formulation had the best result on quality properties of cake.
Material and methods:The materials was used in the production gel Emulsifier includs, glycerol (co-Timer Network Malaysia), sorbitol (Omid company) and Propylene glycol (Kimiya garan Emroz Chemical Industry Co.) was prepared. Materials for production of cakes containing wheat flour ( Khorasan Co.) with moisture content (14%), protein (8.5%), ash (48%), PH (6.2%), eggs (Telavang Co.), vanilla from (AROMA Company), liquid vegetable oil (Laden Company) invert syrup (Simorgh Co) were prepared. baking powder (Mahsa) was purchased from local market. Sugar with fine white crystals bought in batches of 15 kg and was kept in the Store for consumption.Ingredients of gel Emulsifier formulation were mixed together Continuous agitation, the mixture then heated at temperature of 70 ° C In order to prepare the cake batter, the ingredients were weighed according to the formulation. The Moisture content of cup cake was measured 2 hr and 1 week after baking according to AACC- methods (AACC, 2000). Specific volume was determined an hour after baking based on rapeseed displacement method (AACC 2000). TPA test of cup cake was measured by A QTS texture analyser (CNS Farnell, Hertfordshire, UK) to measure the force required for penetration 2h and 1 week after baking. The color of cup cake determined by L*, a* and b* index, by using image j software after 2 hr, by (HP Scanjet , G 3010). Sensory evaluation was performed by 10 trained panellists and the overall quality of cake was evaluated using a ranking scale with scores ranging from 1 (least pleasure) to 5 (best pleasure).In this study, some sensory properties including odor, taste, texture and overall quality (total acceptance) of cup cake were evaluated. Results were reported as the average of three replications (all treatments were evaluated in three batches). In order to assess significant differences among samples, a complete randomized design of triplicate analyses of samples was performed using the Mstat-c. Duncan’s new multiple range tests were used to study the statistical differences of the means with 95% confidence.
Results and discussion:The results showed that gel emulsifier formulation with (10%) concentrations of Datm and (15%) concentration of polyglycerol are suitable in gel emulsifier formulation, This formula was increased the volume, L* index of crust and crumb of cake and sensory properties such as texture, Chewiness and reduced firmness of cake and moisture loss content over 1 week after the baking . Increasing the specific volume of cakes is due to the formation of alpha crystal films around the air bubbles, and trapping air bubbles in the dough. This phenomen was reduced surface tension of fat phase and improved spread ability of the fat phase in the cake batter, thus increasing the volume and softness of cake. Reduction of cake Firmness is due to interaction of emulsifiers with starch that is prevent retrogradation phenomenon. increasing of polyglycerol ester concentration in gel emulsifier formulation, improved the moisture maintain during baking and prevent from rough and wrinkled skins in the final product and therefore increases L* index .
Research Article
Ehsan Azadbakht; Yahya Maghsoudlou; Morteza Khomeiri; Mahboobeh Kashiri
Abstract
Introduction: The edible films and coatings had remarkable growth in recent years to increase the shelf life and to enhance food quality, stability, and safety and expected to have an important impact on the food market in the following years. In addition, these matrices can be used as carriers of antimicrobials ...
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Introduction: The edible films and coatings had remarkable growth in recent years to increase the shelf life and to enhance food quality, stability, and safety and expected to have an important impact on the food market in the following years. In addition, these matrices can be used as carriers of antimicrobials to minimize the risk of foodborne contamination by pathogens and inhibit the development of spoiler microbes. Antimicrobial packaging is a type of active packaging that provides the continuous migration of antimicrobial components to the surface of the foods. Chitosan is a linear copolymer of β-1, 4-linked D-glucosamine and N-acetyl-d-glucosamine. It is a cationic polysaccharide for food packaging applications, due to its unique characteristics of films, including excellent oxygen barrier properties, good mechanical properties, nontoxicity and good antimicrobial activity. Eucalyptus is a plant native from Australia and the Myrtasya family that includes about 900 species and sub-species. There is abundant scientific evidence regarding the efficacy of different species Myrtasya as the antibacterial and antifungal compounds used in health products, and food industry. Using natural antimicrobials are interesting strategies for reducing the use of chemical additives in the food industry. Essential oils (EOs) are defined as a mixture of volatile water insoluble substances to be incorporated into the edible films due to exhibit antimicrobial effects. Moreover, evaluation EOs on the physical, optical and structural properties of the resulting film is also important. Therefore, the aims of this work were to determine the effect Eucalyptus globulus essential oil on antibacterial properties (2) to determine the antimicrobial activity of chitosan based films containing Eucalyptus globulus essential oil against S. aureus, B. cereus, E. coli and S. intertidis.
