Food Technology
Elnaz Milani; Zahra Dehghan; Neda Hashemi
Abstract
Abstract:1 Introduction: Gastrointestinal diseases are very important among human societies, especially in developing countries. One of these diseases, celiac disease, is the result of the interference of gluten in food, the body's immune system, genetics and environmental factors. Therefore, it is necessary ...
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Abstract:1 Introduction: Gastrointestinal diseases are very important among human societies, especially in developing countries. One of these diseases, celiac disease, is the result of the interference of gluten in food, the body's immune system, genetics and environmental factors. Therefore, it is necessary to provide a solution for the production of gluten-free products and also to improve their quality. The increase in the nutritional knowledge of the people of the society has caused the development and production of healthy food products for certain groups to have a growing trend. Baked products such as cookies are very popular among the society because of their textural characteristics as well as flavoring and attractive colors. Therefore, their enrichment is of interest. Most commercial gluten-free bakery products are based on pure starch or the combination of corn starch with gluten-free flour, which is associated with dryness and sandiness in the product. Materials and methods: The aim of this research wass to investigate the functional characteristics of non-extruded and extruded chickpea flour samples and then the effect of adding different levels of it at three levels of 0, 20 and 40% on physicochemical characteristics, textural characteristics, Lightness, porosity and sensory using completely randomized factorial design. The blend of chick pea flour- xanthan gum was extruded by a parallel twin-screw extruder (Jinan Saxin, China). Process was applied at die diameter of 3 mm, and extrusion temperature of 140 ℃. The chemical composition of raw materials was measured by standard AOAC (2000) methods. The hardness of cookies was measured using Texture Analyzer (TA plus Ametek, UK). The cylinder steel probe (2 mm diameter) was set to move at a speed of 1 mm/s The samples were punctured by the probe to a distance of 10 mm. The color parameters L* (lightness), a*(redness), b*(yellowness) values of the samples were determined by the Hunterlab machine (Reston VA, US) (Rhee et al, 2004). Water absorption index in terms of grams of bonded water was calculated by the sample. Sensory evaluation was performed using a 5-point hedonic test. Results and discussion: In general, gluten-free products are unable to store carbon dioxide gas due to the lack of a coherent and uniform gluten network, which causes an increase in volume. As a result, the product is small in volume and the structure of the crumb is compressed. The extrusion baking process had a high potential to improve cookie quality; In such a way that the addition of extruded chickpea flour increased the porosity of the cookie samples, the results of the texture analysis show that the addition of extruded chickpeas up to a minimum of 40% improved the texture of the cookie and also increased its shelf life. Also, the sensory test results showed the favorable effect of adding extruded chickpea flour up to 20%. concequently, by summarizing the results of physical and sensory tests, it was determined that cookies with appropriate sensory and quality characteristics can be produced using 40% of extruded chickpea flour. Peas, and especially extruded peas, due to their protein and dietary fiber content, high water absorption ability, while maintaining moisture, reduced the hardness of the cookie texture. Considering the increase in demand for gluten-free products, it seems that enriching these products with nutrients such as chickpea flour can be an alternative method to improve the nutritional value of these products. Adding legumes is a good way to increase the consumption of legumes, which are rich in the amino acid lysine. Legumes, especially pea seeds, have high nutritional value and functional characteristics, and including them in the diet by adding them to bakery products is a good way to increase their consumption. The use of chickpea flour as a nutrient source in cookie formulation increases the nutritional value, reduces the glycemic index and improves the variety of such products.
Food Technology
Ghazal Shekari; Elnaz Milani; Elham Azarpazhooh
Abstract
IntroductionCeliac disease is one of the most common digestive disorder. Chicken nugget is one of the most popular instant and ready-to-eat foods, and wheat flour is one of its main coating ingredients, which contains approximately 60% gluten. Quinoa is a gluten-free grain, as a good source of dietary ...
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IntroductionCeliac disease is one of the most common digestive disorder. Chicken nugget is one of the most popular instant and ready-to-eat foods, and wheat flour is one of its main coating ingredients, which contains approximately 60% gluten. Quinoa is a gluten-free grain, as a good source of dietary fiber, has various applications in the meat products processing system as a stabilizer, fat substitute, structural components, etc. The addition of hydrocolloids also helps to improve the rheological properties of gluten-free products. The purpose of this research was to evaluate the effect of quinoa-corn mixed flour in the preparation of nugget batter as a gluten-free combination as an alternative to wheat flour, and also to investigate the effect of adding HPMC hydrocolloid on the final product characteristics. In this research, a rotatable central composite design was used to investigate the effect of two independent variables including different proportions of quinoa-corn flour (0-100, 50-50, 100-0%) and different levels of hydrocolloid (0.5-1-1.5%) on the quality characteristics of nugget. With the increase of quinoa replacement level, moisture content (0.60), batter pick up (138) and redness level 5.5 (a*) increased, and oil content (11), hardness (7.5), brightness level 41(L*), yellowness level 20(b*) decreased. The increase of HPMC also caused an increase in moisture content (0.59), brightness level (L*) of 0.39, batter pick up (137) and decrease in oil content (10) and hardness (7). Optimum conditions for the production of gluten-free nugget were determined by considering the optimal amounts for the production of high quality and healthy products, contained 90% quinoa and HPMC at a level of about 1%. Materials and Methods Corn flour was purchased from the pilot of Ferdowsi University of Mashhad. The de-saponified quinoa was prepared from Kashmir and then ground. In order to make the grains more uniform, both flours were sieved using a 30 mesh. Hydrocolloid hydroxypropyl methylcellulose was also prepared from Kian Shimi Mashhad. Oyla frying oil was used for frying the samples.The chicken nugget formulation was a mixture of 86% minced chicken, 10% onion, 1.5% garlic powder, 1% salt and 1.5% pepper. After complete mixing, these materials were poured into a freezer bag until a homogeneous and uniform mixture was obtained, and they were flatted until they reached the desired thickness (1 cm). Plastics containing chicken paste were stored in the freezer for 2 hours to facilitate cutting. Then molding was done with a circular mold with a diameter of 4 cm (Dehghan Nasiri et al., 2012).The batter formulation consisted of flour, water, baking powder, salt and hydrocolloids. In order to investigate the effect of quinoa and corn flours, and hydrocolloids, these substances were added to nugget water paste in different percentages (quinoa-corn ratio: 0-100, 50-50, 0-100 and hydrocolloids at the level of 1-1 / 5 -0.5%) and then mixed with water by mixer for 1 minute. The molded samples were first coated with flour and then immersed in the batter for 60 seconds and dripped for 30 seconds. Finally, deep frying was performed in the fryer at 170 ° C for 3.5 minutes. The fried samples were taken out of the fryer basket and the excess oil on the surface of the nuggets was removed with absorbent paper. The oil was changed after twice frying. After cooling the samples at room temperature, the tests such as moisture content, oil content, texture (hardness), color, batter pick up, peroxide and overall acceptance were performed.In this study, Design Expert 10.0.7 software and a rotatable central composite design to investigate the effect of two independent variables including different ratios of quinoa-corn flour (0-100, 50-50, 0-100%) and hydrocolloid (0.5-1-1.5%), Was used on the quality characteristics of the nugget. Finally, different models were fitted to the data obtained from the experiments and the best model was selected according to the results of analysis of variance. Results and DiscussionWith increasing quinoa replacement level, moisture content, redness (a*) and pH increased and oil content, batter pick up, texture (hardness), brightness (L*), yellowness (b*) and cooking loss decreased. Increasing the HPMC also increased the moisture content, brightness (L*), cooking loss, batter pick up, and decreased oil content and hardness. Optimum condition for production of gluten-free chicken nuggets, considering the appropriate properties was found to be 90% quinoa flour and 1% HPMC. Conclusion In general, it can be concluded that the addition of quinoa and HPMC leads to the production of high quality products with high moisture and low oil content and high nutritional value.
