when near小暑, the weather increasingly hot, willing烹炒inside in the kitchen for frying are becoming fewer and fewer people. Some of my friends opted for microwave cooking, find it quick and convenient, the most appropriate in the summer. However, the last six months, I do not know how many friends asked me the same question: Microwave cooking nutritional losses吗? Microwave heard after all the anti-vitamin-ray, is that true?
discussing this issue, take a look at how the characteristics of a variety of cooking.
boiling method of cooking, such as boiling, burning, scalding cheuk, the basic approach is to rely on water to give the Food and heat transfer, mass hot process a large number of soluble substances into the water. So, if we do not drink decoction, nutrient loss is certainly not small. In contrast, the iron law cheuk入锅temperatures are high, relatively short heating time, so cold water under the pot than the loss of some nutrients.
油炒method of cooking, such as frying, deep-frying, fried, etc., the basic methods of heat transfer oils and fats are the main pot body directly supplemented by the heating method of heat transfer. Cooking it faster, less loss of dissolved water. If you cling too much oil, the loss of nutrients are usually less than the boiling method.
microwave cooking of food molecules are so new ways of heating Express. Heating it, in fact mainly the water molecules in food, so is suitable for a variety of water-rich food. Since the high efficiency of microwave heating, so it will also shorten the cooking time, and almost no loss of dissolved water, and we will not increase in the dishes were too much grease. Its main disadvantage is the aroma enough, it did not have the effect of coke in Lebanon.
, however, and compared油炒and boiled, microwave cooking loss of nutrients in the end what? This kind of thing must not be taken for granted, or to study the results speak.
a study abroad, the cooking of the four kinds of vegetables, including the tender kidney beans, eggplant, blue kohlrabi, radish. Researchers were using traditional cooking methods, pressure cooking or microwave cooking to handle, analyze the situation to preserve their nutrients. The results showed that, regardless of what kind of methods, one of protein, fat, total ash, calcium, phosphorus, iron and dietary fiber content before and after the change in cooking is very small. Change is really a big vitamin C, cooking it at high pressure loss in the largest, followed by microwave cooking and conventional cooking [1].
our country a study found that cooking shepherd's purse, the biggest loss of vitamin C are cheuk hot two minutes, the loss of up to 63% ; and油炒2-minute loss of 23%, and microwave 2 minutes of high fire loss of only 12% [2]. In fact, vitamin loss size, not so much depend on the heating of cooking medium, such as Say not depends more on heating time and final temperature [3]. Microwave cooking because of higher efficiency, the time required for a shorter, less water reaches maturity or achieve sterilization requirements, a variety of vitamin losses are lower than, or at least no higher than油炒cooking method, much higher than water boiling method [4].
It appears that microwave cooking at a slight advantage on vitamin projects. Then, anti-oxidation example? Green asparagus to do a study of the problem. For the production of canned asparagus, the researchers designed a number of sterilization equipment, a microwave heating system of circulating water, and the other is high-pressure water heating system, steam heating system have ordinary. The results show that the asparagus in the most famous antioxidant components - rutin, all kinds of heating methods after the treatment retention rate is very close. Re-determination of antioxidant activity of asparagus and found that microwave sterilization system antioxidant activity than the other two methods is even higher number. Moreover, researchers are pleased to find that microwave treatment of asparagus beautiful green color [5].
Chinese cooking study also found that microwave cooking is one of the major advantages of the color green vegetables. Two studies have found that cooking vegetables, microwave cooking smaller loss of chlorophyll. For example, after chinensis after microwave cooking, chlorophyll loss of only 8.2%, while after scalding cheuk chlorophyll losses amounting to 46.9% [6].
in fact, in the food processing, the appropriate use of microwave heating to replace the traditional methods, often brought about by the loss of nutrients decreased good results, such as garlic deodorization [7] or the production of tomato juice [8].
studies have found that microwave heating time is short, easy to control, it is not easy cause uneven heating and excessive heating of the situation, therefore be able to reduce the food when heated to high temperatures generated by carcinogens, such as proteins formed by heterocyclic amines overheating, overheating have starchy foods, such as produced by acrylamide [9].
All in all, for a variety of high-moisture foods, if properly control the time, at the time required to reach cooking, microwave cooking compared with other cooking methods, preservation of at nutrients have certain advantages.
intimate exhort:
1 microwave itself harmful to health, even though commercial microwave ovens are qualified products, but should as far as possible when using the microwave oven away from it much.
2 suitable for microwave heating of high moisture content of food, grease and many less water not suitable for food, dry food does not fit. Need to cool the surface of brittle food not fit, so it can not substitute for the oven and frying pan.
3 Although microwave cooking is relatively little loss of nutrition, but if excessive heat is another thing back. So should be in accordance with the norms of the time and firepower to cooking, the temperature slightly lower than the traditional cooking in order to exert its advantage to reduce nutrient losses, both energy saving and healthy. For example, heat 1 cup milk, high-firepower required only one minute; heating leftovers half plate need only 1-2 minutes.
4 must want the attention, it is best not to use microwave ovens to heat yogurt and other foods containing live, because it will kill one of the useful bacteria, reducing the value of health care.
5 for insurance purposes, the baby milk powder not be microwave heating.
6 should not use the microwave to the absolute of plasma, or heat a variety of biochemical products, but you will not have nutrition questions.
Main References:
1 Kala A; Prakash J. The comparative evaluation of the nutrient composition and sensory attributes of four vegetables cooked by different methods. International Journal of Food Science and Technology. 2006, 41 (2)
2 Lai Sun Chang. different cooking methods on nutrient composition of wild vegetables, the effects of the food industry Technology, 2005. 26 (4)
3 XIAO Chun-ling. microwave cooking of food nutritional value of the impact of Chinese Food and Nutrition, 2003 (2)
4 Wang. Analysis of microwave processing of food nutrients impact. Jiangsu Food and Fermentation, 2003 (3)
5 Sun, T; Tang, J; Powers, JR. Antioxidant activity and quality of asparagus affected by microwave-circulated water combination and conventional sterilization. Food Chemistry, 2006, 100 (2),
6 Footman Portland,吕蓓red. chinensis by microwave post-treatment analysis of nutrient composition , Xinyang Normal University (Natural Science Edition), 2006 (2)
7 Cao Wei, Wei Ya-Hui. sweetening microwave heating on the effects of garlic nutrition, food science, 2002 (8 )
8 Ping. microwave heating to maintain the nutritional quality of tomato juice, tropical agricultural engineering, 2002 (2)
9 Yi-Jing , LIU Xiao-geng. microwave technology for food safety research, processing of agricultural products (Journal), 2007 (10)
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