Research Article
Safura Jalali; Hossein Jalali; Seyyed Hossein Hosseini Ghaboos
Abstract
Introduction: Cakes by appropriate organoleptic characteristics are considered the most commonly used flour products all over the world. According to the role of dietary fiber on health and its ability to prevent some types of cancer and diabetes, fans of high-fiber foods is increasing. Pumpkin is a ...
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Introduction: Cakes by appropriate organoleptic characteristics are considered the most commonly used flour products all over the world. According to the role of dietary fiber on health and its ability to prevent some types of cancer and diabetes, fans of high-fiber foods is increasing. Pumpkin is a good source of carotene, water-soluble vitamins and amino acids. Pumpkin can be converted to powder with longer shelf-life. Pumpkin flour is used because of its highly-desirable flavor, sweetness and deep yellow orange –red color. In this study, kinetic modeling of pumpkin drying in an infrared-hot air dryer was investigated. Malting is a result of biochemical processes that includes steeping, germination and kilning of cereal in controlled environment in which hydrolytic enzymes are synthesized and cell wall, protein and starch of endosperm are largely digested. The aim of this study was to determine the physico-chemical, textural and sensory properties of sponge cake supplemented with four different levels (0, 10, 20 and 30 %) of pumpkin and malt powder
Materials and methods: Fresh pumpkins (Cucurbita moschata) were obtained from local market. Slices of pumpkin with 5 mm thickness were prepared with the aid of a steel cutter and were immediately placed into the dryer. The pumpkin slices were dried in a hot air dryer (65°C). The effect of pumpkin and malt powder replacement with wheat flour on physicochemical and sensory properties of sponge cake including pH, fat, protein, moisture, ash, fiber, β-carotene, mineral, carbohydrate, texture and color were evaluated. The ingredients used in the sponge cakes formulation were cake wheat flour, sucrose, sunflower oil, fresh eggs, whey, baking powder, vanilla, water and nonfat milk powder. In this study pumpkin and malt powders at four levels of 0, 10, 20 and 30 % as wheat flour replacer were used. For each cake, 40 g of cake batter was poured into a cake pan and baked at 180-200°C for 20-25 min in an oven. Cakes were then allowed to cool for 40 min, and removed from the pans. The cooled cakes were packed in polypropylene bags at room temperature before performing physico-chemical and sensory evaluation s. Moisture content of the samples was determined in an oven at 105°C for 4 h (AOAC, method no. 934.06). For measuring β – Carotene content 1 gram of cake was dried and then crushed in 10-15 ml of acetone with the help of pestle and mortar and few crystals of anhydrous sodium sulphate were added. The supernatant was decanted into a beaker. The process was repeated twice and combined supernatant was transferred to a separating funnel, then 10-15 ml of petroleum ether was added and mixed thoroughly. Two layers separated out on standing. The lower layer was discarded and upper layer was collected in 100 ml volumetric flask. The volume was made to 100 ml with petroleum ether and optical density was recorded at 452 nm using petroleum ether as blank. The crumb color determinations of cake samples from the midsection of the cakes was measured with HP Scanner (Hp Scanjet G3110). L* (lightness/darkness that ranges from 0 to 100), a*(redness/greenness ranges from -120 to 120) and b* (yellowness/blueness ranges from -120 to 120) were measured. In this study, the image analyses of sponge cakes were performed using Image J software version 1.42e, USA. The texture analysis of sponge cake samples (2.5 × 2.5 × 2.5 cm) from the midsection of the cakes was performed using a texture analyzer (TA-XT Plus, Stable Micro Systems Ltd., Surrey, UK) and a test speed of 1.0 mm s−1. The crust of cake samples was removed in cake texture determination. The textural properties were determined using Texture Expert 1.05 software (Stable Microsystems). Each measurement was conducted in triplicate, except for the sensory evaluation (n=16). The experimental data were subjected to analysis of variance (ANOVA) for a completely random design using SPSS 19 and Excel 2010. Duncan’s multiple range tests were used to determine the difference among means at the level of 0.05.
Results & Discussion: The results showed no significant differences between treatment on fat, protein and pH. With increasing of pumpkin and malt powder in sponge cake formulation, significant difference was observed between the fiber contents of cakes. Fiber contentof all treatments was in the range of 0.28-1.13. Redness (a*) and yellowness (b*) indexes of cakes were increased but lightness (L*) index was decreased. Significant difference (P
Research Article
Mina Davoodi; Mahdi Kashani-Nejad; Aman Mohammad Ziaiifar; Mohammad Ghorbani
Abstract
Introduction: There are many methods for freezing and thawing of meat. Suitable technology must be applied for freezing and thawing of chicken to keep the quality of product effectively. Novel methods including high pressure, ohmic heating and high-voltage electrostatic field have been recently considered ...
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Introduction: There are many methods for freezing and thawing of meat. Suitable technology must be applied for freezing and thawing of chicken to keep the quality of product effectively. Novel methods including high pressure, ohmic heating and high-voltage electrostatic field have been recently considered for thawing process. IR heating provides positive advantages compared to conventional heating such as reduced quality losses, shorten heating time, significant energy saving and uniform heating. Although IR has been used for various food treatments but a few researches have been reported for its application in thawing process. This study investigates the effects of this new method on thawing time, thawing loss, thawing rate, water holding capacity, color, pH, shear force, characteristics of frozen ground chicken and also optimizes the thawing conditions using response surface method.Material and methods: Fresh chicken breast was purchased from a local market (Gorgan, Iran). After washing and mincing, they were cut into a cube form (3×3×5 cm3) and stored in the freezer at -20 ℃ for 5 days before thawing process. Thawing was performed using an IR-warm air apparatus consisted of IR lamp (Far IR 1500 watts), heating elements (4 electrical elements with power 750 W), air velocity unit, centrifugal fan and thawing chamber. For thawing of samples, three variables including IR power (12.27- 247.73 W), air temperature (27.57- 49.43℃) and air velocity (0.21- 7.47 m/s) were applied. The central composite rotatable design was created by entering the three independent variables at five different levels in 20 runs with six central points. Response surface analysis was performed using Design-Expert software. The equipment was allowed to work at least 10 min to stabilize the specified conditions before the start of each thawing run. Frozen sample was then removed from freezer and placed under the infrared lamp with 12 cm distance. Quality of ground chicken breast was determined by thawing time, thawing loss, thawing rate, water holding capacity, pH and color indices.Results and Discussion: The methodology and techniques used in freezing and thawing processes play an important role in the preservation the quality of frozen foods. The results showed that increasing IR power, air temperature and air velocity decreased the thawing time (13.5–6.8 min), thawing loss (6.1–0.03 %) and increased thawing rate (11.11-30.67 cm/h), WHC (65.45–94.16 %) and improved the quality characteristics of thawed ground chicken. Generally, the ability of meat to retain free or bound water is one of the important quality characteristic of raw meat. One of the most important indicators of quality on thawing food is water holding capacity. The final pH is dependent on the amount of drip loss between the stocky and tenuous filaments. In addition, the difference in pH can be due to texture damage. Generally, the pH of chicken breast after postmortem is about 5.6- 5.8. The ∆E values and pH of the ground chicken breast was also in the same range during thawing process. Numerical optimization conditions were investigated based on the lowest thawing time, thawing loss and highest thawing rate and water holding capacity. The best suggested condition by the software was IR power 247.73 W, air temperature 38.97℃ and air velocity 6.75 m/s (desirability= 0.79). Based on the obtained result using T-test analysis, there was no considerable difference between the experimental values and the predicted one (P
Research Article
Fatemeh Omranifar; Hassan Ahmadi Gavghili; Mohammad Hossain Azizi; Ataallah Manafzadeh
Abstract
Introduction: Bread as a staple food for different groups of society at every level of income, plays important role in the nutritional basket. So enrichment bread by various components considered an eminent factor in compensating nutritional deficiencies.
Materials and methods: The effect of partial ...
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Introduction: Bread as a staple food for different groups of society at every level of income, plays important role in the nutritional basket. So enrichment bread by various components considered an eminent factor in compensating nutritional deficiencies.
