The effect of microwaves on the fat component and preserve vitamins in foods
The use of microwave oven provides a convenient way to thaw, cook or reheat foods nowadays. Safety of microwave cooking of food is still the subject of research. Wave of interest is caused on the one hand the emergence of new research methods that enable detailed characterization of the processes occurring in the food under the influence of microwaves, on the other hand, – to clarify the influence of the individual components of the diet (trans-fatty acids, the products of oxidation of fats and lipids, conjugated alpha linolenic acid, gamma-aminobutyric acid and others) on human health. Analysis of the collected information on the effect of microwaves on the quality of the vegetable oils, fat component of food, as well as the preservation of water-soluble vitamins and vitamin E is presented. Most studies show that the loss of vitamin E and the formation of fat oxidation products are directly dependent on the power used, and the microwave heating time. Microwaves exposure on fat and fatty foods during less than 3 minutes at average power 500 watts is minimal. Nutritional value of dishes cooked using microwave ovens and using traditional cooking methods are comparable. Information about the use as natural antioxidants polyphenols from various plant extracts (olive leaves, lavender, green and white tea, etc.) are presented. Content of vitamin C in vegetables cooked in a microwave oven is higher than by boiling or baking in most cases. Vitamins (B1, B2, niacin) retention in microwaved foods is equal or better than conventionally prepared foods because of the shorter heating time. Chemical (formation of carcinogens) and microbiological risks associated with microwave cooking, is often lower than in traditional cooking. Microwave cooking (if cooking time required to reach the proper temperature, and power) provides the most complete destruction of germs and worms. The microwave cook of food should be done only in specially designed for this purpose container in connection with the possibility of migration of chemicals from materials in that heats food. Negative influence of microwave cooking food on the functional state of an organism is not revealed. Thus, differences in the nutritional value of dishes prepared using the microwave and traditional way, are minimal. Nevertheless, the possible influence of heat treatment on the keeping quality of the fat components (modules) for fortified and functional foods, especially semifinished products or products to be thawed and / or heating should be taken into account. Search natural ingredients, to possess protective (from the influence of the heat treatment) effect on the fat component, remains an urgent task.
Keywords:microwave, PUFA, oxidative deterioration of fats, vitamin E, vitamin B group, antioxidant activity of plant extracts