The effect of hydrocolloid coatings on reduction of oil absorption and quality improvement of fried foods

As a food component, fat contributes key organoleptical and physiological benefits. Fat play an important role in creaminess, appearance, palatability, texture, and lubricity of foods. Fat can also carry lipophilic flavor compounds, act as a precursor for flavor development and stabilize flavor. Frying is a complex unit operation that is widely used in the food industry. Deep-fat frying involves immersion of food in hot edible oil at a temperature avove the boiling point of water for a given period of time. In this process, the food is in a certain amount of oil is immersed at a temperature above the boiling point. Easy and quick preparation, optimal sensory attributes such as color, texture and flavor in fried foods, increase the desirability of the final product. The fried food contain high content of oil. The attainment to a high and constant quality of fried products with appropriate oil content is of considerable interest to food industry and consumers. Oil uptake is considered the major nutritional critical point of deep-fat frying because of the obesity and the negative effects of excess oil consumption on human health. Oil Uptake is also one of the most important quality parameters of fried food, but this is incompatible with recent consumer trends towards healthier food and low fat products. The consumption of oil and saturated fat in particular is related to significant health problems, including coronary heart disease, cancer, diabetes, and hypertension. Other undesirable effects derived from the high temperatures involved in the frying process and exposure to oxygen are the degradation of important nutritional compounds and the generation of toxic molecules in the foodstuff or the frying oil itself. During deep frying and in the presence of oxygen, nutrient compounds are degraded, toxic molecules are formed in oil or food. Therefore, the use of techniques aimed at reducing the oil uptake by food, will reduce or eliminate the risks associated with the transfer of toxic and carcinogenic components, such as acrylamide. The use of hydrocolloid coatings is one of these approaches. Hyrocolloids are hydrophilic polymers which by increasing water absorption and holding. Reduce the surface tension and. Consequently, form a coating layer on the food during frying. During frying and cooking, the surface layers have the less water and more acrylamide content. In this case, hydrocolloids, as a suitable coating, by maintain water, increase the water activity (a(w) and slow down the Maillard reaction, and subsequently reduce the acrylamide formation. On the other hand, the oil uptake in the product during frying and after it, decreases significantly. This result will play an important role in improving the nutritional quality, specially the sensorial attributes of food, and the promotion of consumer health. The purpose of this study was to evaluate the role and application of hydrocolloids as the effective coating during deep frying of foods.

کلیدواژه ها:

Acrylamide ، Deep frying ، Hydrocolloid ، Oil uptake