Food Technology
Fariba Hadidi; Ali Ganjloo; Mohammad Hadi Fakoor
Abstract
Introduction
The demand for non-dairy and reduced-calorie products has increased substantially for several reasons. Almond (Prunus dulcis) milk is highly appreciated by lactose-intolerant, hypertensive people and celiac patients whom are not able to consume animal's milk. Thus, the development ...
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Introduction
The demand for non-dairy and reduced-calorie products has increased substantially for several reasons. Almond (Prunus dulcis) milk is highly appreciated by lactose-intolerant, hypertensive people and celiac patients whom are not able to consume animal's milk. Thus, the development of various non-dairy products is essential. Desserts are the most common and popular product containing high amount of fat and sucrose. The consumption of sucrose is restricted for diabetic people due to its high glycemic index. Stevia as a low-calorie sweetener is one of the sucrose substitutes in food products. Sucrose substitutes must mimic the techno-functional properties of sucrose. Generally, commercially available sucrose substitutes do not possess all of the required characteristics. Therefore, using them in blend form with sucrose is suggested. Moreover, sucrose replacement especially in desserts generates a negative effect due to low firmness or higher syneresis. In this regard, hydrocolloids can be used to overcome those drawbacks. Therefore, the current study was carried out to investigate and optimize the non-dairy dessert formulation based on almond milk containing Tragacanth gum and stevia. For this purpose, the effect of Tragacanth gum and stevia as a sucrose replacer on the physicochemical properties such as hardness, viscosity, color coordinates including lightness, redness-greenness (a*), yellowness-blueness (b*), total soluble solids and syneresis was evaluated and optimized using Response Surface Methodology (RSM).
Materials and Methods
All of the materials used for the manufacturing of non-dairy dessert including raw almond, stevia and Tragacanth gum were purchased from a local market of Zanjan, Iran. For the production of non-dairy dessert, the almond milk warmed up to 40 ºC and then stevia as a sucrose substitutes and tragacanth gum powder as a stabilizer were added in the ranges of 25-75% and 0.4-1% w/w, respectively. Later, the temperature of the mixture increased to 72 ºC and kept for 10 min and then, the temperature decreased to 42 ºC to inoculate the starter culture (a mixture of Streptococcus thermophilus and Lactobacillus bulgaricus, 2% w/w). The fermentation process was completed at 37 °C for 24 h. Finally, the temperature of non-dairy dessert based on almond milk was decreased to 4ºC and kept at the same temperature until further analysis. The pH of the desserts was measured using a pH meter model AZ 86502 (AZ, Taiwan). Total soluble of the desserts was determined using a refractometer (ATAGO, Japan). Firmness was determined using a STM-5 texture analyzer (SANTAM Co., Iran) equipped with a 20 Kg load cell and 10 mm probe. Viscosity was measured using a programmable Viscometer (R/S-CPS+, Brookfield, USA) equipped with a cone-plate geometry at shear rate of 100 s−1. Instrumental color measurement was carried out by a handheld colorimeter (TES135-A, Taiwan) considering L*, a* and b* as color coordinates. Syneresis was measured by a centrifugation test. Fifteen semi-trained panelists (7 male and 8 female) were selected to evaluate sensory properties of the control (only contains sucrose) and optimized formulation samples for texture, color, appearance, taste, flavor, total acceptance using a 5-point Hedonic scale (1= dislike extremely and 5=like extremely). The RSM-central composite design was used to build up the experimental design and identify the conditions that yield highest firmness, viscosity, L*, and total soluble solids as well as lowest a*, b* and syneresis.
Results and Discussion
The results obtained revealed that the hardness, viscosity, a* and total soluble solids increased significantly (p<0.05) while the lightness, b* and syneresis decreased significantly (p<0.05) with increasing the Tragacanth gum in the formulation of non-dairy dessert based on almond milk. In addition, increasing the replacement of sucrose with stevia significantly (p<0.05) reduced the hardness, viscosity, total soluble solids, and increasing lightness and syneresis. However, increasing the percentage of sucrose replacement with stevia had no significant effect (p>0.05) on the changes of a* and b*. Optimization of non-dairy dessert formulation based on almond milk was carried out using numerical technique. The optimal formula was 1% Tragacanth gum and 45% replacement of sucrose with stevia. Under these conditions, hardness 0.08 N, viscosity 1.20 Pa.s, lightness 82.77, redness-greenness 0.95, yellowness-blueness 5.60, total soluble solids 8.29 ºBrix and syneresis 11.88% were obtained. The results of sensory evaluation showed that addition of Tragacanth gum and replacing stevia at the optimal levels improved the total acceptance score compared to the control sample.