Materials and methods: The foodborne microbial strains were prepared from Persian Type Culture Collection. The essential oil was analyzed by gas chromatography (GC) (Thermoquest 2000, UK). In this study, the antimicrobial activity of Eucalyptus globulus essential oils (EGOs) was evaluated against two gram positive (S. aureus and B. cereus) and two gram negative (E. coli and S. intertidis) bacteria by the agar diffusion technique and microdilution test. The effect of EGO was evaluated in liquid media and vaporous phase too. Chitosan solution were prepared by dissolving 1.5 % (W/V) of chitosan in aqueous solution containing 0.7% (V/V) of acetic acid under a magnetic stirrer at 40°C until chitosan was completely dissolved. Glycerol as plasticizer (10% weight of chitosan powder) was added to the solution and stirred for 10 minutes. The EGO with concentrations of 0.5, 1 and 1.5% v/v was added to the solution and was stirred for 5 minutes. The film forming solutions using a homogenizer (Heidolph, Germany) were homogenized with 12000 rpm for 4 min, then degassed for 5 min and 25 ml were cast on a 10 cm diameter petri dish. After drying the film in the oven at 38°C for 24 h, they were peeled from the plate surface and were evaluated. The antimicrobial activity of the films was evaluated in contact with liquid and vaporous media.
Results and discussion: Minimum inhibition concentration for gram negative (E. coli, S. enteritidis) and gram positive (B. cerus and S. aureus) bacteria showed 3.125 and 1.562 µg/l respectively. The inhibition zone for gram positive bacteria was bigger than gram negatives. The effect of EGO on bacteria based on Log reduction value (LRV) of S. aerus > B. cerus > E. coli> S. enteritidis. Thses results confirmed that gram positive bacteria were more sensitive to inhibition by plant essential oils than the gram-negative bacteria. Our results showed that chitosan film containing 1 and 1.5 % essential oil was able to reduce the density of bacteria. The Log reduction value of chitosan bioactive film was increased by increasing the concentration of E. globulus essential oil than 0.5 to 1.5 % in liquid media. The results of this work had demonstrated that chitosan bioactive film containing 1.5% EGO can be used an effective antimicrobial film for food packaging in direct contact.
Conclusion: Chitosan is a good biopolymer for active food packaging. The result of this study showed that chitosan films containing EGO could be used as active films due to enhanced the antimicrobial properties which are important in food packaging applications. Films containing essential oil had unique properties that are useful for coating of perishable foods such as fish and poultry.
Research Article
Asefeh Latifi; Mohsen Esmaiili
Abstract
Introduction: More than half of the world's people consume rice. Rice consumers, especially in Asia know that cooking properties of rice change with its storage. This phenomenon is called aging. The increase in hardness, decrease in adhesiveness during cooking and decrease in solid loss, are the major ...
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Introduction: More than half of the world's people consume rice. Rice consumers, especially in Asia know that cooking properties of rice change with its storage. This phenomenon is called aging. The increase in hardness, decrease in adhesiveness during cooking and decrease in solid loss, are the major changes in rice which caused by aging. However, while some consumers prefer new rice like Japanese (Zhou, 2002) Iranian and many other consumers prefer aged rice. The change in physicochemical properties of aged rice is caused by the alteration and interaction in lipid, protein and starch (Juliano, 1985; Sodhi, et al. 2003; Teo et al. 2000). The conventional aging of rice takes 3-6 months (Jaisut et al. 2009; Soponronnarit et al. 2008).Yet this method needs more space for storage leading to high operating costs. It is necessary to examine other methods that can reduce the aging time and maintain the rice properties similar to those obtained by the conventional aging process. The process for accelerated aging could be developed either by dry or wet heat (Rayaguru et al. 2011; Rosniyana et al. 2004). The dry heat method was successfully tested with heating of rice in high temperatures in a closed container (Battacharya, 2013). One of the basic problems that occur during dry heating is that any moisture loss leads to cracking. Although the concept is simple in theory, it is complicated in practice. Another drying process for accelerated aging of rice employs a fluidized bed dryer. However, this may decrease head rice yield (Soponronnarit et al. 2008; Wiset et al. 2005), not to mention the fact that these dryers are rare and expensive in rice producing countries. Hence, wet heat is more practical and economical in the mentioned countries. The environmental optimum conditions for accelerated aging of Basmati paddy, at temperature 30–50 °C, relative humidity 50–90% and aging period 3–14 days, has been studied and reported to be 43 °C, 71.0% relative humidity (RH) and 11 days (Rayaguru et al., 2011). Parboiling has been implemented as a method of improving the quality of rice. Nonetheless, it is a lengthy process involving soaking, steaming and drying, which results in the complete gelatinization of starch (Gujral, and Kumar, 2003). According to the importance of accelerated aging, the aim of this study was to evaluate quality attributes and physicochemical properties improvement of Tarom variety of paddy.