Materials and methods: The effect of partial replacement of wheat flour with lentil dahl flour, at 10, 20 and 30 percent and gluten at 2, 4 and 6 percent on quality characteristics of the toast bread (including determination of special volume by using Rapeseed displacement method, color measurement with Hunter Lab colorimeter, ability to hold moisture calculated via weighing of the samples before and after oven incubation, firmness determined with calculation of the maximum force required to compress the height of sample to half of preliminary height with Instron test, also ability to hold moisture and firmness on the first, third, fifth days after production and it’s relationship with staling) were studied. As well as combinational treatment were studied in order to optimization of the enriched toast bread production processes. Statistical analysis of data carried out by factorial test and CRD. Also Duncan test was used in order to find means difference (α˂0.05).
Results and discussion: Results from partial replacement of the wheat flour with lentil dahl flour showed the decrease in specific volume, while both of lentil dahl flour and gluten were led to increase water absorbance. The effect of water holding capacity and special volume on texture of breads is fully understood, therefore as gluten level increase, specific volume and water holding capacity increase which could lead to decrease firmness. The results shown that, replacement of wheat flour with 2-4% gluten leads to increase specific volume (4-4.3 ml/g) whereas decrease in specific volume (4 ml/g) was observed by 4-6% gluten replacement. The moisture retaining of lentil dahl flour increased significantly in the first, third and fifth days after production which caused an elevation of tenderness and softness in texture and suspended staling process in the enriched toast breads containing lentil dahl flour. This claim was validated with scores gained from organoleptic evaluations.
The color of the bread was measured by Hunter Lab colorimeter to determine parameters (a*, b* & L*), as well as ∆E* index. The results indicated that L*was decreased and (a* & b*) increased with increasing partial replacement levelt of the wheat flour with lentil dahl flour. . Highest level of ∆E* index was obtained in treatment with 30 percent of lentil dahl flour and the lowest value was related to treatment with 10 percent of lentil dahl flour and 4 percent gluten.
Conclusion: Finally the treatment contain 20 percent of lentil dahl flour and 6 percent gluten and treatment with 10 percent of lentil dahl flour and 4 percent gluten were earned most score even in some cases higher than control sample and were introduced as optimized samples in the point of fortification and utilize ability after production and in consumption period
Research Article
Zeynab Raftani Amiri; Mohammad Ezazi
Abstract
Introduction: Nowadays, use of by products in formulation of functional foods in order to improve their nutritional value and also avoid environmental pollution in food industry is increasing. Whey, a by product of dairy industry is one of such compounds. The acid whey resulted from concentration of ...
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Introduction: Nowadays, use of by products in formulation of functional foods in order to improve their nutritional value and also avoid environmental pollution in food industry is increasing. Whey, a by product of dairy industry is one of such compounds. The acid whey resulted from concentration of yoghurt, as a by-product, can be applied in whey based fruit beverages due to its minerals and beneficial residual proteins. It represents about 85–95% of the milk volume and contains nutrients, such as lactose as a most content, soluble proteins, lipids, minerals, vitamins, and organic acids. Acid whey has a pH of approximately 4.5 due to the conversion of lactose into lactic acid by lactic acid bacteria during the process of yoghurt production. Lactose is the main ingredient of whey, which comprises 90 percent of whey dry matter. According to FAO, the worldwide production of cheese was estimated to be 19,000 kilo tones (kt) in 2010, thus resulting in approximately 177,000 kt whey as a by product. The annual growth arises to production of approximately 211,000 kt whey in 2020. Therefore, the research for new lucrative whey utilization beside whey protein recovery is an ongoing challenge for the dairy industry. More than 70% of the world’s population suffer from lactose intolerance, which limits consumption of lactose containing dairy products. Lactose intolerant individuals, who consume milk or other dairy products like as acid whey, even at small quantities, facing gastroenterological complications related to the uptake of calcium and certain other nutrients. Thus it is important to reduce the lactose content of mild and dairy by products before using them in new foods formulation. In this study production of low lactose whey by enzyme was investigated. Beta-D-Galactosidases, EC (3.2.1.23), is a hydrolase enzyme that converts lactose into glucose and galactose and increases the sweet taste in products. It is commonly known as lactase, which is one of the most important enzymes in food, dairy and fermentation industries. Mixing of the low lactose whey with fruit compound or concentrates and sweetener agents make delicious and functional new beverage.
Materials and methods: The acid whey resulted from concentration of Greek yoghurt, as a by-product, was applied in whey based fruit beverages. The lactase enzyme (Sapherra FMP) was prepared from Novozyme Company. Pineapple compound prepared by Orana Company from Denmark. The quantity of sugar (Shadianeh) in each sample has been investigated based on the equivalent sweetness recognition by panelists in lactase treated samples in comparison with non treated samples. Premixed sugar and stabilizer in precise amount for each treatment was added to water and agitated in stainless steel agitating mix. After that whey and pineapple compound, and then 1000 ppm enzyme were added to samples and kept at 4 degree Celsius for 3 hours and finally pasteurized. All samples homogenized by 150 bar in 60 degree Celsius. Packaging of samples was done in 250 gram tetra pack container at aseptic condition. The effect of lactase enzyme on sugar quantity and taste improvement of acid whey based beverage produced by 5 percent of pineapple compound, has been investigated by lactase enzyme (0 and 0.1 percent), acid whey (30 and 40 percent), storage temperature (ambient and refrigerator) and time storage (0, 4, 8, 10 and 12 weeks after production) on a factorial experiment in a completely randomized design.
Results and discussion: The results of sensory evaluation in 12 weeks at two different storing temperatures (refrigerator and ambient), showed that addition of lactase enzyme before pasteurization of whey based pineapple flavored compound could kept not only the pH on constant, and reduced the sugar quantity to achieve constant sweetness in all samples, but also improved the sensory specification of beverage, significantly (p
Research Article
Anegol Kheradmand; Ania Ahani Azari; Ahmad Danesh
Abstract
Introduction: In recent years, there have been many epidemic outbreaks caused by consumption of contaminated vegetables. In most cases, Enterobacteriaceae were responsible for these epidemics. The purpose of this study was to investigate antibiotic resistance pattern and frequency of strains producing ...
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Introduction: In recent years, there have been many epidemic outbreaks caused by consumption of contaminated vegetables. In most cases, Enterobacteriaceae were responsible for these epidemics. The purpose of this study was to investigate antibiotic resistance pattern and frequency of strains producing broad-spectrum beta-lactamase (ESBL) isolated from lettuce and spinach produced in Gorgan, Iran.
Material and Methods: After culturing the isolates on MacConkey medium, colonies with specific morphological characteristics were selected. After preparation of pure culture, strains resistant to cefotaxime were identified and strains belonging to the Enterobacteriaceae family were isolated. The isolates were then studied for broad-spectrum beta-lactamases (ESBL) and their antibiotic resistance patterns were determined.
Results & Discussion: The results of this study showed that ESBL Enterobacteriaceae is present in vegetables such as lettuce and spinach. It was also found that all isolated ESBL Enterobacteriaceae from spinach samples were resistant to Cotrimoxazole, Nalidixic Acid, Tetracycline, Chloramphenicol, and Amoxicillin, and sensitive to Imipenem. Isolated ESBL Enterobacteriaceae from lettuce samples was sensitive to Amikacin and Imipenem. Multiple antibiotic resistance was observed in all isolates. Therefore, it can be concluded that use of animal fertilizers increases the risk of antibiotic-resistant bacteria in vegetables and ultimately in humanand animals.
Research Article
Olga Azimi; Reza Farhoosh; Mohebbat Mohebbi; Mahdi Saadatmand
Abstract
Introduction: Discerning the expiration status (rancid and non-rancid) of edible vegetable oils is very significant because of hazardous primary and secondary oxidation products. Oils are a nutritious and valuable food source which play an important role not only in supplying energy but also in sustaining ...
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Introduction: Discerning the expiration status (rancid and non-rancid) of edible vegetable oils is very significant because of hazardous primary and secondary oxidation products. Oils are a nutritious and valuable food source which play an important role not only in supplying energy but also in sustaining a health. Edible vegetable oils such as soya, sunflower, canola, sesame and olive, bring essential nutrient components for human being such as vitamins, fatty acids, and micronutrients, which are necessary for daily life. Lipid oxidation in vegetable oils is associated with unsaturation of the oils. This reaction leads to the formation of a series of intermediate compounds named hydroperoxides. Hydroperoxides are the primary oxidation products of lipid oxidation. Due to the unstable nature of these primary products which leads to their decomposition and turning into secondary oxidation products, such as carbonyl compounds occur soon.