Food Technology
Elham Ghiami; Arash Koocheki; Elnaz Milani
Abstract
Introduction Quinoa, which is known as the mother grain,has higher protein content than common cereals and possesses a large lysine content. Quinoa is composed mainly of carbohydrates (60-75%), of which 10-13% is dietary fiber. Quinoa also has a slightly higher protein content (12-16%) compared ...
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Introduction Quinoa, which is known as the mother grain,has higher protein content than common cereals and possesses a large lysine content. Quinoa is composed mainly of carbohydrates (60-75%), of which 10-13% is dietary fiber. Quinoa also has a slightly higher protein content (12-16%) compared with cereal grains and fat content (5-9%) that is rich in unsaturated fatty acids. Quinoa seeds contain similar or slightly higheramounts of bioactive compounds such as polyphenols (2.7-3.8 g/kg). Moreover, quinoa is gluten-free, thus providing the ability to enhance the selection of gluten-free products forconsumers with celiac disease, but this type of characteristicis challenging to development of bakery products from quinoa with desirable physicochemical properties. Processing of cereal grains and pseudo-cereals into products that deliver a nutritive valueto consumers represents a considerable opportunity for large scale food processing. There havebeen some reported studies on roasting, extrusion, steam pre-conditioning and pearling of quinoafor further uses. Extrusion cooking is a promising technology for improvement of functional properties of quinoa flour. The Evaluation of physicochemical properties and microstructure of Expanded quinoa as affected by extrusion conditions was the main goal of this project. Material and Methods In this study, a parallel twin-screw extruder (Jinan Saxin, China) with die diameter of 3 mm was applied. The effects of extrusion process parameters including feed moisture content (14 and 16%) and die temperature (130, 150 and 170 °C) on final moisture content, bulk density, water absorption index (WAI), color parametersL* (lightness), a*(redness), b*(yellowness), hardness, and microstructure of Expanded quinoa were studied. Extrusion was carried out using a co-rotating twin screw extruder with L/D ratio of 10:1 and die diameter of 4 mm. The feed rate of flour and the screw speed were set at 40 kg/h and 200 rpm, respectively. The physicochemical properties were measured using standard methods. The hardness measurement was performed by a texture analyzer. The cylinder steel probe (2 mm diameter) was set to move at a speed of 1 mm/s The samples were punctured by the probe to a distance of 10 mm . The color parameters of the samples were determined by the Hunterlab machine. The morphology of samples was assessed using a scanning electron microscopy (SEM). Results and Discussion A comprehensive study on impacts of extrusion processing conditions on quinoa flour was conducted. The effect of process variables on the physicochemical attributes of the extrudates was observed. the expanded quinoa with higher feed moisture content had greater moisture and those extruded at higher die temperatures showed lower moisture content (p<0.05). Moisture can reduce the shear force as a plasticizer and increase the amount of moisture absorption of the product. While increasing the die temperature, the effect of shear force on starch dextrification increases and reduces moisture absorption (p<0.05). WAI was significantly influenced by extrusion variables. In fact, feed moisture content and die temperature both positively changed the WAI of quinoa flour so that all extruded samples had significantly higher WAI than the untreated sample (p<0.05). Moreover, the sample with the higher feed moisture content (24%) treated at the highest extrusion temperature (170 °C) showed the largest and lowest water absorption and Hardness respectively (p<0.05). Another important feature of expanded quinoa is the lightness index, the results revealed that extrusion cooking caused a reduction in L* and enhancements in a* and b*. While changes in color parameters were more pronounced at more severe die temperature, higher feed moisture content counteracted the effects of cooking temperature on the color of the products. As expected from changes in the abovementioned color parameters, the sample with lower feed moisture content (16%) treated at the highest extrusion temperature (170 °C) experienced the greatest color change (ΔE). The texture profile analysis (TPA) indicated that higher feed moisture content yielded extrudates with harder texture whereas, extrusion at higher temperature resulted in lower hardness. The scanning electron micrographs showed that the native quinoa flour encompassed both small- and large-sized starch granules while the extruded sample mainly consisted of disaggregated particles. Furthermore, extrusion cooking of samples with higher feed moisture content caused formation of more uniform starch aggregates with smoother surfaces.
Alireza Abbasi; Arash Koocheki; Elnaz Milani; Mohebbat Mohebbi
Abstract
[1]Introduction: Breakfast cereal products are considered as an important meal for athletes and children. By changing eating habits and increasing the consumption of these products, choosing healthy and nutritious raw materials such as whole grains to produce breakfast cereals with great impact ...
