Maryam Sadat Sotoodeh; Nafiseh Soltanizadeh
Abstract
Introduction: Over the last few decades, development of the industrial life has remarkably increased the demand for consumption of ready-to-eat foods. Deep fat frying is a fast and conventional method for cooking and due to creating crispy surface, soft internal texture, desired color and taste has popularity ...
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Introduction: Over the last few decades, development of the industrial life has remarkably increased the demand for consumption of ready-to-eat foods. Deep fat frying is a fast and conventional method for cooking and due to creating crispy surface, soft internal texture, desired color and taste has popularity among consumers. The main problem related to fried food products is the high oil absorption during deep fat frying that is harmful for human health and has negative effects on shelf life of the product. Therefore, the aim of this study was to investigate the role of breading particles size as well as the influence of addition of soy protein isolate in breading and batter layers on properties of chicken nugget. Material and Methods: First, breading was divided to three particle sizes. Sieves with mesh size 40 (0.42 mm) and 60 (0.25 mm) were used for separation of small breading. Also, sieves with mesh size of 18 (1 mm) and 20 (0.84 mm) as well as 10 (2 mm) and 12 (1.68 mm) were used for preparation of breading with medium and large particle size, respectively. Three percent soy protein isolate was separately added to breading with particle size of small, medium and large and used for production of chicken nugget. Also, 3% soy protein isolate was added to batter mixture and then nuggets coated with three different breading particle size without soy protein isolate. Breading pick-up, moisture content, cooking loss, porosity, oil absorption and penetration, color and textural properties of the chicken nuggets were then evaluated. Results and discussion: Based on the results, the coating of chicken nuggets with small breading size led to the product with the highest moisture content and lowest porosity, oil uptake, oil penetration and shear force. However, chicken nuggets coated with small breading size had the highest breading loss. After incorporation of soy protein isolate to breading, the highest hardness and lowest springiness, cohesiveness and gumminess were related to the nuggets coated with small breading size, however, chewiness was not affected by breading particle size. Breading with small particle size containing soy protein isolate caused the highest L*, a* and b* values in fried chicken nuggets. Addition of soy protein isolate to breading layer significantly caused a decrease in cooking loss, porosity, oil absorption and penetration (p < 0.05). These samples had higher moisture content than the control sample. After addition of soy protein isolate to batter layer, color of chicken nugget did not considerably change (p > 0.05). The effect of soy protein isolate on textural properties is dependent on breading particles size. Generally, the addition of this compound to batter layer decreased hardness, gumminess and chewiness; however, its effect on springiness and cohesiveness is dependent on breading particle size. The presence of soy protein isolate in batter layer increased moisture content which in turn could diminish porosity, cooking loss, oil absorption, and oil penetration (p < 0.05). Overall, the comparison between chicken nugget properties when soy protein isolate was added to breading or batter layer indicated that the presence of the protein in breading layer was more effective in retention of moisture, reducing of cooking loss, porosity, oil absorption and oil penetration. However, these samples had more hardness, gumminess and chewiness compared to those containing soy protein isolate in batter layer. Cohesiveness of chicken nugget containing soy protein isolate in breading was not significantly different with those produced with the compound in batter layer.The production of chicken nugget with small breading size containing 3% soy protein isolate in batter layer was proposed for production of products with better nutritional and physicochemical properties.
Hamed Mahdavian Mehr; Arash Koocheki; Mohebbat Mohebbi
Abstract
Introduction: Batter coating is a new technology to reduce fat content of fried foods. The ingredients and flowproperties of batter are the most important parameters to determine the performance of batter coating and quality of the final product. Among batter additives, proteins can be used as an important ...