The use of expired edible oils leads to a decrease in the nutrition value and an increase in potential hazards to people's health, so monitoring the quality and security of edible oils is important. Based on the reports and experimental observation the oil color changed during oxidation. Therefore, it is of utmost importance to find new and fast methods for detecting the quality of oils. Computer vision in food sciences is an affordable technology and is extensively used. The aim of this study was to introduce a simple and feasible method for classifying edible vegetable oils (soya, sunflower, canola, sesame and olive) and also for distinguishing their quality in terms of rancidity. In order to achieve this, multivariate statistical methods based on their rejection point of primary and secondary oxidation products was implemented.
Materials and methods: Digital camera and unsupervised multivariate statistical techniques such as linear discriminant analysis (LDA) and principal component analysis (PCA) were used for pattern recognition and classification. In this study, the physicochemical characterization of 77 oil samples includes their peroxide and carbonyl values were evaluated at 80 ◦C. The color indices L*a*b* were used for this classification. The space that was built for imaging was 120cm ×90cm ×90cm with dark walls to isolate the samples from external light. The compartment has a camera (Canon model, EOS 1000D), which was connected to computer by USB port. The illumination of the compartment was performed by using eight fluorescent lamps with 8 W (white color), the lamps were placed at a distance of 20 cm from the samples. The illustration was performed by Zoombrower EX 0.5, the other characteristics of the camera for imaging were as follow: flash (off), zoom (on), Iso speed (100), Aperture priority (F / 20) and Shutter speed (0.6 Sec). The illumination condition at compartment for each sample was the same. Image color analysis was performed using the Image j (Version: 1.4.3.67) software to convert images from R*G*B color space to L*a*b. The recorded images contained 24-bit (16.7 million colors) and 3888 pixels × 2592 pixels spatial resolution and were stored in JPEG format (jpg). A specific region at the center of each image was selected for converting R*G*B to L*a*b. In this study, three components of color space L*a*b* were extracted from 231 images samples ( 77 images of different types of oil before heating, 77 images at the rejection point based on peroxide value and 77 images on the rejection point based on carbonyl value). The extracted color values were used for linear discriminant analysis classification and principal component analysis. The classification was performed using MATLAB (R2013) software
Results & Discussion: The comparison of the results of the linear discriminant analysis showed that distinguishability between the two types of different oils was 100% and only the distinguishing of one oil type in rancid and non-rancid state resulted in a decrease in accuracy to 97%. Also the overall and simultaneous analysis of oil samples in both states (rancid and non-rancid) by the two classifiers of LDA and PCA showed that the classification of each oil individually has the highest accuracy (100%) and the results of the studying several different oils showed a decreased accuracy (98% and 96%). However, in practice, the result of this classification given the diverse colour range of vegetable oils, is acceptable in terms of accuracy and the linear discriminant analysis classifier acted more successfully compared to principal component analysis classifier by about 40%.
Research Article
Mohammad Ganjeh; Seyed Mahdi Jafari; Mehrdad Niakosari; Ali-Mohammad Tamaddon; Yahya Maghsoudlou
Abstract
Introduction: In recent years, production of nutraceuticals by adding bioactive compounds and nutrients has been grown substantially. These compounds are generally sensitive to environmental or gastrointestinal conditions and their bioavailability is limited due to destructive reactions. One of the common ...
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Introduction: In recent years, production of nutraceuticals by adding bioactive compounds and nutrients has been grown substantially. These compounds are generally sensitive to environmental or gastrointestinal conditions and their bioavailability is limited due to destructive reactions. One of the common methods to reduce or prevent these kind of problems, is microencapsulation of valuable compounds in some materials which can protect them against environmental conditions, and enabling them to controlled release from trapped compounds at specific time and place. Orange peel oil, contains some important bioactive compounds such as limonene that is used in a variety of beverages, foods, cosmetics, pharmaceuticals and chemicals. D-limonene is the main constituent of orange peel oil, because it makes an 80-95% fraction of the orange peel oil volatile compounds, depending on fruit variety. In addition to its technological characteristics (flavor), D limonene can stop or delay the initiation of cancer. It can also be used as a safe alternative to antimicrobial compounds. Nevertheless, technological limitations (hydrophobic structure, high reactivity, sensitivity to oxidation and volatility) often avoid suitable use of this compound as a dietary supplement. Polysaccharides are among of the basic materials which are applied more in this field. Several factors such as cheap and easy access, having active groups interacting with hydrophobic and hydrophilic compounds, biodegradation, biocompatibility and relatively high thermal resistance, have turned them to be superior to lipid and protein carriers. One of the most important polysaccharide compounds existing in nature, is starch. It can be used as a carrier in encapsulation processes with different purposes, having advantages such as inexpensive, non-toxic, capable of recrystallization, the ability to form film and complex and resistant to various degrees of enzymatic hydrolysis. Spatial configuration of amylose is changed in the presence of ligands such as iodine and linear alcohols, resulting in a left-handed helix which can trap ligands within or between curvatures derived from glucose connections. One of the major structures which is created in the interaction of amylose and lipophilic substances, is known as V-amylose structure. V-amylose is a left-handed helix with an inner hole which ligands can be placed within it. The aim of this study was to determine the effectiveness of amylose in nanoencapsulation of limonene as a bioactive compound with desirable sensory characteristics using a thermo-mechanical stress.
Materials and methods: Based on the analysis of pure limonene samples (Sigma-Aldrich) as well as samples used in this study, more than 92% of examined sample comprised of D-limonene. In order to prepare amylose nanoparticles containing limonene, 0.1 molar solution of potassium hydroxide (Merck, Germany) was prepared in deionized water and then high amylose corn starch (HACS) (Sigma-Aldrich (St. Louis, MO, USA) with 70% amylose was added to it in the ratios of 2: 4% while stirring continuously for 30 minutes at 80°C. Limonene was then used in the ratios of 5: 10% of HACS was added to the suspension and stirring continued for 1 minute. Initial suspension has been processed by using ultrasound system (Model UP100- Hescheler Company, Germany) with 100 W power and frequency of 30 kHz for 9 and 18 minutes. The viscosity of amylose suspensions containing nanoparticles with different formulations was measured by using a capillary viscometer (Schott-Gerate-Capillary-Viscometer-525-00- Germany). Size and zeta potential was measured by using dynamic light scattering (DLS) and Nanotrac Flex In-situ Particle Size Analyzer devices and Microtrac ZETA-check determined. The morphology of nanoparticles was studied using a scanning electron microscopy (TESCAN-Vega3- Czech Republic). Microencapsulation efficiency and loading efficiency were determined by using spectrophotometry.
Results and Discussion: In all formulations, particle sizewere less than 50 nm. Starch granules were exposed to cavitation stress by applying the ultrasonic process .The constant formation of bubbles creates a mechanical impact with high energy on starch granules during bursting. Fast impingement of fluid to granule surfaces, hitting particles to each other as well as resistant of the granules against fluid stream cause breaking of starch particles into nanoparticle scales. The highest amount of zeta potential was related to the sample which had the highest starch and limonene concentration. Amylose concentration had the main effect on zeta potential changes. Electrostatic charges can be the main reasons for the higher zeta potential in samples with 4% amylose concentration. More increasing in surface active agents of amylose, namely ionized hydroxyl groups of glucose molecules leads to increasing in surface charge, and results in zeta potential. The most impact on solutions viscosity is related to amylose concentration. Generally, increasing the amylose concentration leads to increasing the solution viscosity, in other side, with ultrasound treatment, the amount of this index was reduced and the solution became more fluent. Microencapsulation and loading efficiency values ranged between 28-82% and 0.38-1.63% respectively. The limonene concentration had the most impact on the efficiency in various formulations. At similar treatments with %4 amylose concentration and 9 min sonication period, by increasing the amount of limonene from %5 to 10, microencapsulation and loading efficiency were increased from %31 to %82 (%62 growth) and from 0.52 to 1.41 (%63 growth) respectively.
Research Article
Samaneh Rezaei; Mohammad Bagher Habibi Najafi; Fereshteh Hosseini; Reza Karazhyan
Abstract
Introduction: Nowadays, with the increasing awareness of the side effects of synthetic additives, consumer’s demand for colorants from natural sources has been increased. Annatto is an allowed natural colorant used in food industries, textiles, cosmetics and pharmaceutical products. The colorant is ...