It can be concluded that in addition to the reliability of the RSM to select the optimal formulation conditions, Tragacanth gum and stevia can be used to produce a new, reduced-calorie and customer-friendly non-dairy dessert based on almond milk.
Food Technology
Dornoush Jafarpour; Parisa Ataei
Abstract
Introduction: Every year during marine fishing, some species that are caught are not suitable for human consumption and they are known as surplus fishing or low consumption, which is an important factor in wasting these rich resources. Therefore, it is necessary to set arrangements to use such species ...
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Introduction: Every year during marine fishing, some species that are caught are not suitable for human consumption and they are known as surplus fishing or low consumption, which is an important factor in wasting these rich resources. Therefore, it is necessary to set arrangements to use such species for human consumption, including the production of surimi. The surimi industry mainly uses Alaska pollock fish as the main source for surimi production. However, due to the increase in the world’s population and partly the depletion of the fish stocks, followed by a reduction in the surimi production of Allaska Pollock fish (due to restrictive fishing laws), the need to use new species is considered urgent. In this regard, additives such as gums can be used to reform and improve the properties of surimi. Therefore, in this study, the possibility of producing surimi paste and gel from Lizardfish and Talang Queenfish was investigated and the effect of Konjac on the physicochemical properties of the product produced from these two types of fish was evaluated. Materials and methods: In this study, Talang Queenfish and Lizardfish with approximate weight of 225.9±33.6 and 275.9±24.4 g and average size of 15.1±2.4 and 17.3± 2.6 cm, respectively, were purchased freshly from the fish market. After preparing surimi paste from both types of fish, Konjac gum in concentrations of 0.25, 0.50 and 0.75 % (w/w) was added directly to the surimi paste. Then to prepare surimi gel, first, the samples were placed in a water bath at 25 ° C for 3 hours for setting and then cooked at 90 ° C for 20 minutes. After that, the prepared gels were cooled in iced water immediately. The produced paste and gel were evaluated in terms of chemical composition, water holding capacity and color factors. Texture and sensory characteristic were assessed on the produced gels of both types of fish and compared with the control sample (without gum). Results and discussion: According to the results, the yield of Lizardfish was 28% and Talang Queenfish was 22%. It seems that the larger size of Lizardfish has been effective in its higher yield than Talang Queenfish. Based on the results, the percentage of ash, protein and fat in the treatments did not change significantly compared to the control sample. Also, there was no significant difference between the two types of fish in the amount of mentioned factors (p>0.05). As the contraction level of Konjac gum increased, the amount of moisture and water holding capacity of the paste samples of both fish increased significantly, which is due to the absorption and binding of water by the Konjac hydrocolloid. The lightness level (L*) of the surimi paste and gel of both types of fish increased significantly with the addition of Konjac, which is related to the increase in water content in the samples. The lightness of the surimi paste and gel of Lizardfish was higher than that of Talang Queenfish, which is due to the presence of more pigments in the Talang Queenfish meat. Control Sample and treatment of 0.25% of Talang Queenfish surimi paste showed more yellowness and redness than Lizardfish, but in the resulting gel, their values were reduced, indicating that the formation of gel structure by Konjac gum and binding to the proteins covered the yellowness and redness of the samples. By increasing the concentration of Konjac in surimi gel of both fish the parameters of texture (firmness, cohesiveness, adhesiveness, springiness, chewiness) breaking force and deformation increased significantly compared to the control sample. Also, the results showed that the surimi gel from Lizardfish has higher firmness, cohesiveness and strength than Talang Queenfish. Sensory evaluations showed that the panelists assigned the highest score for the surimi gel from Lizardfish to the 0.5% treatment and for the Talang Queenfish to the 0.75% treatment of Konjac. Based on the findings of the present study, it was found that surimi gel from Talang Queenfish has a lower quality than Lizardfish, but with the addition of Konjac gum, its properties can be improved.