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[1]Introduction: Breakfast cereal products are considered as an important meal for athletes and children. By changing eating habits and increasing the consumption of these products, choosing healthy and nutritious raw materials such as whole grains to produce breakfast cereals with great impact on people's health. Rice grain as a technologically important source of starch causes the expansion of extruded products. Since in the production of breakfast cereal and baby food products, exclusively starch with low amylose is used, this indicates the suitability of this source for productionof such products. During the dehusking process, about 14% of the rice is broken to smaller grains, which is commercially classified as a low-value product. The broken rice can be converted to rice flour and used as a raw material in various types of food products. To maintain consumer demand for healthy diets, it is necessary to use high-fiber flours because these types of products will be able to modify the process of decomposition of starch. Although the integration of fiber in products has technological challenges, but by using rice grain as an important source of starch, the technological properties, expansion index, volumetric density and texture (texture hardness and brittleness) can be accepted. At present, modified starch derivatives are widely used in the food industry due to the increase in the quality of the final product. In the production of ready-to-use products for flaking, puffing, a process called extrusion is used. In this process, the product suddenly loses its moisture and leads to the creation of a dense structure containing pores. In this study, the effect of extrusion cooking process parameters on the desired characteristics of flax and rice meal breakfast cereal product with desirable physicochemical and sensory properties was investigated. Materials and Methods: Extrusion: In this study, a parallel twin-screw extruder (Jinan Saxin, China) was applied, die diameter of 3 mm, and extrusion temperature of 140 ℃. Central composite statistical design was used to study the effect of feed moisture (12, 15 and 18%), screw speed (140, 170 and 200 rpm) and Flaxseed oil cake addition (10, 20 and 30%) on technological and functional properties expanded extrudates. The chemical composition of flax meal and rice flour was measured by standard AACC (2000) methods. The expansion ratio was calculated by dividing the mean diameter (mm) by the diameter of the extruder die (4 mm) (Brennan et al, 2008). Textural measurement: The hardness of the extruded breakfast cereals was measured using Texture Analyzer (TA plus Ametek, UK). The cylinder steel probe (2 mm diameter) was set to move at a speed of 1 mm/s The samples were punctured by the probe to a distance of 10 mm. Bowl life hardness: Breakfast cereal samples were immersed in whole milk (3% fat) at 5 ° C for 3 minutes, Then rinsing was performed for 10 seconds and finally the samples were tested similar to the tissue hardness test procedure before immersion by a tissue analyzer (Oliveira et al, 2017). The color parameters L* (lightness), a*(redness), b*(yellowness) values of the samples were determined by the Hunterlab machine (Reston VA, US) (Rhee et al, 2004). Water absorption index in terms of grams of bonded water was calculated. The WSI of the dry solids regained through the evaporation of the supernatant obtained from the water absorption test was calculated (Alam et al, 2019). Sensory evaluation was performed using a 9-point hedonic test. Response surface methodology was applied for experimental data using a commercial statistical package, Design Expert (version 7.0) for the generation of response surface plot and statistical analysis of the experimental data. Results and Discussion: One of the most important parameters in the evaluation of breakfast cereal products is the amount of bowl-life hardness, which in this study, the highest amount was obtained at the level of 30% of flaxseed meal, 18% moisture and the lowest amount of screw rotation speed. After immersing breakfast cereal in milk, by increasing the percentage of flax meal due to the harder flow path, moisture absorption decreases and thus prevents the expansion of the product and increases the density of the mass and the hardness of the tissue. Due to the formation of a layer of lipids and micelles on the surface of the product prevents moisture transfer and absorption, so tissue hardness decreases and bowl-life hardness time increases. In fact, the amount of moisture absorption is a good model that shows the potential of bowl hardness-life of the samples. It is also compact and dense, which increases the retention time of breakfast cereal texture. Moisture can also reduce the shear force as a plasticizer and increase the amount of moisture absorption of the product. While increasing the speed of screw rotation, the effect of shear force on starch dextrinization increases and reduces moisture absorption. Another important feature of breakfast cereals is the lightness index, the highest value of which was obtained at the speed of screw rotation, humidity and low flax meal level. In the study of sensory properties of products produced at meal levels less than 20%, moisture content less than 15% and screw speed of 200 rpm showed the highest overall acceptance.
Elnaz Milani; Fakhri Shahidi; Elham Ansarifar; Mohammad KalilianMovahed; Farideh Salehipour
Abstract
Introduction: Extruded snacks were among the most commercially successful extruded foods. Extrusion cooking is the process extensively used for the production of snacks which are mainly produced from cereal flour or starches. Extruded snacks are normally high in calories and fat with low content ...
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Introduction: Extruded snacks were among the most commercially successful extruded foods. Extrusion cooking is the process extensively used for the production of snacks which are mainly produced from cereal flour or starches. Extruded snacks are normally high in calories and fat with low content of protein, fiber, and perceived as unhealthy food to many consumers. Several attempts to improve the nutritional profile of extruded starch by using food by-products have been reported (Onwulata et al., 2001; Stojceska et al., 2008). Zizyphus jujube (Rhamnaceae) is widely distributed in Iran and the fruit of this plant has gained wide attention in native herbal medicine for the treatment of a broad range of disorders. Chemical analysis of the fruit has shown the presence of antioxidants. The high consumption of low-value meals and malnutrition among the population, especially children and adolescents, is one of the problems that exists today in society, Therefore, in this research, production of high-nutritional snack with jujube flour was studied. Materials and methods: Extrusion: In this study, a parallel twin-screw extruder (SAIXIN, model DS56, China) was applied, screw diameter of 15 mm, die diameter of 3 mm, and extrusion temperature of 180°C. Central composite statistical design was used to study the effect of feed moisture (12, 16, 18%), jujube flour addition (5, 10, 15%) and screw speed (120, 150, 180 rpm) on physicochemical properties, texture and color of expanded extrudates based on corn-wheat flour (50-50%). Bulk density was calculated using AACC (2000). The WSI of the dry solids regained through the evaporation of the supernatant obtained from the water absorption test was calculated. Textural measurement: The hardness of the extruded snacks was measured using Texture Analyzer (TAXT plus, England). The cylinder steel probe (2 mm diameter) was set to move at a speed of 1 mm/s. The samples were punctured by the probe to a distance of 8 mm. the color of samples was measured using an image processing technique (Lotfi Shirazi et al., 2020). The color parameters L* (lightness), a*(redness), b*(yellowness) values of the samples were obtained. Response surface methodology was applied for experimental data using a commercial statistical package, Design Expert (version 8.0) for the generation of response surface plot and statistical analysis of the experimental data. The second-order polynomial model was selected to predict the optimal point of the responses. Results & Discussion: Results showed that the addition of jujube flour independently increased the density 0.33, hardness 35.73 N, solubility 42% and redness (a*) 3.41, and reduced the color brightness parameter (L*) 89.1 of the samples. Similar fiber effects for pineapple pulp (Salani et al., 2014), a mixture of barley flour and grape pulp (Altan et al., 2009) and beet fiber (Lue et al., 1994) has been observed. The reduction of bulk density in samples with increasing screw speed is probably due to the starch gelatinization. When gelatinization of the starch material increased, the volume of extruded product also increased giving low density to the samples (Hagenimana et al., 2006). The WSI is a parameter which indicates the degradation of starch granules (Sharma et al., 2015). WSI decreased with increasing feed moisture and increased with increasing jujube flour or screw speed. Increase in solubility of extruded products under mild extrusion condition could result from dispersion of amylose and amylopectin molecules during gelatinization; while, the formation of low molecular weight compounds under severe conditions (low moisture and high temperature) is the main reason for an increase in flour solubility (Colonna et al., 1984). Color changing during extrusion process can provide important information regarding the degree of browning and Maillard reaction, and also pigment degradation. Increasing the feed moisture increased flour L* while it decreased the a* and ∆E of the final product. This is probably due to the decrease in mass residence time inside the extruder which causes shorter residence time necessary for non-enzymatic darkening (Lazou and Krokida, 2011). Texture is one of the most important sensory properties of extruded products in the development of snack products. Increasing the feed moisture and jujube flour increased hardness of samples. This can be explained by the effect of fiber on cell wall thickness. However, the simultaneous effect of two parameters of screw speed and jujube flour improved the properties of the snacks, by which the increase of the screw speed may cause a decrease of the starch viscosity and then lead to extrudates with reduced hardness 1.79 N. Optimum conditions for puffed snack production was found to be 13.19% feed moisture content, 6.30 % jujube flour, 122.2% screw speed.