Materials and methods: In this study, Tarom variety of paddy (a local variety, with high-quality and large area cultivation in Mazandaran province) was chosen. For accelerated aging, two methods were done: Steaming (or steam curing) and controlling the environmental conditions. In steaming method, the paddy was divided into two portions. The first which had an initial moisture content of 24% (wet base) and the second was the paddy which had been rested at the ambient temperature allowing its moisture content to reach 17%. To accelerate aging of the paddy in two moisture levels i.e. 24 and 17%, the samples were treated by steaming (or steam curing) for 5, 10 and 20 min, and then both of samples were dried with fixed bed dryer at 40 ◦C until the grain moisture content reached 11%. Afterwards, the paddy samples were dehusked and polished with satake miller apparatus. Milled whole rice kernels were separated from broken rice for evaluation of physicochemical properties. In controlling the environmental conditions, the samples were dried with fixed bed dryer at 40 ◦C until the moisture content reached 12%, and then stored at 43 °C and RH=74% for 11 days. Similarly, to produce white rice, the paddy samples were dehusked and polished as mentioned above. The control sample which had an initial moisture content of 24% (wet base) was only dried at 40 ◦C to moisture contend wet basis 11%. Several parameters including head rice yield (the percentage of the mass of white rice that remained as head rice after milling), hardness of raw kernel (the maximum force for breakage of raw white rice), color (b value), chalkiness (weight of the kernel that had chalkiness over one half of the kernel surface in 5 gram of white rice), aroma (using hedonic test), pasting properties (including the peak viscosity, final viscosity, breakdown viscosity and setback viscosity), texture profile analysis (TPA) and thermal properties of rice (the onset temperature, peak temperature, conclusion temperature and enthalpy of gelatinization) were determined. The resultant data were subjected to the analysis of variance using SPSS (ver. 19) software. Duncan’s test was used to establish the differences between mean values at 95% confidence interval.
Results and discussions: The quality attributes of the produced white rice were compared with that of the control samples. By doing the steam curing treatment, solid loss of the rice decreased, adhesiveness decreased, gelatinization temperature increased and viscosity changed. All of the mentioned changes were similar to the alterations that occur in naturally aged rice. By controlling the environmental conditions, the solid loss decreased and the elongation increased. According to sensory and apparent characteristics including aroma and chalkiness, treatment by controlling the environmental conditions could be recommended. Steaming treatment for the three levels of time led to complete loss of aroma.
Research Article
Azam Ayoubi; Mahda Porabolghasem
Abstract
Introduction: Increased intake of calorie and decreasing physical activity might increase the risks for cancer, obesity, cardiovascular diseases, diabetes mellitus and hypertension. Using natural sweeteners instead of sugar in food formulations can be a good method to reduce the calorie intake. World ...
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Introduction: Increased intake of calorie and decreasing physical activity might increase the risks for cancer, obesity, cardiovascular diseases, diabetes mellitus and hypertension. Using natural sweeteners instead of sugar in food formulations can be a good method to reduce the calorie intake. World Health Organization recommends limiting added sugar intake to <10% of total energy. Many sugar substitutes were used in food products such as glucose syrup, molasses, fructose syrup, invert syrup and malt extract. Utilization of fruits in food preparation while requiring sweet taste is a wise strategy to reduce the added sugar intake. Dates are ideal fruits to substitute added sugar in foods, and they play an important role in daily nutrition of many people in the arid regions. Date fruits are rich in dietary fiber, phenolic compounds, minerals, vitamins, antioxidant and antimutagenic compounds. Date syrup that produces from date is one of the suitable replacements that can be used for substituting sugar. Date syrup is a high energy food rich in carbohydrate, a good source of minerals; but it is also contains a very complex mixture amino and organic acids, polyphenols and carotenoids. Date syrup contains fructose, glucose and small amount of sucrose. Low quality date cultivation occupies about 60% of the total plantation. These dates are poor in size and taste, unsuitable for consumption. The presence of high sugar content in these low quality varieties makes them suitable for producing date syrup. The purpose of this research was study the effects of substituting sugar with date syrup on physicochemical and sensory properties of cupcake.