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Introduction: Nowadays, with the increasing awareness of the side effects of synthetic additives, consumer’s demand for colorants from natural sources has been increased. Annatto is an allowed natural colorant used in food industries, textiles, cosmetics and pharmaceutical products. The colorant is extracted from the seeds, which are covered by a red, resinous pericarp containing the pigments. The main pigment is bixin (methyl hydrogen 9′-cis-6, 6′-diapocarotene-6, 6′-dioate) which is responsible for the orange red color in the seeds (80% of total carotenoids). Smaller amounts of norbixin are also presented. Bioactive compounds like bixin and phenolic compounds reduce the risks of various chronic disorders, such as cancer, inflammation, cardiovascular, hypercholesterolemia, diabetes, and cataracts (Boschetto, et al., 2014; Somacal et al., 2015; Ezuruike & Prieto, 2014). Moreover many studies have proven antimicrobial activity of annatto extracts (leaves, capsules, seeds…) against several food spoilage and pathogenic bacteria such as Staphylococcus aureus, Escherichia coli and Bacillus subtilis, as well as few fungi such as Candida utilis, and Aspergillus niger. Annatto is a permitted natural food coloring with antioxidant properties, high therapeutic potential and antimicrobial effects. The aim of this study was to evaluate antimold activity of annatto natural dye on 3 important food pathogenic and spoilage molds, Aspergillus niger,Neurospora sitophila and Rhizopus stolonifer.
Material and Methods: Annatto dye was extracted by maceration method and after filtration it was dried by a vacuum oven. Anti-mold activity was evaluated by well diffusion and disk diffusion methods in 1 to 10 percent concentrations of acetone extract of annatto and minimum inhibitory concentration (MIC) was determined using agar dilution method at 48 and 72 h after incubation at 25 °C.
Results and Discussion: The results indicated promising anti-mold activity. The highest mean zones of inhibition in all concentrations were obtained for Aspergillus niger, Neurospora sitophila and Rhizopus stolonifer, respectively. This difference might be due to the more resistance and rapid growth of Rhizopus stolonifer and Neurospora sitophila compared to Aspergillus niger. No inhibitory effect was observed in the concentrations below than 1%, this result is in consistent with Irobi, et al., (1996) findings that proved annatto's organic extract has a weak effect on Aspergillus niger at low concentration (5 mg/ml).In all concentrations, Aspergillus niger showed the highest inhibition zone and the most sensitivity to annatto extract found at Aspergillus niger, Neurospora sitophila and Rhizopus stolonifer, respectively. Disk diffusion method was inefficient to inhibit mold growth. Minimum inhibitory concentration of annatto dye against Aspergillus niger and Neurospora sitophila was determined 6 percent while Rhizopus stolonifer showed 7 percent. According to the results annatto dye was effective to inhibit growth of Aspergillus niger, Neurospora sitophila and Rhizopus stolonifer. Therefore it can be concluded that annatto dye could be used as a functional and inhibitory agent against mold growth in the foods that are susceptible to mold spoilage (e.g. bakery goods).
Research Article
Amir Jajarmi; Bahareh Emadzadeh; Rassoul Kadkhodaee
Abstract
Introduction: Carrageenans are a family of linear sulphated polysaccharides that have broad applications in the food sector and pharmaceutical industry. Based on the degree of sulphation (polyelectrolytes) in carrageenan, only Kappa and Iota carrageenan have the ability of forming a gel structure. The ...
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Introduction: Carrageenans are a family of linear sulphated polysaccharides that have broad applications in the food sector and pharmaceutical industry. Based on the degree of sulphation (polyelectrolytes) in carrageenan, only Kappa and Iota carrageenan have the ability of forming a gel structure. The mechanical characteristics of their gels, however, is affected by the polyelectrolyte nature of their chains. Iota and kappa carrageenan provide elastic soft gel and brittle rigid one, respectively, in the presence of calcium and potassium salts as their favored ions; while their mixture provides a broad range of structures with unique textures. The combination of these two biopolymers would result in a broad range of unique textures for different applications. The aim of this Study was to determine the effect of chain association (molecular association) on the textural properties of kappa- Iota carrageenan mixed gel. The texture of gels was investigated through the puncture test to determine some properties including hardness, toughness, deformability modulus, resilience, yield point, and proportional limit. In addition, the stress relaxation test was applied to evaluate the effect of the chain association formed in the network on the stress decay parameter.
Materials and Methods: A commercial Kappa-carrageenan, Genugel type, and Iota- carrageenan, Genuvisco type without further purification were purchased from CP Kelco (Lille Skensved, Denmark). Potassium chloride (KCl) and calcium chloride dihydrate (CaCl2•2H2O) of analytical grade were purchased from Merck company. The mixtures were prepared in 2:1, 1.5:1.5 and 1:2 ratios and the final concentration of 0.3% w/w biopolymer. Both calcium and potassium chloride were added using a strategy adopted for each salt for keeping the same ionic strength of molar concentrations of 2.5, 5 and 7 mmol in the biopolymer dispersions. The mechanical properties of the gels were investigated using an XT. T2 Texture Analyzer (Stable Micro Systems, Surrey, UK). Peltier system was utilized in adjusting the temperature at 4oC. The samples were equilibrated at least 10 min before performing the test. Crosshead speed was adjusted at 10 mm/min to a 12 mm depth (50% from total length) from the surface of the samples using a 1 mm diameter cylindrical aluminum probe for puncture test and a 2 mm/min crosshead speed using a 75 mm diameter cylindrical aluminum probe in 20% strain was applied for the stress relaxation test during 60 second time interval. Pleg and Normand equation was applied for the determination of viscoelastic properties of samples.
Result & discussion: Among different methods in the mechanical study of biopolymer gel, the puncture test is a promising method due to its ability in applying normal and shear forces on and into the structure simultaneously. In the presence of calcium and Potassium salts, the same pattern in the puncture curve was observed with increasing of ionic strength in the medium. According to the chain association formed as a result of the ion type, the pattern shows a transient from the elastic to the plastic deformation with different limits. The hardness as a parameter that indicates a composite biopolymer network resistance to break up, showed a higher value for the network containing Potassium salt. It would be due to the formed intra chain association in the system. For calcium salt, the results revealed a small variation in the hardness parameter with increasing the ionic strength. The area under the curve of stress- time is defined as toughness of the structure. The network formed by the intra chain association in the presence of potassium shows a free chain movement which leads to a plastic deformation with absorbing more energy before breaking the gel structure. Concerning the type of chain association, higher values of deformability modulus in the gels containing calcium salt is reasonable. Resilience, yield point and proportional limit are the characters related to the network homogeneity and bond stretching. In the networks with no depletion region, applying an external force to the body would lead to a uniform change in the initial state of the structure. In this kind of netwoks, the force distributed in the whole structure uniformly and local stress is not created. The chain movement as a result of bond stretching, causes a back stress occurance in the structure. When the primary stress is eliminated, the accumulated back stress will make the polymer to return to its original form. Interweaving the network by the intra chain association will result in a homogenous network formation and subsequently, to a higher parameter values in the linear region. The large deformation measurements were performed through the stress relaxation test to study the response of the structure during the interval times and to evaluate the viscoelastic properties of biopolymers network. Longer stress decay time was observed for the network developed in the presence of Potassium salt. The result obtained by studying the stress decay rate was in agreement with the properties observed from the evaluation of the linear region in the puncture test. On the other hand, the deformability modulus values conform to the result from hypothetical asymptotic level of the normalized relaxation parameter.
Research Article
Najimeh Taghavi; Aman Mohammad Ziaiifar; Habibollah Mirzaee; Alireza Sadeghi Mahoonak; Mohammad Ghorbani; Hassan Sabbaghi
Abstract
Introduction: Frying is a unit operation in which food is heated in oil to alter its eating quality. First reviews of frying performed on the principles of heat and mass transfer and oil uptake in foods, because during the frying process heat and mass transfer occurred between product and frying medium. ...