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
Hassan Sabbaghi; Aman Mohammad Ziaiifar; Mahdi Kashani-Nejad
Abstract
Introduction: Color is the most important feature of food appearance, since it strongly affects consumer acceptance. The abnormal color is closely related to degradation of food quality or food spoilage. Various factors affecting color of the product include the composition and surface properties of ...
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Introduction: Color is the most important feature of food appearance, since it strongly affects consumer acceptance. The abnormal color is closely related to degradation of food quality or food spoilage. Various factors affecting color of the product include the composition and surface properties of the foodstuff, process conditions (temperature and time), and the type of pretreatment processes. Therefore, for the design of a new process, kinetic modeling is essential for extracting basic kinetic information in a system to predict changes. Intermittent irradiation is the novel processing method in food industry which the surface temperature of product is kept constant. Darkening process occur in the fruit slices during drying, resulting in undesirable color changes. Undesirable color variations can be attributed to Millard's browning reactions between sugar and amine compounds or ascorbic acid oxidation. Thermal degradation kinetic models define maximum maintenance conditions for qualitative factors to produce a safe food. Color descriptive models are known as zero order, first order, and fractional conversion model. The fractional conversion model represents the response rate required at a given time to complete a phenomenon. This modeling is necessary for designing online quality control systems for thermal processing in the food industry and preserving the apparent quality of the product by optimizing the most important drying parameters. In this study, the kinetic of color changes in apple slices was investigated, in order to maintain appearance quality of product during simultaneous infrared dry-blanching and dehydration with intermittent irradiation.
Materials and Methods: Apple slices (Golden Delicious Variety) were dried in three thicknesses of 5, 9 and 13 mm using three constant surface temperatures of 70, 75 and 80 ° C. Image acquisition of apple slices was made use of a flatbed scanner with an interval of 15 minutes during processing. The treated samples were placed on the scanner and then a black box was utilized so as to prevent the interferences of the peripheral lights. The images featured a 300 dpi quality and were saved in TIFF-24 bit format. The color analysis of the images was carried out in color space of L*a*b* by the use ImageJ software, version 1.6.0. The lightness parameter (L), redness (a), yellowness (b), the intensity of the color changes (∆E), chroma (Cr) and browning index (BI) were described during product processing using fractional conversion model. Equilibrium color parameters (Cf) were also used as an indicator to compare different process conditions. The fitting of the model was done using the curve fitting toolbox in the 2009 version of the MATLAB software with 95% confidence level (P
Nazanin Abdi; Neda Maftoonazad; Amir Heidarinasab; Fujan Badii
Abstract
Introduction: The date palm (Phoenix dactylifera), is one of the most important plants of arid desert area of the western and southern Asia and northern Africa for over 5000 years. Date fruit has a great importance in nutrition due to being a main source of carbohydrates, but it is low in fat and protein. ...
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Introduction: The date palm (Phoenix dactylifera), is one of the most important plants of arid desert area of the western and southern Asia and northern Africa for over 5000 years. Date fruit has a great importance in nutrition due to being a main source of carbohydrates, but it is low in fat and protein. Also it is a good source of many minerals and high amounts of antioxidants which prevent some diseases. This fruits is an important element in economy of date growing countries. Some factors such as variety, environmental impact of growing regions and large quantities of the produced date causes postharvest losses resulting in lower quality fruits. These amounts of fruit which are not consumed directly as fresh may have been used as raw materials to formulate some products like date syrup, powder, jam, etc. Date powder is a highly nutritional quality sweetener obtained from date for sucrose substitution in confectionary, bakery or ice cream industry. Stickiness is a problem in production of fruit powder during drying, transportation and storage. Stickiness in fruit powder is mainly due to the presence of low molecular weight sugar such as fructose, glucose, sucrose and organic acids in fruits. These compounds are very hygroscopic in the amorphous state and have low glass transition temperature and leads to increase stickiness and decrease stability of the product in room temperature. This research consisted of two major objectives: i) determination of an optimum proportion of date paste, silicon dioxide and maltodextrin and the most suitable temperature of drying; ii) characterization of physicochemical and thermal characteristics of date powder.
