Full Research Paper
Food Technology
Bahareh Sahraiyan; Fatemeh Pourhaji; Behrooz Alizadeh Behbahani
Abstract
Introduction: Celiac disease leads to the malabsorption of nutrients and damage to intestinal mucosa. High nutritional value is one of the advantages of dairy powders, associated with their high calcium, protein and essential amino acid contents. Research has shown that such powders boost the gluten ...
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Introduction: Celiac disease leads to the malabsorption of nutrients and damage to intestinal mucosa. High nutritional value is one of the advantages of dairy powders, associated with their high calcium, protein and essential amino acid contents. Research has shown that such powders boost the gluten quasi-network by forming interfacial films. They are also able to increase the moisture, improve the organoleptic properties, and retard the staling of gluten-free bakery products. In addition, it has been reported that ultrasonic waves can accelerate the oxidation and increase the aeration, volume, porosity and moisture content of bakery products. They can also reduce the hardness and improve the color of such products, thus resulting in the enhancement of their quality and marketability. Consequently, the aim of this study was to improve the appearance, flavor and texture of the gluten-free cake based on rice, germinated quinoa and potato flour using cheese powder at 0, 3, 6 and 9% and ultrasound intensity of 0, 30 and 70% for 5 min. Material and methods: In this study, cheese powder at 0, 3, 6 and 9% and ultrasound intensity of 0, 30 and 70% for 5 min were used to improve the quality of gluten-free cupcake. Control cake formulation had 70 g rice flour, 15 g germinated quinoa flour, 15 g potato flour, 52 g sugar, 50 g water, 36 g egg, 36 g oil, 12 g invert syrup, 2 g baking powder, 0.2 g vanilla, 1.5 g guar gum and 0.5 g xanthan gum. Moisture, specific volume, firmness, crust and crumb color, sensory properties, porosity and scanning electron microscopy (SEM) (with 100× magnification) were evaluated. To study the effect of processing parameters on color components of gluten-free cupcake, the RGB color space images were converted to L*a*b space. For determination of gluten-free cupcake porosity using image analysis, the color images were first gray scaled and then thresholded using isodata algorithm. The porosity was measured from the ratio of white to the total numbers of pixels. Results were reported as the average of three replications. In order to assess significant differences among samples, a complete randomized design of triplicate analyses of samples was performed using the Mini-Tab17. Turkey’s new multiple range tests were used to study the statistical differences of the means with 95% confidence. Result and discussion: Results revealed that moisture content increased as the cheese powder and ultrasound intensity were elevated. Cheese powder caused the moisture content to increase by boosting the gluten quasi-network and ultrasonic waves brought about this phenomenon by dissociating the polymeric chains of starch molecules and forming hydrogen bonds between water molecules and free hydroxyl groups. The sample containing 6% cheese powder sonicated at 30% intensity had higher specific volume (4/4 Cm3/g) and porosity (31.2%) as well as lower hardness (3.4 and 4.4 N after 2 hours and one week respectively) compared with other samples. Cheese powder, by boosting the gluten quasi-network and improving the dough elastic properties, and ultrasound, through enlarging the air bubbles present in the dough, caused an increase in the porosity, specific volume and softness. The results also indicated that the rise in the cheese powder content up to 6% led to an increase in the L* value (from 44.9 to 53.5) and up to 9% in the a* value (from 2.6 to 8.4) of the gluten-free cupcake crust. On the other hand, the results demonstrated that as the ultrasonic intensity was increased, the L* value of the gluten-free cupcake crumb also increased (from 60.3 to 77.9), while its b* value was reduced (from 17.3 to 7.9). This could be due to the aeration and oxidation acceleration which resulted in the increased whiteness and decreased yellowness of the cake crumb. Finally, the findings of sensory evaluation showed the preference of the samples containing 3 and 6% cheese powder sonicated at 30% intensity (4.2 and 4.4 score). The SEM and binary images of the preferred samples also confirmed the integrity of the internal structure and the gluten quasi-network of these samples, compared with the control.
Full Research Paper
Food Technology
Zahra Kholoosi; Mostafa Mazaheri Tehrani; Seyed Mohammad Ali Razavi
Abstract
Introduction: Proteins and polysaccharides are natural biopolymers that consider among the most widely used hydrocolloids in the food industry (Gaonkar and McPherson 2006) Which are often used simultaneously to improve functional properties. In electrostatic interaction, positively charged proteins with ...
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Introduction: Proteins and polysaccharides are natural biopolymers that consider among the most widely used hydrocolloids in the food industry (Gaonkar and McPherson 2006) Which are often used simultaneously to improve functional properties. In electrostatic interaction, positively charged proteins with polysaccharides containing negative groups below the protein isoelectric point (PI) (LEE, MORR, and HA 1992), Leads to the formation of macromolecular particles by creating molecular aggregates rich in biopolymers suspended in the aqueous phase, called complex coacervate, which cause the coagulation and spontaneous separation of the phase. The ratio of protein-polysaccharide biopolymers and the pH of the mixture are important factors influencing the adsorption and compatibility of protein- polysaccharides as well as the characteristics of their aggregates (Shu et al. 1996). For this purpose, the optical density (turbidity) of protein-polysaccharide mixtures and the yield of dried sediments in this study as a basis for optimizing the complex coacervate process as in previous studies (Wang, Adhikari, and Barrow 2014; Huang et al. 2012) were used. In the present study, the optimization of complex coacervate formation conditions of whey protein concentrate-cress seed gum as well as the foaming properties of complex coacervate were studied for the first time. Whey proteins, as amphiphilic macromolecules, can adsorb at the interface (Scheer, Kruppke, and Heib 2001; Tamm et al. 2012; Wierenga and Gruppen, 2010) and form a viscoelastic adsorbent layer (Wilde 2000). Also, whey protein acts as a foaming agent with the ability to be adsorbed at the joint water-oil and water-air interface through hydrophobic interactions or disulfide bridges, and intermolecular bonds (Nicorescu et al. 2008; Nicorescu et al., 2008; Dickinson, 1992; Forschen, 2017). Cress seed gum has rheological, emulsifying, favorable foaming properties and is stable in a wide range of heat, cold, salt, and pH with synergistic effects in the presence of sugars (sucrose, lactose). These properties are important in stabilizing emulsions and foams. The general purpose of this study was to achieve the optimal point of electrostatic interaction of different ratios of whey protein concentrate with cress seed gum in the pH range of 2 to 7 using response surface methodology and to investigate the foaming properties of the coacervate complex at the optimal point in comparison with Pure control protein in the same ratio. Materials and Methods: The raw materials of this study included cress seed, whey protein concentrate with 80% purity (from Milli com., Germany), and hydrochloric acid with 37% purity (from Merck Com.). Different protein-polysaccharide mixtures were prepared to optimize the electrostatic interaction with the ratio of biopolymers (1: 5 to 5: 1 w / w) and pH of interaction (2 to 7). Mixtures, in the ratio determined by the software and the total concentration of biopolymer (0.3%), were prepared, and after 15 minutes of stirring and equilibration with the environment, were adjusted by hydrochloric acid of 0.1, 0.5, and 1 (n) to the desired pH, and stirred for 5 minutes at each pH with a magnetic stirrer at 400 rpm. Optical Density (OD) of protein: polysaccharide mixtures was evaluated by visible-ultraviolet optical spectrophotometry (Unico, Model S-2150, USA). To optimize the electrostatic complex coacervation process, the coacervation yield was determined. The result of the interaction of whey protein concentrate and cress seed gum as a function of pH and protein to gum ratio was investigated by measuring the sediment phase. For investigation of the foaming properties, the dispersions were homogenized using a homogenizer (Ultra Turrax T25 Digital) for 5 minutes at a speed of 10,000 rpm. After recording the sample volume in the dimension and before homogeneity, the foaming capacity was calculated. To determine the stability of the foam, changes in the volume of the samples were recorded and calculated after 30 minutes of foaming. In this study, the effect of two independent variables including the ratio of biopolymers in the range of 0.2-5 (w/w) and the pH within the range of 2 to 7 were analyzed using Design-Expert software based on two responses including turbidity and yield by the combined central design (CCD) with 5 replications to optimize the electrostatic interaction of whey protein concentrate with cress seed gum.Results and Discussion: The results obtained by using response surface methodology showed that the independent variables (ratio of whey protein to cress seed gum and pH) in this study affected the studied responses (turbidity and sediment percentage), although pH had the greatest effect. Optimal conditions for the formation of the maximum protein-polysaccharide coacervate complex were obtained in the ratio of protein to polysaccharide 5: 1 (w / w) and pH 4.24. The results of foaming properties at the optimal point showed an increase in foaming capacity and foam stability compared to pure protein (control sample). This increase in foaming properties is probably due to the presence of cress seed gum and its effect on the formation of a thick viscoelastic film, improved protein adsorption at the interface, and increased bulk phase viscosity.