Materials and methods: Date syrup purchase from Dambaz Company and wheat flour purchase from Tavakkol factory of Kerman. Other materials purchased from local market of Kerman. In this research four different level of date syrup (25, 50, 75 and 100%) were used in cake formulations as a sugar substitution and the effects of dates syrup on the physicochemical (including weight loss, pH, porosity, density, moisture, hardness of texture and color of crust and crump) and sensory (texture, crust color, taste and total acceptance) properties of cupcake were studied. The weight loss calculated by measuring difference of weight before and after baking. pH was measured by a digital pH meter. cake moisture content was determined by drying samples at 130±2°C in a hot air oven. The volumes of the cake samples were measured by the seed displacement method and then density was calculated by dividing the volume by the weight. For evaluation of porosity used Image j method. Hardness of the cake samples were measured with Instron testing machine. Color measurements were done using a Hunterlab Colorimeter. Analysis of variance (ANOVA) was conducted for data using MSTAT-C software. Differences among the mean values were also determined using Duncan’s Multiple Range test. A significant level was defined as a probability of 0.05.
Results & Discussion: Data analysis showed that the date syrup, significantly affected the physiochemical and sensory properties of the cake. It was discovered that by increasing the percentage of date syrup in cake formulation, weight loss decreased and moisture increased. Sugars make hydrogen bonds with water molecules due to their hydroxyl groups, because of the molecular structure of the sugars like sucrose, fructose and glucose, it seems that increasing functional groups in date syrup sugars compared with sucrose, resulted in the formation of more hydrogen bonds, which caused the reduction in the mobility of free water and therefore make an increase in moisture of cake. According to the results, pH and porosity of the cake decreased as the date syrup level increased. The results showed that increasing date syrup level caused an increase in density. By decreasing the volume of cake density increased. The volume probability decreased because of affecting reduced sugars and changing viscosity and density of the cake batter. Based on the results, hardness increased significantly with increasing replacement of sugar with date syrup. The possible reason for this result was due to decreasing volume and porosity of cake with increasing date syrup content. The color of the cake is due to the Maillard and caramelization reactions during baking. A key element in Maillard reaction is reducing sugar which is abundant in date syrup and able to enhance the brown color. The results showed that the crust and crump lightness (L) decreased significantly with increasing the levels of date syrup. The crust and crump yellowness (b) were significantly less than control. With reducing sucrose level, the redness of the crust and crump increased significantly. According to sensory evaluation results, scores of crust color, texture and total acceptance of the cake remained unchanged when up To 50% date syrup was used. However, further addition of date syrup significantly reduced these scores. The results showed that the cake formulation with 100% date syrup date obtained the lowest score by panelists in terms of taste. Least value of weight loss (19/2%), porosity (19/5%) and most value of density (0/5 g/cm3), darkness of crust (32/47) and crump of cake (35/64) were related to substitution level of 100%. Present study demonstrated that the date syrup could replace up to 50% of the sugar without affecting the quality of cupcakes.
Research Article
Maryam Farahmand; Mohammad Taghi Golmakani; Asgar Farahnaki; Gholam Reza Mesbahi
Abstract
Introduction: The pomegranate (Punica granatum L.) belongs to the family Punicaceae, which is planted around the world in different microclimatic areas. The pomegranate production has grown uninterruptedly, which is presumably due to the increasing consumer awareness of the benefits attributed to pomegranate ...
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Introduction: The pomegranate (Punica granatum L.) belongs to the family Punicaceae, which is planted around the world in different microclimatic areas. The pomegranate production has grown uninterruptedly, which is presumably due to the increasing consumer awareness of the benefits attributed to pomegranate and its polyphenols. Pomegranate fruit has valuable compounds with functional and medicinal effects like antioxidant, anticancer, and anti-atherosclerotic effects. Storage of juice concentrate can have a dramatic impact on physicochemical quality. The bioactive compounds and antioxidant activity in fruit juice products are influenced by many external factors like different storage temperatures. Knowledge of the rheological behaviour of juice products is essential for product development, design and evaluation of process equipment like pumps and piping. Pomegranate concentrate is so susceptible to the condition of storage, which results in a reduction in consumer acceptability and quality losses. Accordingly, the industrial concentrate stores frozen (-20 °C) which has a lot of costs to the producer. The objectives of this study were to evaluate the degradation visual color, the rheological characteristics of pomegranate juice concentrates, the stability of phytochemicals, the antioxidant activity, and the haze formation of reconstituted pomegranate juice concentrate during storage at different temperatures to determine the best storage conditions to reduce the quality losses and solving the problem about high cost of storage.