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Introduction: Frying is a unit operation in which food is heated in oil to alter its eating quality. First reviews of frying performed on the principles of heat and mass transfer and oil uptake in foods, because during the frying process heat and mass transfer occurred between product and frying medium. In fact, the food loses moisture content and lost water will replace with oil. The moisture loss in the product causes rapid formation of the crust while the core remains soft and moist; therefore higher oil uptake occurred in the crust. There is an argument about the effect of frying on the sensory characteristics of foods, changes of nutritional value and health concerns in fried foods and methods applied to reduce oil content. Consumers prefer eating foods with lower oil content. One of the typical methods for reducing oil uptake in food commodities is using of coating before frying process. Edible coatings are known as a thin layer of edible polymers which is placed on the surface of the food. Application of edible coating decreases some destructive factors like the presence of various gases such as oxygen and carbon dioxide and humidity. Hydrocolloides are referred to a group of polysaccharides and proteins which create many features such as consistency in aqueous solutions, foams stability, emulsions, improve the sense of mouth and create a similar state of fatty and oily mode for products with lower content. In fact hydrocolloid coatings can reduce the excessive oil uptake due to their interesting thermogelling properties and at the same time they are invisible and have no negative influence on the sensory attributes of fried foodstuff. Even more, fried products have low fat content with improved nutritional values, higher crispiness and better palatability. Pishmeh is described as deep-fried dough pastry which is usually prepared by local producers of Turkmen (Iran). This product absorbed high oil content during frying process. This study was carried out to evaluate the effects of hydrocolloid coatings including Aloe Vera, Carboxymethyl cellulose (CMC) and Xanthan on the oil uptake of Pishmeh.
Materials and methods: Hydrocholloid materials such as Aloe Vera, Carboxymethyl cellulose (CMC), Xanthan and complex of Xanthan-CMC were used. The gums were prepared at concentrations of 0.5 and 1% by dissolving in water at 70 ° C by stirring with a homogeneous mixer until a clear suspension was obtained. To extract the Aloe Vera gel, first, a thick epidermis (The shell) was separated from parenchyma using cutter. The parenchyma was immersed in a container of distilled water to lose bitter taste for 5 minand then parenchyma was taken out from water and transferred into a mixer (for 1 minute at 25 °C) and finally converted to a uniform colloidal solution. In the next step, the prepared dough samples were immersed in the colloidal suspensions for 1 min and the coated samples were placed on a mesh tray to remove the excess residuary coats. The samples were fried in sunflower oil at 170 °C for 6 min. The samples were then placed on a metal tray after frying to remove excess oil. After removing the oil and reaching the ambient temperature, physical and chemical tests were carried out on the sweet Pishmeh. The experiments included determination of moisture, fat content, measurement of coating parameters (such as coating ratio and frying efficiency) and color analysis.
Results and Discussion: The result showed that coating by hydrocholloid materials was led to decrease water loss in comparison to non-coated sample (control) during frying. Furthermore, oil uptake of coated samples was lower than control sample (p
Research Article
Mohammad Ganjeh; Seyed Mahdi Jafari; Mohammad Hoseinnejad
Abstract
Introduction: Yogurt is the most frequently consumed fermented milk product with a positive impact on human health due to its high nutritional value. Characteristics such as acidity, amount of free fatty acids with sensory characteristics and nutritional properties of yogurt are very important. Food ...
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Introduction: Yogurt is the most frequently consumed fermented milk product with a positive impact on human health due to its high nutritional value. Characteristics such as acidity, amount of free fatty acids with sensory characteristics and nutritional properties of yogurt are very important. Food fortification is defined as addition of one or more essential nutrients at levels higher than naturally presence in food products. The World Health Organization estimates that at least 1 of every 5 people in the world suffer from lack of iodine, zinc, iron, folic acid, calcium, vitamin A and B. The aim of this study was to evaluate the changes in physicochemical, textural and sensory properties of iron and zinc enriched yogurt during the shelf-life period and to assess the extent and the effect of these supplements on these properties.
Materials and methods: To perform enrichment, milk was divided into seven parts: 3 containers for fortification with iron, 3 containers for fortification with zinc and 1 container as the control sample. Fortification with iron and zinc was performed by concentrations of 20, 40 and 60 mg per kg of milk (according to the daily requirement of iron and zinc). The samples were then transferred into the container of 100 grams which were incubated at 45 °C, and after reaching the pH of 4.4 to 4.5, they were transferred to cold storage at 4 °C. To investigate the effect of enriching on the produced yogurt properties, the samples were evaluated after a period of one, seven and fourteen days. The syneresis of yogurt samples was determined by Salvador and Fiszman (2004) method, with slight modification. Water holding capacity was determined by centrifuge (Hettich Universal 320R - Germany) as reported by Sahin et al (2008) with slight modification. The acidity of the yogurt samples was measured by Kim and Lee (2002) method based on the percentage of lactic acid. Sensory characteristics of our samples in terms of taste, odor, color and texture and overall acceptability were evaluated by 12 Panelists (6 males, 6 females, 45- 21 years) by using a five-point hedonic test. Texture analysis was performed using Texture Analyzer (Brookfield Model CT3 Texture Analyzer – USA) based on Supavititpatana et al (2008) method.
Results & discussion: Syneresis of product decreased from 0.24 to zero in yogurt samples containing iron and from 1.20 to 0.81% in zinc treatments. Increasing the storage time in the presence of iron causes a sharp decrease in the amount of the syneresis up to zero. The main reasons for syneresis in fermented products include high incineration temperature, low total solids and inadequate storage temperature. The water holding capacity of the product was shown a relatively increase over time and the highest amount was observed in the treatments containing high concentrations of iron during the early days of storage, while at the same high concentrations in the final days of storage, the lowest water holding capacity was observed, which could be due to the adverse effect of the storage time on this factor. The viscosity increased over time, and the rate of increase in the early days was far higher than the final days (in both iron and zinc treatments). In iron and zinc treatments respectively, water holding capacity increased from 50.08 to 55.50, and 43.57 to 55.47 % and viscosity from 855.55 to 961.11, and 677.78 to 833.30 mPa s. By analyzing data obtained from texture analyzer, important properties such as firmness and springiness increased and the lowest cohesiveness and the highest adhesiveness were observed in the middle of storage time. Both iron and zinc treatments increased the hardness of the product compared to the control samples and the amount of this increase in iron containing yogurt samples was slightly higher than that of zinc. In both treatments, there was a significant decrease in the product adhesion force compared to the control sample. In contrast, the highest continuity of product was observed in the middle days of the storage period.The highest levels of flavor were detected on the seventh day of storage, and changes in the zinc and iron content of the products were almost ineffective in the desirability or taste loss, and only control samples were evaluated with a little higher flavor than other treatments. Sensory properties were not significantly different (P
Research Article
Atefeh Pourmahdi; Mohebbat Mohebbi; Ashraf Gohari Ardabili; Mehdi Varidi; Mohammad Reza Salahi
Abstract
Introduction: Potato is one of the most consumed and highly nutritious vegetables with high energy, dietary fiber, phytochemicals, vitamins, and minerals which offer great benefit for utilization as functional food ingredient. The dried potato powder can be used in formulation of many foods like soups, ...
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Introduction: Potato is one of the most consumed and highly nutritious vegetables with high energy, dietary fiber, phytochemicals, vitamins, and minerals which offer great benefit for utilization as functional food ingredient. The dried potato powder can be used in formulation of many foods like soups, snacks, sauces, noodles, etc. The foam mat drying involves the dehydration of a thin layer of foam followed by its disintegration in order to obtain a powder which can be easily reconstituted in water when added to other foods. Because of the porous structure of the foamed materials, mass transfer is enhanced leading to shorter drying times and consequently acquiring higher quality in the dried product. Food foams can be considered as biphasic systems where a gas (dispersed phase) is embedded in a continuous liquid phase. The foam properties such as structure, density and stability have important influence on moisture migration during drying and accordingly, the quality of final product. Foams that do not collapse for at least 1h are mechanically or thermally stable for the entire drying process. Response surface methodology (RSM) is a combination of mathematical and statistical techniques which used to investigate the interaction effects of independent variables on responses. There is considerable information on foam-mat dried food powders, but there is not any scientific literature that related to study on foam-mat drying of potato puree. The present research was thus focused on optimizing the foaming conditions (potato puree: gum solution ratio; Arabic gum (AG) concentration as the stabilizer and whipping time [WT]) to minimize foam density (FD) and drainage volume (DV) using RSM. Likewise, choosing a suitable model for thin-layer drying of foam and the effect of different drying temperatures (45, 60 and 80°C) on drying behavior were investigated, and the effective moisture diffusivity and activation energy were calculated. The effects of drying temperatures on water activity (aw) and water binding capacity (WBC) were also investigated.