Nasim Hasanpoor; Mohebbat Mohebbi; Arash Koocheki; Elnaz Milani
Abstract
Introduction: Nowadays, frozen dough technology is used to produce bakery, pastry & cakes products. On the other hand, extrusion plays a role as a high-performance process in the food industry, which, given its unique characteristics, can replace many common methods of food processing. This study was ...
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Introduction: Nowadays, frozen dough technology is used to produce bakery, pastry & cakes products. On the other hand, extrusion plays a role as a high-performance process in the food industry, which, given its unique characteristics, can replace many common methods of food processing. This study was carried out aimed to investigate the effect of freezing methods (slow and rapid) and the storage time of frozen dough under freezing conditions on physicochemical and sensory properties of extruded and non-extruded sorghum flour for producing a gluten-free product suitable for Coeliac patients.
Materials and methods: In this study, extruded sorghum flour (an extruder with a temperature of 150-160°C, a moisture content of 14%, a speed of 150 rpm, feeding of 40 grams per minute and circular matrix with a diameter of 5 mm and, in the last step, using a grinding mill and 0.599 mm mesh, flouring is done), non-extruded sorghum flour (100%), Xanthan gum (1% w/w) were used in cookie dough formulation. Two types of slow and fast freezing were used to freeze the dough of cookie. Slow freezing according to the method provided by X.u et al. (2009) and Ke et al. (2013). In a fast freezing method, rapid cooling rooms were used at -40°C for 30 minutes. After freezing, the samples were placed in polyethylene bags and stored for 0, 2, 4, 6 and 8 weeks in a refrigerator at -18°C (X.u et al., 2009). For the thaw process, dough pieces were placed in a refrigerator at + 4°C for 16 hours (Maizani et al., 2012). Baking was performed in a microwave oven at 180°C for 14 minutes. The properties of the final product, such as the ratio of expandability (AACC 10-52), textural properties (cookie texture were carried out using a TA.XTplus Texture Analyzer (Walker et al, 2012)), total gelatinization and enthalpy temperature(Using the DSC device and temperature range 7-157°C and heating temperature 10°C/min), color, percentage of porosity, shell thickness (Image processing technique and ImageJ software) and sensory evaluation were investigated in a completely randomized factorial. Statistical analysis of the results was done using a factorial arrangement of completely randomized design and comparison of the meanings using Duncan's multiple range tests at 5% level. Data analysis was performed with three replications using SPSS 18 software.
Results & discussion: The gelatinization temperature decreased with increasing times of storage; however, the total enthalpy of the process was increased. The results showed that with increasing freezing rate, the gelatinization temperature increased significantly (P≤0.05), and the total enthalpy of the process decreased and the cookie from frozen dough containing extruded sorghum flour has the highest gelatinization temperature and the minimum total enthalpy value. With increasing times of storage, the dough chewiness decreased significantly (P≤0.05) and the adhesion and stiffness of the dough texture increased. The dough chewiness increased with the increase in the freezing rate, however, the adhesion and stiffness of the dough texture decreased and cookie dough containing extruded sorghum flour resulted in a significantly higher chewiness and lower adhesion and stiffness (P≤0.05) of the texture compared to the non-extruded sorghum cookie flour in both methods of freezing. The extensibility ratio has significantly decreased (P≤0.05) with increasing the times of storage. The extensibility ratio of cookie was significantly increased with the increase in freezing rate (P≤0.05) and non-extruded sorghum flour samples showed a lower extensibility ratio relative to the extruded sorghum flour cookies. The dough freezing method also had a significant effect on the final cookie quality (P≤0.05). The stiffness of the cookie texture from the frozen dough decreased by increasing the dough freezing rate and its tissue was softer and cookie samples containing extruded sorghum flour have a significantly lower tissue stiffness compared to other samples. The stiffness of the cookie tissue increased significantly (P≤0.05) with increasing times of storage. L* parameter (lightness) significantly decreased (P≤0.05) with increasing the times of storage and decreased the yellowness factor (b*) and increased the redness factor (a*) significantly (P≤0.05) for the cookie made from frozen dough. The freezing rate had a significant effect (P≤0.05) on the lightness of the cookies. The parameters L* and b* decreased by increasing the freezing rate and the colors of these cookies were darker. Cookies containing extruded sorghum flour had the lowest level of L* and b* and highest level of a*. The porosity% and thickness of crust of cookie decreased significantly (P≤0.05) with increasing times of storage. These parameters increased significantly with increasing freezing rate (P≤0.05) and tissue porosity and thickness of crust of cookies obtained from the frozen dough containing extruded sorghum flour was significantly higher (P≤0.05). The results of the kinetics of cookie mass transfer from frozen dough showed that the effective moisture diffusivity of cookie was reduced by increasing times of storage. Overall, the results showed that the process of extruding sorghum flour has improved the physicochemical properties of the cookie, and the fast freezing process improves the quality of the cookie made from frozen dough, and in this condition extruded flour sorghum can be used as a suitable alternative to wheat. Also, the use of frozen dough for cookie production can be a good way to supply this product.