Full Research Paper
Food Technology
Hassan Sabbaghi
Abstract
Introduction: Doughnut is one of the most widely consumed food products in the world due to its suitable organoleptic properties. Today, with the spread of diabetes and lifestyle changes, consumers are paying more attention to the use of sugar-free foods and dietary products. In the bakery products, ...
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Introduction: Doughnut is one of the most widely consumed food products in the world due to its suitable organoleptic properties. Today, with the spread of diabetes and lifestyle changes, consumers are paying more attention to the use of sugar-free foods and dietary products. In the bakery products, sweeteners play an important role in providing moisture, sweetening, texture formation and increasing the shelf life of the final product. Sweeteners intended to replace sucrose should be water-soluble, with enough flavor, and cost-effective. Also, these compounds must also comply with national and international law. Stevia, which is composed of steviol and glycosides, is resistant to heat and pH and is not fermentable. Therefore, its amount should be chosen in such a way that it has no effect on cooking. In contrast, sweeteners containing dextrose and maltodextrin are also heat-resistant and can affect cooking and maintain the quality properties of fermentation. In order to use stevia in products as a substitute for sugar to maintain the formulation ratios, the fillers including low-calorie sweeteners such as erythritol and maltodextrin should be used. Therefore, in this study, the feasibility of producing sugar-free doughnuts as a dietary product was studied using stevia, erythritol and maltodextrin as sugar substitutes. Materials and Methods: The low calorie sweetener blend (stevia, erythritol and maltodextrin) was designed in the first step. It was found that if 46.175 g of stevia and 1997.82 g of erythritol were mixed and homogenized, a mixture would be obtained with sweetness four times higher than sucrose. So, the "sweetener blend" was used for one-fourth of the sugar removal mass and the rest was compensated with filler as maltodextrin. Instead of sugar, this mixture was added with zero ratio (control), 50 (low sugar) and 100% (no sugar) in the formulation of doughnuts and icing. Evaluation of qualitative characteristic including moisture content, oil absorption, density, color and porosity ratio and sensory analysis for doughnuts were performedThe properties of shelf life, including soft tissue assessment, non-absorption of icing and non-growth of mold were also investigated within 14 days. Statistical analysis was performed in a completely randomized design (p < 0.05). Results & discussion: The results showed that replacing 100% sugar in doughnuts was successful in terms of maintaining quality characteristics. The quality properties of doughnuts with 50% replacement (low sugar product) were not desirable. Sugar-free doughnuts had good quality properties (density, porosity, color and shell-life) compared to the control. Replacing the type of sweetener from sucrose to alcohol sugar can increase the moisture level of the product. As the amount of erythritol increased (no sugar sample), the texture became more moist and soft. The oil uptake of sugar-free doughnut did not show significant difference from the control sample and its sensory evaluation was so favorable. Maltodextrin could act as a bulking agent, stabilizer, and thickener agent in a sugar free formulation. Sugar free doughnuts had more brightness (L*) and less redness (a*), and its yellowness (b*) did not show significant difference with the control sample. It can be said that because more air has penetrated in sugar free doughnut the brightness parameter (L*) increased. The use of polyols (erythritol) results in a brighter color in the product, which is due to the lack of participation of polyols in the Millard reaction because they lack a reactive aldehyde group. The early development of the Millard reaction led to changes in hardness. Therefore, replacing reducing sugars with non-reducing compounds such as alcohol sugars in the formulation decreased tissue changes in the direction of hardening. Because of Millard reaction will reduce the sugars available as a plasticizer in the formulation. Sugar free doughnut showed suitable soft tissue during 14 days and indicated that sweetener has an effect on texture because it controls hydration and tends to disperse starch and protein molecules, thus preventing the formation of a continuous mass. No sugar doughnuts showed suitable sensory evaluation about color, taste, smell, texture, and overall acceptance.Therefore, a mixture of no-calorie and low-calorie sweeteners in this study can be used in the preparation of dietary doughnuts.
Full Research Paper
Food Engineering
Mojtaba Afsharipour; Hadi Samimi Akhijahani; Kazem Jafari Naeimi
Abstract
Introduction: The presence of various impurities leads to the problems in storage time, transmission, selling and consumption process of any product. Thus it is necessary to separate the impurities from the product for industrial processing. Descurainia Sophia is a tiny grain seed in light brown color ...
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Introduction: The presence of various impurities leads to the problems in storage time, transmission, selling and consumption process of any product. Thus it is necessary to separate the impurities from the product for industrial processing. Descurainia Sophia is a tiny grain seed in light brown color with elliptical shape and it grown up in humid climate. Electrostatic method is a proper way for separation and purification of materials which is based on the absorption and diffusion of charged particles in an electrical field with high voltage. An experimental research was carried out for recycling the plastic waste with tribo-electric system. The result of the research on plastic separation of waste materials showed that by increasing the voltage of the system the purification fold increases. The results of the effect of the applied voltage for recycling the plastic particles showed that by increasing the applied voltage in the electrodes the mass and purity of the polycarbonate (PC) increased and the mass and purity of polyamide (PA) decreased. There is a little information about separation and purification of fine grain seeds and this study is about separating of Descurainia Sophia seed and the effect of the parameters using regression analysis. Material and Methods: Descurainiaseed samples were collected from the farms located in Mahan city of Kerman province, Iran. Tribo-airo-electrostatic system contains of funnel and feeding container, the charger unit, the separating unit, air transmission channels and gathering unit. Charging unit consists of two aluminum electrode connected to a high voltage DC power supply adjustable between 0-100 kV. A blower was used to suspend material and increase the exposure time of particles in the electric field. The gathering is a box with different partitions divided by wooden sheets. Separated particles fall in the gaps based on the amounts of charges, weight and shape. The separating process takes place by considering physical properties. There are two important forces that acts on the falling of the object in electric field; the electric force acts in the horizontal direction, gravitational force acts in the vertical direction. Considering the purity of the separated seeds in the box, only four sections of the box were selected for size and frequency analysis. For obtaining gathered seed impurity, the digital pictures of the gathered samples imported in Matlab6.5 software and were analyzed using Image processing toolbar based on the differences between seed and impurity color. For regression analysis of the parameters voltage in the electrodes, the distance of the electrodes, the angle of the electrode and the mass of the boxes was considered. Laser diffraction method used for determination the size of separated particles and for this purpose FRITSCH Laser Particle Size Analyser -ANALYSETTE 22 NanoTec system was used. Results and discussion: The results illustrated that the Descurainiaseed takes negative charge and moves to the positive electrode and impure particles takes positive charge and moves to the negative electrode. The purity calculations of the experiments showed that the average percentage of box No.1 is more than 98%, box No.2 is between 65%-75%, box No.3 is between 30% to 50% and box No.4 is less than 50%. The values of correlation coefficient of the effective parameters for box No.1 was 90% and this means that 90% of the parameters of equation affected on the weight of the box No.1 for about 90%. By increasing the applied voltage and the angle of the electrodes of the separating unit and decreasing the distance of the electrodes, the purity of box increases. The size analysis of Descurainiaseed showed that the particles with larger dimensions take more negative charge and moves to negative electrode. The results of the study showed that tribo-airo-electrostatic system separated Descurainiaseed from waste particles properly. By considering the optimum value of separating parameters the purification increased by 98%. According to the results it can be stated that this system can be used for separation and purification of small grains such as alfalfa and clover.
Full Research Paper
Food Biotechnology
Fatemeh Barmak; Mohammad Bagher Habibi Najafi; Reza Hajimohammadi Farimani; Mohammad Reza Edalatian Dovom
Abstract
Introduction: One of the most important factors in producing yogurt is choosing the right starter. Native isolates of any country are among the genetic resources of that country, which play a major role in the production and development of the organoleptic properties of fermented products. Therefore, ...