Materials and methods: Kabkab date was purchased from local market of Kazeroun, Fars, Iran. Moisture, ash, protein, fat, total sugar and dietary fiber contents were determined by AOAC methods (AOAC, 1997). Date flesh was minced by a kitchen meat grinder to make a smooth paste. Three different proportions of maltodextrin (35, 45 and 55% w/w) and three proportions of silicon dioxide (0, 0.75 and 1.5% w/w) were added to date paste to produce date powders. The mix was then spread to a thickness of about 5 mm on a Teflon coated tray and kept inside an oven dryer at 50, 60 and 70°C. The dry product was then ground in a hammer mill to produce date powder. The powder was immediately collected in plastic pouches and kept in desiccators to avoid moisture absorption from the air. Laboratory test sieves were used to collect date powder with particle size less than 1mm in diameter. Some physical and thermal characteristics of the powders were measured. Response surface methodology with central composite design was applied to minimize total number of experimental runs and to optimize the proportions of maltodextrin and silicon dioxide and also drying temperature. The dependent variables were density, moisture and color parameters. A completely randomized design was applied to analyze the effect of maltodextrin on thermal properties (glass transition temperature and specific heat) of date powder. Significant terms were found using ANOVA (P
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.
Saman Abdanan; Somaye Amraei
Abstract
Introduction:.Color is the first quality attribute of food evaluated by consumers, and is therefore an important quality component of food which influences consumer’s choice and preferences (Maguire, 1994). Color measurement of food products has been used as an indirect measure of other quality attributes ...
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Introduction:.Color is the first quality attribute of food evaluated by consumers, and is therefore an important quality component of food which influences consumer’s choice and preferences (Maguire, 1994). Color measurement of food products has been used as an indirect measure of other quality attributes such as flavor and contents of pigments because it is simpler, faster and correlates well with other physicochemical properties. Therefore, rapid and objective measurement of food color is required in quality control for the commercial grading of products (Trusell et al., 2005). Among different color spaces, L*a*b* color space is the most practical system used for measuring of color in food due to the uniform distribution of colors in this system as well its high similarity to human perception of color. All of the commercial L*a*b* colorimeters generally measure small, non- representative areas (Pathare et al., 2013) while the RGB digital cameras obtain information in pixels. Therefore, this research establishes a computational solution which allows acquiring of digital images in L*a*b* color units for each pixel from the digital RGB image (Fernandez-Vazquez et al., 2011). In recent years, computer vision has been used to objectively measure the color of different foods since they provide some obvious advantages over a conventional colorimeter, namely, the possibility of analyzing of each pixel of the entire surface of the food, and quantifying surface characteristics and defects (Mendoza & Aguilera, 2004). The color of many foods has been measured using computer vision techniques (Pedreschi et al., 2011; Lang et al., 2012). A computational technique with a combination of a digital camera, image processing software has been used to provide a less expensive and more versatile way to measure the color of many foods than traditional color-measuring instruments. This study used four models to carry out the RGB to L*a*b* transformation: linear, quadratic, support vector regression and neural network. This article presents the details of each model, their performance, and their advantages and disadvantages. The purpose of this work was to find a model (and estimate its parameters) for obtaining L*a*b* color measurements from RGB measurements. Materials and Methods: The images used in this work were taken with the following image acquisition system (Samsung, SM-N9005 color digital camera with 13 Mega pixels of resolution ,Fig.1). The camera was placed vertically at a distance of 60 cm from the samples and the angle between the axis of the lens and the sources of illumination