Material and methods: Fresh potato was purchased from a local market (Mashhad, Iran). Arabic gum was procured from Sigma Chemical Company (USA). For preparation of potato puree, fresh potatoes were washed and peeled by steel knife and were washed again and additional water was taken absolutely and then crushed by Phillips home crusher (600W) with maximum speed for 3 minutes to get a homogeneous puree. Based on preliminary tests, AG solutions were prepared by dissolving a suitable amount of the selected gum powder in distilled water and stirring with a magnetic stirrer to obtain a uniform solution. This solution was refrigerated at 4°C overnight to complete hydration. RSM was used to estimate the main effects of the process variables on FD and DV in potato puree foam. The experiment was established based on a face-centered central composite design (FCCD). The experimental range was chosen on the basis of the results of preliminary tests. The independent variables were consisted of potato puree: gum solution ratio (1:1 –2:1 w/w), AG concentration (0.1–0.9% w/w) and WT (3–9 min). According to the experimental design, to prepare 100 g of samples, appropriate amount of potato puree and AG solution were mixed in a 250-mL beaker. The mixture was then whipped with a kitchen mixer (model no. SM88, Sonny, China) at a maximum speed of 1,500 rpm at ambient temperature during given time which was recommended by Design-Expert software. The density of foamed potato puree was determined in terms of mass over volume and expressed in g/cm3. In order to assess foam stability, the drainage test was performed for 1h. To evaluate drying behavior of the optimized foam, drying was carried out in a batch-type thin-layer dryer at temperatures of 45, 60 and 80°C on 3 mm thickness. Ten thin-layer drying models were evaluated in the kinetics research. The higher value of R2 and lower values of χ2, RMSE and SSE were selected as the basis for goodness of fit. Fick’s diffusion equation for particles with a slab geometry was used for calculation of effective moisture diffusivity. The foamed potato puree spread on a tray was considered as slab geometry. Activation energy was calculated by a simple Arrhenius-type relationship, by plotting the ln (Deff) against the reciprocal of absolute temperature (1/T). Furthermore, the effects of drying temperatures on aw and WBC of powders were investigated.
Results and discussions: The quadratic model was selected as a suitable statistic model for both FD and DV. ANOVA showed that this model is significant for both responses. Moreover, lack-of-fit was not significant for response surface models at 95% confidence level, indicating this model is adequately accurate for predicting responses. The optimum values of variables for best product quality in terms of minimum FD and DV corresponded to potato puree to gum solution ratio 2:1(w/w), AG 0.77% (w/w) and WT 6.80 min. The amount of FD and DV for foam at these optimum conditions were 0.30 g/cm3 and 5 ml, respectively.
The result showed that when the drying temperature increased, the drying time decreased. This was due to the quick removal of moisture at higher temperature. Drying rate (DR) versus moisture content of potato puree foam-mats figure showed that DR was higher during the initial stage as compared with the final stage and foam-mat drying was occurred principally in the constant rate period. Due to the increase in surface area and the porous structure, removal of water from the inner surface of potato puree foam to the outer surface was fast enough to preserve the surface moisture. The rate of movement of moisture from the inner surface to the exposed surface decreased with decreasing moisture content, which indicates that the DR decreased and the falling rate period started. The effective moisture diffusivity varied from 3.286×10-9 to 8.032×10-9 m2/s with activation energy value of 30.97 kJ/mol. Statistical analysis results showed that the Weibull distribution model provide the highest R2 and lowest values of χ2, RMSE and SSE at all drying temperatures. The temperature elevation reduced aw. This is due to the fact that at higher temperatures, the rate of heat transfer to the sample would increase, therefore, it provides greater driving force for moisture evaporation which results the dried foams with reduced aw. Drying temperatures did not show any significant effect on WBC of powders.
Research Article
Farnaz Hassanzadeh Rad; Fakhri Shahidi; Mohebbat Mohebbi; Mohammad Reza Salahi
Abstract
Introduction: Kilka Fish is one of the most popular seafood products available for aquaculture development. It is a rich source of proteins, vitamins and minerals such as calcium and phosphor. The highly perishable nature of Kilka fish has strongly attracted researchers to find new methods to extend ...
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Introduction: Kilka Fish is one of the most popular seafood products available for aquaculture development. It is a rich source of proteins, vitamins and minerals such as calcium and phosphor. The highly perishable nature of Kilka fish has strongly attracted researchers to find new methods to extend its shelf life. Kilka fish powder can be used in many foods, such as soups, sauces, snacks, etc. Foam-mat drying is a new effective technique has recently gained much attention because it does not suffer from major problems associated with traditional dehydration methods, such as poor rehydration characteristics, unfavorable sensory profile, and long drying time. The main objectives of this study were: (1) to optimize the effective parameters (egg white powder and xanthan gum concentration, and whipping time) on foaming properties of Kilka fish; (2) to study the effects of drying temperature and foam thickness on the drying characteristics and select a suitable model for thin-layer drying of foam; (3) to compute effective moisture diffusivity and activation energy of foam during drying; and (4) to study the effects of drying conditions on moisture content, water activity, hygroscopicity and color of powders and microstructure of dried Kilka fish foams.
Materials and method: Fresh Kilka fish (C. delicatula) was obtained from the Pak Samar Miroud Company (Mazandaran, Iran). Xanthan gum and egg white powders were purchased from Sigma Chemical Company and Gol Powder Company (Golestan Province, Iran) respectively. The Kilka fish skin removed and cleaned, and then crushed using a kitchen blender to obtain a homogeneous and uniform mixture. Based on preliminary tests, xanthan gum solution was prepared by dissolving a suitable amount of the selected gum powder in distilled water and mixed with a magnetic stirrer to obtain a uniform solution. The resulted solution was cooled at 4°C for 18–24h to complete hydration. According to the experimental design, to prepare 100 g of samples, appropriate amount of fish, egg white powder, xanthan gum solution and distilled water were mixed a 250-mL beaker. The mixture was then whipped with a mixer (Gosonic, model No. GHM- 818, 250W, China) with maximum speed at ambient temperature during given time, which was recommended by Design-Expert software version 6.02 (Stat-Ease, Inc., Minneapolis, MN). Foaming conditions, namely amount of egg white powder, xanthan gum and whipping time, optimized using response surface methodology (RSM) for minimizing foam density (FD) and drainage volume (DV). To evaluate drying behavior of the optimized foam, drying was carried out in a batch-type thin-layer dryer at three drying temperatures (45, 60 and 75°C) on 3- and 5-mm thicknesses. Ten thin-layer drying models were evaluated in the kinetics research. The higher values of R2 and lower values of χ2 and RMSE were selected as the basis for goodness of fit. The effective moisture diffusivity was calculated using method of slopes. A Fick’s diffusion model with slab geometry was used to describe the transport of moisture during drying inside a single Kilka fish foam mat. Activation energy was calculated by a simple Arrhenius-type relationship, by plotting the ln (Deff) against the reciprocal of absolute temperature (1/T). The microstructure of the dried fish foam-mats was analyzed by a scanning electron microscope. Finally, the effects of drying conditions on physicochemical properties of fish powder including moisture content, water activity, hygroscopicity and color were investigated.
Results and Discussion: The optimum values of variables for best product quality in terms of minimum FD and DV corresponded to egg white powder 3.67 % (w/w), xanthan gum 0.28% (w/w) and whipping time 8.93 min. The amount of FD and DV for foam at these optimum conditions were 0.92 g/cm3 and 0 ml, respectively. As expected, the increase in drying temperature and decrease in foam load led to acceleration of the dehydration of Kilka fish foam. Based on the statistical tests performed, Weibull distribution model can describe drying behavior of foams for all drying processes. Moreover, Fick’s second law was employed to calculate the effective moisture diffusivity that varied from 7.266×10-8 to 1.31×10-7 m2/s and from 7.404×10-8 to 1.693×10-7 m2/s with activation energy values of 18.201 and 25.615 kJ/mol for foam thicknesses of 3 and 5 mm, respectively. It was noted that the effective moisture diffusivity was increased when the drying temperature increased. Results showed that at the higher thickness, the internal moisture migration occurs along a longer distance rather than lower thickness. Therefore, an increase in moisture diffusivity occurs both with increase in drying temperature and sample thickness. The analysis of scanning electron microscopy (SEM) micrographs showed that there is wide porous structure of dried foams at higher speeds drying. With increasing drying temperature (due to reduction of drying times), combination of adjacent bubbles and therefor, collapse of foam structure occur less. Higher temperature reduced moisture content and aw , and thickness rise increased moisture content and aw under the same thickness and drying temperature, respectively. This is due to the fact that at higher temperatures, the rate of heat transfer to the sample would increase, therefore, it provides greater driving force for moisture evaporation which results the dried foams with reduced moisture content and aw. Moreover, with increasing foam thickness due to increased drying times and probably collapsed structure of foams and therefor weak pore structure, drying was performed difficultly which causes to retain more water in dried foams. Drying conditions had significant effect on hygroscopicity of powders. Results of color investigation showed that in both thicknesses, powder produced at 60°C have higher L* and lower a*.
