Optimization of frying process in food safety

Abstract

The mechanics of frying are fairly simple. Hot oil serves as a heat exchange medium in which heat is transferred to the food being fried. As a result, the heat converts water within the food to steam and melts the fat within the food. The steam and fat then migrate from the interior of the food through the exterior and into the oil. Conversely, some of the frying oil is absorbed into the food being fried. The chemistry occurring in the frying oil and in the food being fried includes a myriad of thermal and oxidative reactions involving lipids, proteins, carbohydrates and minor food constituents. Decomposition products by autoxidation above 100°C, polimerization without oxigen between 200-300°C and thermal oxidation at 200°C, can be produced in frying oil and their amounts are related to different chemical and physical parameters such as temperature, heating time, type of oil used and food being fried, oil turnover rate, management of the oil and finally type of equipment used. Different studies have remarked as the toxicity of these by-products, is due to their chemistry and concentration. Since the prime requirement in food quality is the safety of the products, attainable through preventive analysis of the risks and total control through all frying processes, in this work the critical points of particular importance are identify and showed: Oil composition, and in particular its antioxidant capacity. Proper fryer design. Food/oil ratio. Good manufactured practice. Beside the quality screening has to be direct towards the chemical quality evaluation by easy and rapid analysis of oil (colour, polar compounds, free fatty acids and antioxidant capacity) and food fried (panel test and/or consumer test). Conclusion, to maintain high quality in the frying medium, choose efficient equipment, select a fat with desirable flavour and good antioxidant capacity, eliminate crackling as soon and often as possible, choose better components with minimal but desirable browning tendencies, and monitor the quality of the fat being used.