Food Technology
Maryam Davtalab; Sara Naji-Tabasi; Mostafa Shahidi
Abstract
IntroductionRice is a strategic product and considered as staple food of over half of the world's population particularly in Iran. Considering the high levels of rice waste, including broken grains or those of lower quality, it can be utilized for producing value-added foods and reducing waste. Extrusion ...
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IntroductionRice is a strategic product and considered as staple food of over half of the world's population particularly in Iran. Considering the high levels of rice waste, including broken grains or those of lower quality, it can be utilized for producing value-added foods and reducing waste. Extrusion is a process widely used to improve food products and develop fortified foods. Quinoa flour is rich in phenols, and can be utilized to produce fortified extruded rice. The extrusion of gluten free flours like rice and quinoa has different challenges. In this study, sodium alginate was used to prepare emulsion filled gel to enhance the stability of Pickering emulsions containing β-carotene and also structuring rice during extrusion process. Pickering emulsion is one of the encapsulation methods suitable for encapsulating lipophilic compounds like β-carotene. Emulsion-filled gels, developed using hydrocolloid mixtures, significantly enhance emulsion stability and make them suitable for aqueous food environments. Finally, extruded rice based on a mixture of rice- quinoa flours and fortified with beta-carotene was prepared, and its physico-mechanical properties were evaluated.Materials and MethodsPickering emulsions were stabilized using whey protein- cress gum soluble complex nanoparticles. Beta-carotene was dissolved in the oil phase at a concentration of 0.1%. Subsequently, 4% (w/v) sodium alginate was used to develop emulsions filled-gel.The Pickering emulsion was dispersed in the sodium alginate gel at a ratio of 15:85. Extruded rice was then prepared using an equal ratio (50:50) of broken rice flour and quinoa flour via a cold extruder. To evaluate the impact of the gel-filled emulsion on improving the characteristics of rice grains, different concentrations (30%, 35%, and 40% w/w) of the gel-filled emulsion (based on flour weight) were added to the mixture. The physico-mechanical tests (moisture content, ash content, optimum cooking time, water absorption ratio, cooking loss, lateral expansion, textural characteristics of rice, color properties, sensory analysis, structural morphology, Beta-carotene stability) were conducted. Duncan test was utilized to identify statistically significant differences (p<0.05) among the means, while one-way analysis of variance (ANOVA) was employed to investigate the impact of various factors. Results and DiscussionThe incorporation of emulsions filled-gel into quinoa-rice blend significantly influenced the physico-mechanical properties of extruded rice. As the concentration of emulsions filled-gel increased from 30% to 40% (w/w), there was a significant increase in moisture content, ash content, expansion ratio, and cooking time. Extruded rice samples with emulsion-filled gel exhibited significantly greater β-carotene stability than those without, both after cooking and during storage. Conversely, adhesiveness decreased while hardness increased with increasing emulsion filled-gel concentrations. The control sample exhibiting the highest adhesiveness and lowest hardness. The lightness of the extrudates was also improved with increasing emulsion filled-gel levels, reaching a maximum at 40% (w/w). Sensory evaluation revealed that the 40% emulsion filled-gel level was the most preferred sample by panelists. The optimized extruded rice closely resembled natural Hashemi rice in terms of sensory and textural properties.ConclusionThe findings of this study demonstrate that the addition of emulsions filled-gel enriched with beta-carotene can effectively enhance the physico-mechanical properties of extruded quinoa-rice blends. Specifically, increasing the emulsion concentration resulted in improving expansion, textural, and appearance properties of the rice. 40% emulsion filled-gel was found to be optimal, resulting in a product with desirable sensory attributes. This research proposes that extruded rice based on mixed rice-quinoa flours enriched with beta-carotene-loaded emulsion-filled gel can provide a nutritious and appealing alternative to broken rice products, leveraging the nutritional benefits of quinoa. Sensory and textural evaluation revealed that the extruded rice exhibited sensory properties highly similar to natural Hashemi rice, coupled with favorable cooking characteristics. Consequently, it can be introduced as a suitable substitute for natural rice.
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.