was approximately °45. Illumination was achieved with 4 natural daylight 150 W lights. Fig. 1. Schematic diagram of image acquisition system. In order to calibrate the digital color system, the color values of 42 color charts were measured. Each color chart was divided into 24 regions. In each region, the L*a*b* color values were measured using a Minolta colorimeter. Additionally, a RGB digital image was taken of each chart, and the R, G and B color values of the corresponding regions were measured using a Matlab program which computes the mean values for each color value in each region according to the 24 masks. In this study four models for the RGB to L*a*b* transformation namely: linear, quadratic, artificial neural network (ANN), support vector regression (SVR) have been used. Results and discussion: In the evaluation of the performance of the models, the support vector regression and neural network model stands out with an error of only 0.88 and 2.37, respectively. Leon et al. (2004) investigated some models for the RGB to L*a*b* conversion. In the evaluation of the performance of the models, the neural network model showed an error of only 0.93%. In another research Yagzi et al. (2009) measured the L*a*b* values of atlantic salmon fillets subjected to different electron beam doses (0, 1, 1.5, 2 and 3 kGy) using a Minolta CR-200 Chroma Meter and a machine vision system. For both Minolta and machine vision the L* value increased and the a* and b* values decreased with increasing irradiation dose. However, the machine vision system showed significantly higher readings for L*, a*, b* values than the Minolta colorimeter. According to the construction of these models, the correlation between measured and predicted color is well established; therefore, based on the promising obtained results from Computer vision, it is possible to find a L*a*b* color measuring system that is appropriate for an accurate, exacting and detailed characterization of a food item based on a color digital camera. In order to show the capability of the proposed method, the color of an orange was measured using both a Minolta colorimeter and the studied approach. The colorimeter measurement was obtained by averaging 6 measurements in 6 different places of the surface of the orange, whereas the measurement using the digital color image was estimated by averaging all pixels of the surface image. The results are summarized in Fig. 2. b* a* L* Measurement Method 35.49 28.32 58.98 Minolta colorimeter 37.35 27.30 61.20 Machine Vision (SVR) 30.60 30.19 60.18 Machine Vision (ANN) Fig. 2. Estimate of L*a*b* values of an orange
Fatemeh Heydari; Mohammad Javad Varidi; Mehdi Varidi
Abstract
The objective of this study was the evaluation of pH, Color parameters [lightness (L*), redness (a*), yellowness (b*), chroma (C*), hue (H*), a*/b* ratio, and color differences (ΔE)], Mb, MetMb, OxyMb, DeoMb and WHC in minced meat. Three types of meat ( Beef, camel and ostrich) and four mincing ...
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The objective of this study was the evaluation of pH, Color parameters [lightness (L*), redness (a*), yellowness (b*), chroma (C*), hue (H*), a*/b* ratio, and color differences (ΔE)], Mb, MetMb, OxyMb, DeoMb and WHC in minced meat. Three types of meat ( Beef, camel and ostrich) and four mincing processes (three using a grinder with 7.5, 4 and 3 mm diameter holes in the plate, and a fourth in which a cutter was used to obtain a finely minced product) were studied. The intact meat was used as the control. Significant differences were observed in the pH, Color parameters [lightness (L*), redness (a*), yellowness (b*), chroma (C*), hue (H*), a*/b* ratio, Mb, MetMb, DeoMb and WHC of various types of meat (P 0.05). WHC and chroma showed statistically significant differences (P 0.05) for the mincing treatment. The ΔE and OxyMb showed no significant differences (p>. 0.05) for mincing and also in meat types. High correlation between pH and L* (R2=0.999), pH and WHC (R2=0.997) confirms the decrease in L* and increase in WHC along with increase in pH.
Sara Hoseinpoor; Mohammad Hadi Eskandari; Gholam Reza Mesbahi; Shahram Shekarforoush; Asgar Farahnaki
Abstract
Nitrite is responsible for some characteristics of cured meat products such as color, flavor and suppressing
the outgrowth and production of toxin from Clostridium botulinum. Despite all of its desired properties, nitrite is
responsible for the formation of carcinogenic N-nitrosamine. In this study, ...