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Introduction: One of the most important factors in producing yogurt is choosing the right starter. Native isolates of any country are among the genetic resources of that country, which play a major role in the production and development of the organoleptic properties of fermented products. Therefore, it seems necessary to study the industrial applications of native isolates. In this study, the production of yogurt was investigated by using native starter isolates from traditional Khorasan yogurts and its comparison with yogurts produced with two types of commercial starters. Materials and methods: Six strains of Streptococcus thermophilus and three strains of Lactobacillus delbrueckii subsp. Bulgaricus isolated from traditional Khorasan yogurts were selected. The proteolytic activity of Streptococcus thermophilus strains was determined according to the method of Erkus et al(2012) and the proteolytic activity of Lactobacillus delbrueckii subsp. Bulgaricus was determined according to the method of Nespolo et al.(2010). Milk acidification activity byall examined strains was evaluated according to the method of Erkus et al.(2012). The production property of gamma-aminobutyric acid of native isolates was also evaluated using the method of Lacroix et al. (2013). Yogurt was produced using commercial starters and native isolates. Acidity and pH were measured according to Iranian National Standard No. 2852. Synersis of yogurt samples was measured using centrifugation according to Çelik (2007) method. In order to measure textural properties, a combination of backward extrusion techniques and Texture Profile Analysis (TPA) was used (Yang et al, 2010). Sensory characteristics of yogurt samples were evaluated by 20 panelists using five-point hedonic scale. This study was conducted based on factorial experiment using a completely randomized design. Statistical analysis of data was performed using Minitab Statistical Software (version 17) and ANOVA. Comparison of means was performed using Tukey’s test at the significant level (p < 0.05). Results and discussion: The results of proteolytic activity of Lactobacillus delbrueckii subsp. Bulgaricus showed that the L3 code was weaker than the other two strains. All Streptococcus thermophilus strains were positive protease. All Streptococcus thermophilus strains of the study decreased the pH of the milk to 4.6 in less than five hours, and Streptococcus thermophilus strain S6 code, as the fastest acid producer, decreased the pH of the milk to 4.6within 3 and half hours (Figure 2). The results of GABA production showed that among the streptococcus thermophilus strains, S1, S5 and S6 codes had distinct blue discoloration. Among the Lactobacillus strains, except the L3 strain, two other strains produced green color. Of the 18 samples of the yoghurt, S5L2 and S2L2 samples showed the highest decrease in pH and increased in acidity compared to other samples after being stored refrigerated overnight (P <0.05). The other samples had the same pH and acidity changes as the control samples after overnight refrigeration. The results show the ability of yogurt producion by native starters to compete with those produced by commercial starters in terms of technological characteristics. Thus, samples with codes S2L2, S3L1, S3L2, and S1L1 showed less Synersis of yogurt than commercial starters. This decrease in the Synersis of yogurt might due to the possibility of exopolysaccharide production by these strains. Textural characteristics of yogurt samples were the hardness of the samples in the range of 3 to 4 N, which was significantly different (P <0.05). The lowest hardness was observed for the S3L3, which can be attributed to the poor proteolytic activity of the strain. L3, S6L2, S3L2 and S2L2 had the highest hardness compared to other compounds and control samples (P <0.05). This differences in the hardness of the samples can be attributed to the possible production of some metabolites by the strains. There was no statistically significant difference in the adhesion properties of the samples (p <0.05). Considering the sensory evaluation scores, it was found that in all respects, S3L3 had the lowest score among the other samples (P <0.05). This was in good correlation with the results of the textural properties of the test. Therefore, this compound was eliminated compared to the control samples. Finally, considering the proteolytic behavior of the strains and the ability to produce acid and GABA, as well as the sensory, rheological and physicochemical properties of 18 samples in comparison to the two control samples, Streptococcus thermophilus strains with codes S4, S2, S5, S1, S6, and Lactobacillus delbrueckii subsp. Bulgaricus strains with codes L1 and L2 have the potential to be used as commercial starters in the form of compounds S1L1, S2L2, S5L1, S6L2, S4L2.
Full Research Paper
Food Technology
Khadije Sadat Tabatabae; Mohammad Fazel
Abstract
Introduction: Nowadays, lack of time and busy work schedules have led to increase the demand for ready-to-eat foods. Furthermore, as cardiovascular diseases are on the rise in the world including our country, with nearly 40 percent of deaths being linked to these diseases, there is a growing demand for ...
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Introduction: Nowadays, lack of time and busy work schedules have led to increase the demand for ready-to-eat foods. Furthermore, as cardiovascular diseases are on the rise in the world including our country, with nearly 40 percent of deaths being linked to these diseases, there is a growing demand for low-fat products. The main purpose of the deep frying process is to preserve the aroma and flavor of the ingredients in a crispy crust by immersing the food in hot oil. Frying at high temperatures affects the transfer of mass and heat, which causes some of the water to evaporate and be removed from the product, and the oil is moved into the product, replacing the extracted water. This study aims to use methods that reduce the absorption of oil in the fried product, which can reduce health concerns and increase consumer acceptance of the product. Materials and methods: In this study, a day-old chicken breast fillets were used to prepare the samples. The weight of the samples was between 14.5 and 15 grams, with a diameter of 3.7. Coating solutions include aloe vera gel powder at three levels of 1.5, 3, and 4.5 % (w / v) and whey protein concentrate (WPC) at three levels of 2.5, 5 and 7.5 % (w / v), made with distilled water at 25C. Baguette bread was also used to make breadcrumbs. To coat the chicken breast fillet, the samples were immersed in the coating solution (control samples in distilled water) for 1 minute and then placed in breadcrumbs. After preparation, the samples were fried in an automatic fryer at a controllable temperature of 140 C for 6, 8, and 10 minutes, then the samples were cooled to room temperature for 10 minutes and tested for physicochemical properties. The tests included coating, weight loss, moisture content according to the standard AACC method, adsorption of oil by standard method AOAC, tissue measurement test based on the stiffness of the chicken tissue cutting (catching test), and color analysis of chicken samples using CIE Lab colorimetric system through the determination of color characteristics were performed. Results & discussion: The results showed that the coated samples increased the absorption of the coating glaze due to the increasethe viscosity and thus the absorption of baking powder compared to the non-coated sample. The coating with hydrochloric materials based on barrier properties through strong hydrogen bonds between water molecules forms a gel layer with a high water holding capacity that prevents moisture from escaping. This subsequently reduces weight loss. Moreover, due to the inverse relationship between water and oil content, oil absorption was significantly decreased (p<0.01). Among the studied coatings, the highest moisture retention rate and the lowest oil absorption rate are related to the coated sample with 4.5% aloe vera and 7.5% WPC. As the concentration of aloe vera increased, the hardness of the samples decreased, which may depends on the effect of the meat protein to polysaccharide ratio. As the concentration of WPC increased, the stiffness of the samples increased, increasing the sulfhydryl groups, increasing the disulfide bonds in the meat's myofibrillar protein, and thus increasing the tissue stiffness. Increasing the frying time reduced the moisture and increased the oil absorption, weight loss, and stiffness of the samples. The coating reduces brightness due to the presence of various phenolic pigments, especially light- and heat-sensitive anthraquinones in aloe vera and lactose in WPC, and Maillard's reaction at high processing temperatures, resulting in increased browning index and darkening with increasing product color time. This is correlated with the Maillard reaction. Coating with aloe vera gel and WPC is effective in improving the physicochemical properties of fried chicken.
Full Research Paper
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.
Full Research Paper
Food Biotechnology
Elahe Isvand Heydari; Hossein Jooyandeh; Mohammad Hojjati; Behrooz Alizadeh Behbahani; Mohammad Noshad
Abstract
Introduction: Probiotics are viable microbial food supplements that, when well-arranged in adequate amounts, confer a health advantage on the host. Probiotics have different positive health impacts such as equilibration of intestinal microbiota, prevention of cancer and diarrhea, reduction of cholesterol ...