Sorour Lotfi Shirazi; Arash Koocheki; Elnaz Milani; Mohebbat Mohebbi
Abstract
Introduction: Snack foods have become an important part of the people’s diets. During last decade demands for utilization of fruit and vegetable waste in order to their dietary fibers in value added food products has been increased. Carrot pomace is rich in dietary fiber that contains important functional ...
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Introduction: Snack foods have become an important part of the people’s diets. During last decade demands for utilization of fruit and vegetable waste in order to their dietary fibers in value added food products has been increased. Carrot pomace is rich in dietary fiber that contains important functional and nutritional properties. Barley contains a high amount of dietary fiber, especially soluble fiber, which has essential role in reducing blood cholesterol level.
Materials and methods: In this project based on Central Composite Design, the effect of independent variables containing extrusion temperature (120-170 °C), moisture content (14-20%) and carrot pomace level (10-25%) were evaluated on expansion ratio, bulk density, WAI, WSI, hardness, color snacks were evaluated by panelists in terms of acceptance or non-acceptance.
Results and discussion: Results expressed that expansion ratio, lightness, total acceptability and WAI decreased by increasing the amount of carrot pomace. Reduction of expansion ratio and WSI and improvement of lightness and WAI were shown as increased in moisture levels. The hardness and bulk density decreased with an increase in temperature. When temperature increased up to 145°C, expansion ratio, lightness, WAI and WSI increased and decreased thereafter. The optimum conditions for barley flour-carrot pomace snack were determined at the maximum expansion ratio, L*, WAI and overall acceptability with minimum bulk density and hardness in a snack. The optimum condition provides the highest value of expansion ratio 296.1 (%), L* 65.087, WAI 4.931 (g/g) and overall acceptability 4.502 with lowest bulk density 1.22 (g/cm3) and hardness 6.756 (N). Accordingly, the optimum conditions for the snack are 10% carrot pomace, 148°C die temperature and 15.49% moisture. The approximate composition of the snack extruded and unextruded obtained under the optimal conditions. Extrusion did not affect the protein and ash contents but it decreased the fat content of snack. During the extrusion, the SDF increased from 7.63 to 9.27 g/100g while the IDF decreased from 5.24 to 3.71 g/100g. Extrusion cooking did not affect the TBG content in barley flour-carrot pomace snack. Extrusion cooking resulted in the conversion of insoluble to soluble fiber and well balance of both types of the fiber
Mohammad Farhadi Chitgar; Mehran Alami; Elnaz Milani; Yahya Maghsoudlou
Abstract
Introduction: Barberry (Berberis vulgaris) from the distant past has been used as one of the main medicinal plants in Iran and many other countries. Currently, it has been known for pharmaceutical active compounds such as berberine, which has wide application in pharmaceutical industry. Barberry fruits ...
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Introduction: Barberry (Berberis vulgaris) from the distant past has been used as one of the main medicinal plants in Iran and many other countries. Currently, it has been known for pharmaceutical active compounds such as berberine, which has wide application in pharmaceutical industry. Barberry fruits are used in preparing sauces, jellies, candies, marmalades and especially fruit juices. Also, the fruit contains health promoting compounds such as polyphenols and anthocyanins. Anthocyanins are bioactive compounds present in many fruits, vegetables and their products. They are responsible for the wide array of colors present in flowers, petals, leaves, fruits and vegetables and are a sub-group within the flavanoids characterized by a C6-C3-C6 skeleton. A substantial property of anthocyanin is their antioxidant activity, which plays an important role in prevention of neuronal and cardiovascular illnesses, cancer and diabetes, among others. Therefore, preservation of these compounds during processing of barberry juice is very important. Conventional thermal pasteurization is the common preservation technique used for fruit juice processing. Although this method inactivates microorganisms and enzymes causing spoilage and extends the shelf life of juices, but also it causes degradation of anthocyanins and loss of the nutritional quality of these products. Moreover, the increasing demand for natural and fresh fruit juice resulted in the development of various non-thermal technologies, such as radiation processing, osmotic dehydration, pulse electric field, sonication and high pressure. Power ultrasound has shown important advances in food processing and has a potential to meet the FDA requirement of a 5 log reduction in pertinent microorganisms found in fruit juice. Physical (cavitation, micromechanical shocks and mechanical effects) and chemical (formation of free radicals) mechanisms are responsible for the biocidal effect of sonication. Other advantages of this technology include low cost, reduced processing time and environmentally friendly technique. However, ultrasound by itself is not very effective for microbial inactivation and the use of other technologies during sonication such as temperature (thermo-sonication) and pressure (mano-sonication) has shown efficient results in inactivation of microorganisms. Thermosonication has been reported as an alternative to thermal pasteurization for processing of fruit juices such as strawberry juice, blackberry juice and orange juice. According to the negative effect of thermal processing on color and anthocyanins of barberry juice this study aimed to evaluate the effect of thermo-sonication as an emerging technology in two intensities 18.32 and 27.62 W/cm2 at 45°C for 5 and 10 minutes on the quality of barberry juice.
Material and methods: Barberry (B. vulgaris) ripe fresh fruits were collected from gardens of Qaen. Fruits were crushed into pieces in an electric blender. The mixture was then filtered through a nylon filter and kept in dark condition at 4°C before subjecting to thermosonication. Barberry juice was sonicated at 200W capacity batch sonication system (Sonopuls HD 3200 BANDELIN, Germany) and a constant frequency of 20 kHz with a 13mm probe. Barberry juice samples of 60 mL were placed in a 100 mL double wall cylindrical vessel pyrex glass through which water at 4±1°C and a flow rate of 0.5 L/min was circulated to attain a constant temperature in the juice sample during sonication. The samples were sonicated at 70 and 100% amplitudes levels for 10 and 15 min at 45°C with pulse durations of 15s on and 5s off (US70-5, US70-10, US100-5 and US100-10). After the sonication treatment, juice samples were kept in sterilized bottles and were stored at 4°C until further analysis. Total anthocyanin content of barberry juice was determined by the pH differential method and the color of juice samples was determined using a Chroma Meter (Color Flux, USA). The color values were expressed as L* (lightness), a* (redness/greenness) and b* (yellowness/blueness). The total phenolic content and antioxidant activity was determined by modified Folin–Ciocalteu method and DPPH radical scavenging activity. The counting of microorganisms was made using standard techniques (AOAC 1984), and included total plate counts and yeasts and molds. All experiments were carried out in at least three replicates and the results were expressed as mean ± SD. The significant differences between mean values of juice samples were determined by analysis of variance (one way-ANOVA) using Dunkan’s test at a significance level of P< 0.05. Data evaluation was performed using the SPSS software version16.