Research Article
Mohammad Farhadi Chitgar; Mehran Alami; Yahya Maghsoudlou; Mohammad Reza Ataroudi
Abstract
Introduction: Gummy candies are included in many confectionery products, such as jellies, pastilles and etc. The texture of gummy candies is achieved by using various gelling agents, such as gelatin, starch and pectin. Color is the most important quality attribute of gummy candies because it is appreciated ...
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Introduction: Gummy candies are included in many confectionery products, such as jellies, pastilles and etc. The texture of gummy candies is achieved by using various gelling agents, such as gelatin, starch and pectin. Color is the most important quality attribute of gummy candies because it is appreciated for its intrinsic aesthetic value and also allows us to estimate food quality. Synthetic dyes have commonly been applied for food coloring purposes because of their stability against light, oxygen and heat. However, some of these synthetics have been related to toxic effects and it has been reported that their consumption affects children's behaviors. Therefore, synthetic dyes are being increasingly replaced by natural pigments. The principal groups of natural food colorants are anthocyanins, betacyanins, carotenoids, curcuminoids, and chlorophylls. Among these pigments, anthocyanins have gained growing interest because they are widely distributed pigments in nature and represent a wide range of color from red and orange to purple and blue. Berberis b .L (barberry) is the largest genus in the family Berberidaceae and contain about 450–500 species of deciduous or evergreen shrubs. Iran is the largest producer of barberry (B.vulgaris) in the world. Besides, other species in different parts of Iran, especially North Khorasan province, grow wildly. B.cratagina is one of the wild barberries which is known as black barberry among Iranian people. B. cratagina contains large amounts of anthocyanin that can be used as an alternative to synthetic colorants. However, its successful application mainly depends on the stabilization of its anthocyanins. Studies have been shown that some hydrocolloids especially pectin can enhance the stability of anthocyanins. So, the aim of this study was to evaluate the effect of different concentrations of high methyl esterified apple pectin on the degradation kinetics of monomeric anthocyanin and visual color parameters (L, a*, b* and TCD) of black barberry in a fruit pastille model system.
Material and Methods: The fruit pastille prepared according to Demars & Zeigler (2001) recipe. Six g gelatin was mixed with pectin (the amount of pectin was varied between 0.5, 1, 1.5 and 2 g) and 20 g water in a beaker. The mixture was heated and deairated in a water bath. Additionally, 30 g of sucrose, 25 g of glucose syrup (80°Brix) and 10 g of water were combined, the mixture was heated at 115°C(2 min), resulting in a total soluble solids content of 80°Brix and added to the gelatin solution. Subsequently, after cooling to 80°C the Berberis juice (10 g ) was added to the mixture Finally, the gel solution was poured into a plastic molds, stored at 4°C for 24h and dried at 25°C until aw=0.6. For shelf life experiments, samples were stored under dark (20±0.5°C) condition for a period of 30days. Samples were drawn at regular intervals of 6 days to quantify total anthocyanin and for color analyses. Total anthocyanin content of samples was determined by the pH differential method and color analysis was performed using computer vision. Linear regression analysis was applied using Slide write software version7.0 to obtain the kinetics parameters. All experiments were repeated at least three times and results were expressed as mean ± SD. Significant differences (α=0.05) of physicochemical properties and kinetic parameters throughout storage were determined using the Duncan's test for differences between independent samples. Data evaluation was performed using the SPSS software version16
Result and Discussion: There was a significant difference (P
Research Article
Zahra Mohammadi; Mahdi Kashani-Nejad; Aman Mohammad Ziaiifar; Mohammad Ghorbani
Abstract
Introduction: The commercial lye peeling method used in kiwifruit processing industry is water and energy intensive process and has negative impact on the environment. Infrared (IR) technology has been proposed as an alternative to food processing technologies with attractive merits such as uniform heating, ...
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Introduction: The commercial lye peeling method used in kiwifruit processing industry is water and energy intensive process and has negative impact on the environment. Infrared (IR) technology has been proposed as an alternative to food processing technologies with attractive merits such as uniform heating, high heat transfer rate, reduced processing time and energy consumption, and improved product quality and safety. However, no previous reports were found on the feasibility of kiwifruit peeling using IR heating technology. Therefore, the goal of this research was to develop a new and sustainable peeling technology for kiwifruit using IR radiation heating.
Materials and methods: A lab scale IR dry-peeling system for kiwifruit was designed and constructed. The system consisted of two major sections including the IR heating and rotating rollers. The rotating kiwifruits (Actinidia deliciosa cv Hayvard) were heated using a ceramic IR element. The effects of IR radiation power (250-850 W), distance between IR emitter and sample (10-70 mm) and heating time (45-125 s) on the peeling performance of kiwifruit were investigated. The lye peeling method including 15% NaOH solution at 95 ͦC for 4 min was selected as a control treatment. The operating parameters of IR peeling were optimized using RSM.
Results and Discussion: The second-order polynomial models predicted by RSM showed a significant fitting (p < 0.0001), and the lack of fit for all fitted models was found to be not significant (p > 0.1105). The validation experiments were in good agreement with the predicted values by the fitted models. The heating with a power of 446 W at the distance of 70 mm for 125 s were found as the optimum operating conditions for kiwifruit IR peeling. The comparison of the peeling performance of kiwifruit peeled by IR and by lye peeling showed that both the IR and lye peeling could produce a satisfactory peelability (> 90%) and ease of peeling (> 4.5) for kiwifruit. The IR peeled kiwi had significantly low weight loss (4.5% vs. 11.7%), surface temperature (64.1 ͦC vs. 95 ͦC) and color difference (2.4 vs. 11.4) and high firmness (57.5 N vs. 40 N) compared to lye peeled treatment. Because the dry-peeling is a chemical- and water- free process, residuals of kiwifruit skins after IR peeling could be easily utilized as value-added by products. Based on the research results, it is concluded that IR dry-peeling has a promising potential for commercialization. This investigation should also help kiwifruit processing industry in developing the environmentally safe IR peeling technique to produce high quality products from kiwifruit.
Research Article
Samaneh Joodi Attar; Vahid Hakimzadeh; Hassan Rashidi
Abstract
Introduction: Cheese is a dairy product that commonly used and has lots of variety in the world. Among the various types of cheese, UF cheese is attracting more consumers in Iran. The need to change the flavor and make a diversity in this product has been considered for long time. Since high fat foods ...
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Introduction: Cheese is a dairy product that commonly used and has lots of variety in the world. Among the various types of cheese, UF cheese is attracting more consumers in Iran. The need to change the flavor and make a diversity in this product has been considered for long time. Since high fat foods such as cheese are the main cause of some disorders like cordial disease, cancer, obesity and diabetes, formulation of dairy products with modified fat or fat replacer was considered by many researchers and suppliers. Vegetable oils can be used as a substitute for milk fat in cheese. Flaxseed oil consists high level of alfa-linolenic acids (Omega-3) and suitable amount of proteins could noticed as a fat replacer. In this study, we investigated the effect of milk fat replacement with flaxseed oil on the production of functional Feta cheese. The rheological, physicochemical, and organoleptic characteristics of such cheese and its optimal formulation were also determined
Materials and methods: The effect of Flaxseed oil (FSO) at a range of 0-100 % and whey protein concentrate (WPC) (0-15%) was investigated on pH, synersis, Dry Matter, hardness, springiness as physicochemical and mechanical properties and mouth feeling, odor, taste overall acceptance as organoleptic properties of UF cheese production by RSM. For the preparation of cheese, a free fat retentate powder was used. To adjust fat to 20%, cream was used with 70% flaxseed oil and homogenized by ultraturrax method. All of the physicochemical, mechanical and organoleptic tests accomplished according to theIranian national Standards/
Results and discussions: Results showed that by increasing the amount of FSO in the formulation of cheese, pH, stiffness and synersis increased. Also, with increasing flaxseed oil, the elasticity was initially decreased and increased in greater quantities afterward. However, by increasing the WPC, the elasticity decreased. The increase of flaxseed oil had a reversible effect on the taste, smell, color and overall cheese acceptance score compared with the control samples due to the presence of some impurities in oil. Increasing the amount of WPC and FSO also caused a decrease in pH and fat during ripening of cheese. Although increasing the level of WPC improved the odor of cheese, but did not have positive effect on appearance, color and general acceptance. The result of optimization of UF cheese production with the following indices: pH 4.82%, synersis 1.35%, fat 20.3%, dry matter 32.45%, hardness 631.46 nm, elasticity 0.94 mm, color 3.4, Odor 3.1, flavor 2.8, texture 3.1 and final acceptance 3.11, showed that the best formulation needs 96.01% of flaxseed oil and 9.73% whey protein concentrate. Finally, the predicted optimal formula by software was also determined as follow: pH 4.78, synersis 1.27%, fat content 19.8%, dry matter 31.4%, the firmness index 618.02, the elasticity 1.03 mm, and the sensory scores included color 3.4 , odor 3.15, Taste 2.97, Texture 3.64 and Final acceptance 3.21.