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Introduction: Probiotics are viable microbial food supplements that, when well-arranged in adequate amounts, confer a health advantage on the host. Probiotics have different positive health impacts such as equilibration of intestinal microbiota, prevention of cancer and diarrhea, reduction of cholesterol and blood pressure, adaptation to lactose intolerance, improvement of immune system, decrease of allergic symptoms, inhibition of pathogenic microorganisms etc. Lactic acid bacteria (LAB), are the most common bacteria introduced as probiotics. Materials and methods: In this research, a strain of Lactobacillus planetarium LZ95 was utilized and its probiotic potential was evaluated. This strain had been isolated from a traditional Iranian fermented food known as Ash-Kardeh and had been identified using culture-dependent methods and molecular techniques. Lactobacillus planetarium, is one of the known LAB bacteria. The aim of this study was to evaluate the probiotic potential of Lactobacillus plantarum LZ95 in relation to its resistance to acid (pH 2.5, 3.5 and 5.5), its ability to grow in different bile salt concentrations (0.2, 0.5, 0.8, 1.2 and 3%), its resistance against chloramphenicol, tetracycline, penicillin and gentamycin antibiotics, and its antimicrobial activity against Listeria innocua, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli by using “Lawn on the spot” method. Results and discussion: Results shown that the viability of Lactobacillus plantarum ranged from 0 to 97.69 percent. The highest and the lowest bacteria viability were determined at pH=5 and 2, respectively. The results revealed that Lactobacillus plantarum was able to grow at all tested bile salt concentrations (0.2, 0.5, 0.8, 1.2 and 3%), and the lowest and the highest viability was found at 0.2 and 3 percent of bile salt levels, respectively. Lactobacillus plantarum was susceptible to all tested antibiotics. Results also shown that chloramphenicol with an inhibition zone diameter of 30.10 mm had the highest anticipation effect on the strain. Antimicrobial activity of Lactobacillus plantarum against Staphylococcus aureus (gram positive) and Escherichia coli (gram negative) with inhibition zone diameters of 11.30 and 7 mm was the highest and the lowest, respectively. The inhibition zone diameter around the strain of Lactobacillus plantarum revealed its ability to inhibit the growth of selected pathogenic bacteria. Based on results, the inhibition zone diameter against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Listeria innocua were 11.30, 7.00, 10.70, and 8.90 mm, respectively. In general, the isolated strain of Lactobacillus planetarium LZ95 had an acceptable probiotic potential such as resistance to bile salt and acidic conditions, susceptibility to some commonly antibiotics, and appropriate antimicrobial activity against food pathogenic bacteria. Therefore, this strain can be used in food industry to produce functional food products.
Full Research Paper
Food Technology
Behdad Shokrollahi; Mohammad Ali Hesarinejad; Zahra Zamani; Negin Yousofi; Anna Abdolshahi; Ashkan Jebelli
Abstract
Introduction: Due to increasing the demand for new sources of protein and the lack of animal protein sources, using and replacing of plant proteins is widely considered. The purpose of this study was to identify the potential of Vicia villosa flour as a native and novel source of protein. In this research, ...
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Introduction: Due to increasing the demand for new sources of protein and the lack of animal protein sources, using and replacing of plant proteins is widely considered. The purpose of this study was to identify the potential of Vicia villosa flour as a native and novel source of protein. In this research, the physical properties of vicia villosa seed and chemical composition (protein, fat, ash, and carbohydrate and moisture contents) and color parameters of its full fat flour were determined and compared with defatted flour as well as the effect of defatting and pH on the functional properties of full fat and defatted vicia villosa flour were investigated. Materials and methods: Vicia Villosa seed was obtained from the local market in Chaharmahal and Bakhtiari province and was cleaned, skinned and, milled. Half of the full fat flour was defatted. The obtained flours were then refrigerated at 4°C for further analysis. Physical properties of the seed including size, dimension, mass, true and bulk density as well as porosity were measured using standard methods and calibrated equipments. Chemical composition of both the seed and skinned seed’s flour (moisture content, fat, protein and ash) were determined using standard methods (AACC, 2003). The carbohydrate content of the samples was determined by subtraction of the sum of other compositional substances from 100. Color properties, protein solubility, water soluble index, water and oil absorption capacity, least gelation concentration, foaming capacity and emulsifying capacity and emulsion stability and foaming stability were also measured for the full fat and defatted Vicia Villosa flours. Results and discussion: The results obtained from the measurement of physical properties for the Vicia Villosa seed showed that length, width, and thickness of the seeds were 5.4 mm, 5.37 mm, and 5.38 mm respectively. The surface area of seeds was found to be 90.98 mm2. True density, bulk density, and porosity of samples were found to be 1286.3 mm3, 788.8 mm3, and 38.67%, respectively. The amount of protein for full fat and defatted Vicia Villosa flour was 28.3% and 31.02%, respectively. L* was measured for the obtained flours and the highest L* was belonged to defatted Vicia Villosa flour, probably due to the removal of the seed shells in the solvent removal stage. Defatting of flour would result in brighter and increase in protein content of flour. The test on protein solubility showed the high dependency of this parameter to pH of the flour proving the U form dependency in the pH range of 2-12. At an isoelectric point of 4.5, the minimum solubility of existing proteins was shown. Water and oil absorption capacity of Full fat were 1.33± 0.4 and 0.85± 0.07 and Defatted Vicia Villosa flour,were 1.94± 0.2 and 1.19± 0.1 respectively (grams of water or oil per grams of the sample). Furthermore, at pH= 4.5, the emulsion and foaming capacity decrease due to its proximity to the isoelectric point. It is noteworthy that in isoelectric pH, the highest foaming stability and the lowest emulsion stability were observed. In addition, the results showed that pH and defatting conditions have a significant effect on functional properties that can be created by changing these parameters, flours, and products with various characteristics. The results showed that changes in pH and defatting process affected the solubility, water and fat absorption, least gelation concentration, foaming capacity and emulsion capacity of flour, so that by defatting and changing pH, functional properties improved significantly.
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Food Technology
Elham Aminpour Daphchahi; Eshagh Zakipour Rahimabadi; Hanieh Rostamzad; Ensieh Nejat Pirsaraii
Abstract
Introduction: The relation between food and health has had an increasing impact on food innovation, due to the popularity of the concept of functional food. Most bakeries products can easily be enriched and fortified with proteins, vitamins and minerals to meet specific needs of the target groups of ...
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Introduction: The relation between food and health has had an increasing impact on food innovation, due to the popularity of the concept of functional food. Most bakeries products can easily be enriched and fortified with proteins, vitamins and minerals to meet specific needs of the target groups of the population. Biscuits are the most popular bakery products worldwide. Biscuits are ready to eat, cheap and conventional food. Protein fortification of biscuits is of current interest, because of increasing awareness of consumers towards health. Fish protein products such as FPP are low cost animal protein with high quality, so it can be used as a protein supplement to increase nutritive value of foods. This research was aimed to evaluate the quality and sensory properties of biscuits enriched with fish protein powder (FFP). Materials and methods: For this purpose, Fish protein power (FPP) of silver carp was used in production of biscuits by replacing it with wheat flour by 0 % (as control treatment), 2.5% (treatment 1) and 5% (treatment 2). Amino acid profile, PV, TBA, chemical composition and sensory analysis was done during 3 months storage at room temperature. Results and discussion: Seventeen kinds of amino acids were identified in fish protein powder of silver carp. The total content of amino acids fish protein powder were 975.19 mg/100 gr. Total essential and non-essential amino acids in control treatment were 36.50 mg/100 gr, that after using fish protein powder in enrichment of biscuits at the level of 2.5 and 5% increased to 50.91 and 67.37 mg/100 gr, respectively. Evaluation of sensory characteristics of biscuits samples did not showed a significant difference between control and enriched treatments (P>0.05).
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Food Technology
Fahimeh Hajinia; Alireza Sadeghi; Alireza Sadeghi Mahoonak; Morteza Khomeiri; Yahya Maghsoudlou; Ali Moayedi
Abstract
Introduction: Bread is the main source of nutrients and it is a cheap staple food in the daily diet of people in many parts of the world. One of the most important ways to improve the quality of bread is to ferment cereals and use fruit resources. Cereal fermentation has a well-known potential to improve ...