Results and discussion: The result showed that the processing in all treatments completely inactivated the microbial population. The reduction of total plate counts and yeast and mold counts after processing was equal to 3.68±0.1 and 3.34±0.48, respectively. Thermo-sonication, especially in low intensity (32/18 w/cm2) had little effect on total anthocyanin compounds of barberry juice. The losses in total anthocyanin content of juice samples were 0.03%, 1.14%, 1.56% and 10.79% in TS-70-5, TS-70-10, TS-100-5 and TS-100-10, respectively. Hydroxyl radicals produced by cavitation can be involved in the degradation of anthocyanins by opening of rings and formation of chalcone. Thermosonication had significant effect on color parameters of barberry juice. All the color values (L*, a*, b* and C*) of barberry juice treated with thermosonication treatment were decreased as compared to control. The color loss of barberry juice samples decreased with increasing the amplitude and time of thermosonication. Extreme physical conditions which occur within the bubbles during cavitational collapse at micro-scale reaction may be responsible for the degradation of color in fruit juices. A significant increase (p˂0.05) in both total phenolic content and antioxidant activity of samples treated at TS-70-5 and TS-70-10 was observed. However, higher amplitude significantly decreased the total phenolic content and antioxidant activity of barberry juice. It has been shown the enhancement of total phenolic content in juices after sonication might be attributed to the facilitation the release of bound phenolic present in the suspended particles. Since there is a correlation between total phenolic content and antioxidant activity, the extraction of bound polyphenols due to cavitation can be presumed the increase in antioxidant activity. The result of this study showed that thermo-sonication could be used as an alternative to thermal treatment.
Ali Shahdadi Sardoo; Nasser Sedaghat; Masoud Taghizadeh; Elnaz Milani
Abstract
Introduction: In Iran, the main problem in greenhouse cucumber production and post-harvest shelf life is short due to the application of traditional packaging and storage methods. This research was carried out in order to investigate on the effects of packaging type and chitosan edible coating on the ...
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Introduction: In Iran, the main problem in greenhouse cucumber production and post-harvest shelf life is short due to the application of traditional packaging and storage methods. This research was carried out in order to investigate on the effects of packaging type and chitosan edible coating on the physicochemical and sensory characteristics of Royal Greenhouse cucumber during storage conditions, in order to prevent of Royal greenhouse cucumber postharvest losses.
Materials and methods: Royal greenhouse cucumbers placed inside the three-layer plastic bags of PE/PA/PE and the effect of different chitosan coating (0, 0.5 & 1 %), concentration of oxygen (3,12 & 21%), storage temperatures (5, 15 & 25 ˚C) and storage time (3, 12 & 21 days) on cucumber quality and shelf life was studied. The quality of cucumber samples was evaluated by weight loss, firmness retention, surface color development (L*, a*, b*), shrinkage and sensory evaluation (taste and freshness).
Results and discussion: The obtained results showed that firmness and organoleptic properties decreased with increasing temperature and time storage, while weight loss and shrinkage was increased, that Leading to loss of cucumber samples quality during storage. Increasing of chitosan coating to 0.5% also showed a beneficial effect on physicochemical and sensory characteristics of the samples during the storage time compared to the control fruit, but by increasing it to 1%, decreased the quality of the final product. The results showed that using modified atmosphere packaging and storage at low temperatures can be in addition to the slow breathing fresh cucumbers from softening and prevent moisture loss the maintenance of cucumber. MAP packaging leads to keeping cucumber green and quality properties compared to the control samples. The optimum condition was obtained at chitosan coating 0.5 %, O2concentration 8.5 %, storage temperatures 9˚C and storage time of 14 days. At this optimum point maximum of firmness, L*, taste, freshness and minimum of shrinkage, weight loss and a* were found to be 10.4 (N), 48.9, 4.35, 4.5, 6.25 %, 2.75 % and -37.28 respectively.
Seyed Ali Mortazavi; Elnaz Milani; Marzieh Moeenfard
Abstract
Kurdish cheese is semi-firm cheese which has been traditionally manufactured from whole raw cow or sheep milk, in the East of Iran. It is ripened in goat’s skin bags. The microbial diversity of kordish cheese originates from natural microbiota present in the raw milk and its unique organoleptic ...
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Kurdish cheese is semi-firm cheese which has been traditionally manufactured from whole raw cow or sheep milk, in the East of Iran. It is ripened in goat’s skin bags. The microbial diversity of kordish cheese originates from natural microbiota present in the raw milk and its unique organoleptic properties have made it excellent among other traditional cheeses in Iran. This study has been conducted to evaluate microbiological diversity during ripening of Kurdish cheese. Samples were taken from 6 batches of cheese on day 1, 20, 40 and 60. Sensory properties of Kurdish cheeses were determined at 60,120 and 180 days of ripening. Based on results, the diversity and microorganisms count of were mainly influenced by ripening time. Lactic acid bacteria and Enterobacteriaceae were the predominant families of micro-organisms during the first 20 days of ripening and lactobacilli was the most abundant lactic acid bacteria in cheese. Coliforms and E.coli decreased more rapidly in cheese, whereas mows and yeasts decreased gradually and then increased in ending days. At the end of ripening period, mo coliforms, salmonella and coagulase positive staphylococcus were detected in the samples. Changes in textural and chemical characteristics in relation to ripening time showed that; pH, Moisture, Total solid, aw and fat content of samples decreased during 40d and reached to 4.69, 33.9, 64.07, 0.927, 28.1 at 60 days respectively. no significant variations observed in Protein values during ripening period. The values for sensory characteristics such as taste, aroma, colour and total acceptance of the full-ripened cheeses (120th days) increased as ripening progressed. According to our results, from a safety point of view, the optimum time for consuming Kurish cheese would be after passing ripening time of 60 days (during 1-2 months) due to decrease in pH, undesirable flora and increase in desirable LAB counts.