Materials and methods: The concentrated pomegranate (Punica granatum (L.) cv. Rabab) juice used in this study supplied from Narni (Green farm, Neyriz, Iran) factory. The pomegranate juice concentrate was poured into falcons for measuring physicochemical attributes, and micro tubes for determination of antioxidant activities. Then the samples were divided into four parts and stored equally in four different temperatures (-20, 4, 20, and 35 °C). The control samples were stored at -80 °C as fresh sample for the storage period (140 days). Folin-Ciocalteu reagent and 2,2-diphenyl-1-picrylhydrazyl radical (DPPHº) were supplied from Sigma-Aldrich Company (St. Louis, MO, USA). All other chemicals were of analytical grade and purchased from Merck Company (Darmstadt, Germany). The total soluble solid (TSS) was determined with a digital refractometer (Carl Zeiss, Germany). Total insoluble solid was measured by centrifugation at (5,000 × g) according to the IFFJP method 60, using a high speed centrifuge (Ibarz et al., 2011). The haze formation of reconstituted juice was determined by “settling” in a glass tube for 3 hour at room temperature. Color measurements of the juice samples were carried out using a HunterLab (CHROMA METER CR-400/410, KONICA MINOLTA, Japan) after dilution. The rheological characteristics of the pomegranate juice concentrate stored in different temperatures were studied by using a computer controlled rotational viscometer. Sample compartment was monitored at a constant temperature (25°C) using a water bath/circulator, while TSS was 65 °Brix. The viscosity measurements, was carried out According to the methods described by Cárdenas et al., (1997), using a Brookfield cone and plate viscometer (DVII pro Brook field, USA) between the shear rate of 0.5–200 (1/s). Total phenolic content of samples was measured according to the Folin-Ciocalteu colorimetric method (Sun et al., 2007). Total flavonoid content in juices was determined via a spectrophotometer according to the method of Chang et al. (2002). Radical scavenging activities of the samples were measured by using DPPHº as described by Mazidi et al., (2012). The ferrous ion reducing antioxidant power (FRAP) of the samples was measured calorimetrically according to the method by Fawole and Opara (2013). All analyses were performed by the Statistical Analysis System (SAS) software V 9.1 (SAS Institute, Inc., Cary, NC, USA). By using the analysis of variance (ANOVA), the differences among means were determined for significance at P< 0.05.
Results and discussion: The industrial pomegranate juice concentrate stored at (-20, 4, 20, and 35 °C) for 20 weeks, and some physicochemical properties like the second turbidity, CIE Lab color parameters, the rheological properties, the bioactive component (total phenolic and flavonoid contents), and antioxidant properties (FRAP and DPPH) investigated in order to determine the best condition of storage. The second turbidity was obvious among the samples stored at 35 °C in the last fourth weeks. Although there were no significant differences among L* value of the samples stored at -20, 4, and 20 °C, a* and b* value of the samples stored at -20 and 4 °C had the same reduction trend for 14 weeks. Even though the control samples had shear thinning behavior, the samples showed a dilatant behaviour after storage. Antioxidant activities measured via DPPH and FRAP sowed reduction with increasing time and temperature. Flavonoid content increased by increasing time and temperature. In conclusion, storage at 4 °C for 14 weeks was the best storage condition to keep the quality and reduce the costs.
Research Article
Reza Amir Khamirian; Hossein Jooyandeh; Javad Hesari; Hassan Barzegar
Abstract
Introduction: Nowadays an increasing demand for whey products particularly whey protein concentrate (WPC) and whey protein Isolate (WPI) resulted in considerable amount of permeates production, which its rejection causes environmental pollution. The bioconversion of whey and permeate is an appealing ...