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Introduction: Batter coating is a new technology to reduce fat content of fried foods. The ingredients and flowproperties of batter are the most important parameters to determine the performance of batter coating and quality of the final product. Among batter additives, proteins can be used as an important and effective component, because of their emulsifying properties, water absorption, and barrier properties. Previous studies have shown that soya protein isolate (SPI) is a very good hydrophilic protein which could be used to control the viscosity of batter. The batter temperature has direct effect on its flow behavior's properties and has a major impact on the quality of final coated product. Therefore, the aim of the present study was to evaluate the effects of temperature (5, 25 and Cº45) and SPI content (2 and 4%), on flow properties of the batter and quality of deep-fried chicken nuggets. Materials and methods:Raw materials such as fresh chicken breasts, onion, salt, hot pepper, wheat flour, baking powder, and 100% pure sunflower oil were purchased from local markets. SPI (92% protein) were obtained from GolharKhorasanRazavi Company. The batter formulations consisted of wheat flour, salt (1.5% w/w, db), baking powder (0.5% w/w, db) and SPI (2 and 4% w/v, db). For all samples, water/dry mix proportion had always been 5:3. Rheological properties of the batters were carried out using a Bohlin rotational viscometer. For each test, shear rate increased from 0 to 300 s−1, followed by a logarithmically decrease from 300 to 0 s−1. The flow behavior index (n) and consistency coefficient (k) values were computed by fitting the power law model, and time dependency properties of the batters were obtained from the area between the upward and downward curves. Temperature dependency of consistency coefficients were assessed by fitting the Arrhenius model. The batter coating on the chicken substrate was appliedat three temperatures (5, 25 and 45 Cº), and batter pickups (%) were calculated by the weight difference between the chicken nuggets after coating to the weight of chicken nuggets before coating. Coated samples were stored at -18 Cº for two weeks. After thawing, chicken nuggets were fried at 180°C for 3 min in sunflower oil using a programmable deep fat fryer. The influence of SPI concentrations and batter temperature on color and crust adhesion of deep-fat fried chicken nuggets was measured with image processing. In brief, images were taken by a digital camera under controlled conditions, and then analyzed by Image J software. The Percentage of adhesion (CRA), obtained by calculating the ratio of the pixels corresponding to the perimeter of the substrate where coating is adhered to the pixels corresponding to the total perimeter of the substrate. The color of deep-fat fried chicken nuggets were examined in terms of L*, a* and b*values. Oil and moisture content of the chicken nuggets was determined by standard techniques. Results & Discussion: Results showed thatall samples had a shear-thinning behaviour at all batter temperatures (n≥0.539). Power law model was adequately suitable to describe the flow behavior of the batters (R2≥0. 994). The activation energy was between 5.106 to 5.630 (kj/mol).Addition of soy protein isolates into the batter, enhanced the time dependency, whereas, the increase of temperature decreased the hysteresis area. The relative increase in apparent viscosity with increasing SPI might be attributed to the high capacity of SPI to absorb free water. However, decrease in apparent viscosity and time dependency of batters with increasing the temperature could be due to the intermolecular interactions in batter system. An increase in temperature weakens the intermolecular interactions and increases the mobility of macromolecules which reduces the batter resistance to shear force. The batter temperature and formulation had significant effect on the batter pickup. This effect was mainly due to the changes occur on flow properties of batter. Using SPI increased the a* and decreased the L* of the final product. This could be due to the active participation of SPI in the Millard reaction. The data obtained for crust adhesion revealed that the increase in SPI concentration lead to a decrease in batter adhesion to the crust. In other words, the ability of soya proteins to form film during early time of frying reduces the moisture migration from the substrate to oil, which creates a positive pressure in the inner layer of crust and reduces the adhesion. Conclusion: Chicken nuggets coated with batter containing SPI had higher moisture and lower oil content than the control sample. Finally, the change in batter temperature had no significant effect on the crust adhesion and oil and water content in the final product.
Elham Ansarifar; Mohebbat Mohebbi; Fakhri Shahidi; Mehdi Varidi
Abstract
The objective of this study was to evaluate the effect of frying temperature, time and different batter formulations on the rheological properties and mass transfer during deep fat frying of Kurdish cheese nuggets. The effects of white egg (0, 5, 10%) addition to the batter formulation of cheese nuggets ...
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The objective of this study was to evaluate the effect of frying temperature, time and different batter formulations on the rheological properties and mass transfer during deep fat frying of Kurdish cheese nuggets. The effects of white egg (0, 5, 10%) addition to the batter formulation of cheese nuggets and frying at 150, 170 and 190◦C for 0, 1, 2, 3 and 4 min have been investigated. The results showed an interaction effect of these processing conditions on mass transfer. The most reduction in fat absorption was observed when samples were coated with batter containing 10% white egg and fried at 150 ◦C. The kinetic model based on the Fick’s law was used to describe moisture transfer data. The effective moisture diffusivity of batter without white egg was within the range of 3.97×10−8 and 7.51×10−8m2/s with R2 between 0.91 and 0.86 .In the samples coated with the batter including white egg, the effective diffusivity ranged between 2.26×10−8 and 5.96×10−8m2/s with R2 between 0.98 and 0.87, and fat transfer rate constant was between 1.1×10−3 and 8.9×10−3 s−1 with R2 from 0.82 to 0.99. Activation energy obtained from the Arrhenius plot for the effective moisture diffusivity of batter with and without white egg was 30.01 kJ/mol and ranged from 38.42 to 36.52 kJ/mol, respectively
