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.
Elham Azarpazhooh; Parvin Sharayei; Farzad Gheibi
Abstract
Introduction: The current study was carried out to investigate the kinetics of infusion of phenolic compounds extracted from grape pomace (Argol) into Aloe vera gel cylinders. Aloe vera gel was treated at 50 °C in different osmotic solution with (40, 50 and 60) % sucrose plus (10, 20 and 30) % Argol, ...
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Introduction: The current study was carried out to investigate the kinetics of infusion of phenolic compounds extracted from grape pomace (Argol) into Aloe vera gel cylinders. Aloe vera gel was treated at 50 °C in different osmotic solution with (40, 50 and 60) % sucrose plus (10, 20 and 30) % Argol, for 0–120 min. The fruit to solution ratio was kept 1:4 (w/w) during all experiments. A two parameters model was used for prediction of kinetics of mass transfer and values of equilibrium moisture loss and solid gain. Moisture and solid effective diffusivities were estimated using Fick’s second law of diffusion. Results showed that Azuara model has the potential for estimating the equilibrium points. In addition, a good correlation between predicted and experimental values were obtained by this model. Besides, moisture and solid effective diffusivities increased by increasing sucrose solution and Argol from 40 to 50 percentage and 10 to 20 percentages, respectively. Moisture and solid diffusivities were found in the range of 0.61–4.23×10−9 m2/s and 2.13 –2.77 × 10−9 m2/s, respectively. Functional food is an emerging field in food science due to its increasing popularity with health-conscious consumers and the ability of marketers to create new interest in existing products. New by-product application should be investigated to have a positive environmental impact or to turn them into useful products. The use of by-product such as the grape juice pomace (Argol), results in the return of these valuable sources into the food cycle as well as an improvement in nutritional value and functional products in the food industry. Red grape (Vitis vinifera L.) pomace contains a large amount of polyphenolic compounds, therefore extraction of bioactive compounds promote human health. It is not as easy to mix the functional ingredient in the solid system as it is, in the case of the powder and liquid products. With the help of osmotic dehydration, many researchers have demonstrated the infusion of active compounds such as mineral, phenolic compounds, curcuminoids, probiotics and vitamins into solid food tissue. Fruits such as aloe vera, which have a short shelf life and are suitable system models for infusion of phenolic compounds during osmotic dehydration. Osmotic dehydration can prove useful in drying aloe vera (Aloe Barbadensis Miller) which contains several nutritional compounds, including polysaccharides, phenolics, antioxidants, vitamins, enzymes, minerals, and so forth. The phenomenon of osmotic dehydration can be modeled by the fundamentals of mass transfer that describe the origin of the diffusive forces that are involved in and control these processes. A two-parameter equation of Azuara was used to predict the kinetics of osmotic dehydration and the final equilibrium point. The internal mass transfer occurring during osmotic dehydration of food is usually represented by Fick’s second law which is the best known phenomenological model to represent the diffusional mechanism is the model of Crank, consisting of a set of solutions of Fick’s law of diffusion for different geometries, boundary conditions and initial conditions. To date, there is no research on mass transfer during osmotic dehydration of aloe vera. Therefore, the objective of the present work was the infusion of Argol phenolic compounds in alo vera gel through osmotic dehydration treatment to investigate mass transfer during osmotic treatment.
Material and methods: The Aloe Vera was added to agar and shaped into cylindrical pieces (20×20 mm). Afterwards the pieces were floated in a solution of sugar (40, 50 and 60) percentage and Argol (10, 20 and 30) percentage. The weight ratio of osmotic medium to fruit sample was 4:1 to avoid significant dilution of the medium and subsequent decrease of the driving force during the process. The experiment was performed with constant temperature of 50 °C. Samples were removed from the solution at 30, 60, 90, 180, and 120 min of immersion, drained and the excess of solution at the surface was removed with absorbent paper. Afterward, the dehydrated samples from each group were drained and blotted with absorbent paper to remove excess solution. Each assay was made in triplicate. Weight and moisture content of the samples, and moisture loss (ML) and solid gain (SG) were calculated. The curves of moisture loss and salt gain as a function of time were constructed using experimental data. A two parameters model was used for prediction of kinetics of mass transfer and values of equilibrium moisture loss and solid gain. Moisture and solid effective diffusivities were estimated by using Fick’s second law of diffusion.
Results and discussion: Results showed that in all of the studied conditions, the levels of moisture loss and solid gain had a non-linear increase with more floatation time in the solution. Moreover, the absorption rate of solid gain was faster in the beginning but eventually slowed down. Azuara model has the potential in estimating the equilibrium points. In addition, a good correlation between predicted and experimental values was obtained by this model. Besides, increasing the concentration of sucrose and Argol from 40% to 50% and 10% to 20% respectively, the coefficient of effective penetration for both parameters (water loss and solid substance absorption) improved. In addition, the coefficient of effective penetration displayed that different levels of sucrose and Argol had a notable effect on this coefficient.