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Introduction: Nowadays an increasing demand for whey products particularly whey protein concentrate (WPC) and whey protein Isolate (WPI) resulted in considerable amount of permeates production, which its rejection causes environmental pollution. The bioconversion of whey and permeate is an appealing procedure regarding to human nutrition, particularly for its functional properties. Functional foods are foodstuffs, which have specific functions in the human, resulting health benefits besides energy and nutrients. Fermented dairy products containing probiotic bacteria are group of functional foods, which have received increasing attention in recent years, including the development of the market with large commercial and research interests. Production of probiotic beverages from permeate could be considered as a simple solution to prevent permeate rejection and produce an economical product with appropriate functional properties. Definitely, dairy products are the foremost vehicle for probiotic supplementation. However, other nondairy probiotic products such as fruit and vegetable juices have been shown to afford health benefits. Therefore, the aim of this study was optimizing formulation of permeate-based lemon juice beverage and producing probiotic beverage from optimized beverage.
Materials and methods: Based on primary experiments, lemon juice beverages containing permeate were produced with different concentrations of water (19.77, 30, 45, 60, and 70.22 ml), permeate (12.95, 30, 55, 80 and 97.04 ml) and LEMON juice concentrate (5.95, 8, 11, 14, and 16.04 g). To estimate the impact of these independent variables and determination of optimized sample (non-probiotic beverage), response surface methodology (RSM) founded on central composite design (CCD) was applied. According to CCD design, 20 tests with six replicates as the center points were performed. Quadratic polynomial model were considered for the relationship between the predicted responses with the independent variables. The optimization was performed based on physicochemical (pH, acidity, total solids and brix) and sensory (taste, color, odor, after taste and total acceptability) characteristics of beverage samples. At the second stage, the best sample was inoculated with Lactobacillus acidophilus (La5) and its physicochemical properties, antioxidant capacity, sensory attributes and probiotic cell count were monitored during a 28-day storage period under refrigerator temperature (4°C).
Results and discussion: The results showed that all fixed factors, i.e. amount of water, permeate and lemon juice concentrate, had significant impacts on the physicochemical and sensory properties of lemon juice-permeate beverages. By increasing the amount of water up to 45 ml, permeate up to 55 ml and lemon juice concentrate up to 11 g in the formulation, the taste, after taste and total acceptability scores were significantly (p
Research Article
Layla Zaghari; Alireza Bassiri; Somaye Rahimi; Ali Zonousi
Abstract
Intoduction: Probiotics are defined as essential live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. The range of beneficial properties reaches from lowering cholesterol to preventing cancer. The most important probiotic microorganisms belong to the group ...
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Intoduction: Probiotics are defined as essential live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. The range of beneficial properties reaches from lowering cholesterol to preventing cancer. The most important probiotic microorganisms belong to the group of lactic acid bacteria. Lactobacillus reuteri which naturally occurs in the human intestine possess probiotic properties with good colonization potential. The development of probiotic foods presents many challenges, particularly with respect to the stability of the bioactive compounds during processing, storage and passage through acidic gastric environment. Therefore, it is a great challenge to bring the probiotics into a stable form, which guarantees, that the microorganisms reach their target location, the human intestine, in an adequate amount. Microencapsulation helps improve survival probiotic bacteria from environmental stresses. In most studies, probiotic bacteria are entrapped in a gel matrix of natural biological materials such as alginate, or gellan. The core and wall solutions are turned into drops of the desired size by employing an emulsion method. The main problem in the probiotic entrapment approach is that gel bead entrapment technologies generally stabilize the bacteria in liquid products and are difficult to scale up. In order to extend the shelf life of encapsulated probiotics, a glassy state form of the embedding matrix is required. This can be achieved by employing such as air-suspension fluidized-bed coating. In the present research, an air-suspension fluidized-bed technique for generation of core and shell microcapsules containing probiotic Lactobacillus reuteri cells and the efficacy of shellac and sodium alginate at different concentrations on viability of capsules in simulated gastrointestinal conditions was evaluated.