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Introduction: Bread is the main source of nutrients and it is a cheap staple food in the daily diet of people in many parts of the world. One of the most important ways to improve the quality of bread is to ferment cereals and use fruit resources. Cereal fermentation has a well-known potential to improve the nutritional properties of the baked goods. It stabilizes the levels of various bioactive compounds, retards starch retrogradation and increases mineral bioavailability. A diet rich in cereal and fruit-based products could improve human health. Oat grain has a high functional potential due to its composition. This grain is known to be an excellent source of dietary fiber, antioxidants and a well-balanced protein fraction. Jujube fruit is also getting popularized due to the high content of vitamins, phenolic, polysaccharides and natural colorant agents. The quality of available commercially jujube depends on the contents of its bioactive compounds and micronutrients. There is no report about simultaneous application of fermented oat and jujube powder in processing of wheat bread. Accordingly, the aims of this study were to produce a supplemented wheat bread containing these ingredients, and evaluate the textural and antioxidant properties of the product. Materials and methods: In the present study, controlled fermented oat containing selected LAB isolated from oat sourdough (as starter culture) was used to produce supplemented wheat bread. Crumb hardness, porosity, specific volume, overall acceptability and antioxidant activity in wheat bread containing fermented oat, jujube powder and their mixture were investigated in comparison with the control (wheat bread). All the experiments were done in triplicates. A complete randomized design with the least significance difference (LSD) post-hock was also used to statistical analysis of the data at p < /em>< 0.05 by SPSS (version 20) software. Results and Discussion: The highest amount of crumb hardness was observed in the sample containing mixture of controlled fermented oat and jujube powder, meanwhile the lowest amount of hardness was belonged to the control sample. The results of specific volume showed an inverse relationship between the values of hardness and specific volume, and the lowest specific volume was observed in sample containing controlled fermented oat along with jujube powder. The highest amount of specific volume was also observed in the control sample. The porosity of all the produced breads was also significantly (p < /em><0.05) higher than the control sample, and the highest porosity was observed in the sample containing controlled fermented oat. The amount of produced gaseous compounds and carbon dioxide during fermentation affect the porosity of the produced bread. Furthermore, water retention capacity is also involved in increase in bread specific volume. Water reduces the stiffness of protein structures and allows better air to enter the dough texture and more specific volume of the product. Wheat breads containing controlled fermented oat + jujube powder and jujube powder (alone) had the highest antioxidant activity, and the control sample had the lowest antioxidant activity. During fermentation, the amount of phenolic compounds or flavonoids increases, and fermentation also causes the synthesis or release of various compounds that have antioxidant properties. Characterization of wheat bread containing the optimal formulation of controlled fermented oat and jujube powder didn’t show significant effect on the overall acceptability of the product. The presence of fiber in fortified breads is likely to increase water uptake, which in turn increases water retention capacity, reduces dough stability and increases overall acceptability. Fruits and whole grains are rich in phytochemicals such as phenolic compounds. Application of phenolic compounds in bread processing, in addition to improve antioxidant properties, affects the physicochemical properties of the dough and the quality characteristics of the produced bread due to various interactions with flour compounds such as gluten and starch. Accordingly, the combined use of plant-rich resources such as jujube powder and fermented oat, which are rich in minerals and micronutrients, can be used to improve the nutritional and quality characteristics of the supplemented wheat bread as a simple and efficient method. Due to the adverse effects of chemical additives and improvers, the importance of providing natural alternatives such as fermented substrates and plant resources in wheat bread processing is quite necessary. The best alternatives for this purpose include sourdough and fiber-rich plant. Wheat bread containing a mixture of controlled fermented oat and jujube powder had the highest crumb hardness and the lowest specific volume. Antioxidant activity in all samples was significantly higher than the control sample and wheat bread containing a controlled fermented oat and jujube powder with 90.52% had the highest amount of antioxidant activity. According to the results, controlled fermented oat and jujube powder, as functional ingredients, may be successfully incorporated into the wheat bread with positively effects on its quality characteristics.
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Food Technology
Mohammad Ali Hesarinejad; Atefeh Arefkhani; Ali Rafe; Fatemeh Javidi; Alireza Sadeghian
Abstract
Introduction: Improving the texture and sensory properties of Iranian white cheese by reducing fat content is one of the most important issues that are considered both technologically and economically. Meanwhile, controlling the amount of water absorption in cheese usually causes textural problems in ...
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Introduction: Improving the texture and sensory properties of Iranian white cheese by reducing fat content is one of the most important issues that are considered both technologically and economically. Meanwhile, controlling the amount of water absorption in cheese usually causes textural problems in cheese, including the softness of the cheese texture. Therefore, this problem will be solved if the amount of water absorption in the cheese can be controlled in such a way that the resulting cheese texture does not change and even its quality improves. Currently, the demand for the use of compounds or methods to achieve this goal is increasing. Hydrocolloids are compounds that, due to their inherent nature in absorbing water and creating a mouth-feel like fat, can have a special effect on fat replacement. Therefore, creating a suitable formula in the composition of hydrocolloids can complement the qualitative improvement of cheese texture. Basil seed gum (BSG) is a native hydrocolloid that has shown good stability and emulsifier properties, making it a potential functional ingredient in the food industry. Xanthan gum (XG) is also used in food as a thickener and stabilizer, and also can acts as a gelling agent along with other gums. In this study, by creating a suitable formulation in the use of these hydrocolloids, an attempt is made to improve the texture and sensory properties of cheese. Materials and methods: The effect of different concentrations of mixed-hydrocolloids based on XG/BSG, and Guar gum (GG)/BSG on the textural attributes of Iranian white cheese was investigated. Four cheese treatments (without hydrocolloids or with 0.25, 0.5, or 0.75 g/kg of milk) were produced to study the effects of hydrocolloid content on the textural properties of the product. Cheese samples were analyzed with respect to physicochemical, color, sensory characteristics, textural properties, and microstructure. Results and discussion: The results showed that the higher concentration of hydrocolloids from 0 to 0.075% used, the higher the increasein the moisture content of cheese samples. The results also showed that samples containing GG had higher moisture content than samples containing XG, which is probably due to the higher water absorption capacity of GG than XG. Increasing the concentration of hydrocolloids reduces the fat in the sample, which is due to the absorption and retention of more water in the cheese due to the hydrophilic properties of hydrocolloids. Samples containing GG had a lower fat content than samples containing XG. As the concentration of hydrocolloids increased, lightness increased, indicating the effect of hydrocolloids on the increase in whey cavities. The results also showed more lightness of XG samples than GG samples. Samples containing XG were more rigid, possibly confirming that this hydrocolloid has a greater effect than a mixture containing GG in the strength of the cheese and the effect of the GG is merely thickenning. With the increase in the concentration of BSG/XG (from 0.025 to 0.075%), the hardness increased from 260.96 to 364.23 g. The springiness of all samples also ranged from 0.99 to 1 mm, indicating good reversible behavior. It was found that the formula containing BSG/XG at a concentration of 0.50% had the highest overall acceptance after the sample containing BSG/XG at a concentration of 0.075%. Samples containing gum had low sensory evaluation results, possibly due to high moisture content, and were reported to be undesirable. In terms of taste, the samples did not differ significantly from each other. According to the results of textural analysis and sensory evaluation, the formula containing BSG/XG at 0.075% concentration, due to having the highest score of sensory evaluation and desirable textural characteristics, was selected as the optimal sample. In the microstructure of the desired cheese sample, the location of the whey serum has been determined. By adding hydrocolloid to the cheese, the protein matrix opens. When the sample was prepared for SEM analysis, the moisture was removed. Therefore, the effect of hydrated hydrocolloid was observed in the form of cavities. This structure has enough space to trap water and form a suitable gel.
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Food Engineering
Ghazale Amini; Fakhreddin Salehi; Majid Rasouli
Abstract
Introduction: The dispersion of water soluble hydrocolloids (gums) in the aqueous system provides great technical importance, because they can improve the gel or enhance the thickening properties of food products. Wild sage seeds have significant amounts of gum with good functional properties that after ...