Research Article
Samira Abbaspour Monjezi; Mohammad Reza Edalatian Dovom; Mohammad Bagher Habibi Najafi; Arash Koocheki
Abstract
Introduction: Nowadays, consumers prefer foods produced without synthetic preservatives. These chemical preservatives have been gradually replaced by natural preservatives in formulation of edible films and coating. Since, edible films can be applied as carriers of antimicrobial agents, so, these aforementioned ...
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Introduction: Nowadays, consumers prefer foods produced without synthetic preservatives. These chemical preservatives have been gradually replaced by natural preservatives in formulation of edible films and coating. Since, edible films can be applied as carriers of antimicrobial agents, so, these aforementioned ingredients can be incorporated in such films. Among edible films, protein-based films such as whey protein concentrate (WPC)-based films are more attractive because they also supply valuable nutrients and introduce acceptable mechanical resistance. On the other hand, these films present moderate barriers to moisture due to the hydrophilic nature of whey proteins. Essential oils (Eos) can be incorporated in to edible films in order to compensate (overcome) this defect. Since no published research has been found on integrating mastic tree sap (Pistacia atlantica sub sp. kurdica) essential oil into whey protein edible films, this essential oil was applied for WPC-based film in this research. Some species belong to Penicillium have been known as contaminants of dairy and fruit products. Among Penicillium sp., P. expansum is more popular for causing post-harvest damage of apples. In this study, our objective was focused on mechanical and anti-fungal properties of WPC-based films incorporated with mastic gum essential oil.
Materials and methods: WPC, mastic tree sap and P. expansum were obtained from Multi Milk Company, Kurdistan mastic Gum Company and Persian Type Collection Culture, respectively. Extraction of EO from mastic gum was accomplished using water distillation or hydro distillation with the help of Clevenger-type apparatus for 5 hours to obtain a pale yellow oil. Solution (10%w/w) of WPC in distilled water was prepared. Glycerol (as plasticizer) was added to WPC solution at a ratio of 1:1 WPC: Glycerol. Then concentrations of EO (1000, 2000, 3000 and 4000 ppm) was added to solution and mixed for 2 min. In the next step, some characteristics of film were measured including: thickness and density, water solubility, stability in acidic and alkaline solutions, water vapor permeability and light transmission / film transparency. Some mechanical properties of films such as tensile strength (TS) and elongation at break (%E) of films were also determined.
Regarding microbial assays, following the activation and preparation of fungi spore, MIC was determined using Agar Dilution Method. Determination of antimicrobial activity of film was performed according to film disk agar diffusion assay
Results & Discussion: With increasing essential oil concentration, film thickness exhibited increasing trend which was due to entrapment of micro-droplets of essential oil in film. Along with increasing EO concentration in film samples, WVP declined significantly (P-value
Research Article
Sara Bahadoran; Javad Keramat; Mohammad Hojjatoleslami
Abstract
Introduction: The diet regulation is one of the primary principles for maintenance of physical and mental health. Flax is an annual plant from the genus Linum with the scientific name “Linaceae” which it grows as a shrub. Flaxseed is in the category of the oilseeds. In Iran, the Flaxseed meal wasted ...
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Introduction: The diet regulation is one of the primary principles for maintenance of physical and mental health. Flax is an annual plant from the genus Linum with the scientific name “Linaceae” which it grows as a shrub. Flaxseed is in the category of the oilseeds. In Iran, the Flaxseed meal wasted even though it is a good source of protein. Flaxseed components that have the health maintenance and nutritional properties are including fiber, lignans and linolenic acid. Furthermore, Flaxseed is a good source of excellent quality protein and soluble fiber and phenolic compounds.
Materials and Methods: Flaxseed meal from KashanBarij Essence Pharmaceutical Company, converted to flour and half of it was extracted using solvents. 10, 15, 20 percentages of the wheat flour replaced with both types of the prepared flours (NF and PDF). The flaxseed meal flours were detoxified using a microwave. In the cakes preparation, the sugar and oil were mixed. The eggs and the remained materials and water were added and mixed for uniformness of the cake batter. Then, it filled the cake mold and placed into the oven at 200°C for 15 minutes. The volume measurement of the prepared cake was carried out according to the seed displacement method using millet seeds. Three methods consist of texture profile analysis, cut and punch method were used in the four days, first, tenth, twentieth and thirtieth day for textural properties assessment. To evaluate the color parameters (L*a*b*), the photos which were taken from the surface of the cake in the special box were evaluated with image analyzer software. Then the hue angle (H), saturation index (SI) and color changes (ΔE) calculated from following equation. For evaluating the porosity the cake was cut into the slices and put into the special box and photos were taken. The photos were evaluated with image analyzer software and the number of pores was determined. Statistical analysis with the completely randomized design with three replications and means comparison in 95% confidence level were employed using the SPSS-20 software.
Results & Discussion: By increasing flour substitution, the volume of the cakes reduced. It could be due to increasing flour replacement with cellulose, which makes the gluten network weak that is responsible for keeping gas into the bakery product. These samples contain flaxseed meal flour were softer than the control. It is due to the presence of some gum and fiber in the chemical composition of flaxseed which absorbs moisture and prevents its transfer to the starch. So, the starch crystallization delayed. During storage, the samples contain 20% flaxseed meal flour were harder than the control sample. The cohesiveness decreased during storage until the twentieth day and then increased. It is due to changes in moisture during storage. The cohesiveness of samples increased by increasing the flaxseed meal flour which it can be associated with more gum and fiber as well as protein in the samples. The cohesiveness of the samples containing 20% flaxseed meal flour was less than others on the first day of storage which is due to the high water bonded by larger amounts of gum and fiber. But, on the thirtieth day, even with reducing bonding strength due to retrogradation, the cohesiveness in the samples containing 20% flaxseed meal flour is more than other samples because of larger amounts of moisture in higher percentages. The springiness reduced in all treatments during storage until the twentieth day and then increased which these changes are not significant for the samples containing 20% flaxseed meal flour and the control sample. The springiness was changed according to changes in moisture during storage. The difference in the springiness among the control samples and treatments on the first day, tenth, and thirtieth of storage was not significant. The springiness reduced with increasing the flaxseed meal flour percentage which is due to the weakening of the gluten network. Between all treatments, the only significant difference in the result of the crust cutting test was among the samples containing 20% PDF and control sample and there was no significant difference between other treatments and control sample in all measurement days. The increase of the force needed to cut samples over the time could be attributed to the transfer of moisture from the center to the round of the cake. The addition of flaxseed meal flour and the storage time had a significant effect on the required force to punch the cake. The force required to punch the cakes increased until the thirtieth day which is consistent with the analysis of moisture during storage. The reason for an increase in the required force for punching the cakes due to increasing the flaxseed meal flour percentage was the cake batter viscosity increases which lead to hardening of the cake texture, subsequently. It can be seen that the number and diameter of the pores reduced by increasing the flour substitution percentage. It could be related to the viscosity of the batter. Due to increasing the batter viscosity, the carbon dioxide, and water vapor bubbles in the batter cannot grow well. The L* index decreased by increasing the flour substitution percentage, which reflects the darkening of the surface and the center of the product. By increasing the flour replacement, the redness (a*) and blueness (b*) index, increased and decreased, respectively. The saturation index (SI) of the surface and center for all treatments was less than it for the control samples. Also, the saturation index among the treatments decreased with increasing the flour substitution percentage significantly which it indicated an increase in the color turbidity of the samples. The color changes (ΔE) of the surface and center of the samples increased with increasing the flour substitution percentage which it showed the significant color difference between all treatments and the control sample. The BI of the surface and center of all samples was less than it for the control samples.