Elnaz Milani; Fakhri Shahidi; Seyed Ali Mortazavi; Seyed Alireza Vakili
Abstract
Traditional raw milk cheese is one of the most consuming cheeses in the world. Kurdish cheese is a semi-firm, traditionally made in the East of Iran. It is manufactured from raw sheep or cow milk and kept in goat’s skin bags during ripening period. As a result Kurdish cheese is often more complex ...
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Traditional raw milk cheese is one of the most consuming cheeses in the world. Kurdish cheese is a semi-firm, traditionally made in the East of Iran. It is manufactured from raw sheep or cow milk and kept in goat’s skin bags during ripening period. As a result Kurdish cheese is often more complex in different varieties of microorganisms, which whose organoleptic properties make it highly esteemed. Changes in free fatty acid (FFA) and free amino acids (FAA), could have great importance in Kurdish cheese final Characteristics. In this project, Changes in FFA and FAA contents of Iranian Kurdish cheese, in local condition, during 10, 30, 50 and 70 days of ripening periods were evaluated. Most FFA significantly increased throughout maturation (P
Abbas Ahmadi; Seyed Ali Mortazavi; Elnaz Milani; Reza Rezaeemokaram
Abstract
In this study, frozen yoghurt was produced as a synbiotic product. A food product containing both probiotics and prebiotics is named as synbiotic or functional food. Lactobacillus acidophilus (La-5) as a probiotic bacteria was added to frozen yoghurt in two types; free and encapsulated, and its survivability ...
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In this study, frozen yoghurt was produced as a synbiotic product. A food product containing both probiotics and prebiotics is named as synbiotic or functional food. Lactobacillus acidophilus (La-5) as a probiotic bacteria was added to frozen yoghurt in two types; free and encapsulated, and its survivability was evaluated during 60 days storage at -18 °C . Also Fructo-oligosaccharide as a prebiotic compound was used for producing frozen yoghurt in different levels (0%, 0.4% and 0.8% (w/w)). The viable cell number in free state in samples with (0%, 0.4% and 0.8% (w/w)) Fructo-oligosaccharide was 3.8×109 cfu/ml, 3.5×109 cfu/ml and 3.8×109 cfu/ml and after 60 days of storage these numbers were decrease to 2×107 cfu/ml, 2.2×107 cfu/ml and 2.2×107 cfu/ml respectively. Whereas in encapsulated state, the viable cells in samples with (0%, 0.4% and 0.8% (w/w)) Fructo-oligosaccharide these numbers was 7.5×109 cfu/ml, 8.9×109 cfu/ml and 9.8×109 cfu/ml and after 60 days, these numbers were decreased to 2.13×109 cfu/ml, 2.5×109 cfu/ml and 2.9×109 cfu/ml.The results indicated that encapsulation of L. acidophilus could significantly (p
Elnaz Milani; Hajar Naeemi; Seyed Ali Mortazavi; Arash Koocheki
Abstract
In this study, symbiotic yog-ice (rozen yogurt) was produced that was inoculated with different levels of inulin(0,2.5 amd 5%)as prebiotic compound and Lactobacillus Casei as probiotic bacteria in two types; free and encapsulated with Sodium Algint-Whey Protein Concentration for low fat yog-ice cream.The ...
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In this study, symbiotic yog-ice (rozen yogurt) was produced that was inoculated with different levels of inulin(0,2.5 amd 5%)as prebiotic compound and Lactobacillus Casei as probiotic bacteria in two types; free and encapsulated with Sodium Algint-Whey Protein Concentration for low fat yog-ice cream.The survivability of this probiotic bacteria was evaluated under simulated gastro-intestinal conditions ,during 30 days storage at -18oC. In the samples with free state of probiotic bacteria, the number of viable cells ,after 1h exposuring simulated gastric juice(pH=2,pepcine) decreased from 9.78-9.81 log cfu/ml to 6.97-7.26 log cfu/ml,at the end of 30 days storage at -18oC,while, the viable number of encapsulated state of probiotic bacteria, after 1h exposuring simulated gastric juice, decreased from 8.15-8.66 log cfu/ml to 6.80-7.09 log cfu/ml at the end of 30 days storage at -18oc.After exposuring simulated gastric juice, samples was ezposured 2.5h under simulated intestinal juice(pH=7.4,panceratin), and the results that was gained showed that, the samples containing free probiotic bacteria after 2.5h exposuring simulated intestinal juice decreased from 8.808-9.355 log cfu/ml to 5.159-5.9 log cfu/ml at the end of 30 days storage at -18oC.While, in the samples containing sodium alginate-whey protein concentration capsules, the viable number of cells decreased from 7.38-8.201 log cfu/ml to 6.151-6.672 log cfu/ml, at the end of 30 days storage at -18oC. The results indicate that there are significant differences (p
Elnaz Milani; Homa Baghaei; Seyed Ali Mortazavi
Abstract
Yog-ice cream (Frozen yogurt), is a kind of frozen dessert which has similar features to ice cream in physical and appearance characteristics. Recently, there has been a growing interest in using frozen yogurt due to existence of lactic acid bacteria & fermentation processing. Besides, yog-ice cream ...
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Yog-ice cream (Frozen yogurt), is a kind of frozen dessert which has similar features to ice cream in physical and appearance characteristics. Recently, there has been a growing interest in using frozen yogurt due to existence of lactic acid bacteria & fermentation processing. Besides, yog-ice cream contains lower levels of sugar, fat & emulsifiers than ice cream. This Research was conducted to examine the effect of date syrup with different concentrations (0, 25 and 50% as a sugar replacement) & guar gum addition (0, 0.1, 0.2 & 0.3% as a fat replacer) on rheological properties of low fat orange yog-ice cream. The results showed that by increasing the date syrup and guar concentration, the viscosity of mixture increased but overrun decreased significantly in all samples (p< 0.05). Results for stickiness of the yog-ice cream samples indicated that the low fat yog-ice cream was considerably less adhesive/sticky than both low fat product containing guar and date syrup. Hardness of low fat yog-ice cream samples was observed to be considerably higher than the samples with guar and date syrup, whilst the addition of guar and date syrup up to 0.3% & 25%, decreased the hardness of the low fat product.