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Introduction: The dispersion of water soluble hydrocolloids (gums) in the aqueous system provides great technical importance, because they can improve the gel or enhance the thickening properties of food products. Wild sage seeds have significant amounts of gum with good functional properties that after extracting from seeds (mucilage) and drying, can be used in formulation of various products (Salehi, 2017, 2020a). The physicochemical properties and rheological behaviour of seed gums depend on the method and condition of drying. Also, the color of dried product is an important quality factor, which is affected by drying conditions (Amid and Mirhosseini, 2012; Nep and Conway, 2011). For example, effect of different drying methods (oven drying (40-80°C), freeze drying and vacuum oven drying) on rheological behaviour, color and physicochemical characteristics of BSM were investigated by Salehi and Kashaninejad (2017). Drying is one of the simply available and the most common processing approach that has been used traditionally for preservation of food product. One of the best way to reduce the drying time is to use IR radiation heating. IR methods could be used as substitution to the current drying methods for producing high-quality dried hydrocolloids. IR heating has many advantages include high heat transfer rate, uniform heating, low processing time, high efficiency (80-90%), lower energy consumption, lower energy costs, and improves final product quality (Aktaş et al., 2017; Salehi, 2020c). The performance of artificial neural networks (ANN) as an analytical alternative to conventional modeling techniques was reported by some researchers. They reported that these approaches are able to estimate the drying kinetics of various fruits and vegetableswith high precision. It has been shown that nonlinear approaches based on ANN are far better in generalization and estimation in comparison to empirical models (Bahramparvar et al., 2014; Salehi, 2020b; Zhang et al., 2014). It is difficult to predict the combined effects of treatment time, IR power, lamp distance and mucilage thickness on drying kinetics (moisture content and moisture ratio) of fruits and vegetablesusing conventional models. Therefore, the target of this study was to investigate the effect of IR dryer parameters on moisture content and moisture ratio of wild sage seed mucilage during IR drying and studying the performance of ANN method for estimation of these parameters. Materials and methods: Wild sage seeds was physically cleaned and all foreign stuffs were removed. Then, the pure wild sage seeds were immersed in water for 20 min at a seed/water ratio of 1:20 at 25°C and pH = 7. In the next step, the gum was separated from the inflated seeds by passing the seeds through an extractor (M-J-376-N, Nikko Electric Industry Company, Iran) with a rotating disc which scratches the mucilage layer on the seed surface. The initial moisture content (MC) of WSSM was 99.4% (wet basis). Finally, the obtained WSSM was immediately placed into IR dryer. In this study, for wild sage seed mucilage drying, infrared radiation (IR) method was used. The effect of infrared lamp power (150, 250 and 375 W), distance of samples from lamp (4, 8 and 12 cm) and mucilage thickness (0.5, 1 and 1.5 cm) on drying time of wild sage seed mucilage were investigated. Results and Discussion: The results of wild sage seed mucilage drying using infrared method presented that by increasing the lamp power and decreasing the sample distance from the heat source, drying time was decreased. With lamp distance increasing from 4 to 12 cm, the average drying time of wild sage seed mucilage increased from 72.04 minutes to 160.81 minutes. When it comes to sample thickness, we found that by increasing the thickness of mucilage (0.5 to 1.5 cm) drying time of sample increased from 55.59 to 173.67 min. The process was modeled by an artificial neural network with 4 inputs (radiation time, lamp power, lamp distance and thickness) and 2 output (moisture content (MC) and moisture ratio (MR)). The results presented that mucilage drying time significantly increased by decreasing power of lamp (375 up to 150 W) and increasing the heat source distance from sample (4 to12 cm). The results of artificial neural network modeling showed that the network with 8 neurons in a hidden layer and with using the sigmoid activation function could predict the moisture content and moisture ratio of wild sage seed mucilage during infrared drying in various times (r=0.974 for MC and r=0.997 for MR).
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Food Chemistry
Mohammad Taghi Golmakani; Gholam Reza Mesbahi; Nasireh Alavi; Azita Hosseinzade Farbudi
Abstract
Introduction: Food wastes and losses are produced during all phases of food life cycles. The highest wastes belong to the processing of fruits and vegetables. Bioactive compounds have the potential to be extracted from the by-products of fruits and vegetables which can be used in the food processing. ...
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Introduction: Food wastes and losses are produced during all phases of food life cycles. The highest wastes belong to the processing of fruits and vegetables. Bioactive compounds have the potential to be extracted from the by-products of fruits and vegetables which can be used in the food processing. Extraction of flavor compounds, phenolic compounds, enzymes, and organic acids from wastes of fruits – pomace, peel, and seeds of citrus fruits, pomace and leave of apple, seeds of grape, and peel of kiwifruit – and vegetables – pomace of carrot, husk of garlic, skin of onion, peel of potato, and skin of tomato – have been reported (Sagar et al., 2018).Sour orange, Citrus aurantium, is one of the species of citrus fruits. Sour orange seeds contain fats, protein, and bitter compounds which affect citrus processing (Ye et al., 2017). Naringin, neohesperidin, flavon, caffeic acid, p-coumaric acid, ferulic acid, and sinapic acid have been detected in methanolic extract of sour orange seeds (Bocco et al., 1998).Bioactive compounds are recovered from food wastes through various conventional and novel extraction techniques. Microwave-assisted extraction is one of the most used novel and environmentally friendly extraction methods. Advantages of microwave-assisted extraction over conventional extraction techniques include automated operation, more effective and selective heating, and less extraction time (Vinatoru et al., 2017).The objective of this study was optimization of microwave-assisted extraction of sour orange seed coat extract in terms of microwave power level, extraction time, sample quantity, and solvent volume on yield, bioactive compounds (total phenolic content and total flavonoid content), and antioxidant activity (free radical scavenging activity, ferric ion reducing antioxidant power, cupric ion reducing antioxidant capacity, and ferrous ion chelating). Also, optimum conditions of microwave-assisted extraction was compared to that of conventional magnetic stirrer-assisted extraction method. Materials and methods: Sour orange seeds were purchased from Limondis Company (Beyza, Fars province, Iran). Microwave-assisted extraction conditions including microwave power level (100, 200, and 300 W), extraction time (5, 10, and 15 min), sample quantity (5, 10, and 15 g), and solvent (methanolvolume 100, 150, and 200 mL) were optimized. Yield, bioactive compounds (total phenolic content (Habibi et al., 2015) and total flavonoid content (Habibi et al., 2015)), and antioxidant activity (free radical scavenging activity (Habibi et al., 2015), ferric ion reducing antioxidant power (Rekha et al., 2012), cupric ion reducing antioxidant capacity (Pascu et al., 2014), and ferrous ion chelating (Oyetayo et al., 2009)) of sour orange seed coat extract were evaluated. After determining the optimum conditions of microwave-assisted extraction, yield, bioactive compounds (total phenolic content and total flavonoid content), and antioxidant activity of sour orange seed coat extract were compared to those of conventional magnetic stirrer-assisted extraction method. Design Expert software (Version 10, Stat-Ease, Minneapolis, MN) was employed for analyzing four variables – microwave power level, extraction time, sample quantity, and solvent volume – at three levels consisting 30 experimental runs. Response surface methodology concerning central composite design (6 center points, quadratic model, and face center = 1) was applied. Results and discussion: Optimum conditions of microwave-assisted extraction were microwave power level of 200 W, extraction time of 12 min, sample quantity of 5 g, and solvent volume of 200 mL. Under optimum conditions, yiled, total phenolic content, total flavonoid content, IC50, ferric ion reducing antioxidant power, cupric ion reducing antioxidant capacity, and ferrous ion chelating were11.57%, 15550.50 µg gallic acid equivalent/g, 1476.22 µg quercetin equivalent/g, 11.33 mg/mL, 7.12 mg ascorbic/g, 6.44 mg ascorbic acid/g, and 0.43 mg EDTA/g, respectively. Intermediate microwave power level (200 W) can be more suitable from an industrial perspective and energy consumption (Jokić et al., 2012). Further increase in microwave power level, i.e. higher than 200 W, causes thermal degradation of bioactive compounds (Dahmoune et al., 2013), decreasing total phenolic content, total flavonoid content, and antioxidant activity of sour orange seed coat extract. The highest extraction time gives the bioactive compounds a chance to diffuse and release from the cell matrix to the surrounding environment (solvent). The highest solvent volume was selected as the optimum extraction condition. By increasing solvent volume up to 200 mL, meaning a greater gradient in bioactive compound concentration, mass transfer was also improved (Dahmoune et al., 2013). Also, the minimum sample quantity (5 g) was determined in optimum conditions. Increasing sample quantity (while the solvent volume remained constant) reduces the surface area available for the solvent to penetrate the sample matrix. As a result, higher sample quantity caused lower extraction of bioactive compounds (Ballard et al., 2010). There were no significant differences between yield, bioactive compounds, and antioxidant activity of extract obtained by conventional-assisted extraction method in comparison with those of microwave-assisted extraction. In conclusion, microwave-assisted extraction, as a green and fast method, can be proposed as a suitable and practical method for extraction of bioactive compounds from sour orange seed coat.