Materials and methods: Pure freeze-dried Lactobacillus reuteri PT-1655 were obtained from Persian Type Culture Collection (Tehran, Iran) and were activated by inoculation in the MRS broth at 37°C for 36-48 h. The air-suspension process was performed in a Wurster coater system with a bottomspraying atomizer. The growth curve of lactobacillus reuteri were determined by measuring the optical density (turbidity) at 600 nm to estimate the time when the growth curve enters a stationary phase in which bacteria develop a general stress resistance and are thus more resistant to various types of stresses. In various pretests the fluidization pressure, the atomization pressure and the spraying rate of the microencapsulation process were varied to examine their influence on process conditions, especially on the particle development. Several different solutions of Lactobacillus reuteri were prepared and evaluated for percentage survival during the coating. The solution containing Lactobacillus reuteri (6–12 g/100 g solution), maltodextrin (4–7 g/100 g solution) and sorbitol (4–7 g/100 g solution) concentrations was spray-coated at three inlet temperatures: 37, 47 and 62°C onto and absorbed by the inert carrier microcrystalline cellulose to produce nonagglomerating dry coated. For the coating processes an aqueous shellac solution at 3 concentrations (16, 17 and 18% (w/v)), containing plasticizers in the ratios of 95 + 5 and an aqueous sodium alginate solution at 3 concentrations (0.5, 1 and 1.5% (w/v)), were used. Simulated gastric juice was prepared fresh daily containing 3.2 mg of pepsin, 1 ml of NaCl solution (0.5%) and acidified with HCl (1.2 M) to pH 1.5 ± 0.5. Tolerance to gastric juice was examined by placing freshly prepared cells in a tube containing sterile simulated gastric juice for 1 h and incubated at 37°C for 2 h. To characterize the morphology of the MCC particles coated with the different matrix formulations, SEM images were taken. Experimental data have been represented as the mean with standard deviation (SD) of different independent determinations. The significance of differences was evaluated by analysis of variance (ANOVA). Differences were considered statistically significant at p
Research Article
Mersad Ghorbannejad Shahroudi; Abdollah Golmohammadi; Davood Kalantari
Abstract
Introduction: Mechanical damages in agricultural products cause wastes directly and indirectly. Bruise damage due to quasi static load is one of the most important reasons of fresh fruit quality loss. Agricultural crops undertake many mechanical loads and physical damages during different stages of harvesting ...
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Introduction: Mechanical damages in agricultural products cause wastes directly and indirectly. Bruise damage due to quasi static load is one of the most important reasons of fresh fruit quality loss. Agricultural crops undertake many mechanical loads and physical damages during different stages of harvesting and post-harvest such as handling, transport, storage and processing. In many cases imported loads cause mechanical damages and cellular wall rupture and this rupture leads to perturbation of natural cellular interchanges. This object is one of the important problems of modelling and experimental studies in Biosystems engineering sciences. Tomato is one of the most important horticultural products and a widely produced products in the world. Larg amounts of tomato products are destroyed during the different stages of harvesting, transport and packaging. To study the viscoelastic behavior of agricultural crops, rheology science is used which is the science of biological materials deformation and flow ability under affection of loads at different times. For prediction and classification of materials behavior under different conditions of stress and strain, different rheological models are used. These models include different combinations of metallic body (spring) and Newtonian liquid body (dashpot) that illustrate complex behavior of agricultural products. Determining of factors that affect deformation value of tomato, lead to reduction of product waste.
Materials and methods: In this study, the effect of some important parameters such as static loading at three levels (2, 6 and 10 N), storage temperature at two levels (4 and 25 ˚C), loading at two directions for two cultivars (Supper-Beta and Petoerly-CH), were studied on deformation value. Samples were handy harvested at approximate ripeness level (reddish pink) from greenhouse and transported to the Lab. Some physical properties (mass, volume, major and minor diameters, height, sphericity coefficient, surface area) were measured. Samples were subjected to compressive loading using university made apparatus. The Experiments were performed in a fifteen-day period, at two different conditions, ones at temperature 4 ˚C and the other at environmental temperature 25 ˚C, using factorial test in form of completely randomized design. The first test was performed under constant load of 6 N in two directions of fruit axials (Z and Y directions), The second test was performed in three levels 2 and 10 N in direction of calyx face. By indicator, deformation value of tomatoes at 2, 4, 7, 10, and 15 days after loading was investigated. The third test was performed under constant loads of 15 N and deformation values of samples were recorded every 10 mins during a 60-minute period.
Results and conclusions: The Results showed at temperature 25 ˚C, with increasing load from 2 up to 10 N, deformation value of the product would be increased about 65%. Increase of deformation value indicates the effect of loading time for products such as tomatoes. This phenomenon can be a result of bulk density ratio reduction of product during the storage, because biochemical reactions are effective in fruit ripening, activating the destructive enzymes of cellular wall during the storage, softening and color changes. Maintaining fruits in direction of calyx face leads to lower deformation in comparison with 90 degrees proportion to calyx. This phenomenon is because of tomato tissue, its tissue in direction of calyx is harder and stiffer of normal direction, because of being flower. By reducing temperature from 25 to 4 ˚C, at constant load of 6N, deformation was decreased about 40%. With decreasing temperature, viscosity of biologic products would be increased and cellular walls get brittle and tissue stiffness increase. Therefore, it seems logical that deformation value of product at lower temperature decreases. Super-Beta cultivar had more durability in comparison with Petoerly-CH against compressive static loads. Under constant loading conditions, General Kelvin rheological model was considered suitable to estimate the strain versus time.