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Nitrite is responsible for some characteristics of cured meat products such as color, flavor and suppressing
the outgrowth and production of toxin from Clostridium botulinum. Despite all of its desired properties, nitrite is
responsible for the formation of carcinogenic N-nitrosamine. In this study, nitrite-free and low-nitrite meat
curing systems were developed to eliminate or reduce nitrite from meat products. Thirteen different formulations
were made including standard frankfurter ingredients with or without nitrite in combination with cochineal and
paprika as natural coloring agents. For example, control sample was with 120 mg/kg nitrite, low-nitrite sample
was contained 40 mg/kg nitrite and some samples were without nitrite. The samples were stored at 4 oC for eight
weeks. During the storage, color changes (L*, a*, b*) were determined and evaluated. Also, the produced
samples were exposed to natural and artificial light and their color stability were compared. In addition, the
colors of samples were evaluated by trained panelists. The results showed that the sample with 40 mg/kg nitrite
and 0.002 % cochineal, the sample contained 40 mg/kg nitrite and 1 mg/kg paprika and the sample without
nitrite and contained 0.015 % cochineal had no significant different color (p
Azam Hajmohammadi; Javad Keramat; Mohammad Hojjatoleslami; Hooman Molavi
Abstract
The increasing tendency for health oriented products caused considerable research has studied on
increase and maintaining quality of different products. Sponge cake is one of the cereal products which
itsmain problems arereterogradation and lack of soluble dietary fibers which has many health benefits. ...
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The increasing tendency for health oriented products caused considerable research has studied on
increase and maintaining quality of different products. Sponge cake is one of the cereal products which
itsmain problems arereterogradation and lack of soluble dietary fibers which has many health benefits. In this
research, therefore, the effects of adding oat β-D-glucan on the physical properties of sponge cake were
investigated. Samples were produced by different concentrations of β-D-glucan (1, 2, 3 and 4%)with control
sample. Physical properties of samples including volume index, porosity, hardness, color and sensory properties
were examined. The results showed that the addition of β-D-glucan up to 2 (%) softened the cakes without
unpleasant changes in sensory properties, also increased volume index, porosity and color of the cakesamples
Atena Pasban; Mohebbat Mohebbi; Hashem Pourazerang; Mehdi Varidi
Abstract
Enzymatic browning and formation of brown pigments are some of the most important problems in preparation of mushroom purees. In this study, the effect of some anti browning agents including sodium metabisulphite, ascorbic acid, and citric acid on the whiteness and foaming properties of mushroom purees ...
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Enzymatic browning and formation of brown pigments are some of the most important problems in preparation of mushroom purees. In this study, the effect of some anti browning agents including sodium metabisulphite, ascorbic acid, and citric acid on the whiteness and foaming properties of mushroom purees was investigated. The results showed that soaking with acids and sodium metabisulphite significantly (p
Mahboubeh Ostadzadeh; Soleiman Abbasi; Mohammad Reza Ehsani
Abstract
Despite the potential of high intensity ultrasound treatment on homogenization of milk and dairy based products, this treatment, under certain conditions, may lead to produce off-odors which can influence its applicability in the food industry. Therefore, in this research, cacao flavored milk (chocolate ...
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Despite the potential of high intensity ultrasound treatment on homogenization of milk and dairy based products, this treatment, under certain conditions, may lead to produce off-odors which can influence its applicability in the food industry. Therefore, in this research, cacao flavored milk (chocolate milk) was treated using ultrasound at various levels of power intensity, exposure time, and treatment temperature. A light microscope equipped by high resolution digital camera was used to evaluate the size distribution of cocoa particles. Finally, the color, flow and viscosity, and sensory characteristics of stabilized samples were determined. According to the findings, increase of power intensity and exposure time led to a significant increase on the degree of homogenization, and subsequently a paramount decrease on the size of cocoa particles. The cocoa particle diameters of chocolate milk which sonicated at 65 ºC were significantly smaller than the other temperatures. Moreover, the stabilized samples showed Newtonian behavior where the viscosity of control was lower than those treated by ultrasonic. With increase of ultrasound power intensity and exposure time, the viscosity of treated samples decreased. In terms of color, the sonicated samples showed higher L* values and the increase of power intensity and exposure time led to a significant increase on L* value. These samples gained lower sensorial scores than control mostly due to their ‘rubbery’ aroma. But, overall acceptance of treated samples had no significant difference against control. The ultrasound is an effective, rapid, and novel technique which can reduce the size of cocoa particles in order to produce stabilized chocolate milk where its color, sensory and rheological properties was very similar to one treated by conventional heat treatment. These findings can open new approaches in terms of its applicability in dairy industry.