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Food Technology
Somayeh Damirchi; Mania Salehifar
Abstract
Introduction: Regarding the problem of celiac patient's intestinal intolerance to gluten-containing products, these people have to use gluten-free products, mostly with a variety of foreign and high prices ingredients that are not conform to Iranian tastes. The aim of this study was to evaluate the possibility ...
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Introduction: Regarding the problem of celiac patient's intestinal intolerance to gluten-containing products, these people have to use gluten-free products, mostly with a variety of foreign and high prices ingredients that are not conform to Iranian tastes. The aim of this study was to evaluate the possibility of producing gluten-free chocolate cake with Acorn flour (30 and 40 percent) and powdered squash (5, 10 and 15 percent) Along with rice flour (100% Control sample, 45, 50, 55, 60, 65 percent with Acorn flour and pumpkin powder. Acorn flour may be used in gluten-free flour breads due to its nutritional and health benefits. Acorn flour contains high quality proteins with essential amino acids (4–7%), relatively high amount of sugar (20–32%), starch (50–60%), dietary fiber (4–10%), and low amount of fat (2‒4%). It also contains vitamins E, and B, potassium, phosphorous, and magnesium. Pumpkins. are extensively grown in tropical and subtropical countries. They are traditionally consumed as freshly boiled and steamed or as processed food items such as soup and curry. Pumpkin is high in carotene, which gives it yellow or orange color. It is also high in carbohydrates and minerals. Beta-carotene in plants that have a pleasant yellow-orange color is a major source of vitamin A.Materials and methods: In this study, the effect of Acorn flour and pumpkin powder on the nutritional properties of cakes (fiber, beta-carotene), moisture, water activity, stale, special volume, stiffness and sensory properties were tested. Increasing levels of employing Acorn flour and pumpkin powder in the formulation gluten-free chocolate cake directly increases water activity, including dietary fiber and beta-carotene content in chocolate cakes. It was also found that by increasing the percentage Acorn flour and pumpkin powder in the formulation gluten-free chocolate cake staling rate was decreased. Based on the results from sensory evaluation by trained evaluators, all sensory characteristics (texture, taste, smell and appearance) was significantly (p <0.05) affected by different levels of Acorn flour and pumpkin powder. Result & discussion:Addition of pumpkin powder resulted in considerable increase of batter viscosity while the addition of Acorn flour had no significant effect on viscosity (p> 0.05). The higher viscosity was expected to have higher resistance to the applied shear during the mixing process leading to a lower amount of air being incorporated. Peak viscosity increased with increasing Acorn flour content. Acorn flour and pumpkin powder substitution, increased the fiber content of flours and increase the absorptive and maintenance capacity of water, as well as the dough viscosity of gluten-free chocolate cake. Addition of 30% Acorn flour and 10%pumpkin powder was found to increased batter viscosity, apparent density, cake moisture. The specific volume of cakes were decreased due to the inverse relationship between volume and apparent density. The effects of Acorn flour and pumpkin powder as a staling retarder was further due to increase in fiber content which results in moisture retention of cakes. Hardness of all samples including control, were significantly increased during storage (p <0.05) which is indicative of staling during the storage period. The maximum firmness of samples was achieved in control and the minimum was seen in samples with high levels of Acorn flour and pumpkin powder. Substitution of Acorn flour and pumpkin powder into cakes, seems to reduce the rate of firming during storage. Acorn flour and pumpkin powder showed an anti- staling effect, retarding the cake firmness during storage. The main reason of staling in gluten free products is moisture migration from crumb to the crust which is due to the absence of gluten. Fibers are expected to increase water retention and loaf volume and to decrease firmness and starch retrogradation. The highly hydrophilic nature of fibers also helps to prevent the migration of water from the substrate to the coating, which improves shelf life of the product. According to the surveys and assessments carried out, in term of physico-chemical, treatments sensory of T2 (with 30% Acorn flour, and 10% pumpkin powder. And 60% Rice Flour) were proposed as a selected treatment.
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Food Biotechnology
Nafiseh Davati; Sahar Bahrami
Abstract
Introduction: The consumption of local and traditional dairy products have increased in recent years and some local cheeses as functional foods with desirable organoleptic attributes have positive effects on human health. However, there is concern that consumption of these products may increase the risk ...
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Introduction: The consumption of local and traditional dairy products have increased in recent years and some local cheeses as functional foods with desirable organoleptic attributes have positive effects on human health. However, there is concern that consumption of these products may increase the risk of exposure to food born bacteria such as Enterobacteriaceae family, Staphylococcus aureus, and Listeria monocytogenes. The microbiome of fermented products such as cheese is one of the most powerful and important parameters in flavor development and ripening. Furthermore, cheese flavor formation as a dynamic biochemical process is related to environmental conditions including milk source, ripening time, and temperature of storage. These parameters affect the microbial community structures and metabolic pathways. Materials and Methods: In this study, a local cheese made from cow milk was prepared based on a local recipe. The traditional cheese was manufactured using mesophilic starter culture. The cheese was ripened at 10°C for 3 months. The samples were collected from the surface of the cheese. The serial dilution was performed until 10-10 dilution in sterile ringer. For isolation and phenotypic identification of lactic acid bacteria, a 100 µl of diluted sample was cultured on MRS agar and M17 agar, followed by incubation at 37°C for 48 h under anaerobic conditions with Gas-Pak A. After purification of colonies, the Gram-positive and catalase-negative isolates were phenotypically identified at genus level using physiological tests including capacity of gas production, growth at different pHs (9.6 and 4.4), salt tolerance (%6.5 and 18%), and different growth temperatures (10°C and 45°C). DNA extraction was performed with DNeasy®Blood & Tissue Kit. The microbial population of the cheese and its functional potential for ripening were investigated by whole-metagenome sequencing. The prepared library using Nextera™ DNA approach was sequenced by using the Illumina HiSeq® 2000, 2×100 bp paired- end reads. The metagenomics data of cheese microbiome were analyzed for taxonomic profiling and functional potential by De Novo Assemble Metagenome and Bin Pangenomes. The metabolic pathways were extracted from the KEGGdatabase. Results and Discussion: The results of phenotypic identification showed that most of the lactic acid bacteria strains belonged to Streptococcus, Lactococcus, and Lactobacillus. Also, the results of metagenomics analysis showed that there were various genera including Streptococcus, Lactococcus, Lactobacillus, Acinetobacter, Enterococcus, Glutamicibacter, and Weissella in cheese. Streptococcus thermophilus, Lactococcus lactis, and Lactobacillus helveticus were identified as dominant species. Pathogenic bacteria such as Enterobacter, Listeria, and Staphylococcuswere also slightly found and therefore there is nearly no concern for consumers and human health. The microbiome of this cheese showed the metabolic potential for the biosynthesis of a wide range of aroma compounds and associated with flavor development that related with the metabolism and biosynthesis of methane, branched chain amino acids (isoleucine, valine, and leucine), aromatic amino acids (tyrosine, tryptophan, and phenylalanine), other amino acids (beta-alanine, L-lysine), fatty acids (arachidonate, palmitate, stearate), and monosaccharides. The enzymes related to biosynthesis and metabolism of amino acids were found during ripening of this cheese. These enzymes included 4-hydroxy-tetrahydrodipicolinate reductase, 2-isopropylmalate synthase, 3-dehydroquinate dehydratase, 3-hydroxyisobutyryl-CoA hydrolase, 5-carboxymethyl-2-hydroxymuconate delta-isomerase, and 3-hydroxyacyl-CoA dehydrogenase. Based on the results of KAAS (KEGG Automatic Annotation Server), proteins involved in metabolic pathways of microbial community on the surface of the traditional cheese included Cytochrome P450 Photosynthesis Proteins, Peptidases & Inhibitors, Glycosyltransferases, Lipopolysaccharide Biosynthesis Proteins, Peptidoglycan Biosynthesis and Degradation Proteins, Lipid Biosynthesis Proteins, Protein Kinases, Polyketide Biosynthesis Proteins Prenyltransferases, Protein Phosphatases & Associated Proteins, and Amino Acid Related Enzymes. The cheese under our study as a functional food showed health benefits for consumers due to the presence of probiotic bacteria and genes encoded for biosynthesis of valuable compounds including antibiotics, drugs, and antioxidants.