Keywords: Low-fat yog-ice cream, Guar, Dates syrup, Rheological properties
Arash Koocheki; Fakhri Shahidi; Seyed Ali Mortazavi; Mahdi Karimi; Elnaz Milani
Abstract
The effect of xanthan and Qodume shirazi seed gum on fresh bread quality and its influence on dough rheology were studied. Incorporation of 0.3 to 1% of these two gums was investigated to evaluate its effect on the Mixing tolerance index (MTI), dough development time (DDT), gelatinization temperature ...
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The effect of xanthan and Qodume shirazi seed gum on fresh bread quality and its influence on dough rheology were studied. Incorporation of 0.3 to 1% of these two gums was investigated to evaluate its effect on the Mixing tolerance index (MTI), dough development time (DDT), gelatinization temperature (GT), viscosity, dough stability and quality of wheat flour. Addition of xanthan and Qodume shirazi seed gum increased the water absorption, viscosity and dough stability. In contrast, MTI and GT decreased with increase in gum concentration. DDT remained statistically unaffected by all the levels of gum. There was increase in softness of bread with increase in the level of these gums up to 1%. Hardness values indicated that the breads containing xanthan gum was softer than the one with Qodume shirazi seed gum. However, Qodume shirazi seed gum could also improve these qualities so that it could be used as a new source of hydrocolloid in bread.
Keywords: Bread, Gum, Alyssum homolocarpum seeds, Rheology, Hardness
Elnaz Milani; Hashem Pourazerang; Shahrzad Vatankhah; Haneh Vakilian
Abstract
Inulin is widely used in functional foods throughout the world for its health-promoting and technological properties. Helianthus tuberosus is cultivated widely in the northern part of Iran. Helianthus tuberosus can be a valuable source of Inulin. To optimize conventional extraction of Inulin, various ...
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Inulin is widely used in functional foods throughout the world for its health-promoting and technological properties. Helianthus tuberosus is cultivated widely in the northern part of Iran. Helianthus tuberosus can be a valuable source of Inulin. To optimize conventional extraction of Inulin, various combinations of time, temperature, and solvent: solid ratio, were used. In this research, a series of statistically designed studies were performed to investigate the effect of each of the independent variables (temperature and pH of extraction medium, extraction time, and solvent: solid ratio). The following variables: solvent: solid ratio (5-12 v/w), temperature (40-90°C) and time (5-40 min) were studied. The central composite design (CCD) and response surface methodology (RSM) were employed as experimental design and statistical analysis. Based on canonical analysis, the optimal conditions for maximizing Inulin extraction yield (42.2%) were 76.64°C for 23.90 min and solvent: solid ratios of 12:1 (v/w).
Keywords: Inulin, Extraction, Helianthus tuberosus, Response surface methodology
Elnaz Milani; Hashem Pourazerang; Rassoul Kadkhodaee; Haneh Vakilian; Shahrzad Vatankhah
Abstract
Inulin is widely distributed throughout the plant kingdom. It has been increasingly used in various foods due to its beneficial nutritional attributes as prebiotic ingredient. The Helianthus tuberosus could be a source of inulin, but scarce studies about its extraction exist. Ultrasound has attracted ...
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Inulin is widely distributed throughout the plant kingdom. It has been increasingly used in various foods due to its beneficial nutritional attributes as prebiotic ingredient. The Helianthus tuberosus could be a source of inulin, but scarce studies about its extraction exist. Ultrasound has attracted considerable interest in food science and technology due to its promising effects in food processing and preservation. The use of power ultrasound significantly improves the extraction of organic compounds contained within the body of plants and seeds. The mechanical effects of ultrasound provide a greater penetration of solvent into cellular materials and improve mass transfer. In some cases sonication increased the efficiency of extraction at lower temperatures producing a purer product in a shorter time. It seems that the application of ultrasound would be a promising method to enhance the extraction process. The objective of this study was to develop a set of optimum extraction conditions for Helianthus tuberosus with an aim towards improving inulin extraction yield. Experiment design employed central composite design (CCD) and response surface methodology (RSM). Determination of inulin content was measured with the difference between total carbohydrate and reducing sugars. Then, Inulin extraction yield (%) was calculated too. Based on canonical analysis, the optimal conditions for maximizing inulin extraction yield (91.26%) were at 45.95 °C for 31.44 min and amplitude of 100%.
Keywords: Inulin, Extraction, Helianthus Tuberosus, Ultrasonic technique
Seyed Hashem Hosseiniparvar; Javad Keramat; Mehdi Kadivar; Elham Khanipour; Elnaz Milani
Abstract
Gelatin is a protein hydrocolloid. Because of its unique characteristics such as gel forming, thickening, stabilizing, emulsifiing, foam and film forming, is widely used in food industries. In this research, in order to optimize the factors which affect enzymatic extraction method of gelatin ,the effects ...
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Gelatin is a protein hydrocolloid. Because of its unique characteristics such as gel forming, thickening, stabilizing, emulsifiing, foam and film forming, is widely used in food industries. In this research, in order to optimize the factors which affect enzymatic extraction method of gelatin ,the effects of three variables, enzyme concentrations(2-10 ppm), time(8-16 hours) and temperature(60-80 ˚C) on the yield of extraction, gel strength, viscosity and absorption in 420 nm were investigated. The rotatable central composite experimental design was used, and the data were analyzed by using of response surface regression(RSREG).Correlation coefficients of fitted regression models of yield, gel strength, viscosity and absorption for enzyme extraction method were determined as 0.953 , 0.998 , 0.995 and 0.935 , respectively.Analysis of variance for the overall effects of process variables in enzymatic extraction method on regression models showed that the enzyme concentration, the time of enzyme treatments and temperature had significant effects on gel strength and viscosity regression models, however the effect of temperature on both yield and absorption regression models was not significant(p > 0.05).The optimum conditions obtained from response surface regression models in enzymatic extraction method for yield, gel strength, viscosity and absorption which were verified experimentalls were (6.1 ppm, 15.6 hours, 70 ˚C), (9.1 ppm, 11.9 hours, 70.3 ˚C), (7.86 ppm, 14.9 hours, 77.5 ˚C) and (2.8 ppm, 10 hours, 60 ˚C), respectively.
Key words: gelatin, enzymatic extraction, response surface optimization