Research Article
Mehran Nouri; Behzad Nasehi; Vahid Samavati; Saman Abdanan
Abstract
Introduction: Fried foods such as donuts enjoyed worldwide for their taste, distinctive flavor, aroma and crunchy texture. There is, however, grave health concern over large fat content of fried foods (Melito and Farkas, 2013). There are several ways to lower fat content in deep-fried foods. One method ...
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Introduction: Fried foods such as donuts enjoyed worldwide for their taste, distinctive flavor, aroma and crunchy texture. There is, however, grave health concern over large fat content of fried foods (Melito and Farkas, 2013). There are several ways to lower fat content in deep-fried foods. One method is to reformulate the product by adding hydrophilic ingredients such as dietary fibers to reduce oil uptake during frying. Another method to reduce fat content is to partially cook the food using another heating method (Melito and Farkas, 2012). There is an increasing interest in microwaving foods for several reasons: it is faster than conventional methods, the energy consumption is often lower and foods cooked by microwaving maintain nutritional integrity.vIn foods, the appearance is a main criterion in making purchasing decisions. Appearance is used throughout the production –storage-marketing-utilization chain as the key means of judging the quality of individual units of product. The appearance of unities of products could be assessed by considering their color and surface texture. The use of computer-vision technology has quickly increased in the fields of quality inspection, classification and evaluation in processing a large number of food products (Brosnan and Sun, 2004). Therefore the aim of this study was to study the effects of microwave pre-treatment on sensory and appearance properties of donut.
Materials and methods: Response surface methodology and Box- Behnken design were applied to evaluate the effects of independent variable include microwave power (300-900 W), microwave time (30-90 s) and frying time (70-130 s) on sensory and appearance properties of donuts. Donuts were prepared according to the formulation by Melito and Farkas (2012) with some modifications. Ingredients used in donuts formulation were consisted of 100 g of wheat flour (9 g/100g), 52 g of water, 9.75 g of Shortening, 14 g of Egg, 14 g of water for yeast, 6.80 g of sugar, 6.80 g of nonfat dried milk powder, 3.25 g of active dried yeast, 1.70 g of Vanilla extract, 1.7 g of baking powder, 1.70 g of Salt, 1.3 g of Persian gum and 7.00 g of carrot pomace powder. The dough was cut into squares approximately 50 mm on each side. Then, the dough pieces were allowed to proof for 30 min at 27 ºC. The proofed samples were pre-treated using a microwave oven at different levels of microwave power and microwave time in accordance with the experimental design. Formerly, the per-treated donuts were deep-fat fried in a Moulinex deep-fat fryer (model F18-RA, France) filled with 1.5 L of vegetable frying oil (A mixture of Sunflower, palm, and soybean oil; Behshahr CO., Tehran, Iran) at different levels of frying time in accordance with the experimental design. The oil was preheated for 30 min prior to frying and replaced with fresh oil after every frying process. After frying, donuts were removed from the fryer and allowed to cool for 30 min on paper towels. They were then stored in coded sealed polyethylene bags.The evaluation of the crumb grain and crust color of donuts was performed using an image analysis system consisted of a Canon digital camera (model SX60 HS, Japan) and a personal computer with a Pentium(R) Dual-Core processor and Windows 7 Ultimate. The samples were photographed at a fixed distance of 30 cm from the crumb of samples, which were sitting inside a black box. The captured images were analyzed using the MATLAB R2014a software (The MathWorks Inc., Natick, Mass, USA).The CIE L*a*b* (or CIELAB) color model was used for determination of the crust color of donuts. Crumb grain features of the donut samples were obtained with described digital image analysis system. After imaging, each image was converted from RGB format to 8 bits (grey level) using the MATLAB software. In this format, an area of 3 × 3 cm2 was selected at the center of the captured image. After contrast enhancement of image, the image segmented using the Otsu algorithm, which produces highly uniform binary images (Otsu, 1979). Finally, crumb grain properties of donuts were studied by determination of cells densities and area of cells. Sensory evaluation of donut samples was carried out by assigning scores for crust appearance, crumb appearance, crust color, aroma, texture, taste and overall acceptance parameters based on a nine-point hedonic scale. (Stone et al., 2012).
Results and discussion: Results showed that roughness of the donuts surface increased significantly (p