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Food Biotechnology
Elham Rouhi; Alireza Sadeghi; Seyed Mahdi Jafari; Mohammad Abdolhoseini; Elham Assadpour
Abstract
< p >Introduction: Evaluation of probiotic and antifungal properties of lactic acid bacteria (LAB) isolated from fermented substrates has great importance in order to provide microbial cultures for fermentation industries. Among the fermented foods, dairy products play the main role as carriers ...
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< p >Introduction: Evaluation of probiotic and antifungal properties of lactic acid bacteria (LAB) isolated from fermented substrates has great importance in order to provide microbial cultures for fermentation industries. Among the fermented foods, dairy products play the main role as carriers of probiotics. Meanwhile, non-dairy fermented foods have been rarely studied in order to isolation and characterization of their probiotic microorganisms. Sourdough as a mixture of flour and water is a proper fermented ecosystem to isolate probiotic and antifungal LAB. Besides their desired health, probiotics must become active in the consumer''s gastrointestinal tract without any adverse effect. These bacteria can be used as starter, adjunct or preservative cultures to produce different fermented foods. Furthermore, antimicrobial metabolites of the LAB have also numerous potential applications as bio-preservatives in food and/or medical technologies. < p > < p >Materials and methods: In the present study, after continuous back-slopping process, predominant LAB was isolated from fermented quinoa. Then the LAB isolate was identified using PCR amplification of its partial 16S rDNA gene. Subsequently, probiotic properties of the LAB including its resistance to low pH and bile salt, antibacterial effects, aggregation potentials, antibiotic susceptibility and haemolytic activity were investigated. Antifungal effect of the LAB on Aspergillus niger was also determined using overlay bioassay. Finally, the one way analysis of variance (ANOVA) with the least significant difference (LSD) post hock (at p < /em> < p >Results and discussion: Sequencing results of the PCR products led to the identification of Enterococcus hirae as predominant LAB isolated from quinoa sourdough. Sourdough fermentation depends on the several technological and environmental factors and therefore, different types of these complex stressful ecosystems have their specific microflora with unique properties. The LAB isolate had proper survival after continuous pH and bile treatments. Resistance to low pH and bile salt is not sufficient to predict the survival of the probiotics in the actual conditions of the gastrointestinal tract. However, these properties are necessary for assessment of viability and activity in this situation. Furthermore, the highest antibacterial activity of the LAB was observed against Bacillus cereus among the studied food borne indicator bacteria. The effect of crude cell free supernatant (CFS) obtained from LAB isolate on indicator bacteria was significantly (p < /em>
Full Research Paper
Food Chemistry
Atefeh Irankhah; Leila Nateghi; Simin Asadollahi
Abstract
Introduction: Currently, synthetic antioxidants are used to reduce the oxidation of oils and fatty foods and to prevent the reduction of the nutritional value and sensory properties of edible oils. Due to the adverse effects of synthetic antioxidants, the use of natural antioxidants seems essential. ...
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Introduction: Currently, synthetic antioxidants are used to reduce the oxidation of oils and fatty foods and to prevent the reduction of the nutritional value and sensory properties of edible oils. Due to the adverse effects of synthetic antioxidants, the use of natural antioxidants seems essential. Ferulago angulata extract is a natural source of antioxidants that, in addition to enhancing flavor, help extend the shelf life of the product. The aim of this study was to investigate the antioxidant effect of Ferulago angulata extract on the physicochemical and sensory characteristics of potato- chips and the resulting oil during shelf life. Ferulago angulata plant was purchased from the local market of Sarpol-e-Zahab city in Kermanshah province and was extracted using 96% ethanol soaking and solvent by distillation machine. The thin sheets of potatoes were fried in oils containing 1000, 2000, 3000 and 4000 ppm of chamomile extract and the oil containing 100 ppm of synthetic antioxidant TBHQ at 190°C for 9 minutes. The ability to inhibit DPPH free radicals, total phenolic compounds, and sensory evaluation on potato chips and peroxide, acidity, and thiobarbituric acid tests on oil from frying potato chips over time 1, 15 and 30 days of storage were evaluated. The results showed that the use of Ferulago angulata extract increased antioxidant power in inhibiting DPPH free radicals and total phenolic compounds and reduced the amount of peroxide, acidity and thiobarbituric acid, so that the lowest amount of peroxide, acidity. And thiobarbituric acid and the highest amount of total phenolic compounds related to treatment containing 4000 ppm of Ferulago angulata extract. A treatment containing 4000 ppm of chamomile extract has the highest resistance to oxidative spoilage and can be compared to synthetic antioxidant TBHQ. The results of this study showed that using Ferulago angulata extract with a concentration of 2000 ppm, a potato chips with desirable organoleptic properties can be obtained and used as a suitable alternative to synthetic antioxidants such as TBHQ in food and oil oxidation. Materials and Methods: Ferulago angulata plant was purchased from the local market of Sarpol-e Zahab city in Kermanshah province. Then, by Herbarium of Medicinal Plants, Faculty of Pharmacy, University of Tehran, its scientific name was confirmed as Boiss (Schlechat) Ferulago angulata, belonging to the Apiaceae family. 96% ethanol soaking and solvent were used for extraction. For this purpose, 100 grams of powdered leaves of Ferulago angulata plant were carefully weighed by a digital scale balance. Then, to prepare ethanolic extract, 500 ml of 96% ethanol was added to the Erlenmeyer flask. For 72 hours, the flask was placed at room temperature on a 1500 rpm magnetic shaker to fully extract the Ferulago angulata t. The solvent mixture and the plant were then separated by filter paper. Then squeeze the pulp until it is completely emptied and finally the initial extract is obtained. The initial extract was centrifuged for 10 min at 3000 rpm. The resulting extract was then poured into a vacuum distiller (rotary) and heated to 80 °C for one hour to evaporate the solvent from the extract. The concentrated extract contained 4.0623 mg of gallic acid per gram, total phenol and IC50. Ferulago angulata extract in concentrations of 1000, 2000, 3000 and 4000 ppm and TBHQ synthetic antioxidant with a concentration of 100 ppm in frying oil (a mixture of super olein, soybean and sunflower oils) without antioxidants in dark color glass was added and a sample of oil without antioxidants was prepared. Variegated potatoes are washed, peeled and then cut into thin slices using a slicer and immersed in water until fried. Immediately after the dewatering, the potato slices were transferred to a frying pan containing a variety of oils and fried for 9 minutes at 190 °C. The fried sheets were then cooled to room temperature. The frying oil was kept in a 20 °C oven. Then, at 1, 15 and 30 days after storage of frying oil in a 20 °C oven, t the acid number, peroxide and thiobarbituric acid on the oil from frying the potato chips were determined. Sensory and phenolic compounds and DPPH were performed on potato chips. Data analysis was performed using Minitab-16 software and ANOVA. Results and Discussion: The aim of this research was to investigate the antioxidant effect of Ferulago angulata extract on the physicochemical and sensory properties of potato chips and the resulting oil during its shelf life. According to the results, the highest and lowest levels of acidity, peroxide and thiobarbituric acid were assigned to the control treatment (synthetic anti-oxidant oil) and the treatment containing 4000 ppm of Ferulago angulata extract, respectively. Examination of phenolic compounds showed that by using Ferulago angulata extract and increasing its concentration, antioxidant properties increased and the highest antioxidant property was belonged to the treatment containing 4000 ppm of Ferulago angulata extract, which contained higher phenolic compounds. The results of sensory evaluation showed that the highest score of sensory properties was given to the control treatment and treatments containing 1000 and 2000 ppm of Ferulago angulata extract. As can be seen, antioxidant properties and polyphenolic compounds had the opposite effect on sensory scores. The fried chips in oil containing 2000 ppm of Ferulago angulata extract were selected as the optimal treatment in terms of the highest score of sensory evaluation. The results showed that the extract of Ferulago angulata plant could be a good alternative to synthetic antioxidants in frying oils to delay the oxidation of frying oil, and in addition to its antioxidant properties, it can create desirable sensory properties in fried foods and reduce the risk of consuming these foods.
