How many of these rumors about food nutrition have you believed?

A healthy diet is the starting point of a healthy life.

Ruan Guangfeng, Director of the Ministry of Science and Technology, conducts scientific review

Since Dr. Zhang Wenhong began advocating less porridge for breakfast and more nutritious foods such as eggs and milk, my friends have started to become food "ingredient parties", checking this and that every day, hoping to eat nutritiously and healthily. This attitude towards life is certainly good, but be careful of online rumors, as believing them easily can easily lead to failure~

Canned foods contain a lot of preservatives and lack nutritional value?

When it comes to canned food, most people's reactions are "long shelf life", "many preservatives", and "no nutrition". In fact, the core of canned food is to fully heat the food sealed in the bottle to kill all the bacteria in it, and use the seal to isolate it from the air so that bacteria can no longer enter the food, so the food can be stored for a long time without going bad. Canned food will not "rot", so generally speaking, it does not need to be "preserved".

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Many people think that canned food has "no nutritional value", but a study by the University of Illinois found that the levels of vitamin C, B vitamins and polyphenol compounds in canned foods are indeed lower than those in fresh and frozen foods. However, the decline in these substances in fresh and frozen fruits and vegetables due to storage is much higher than in canned foods.

In addition, these nutrients in fresh and frozen vegetables will further decrease after cooking. Canned foods are cooked, and these nutrients do not decrease significantly during storage, and they do not need to be cooked again when eaten. Therefore, it is not reasonable to compare the content of these nutrients in fresh fruits and vegetables with that in canned foods.

For example, the content of nutrients such as carotenoids, vitamin E, minerals and dietary fiber in canned foods is very similar to that in fresh foods and frozen foods.

Image source: pixabay

Are free-range eggs more nutritious?

People usually think that the food of free-range chickens is more natural than the feed of artificially fed chickens, so free-range eggs are also more nutritious than ordinary eggs. Is this really the case? Ma Guansheng, professor of the Department of Nutrition and Food Hygiene at the School of Public Health of Peking University, said that due to the different feeding methods, free-range chickens do get more comprehensive nutrition than chickens in chicken farms. However, from the perspective of the nutritional composition of eggs, the protein, carbohydrates, cholesterol, calcium, zinc, copper and manganese in free-range eggs are higher than those in ordinary eggs, and the cholesterol content in free-range eggs is more than 2 times higher than that in ordinary eggs, which is related to the larger proportion of yolk; however, the fat, niacin and selenium in free-range eggs are lower than those in ordinary eggs; other nutrients are not much different.

It can be seen that the nutritional value of free range eggs and ordinary eggs has its own advantages. People can choose according to their own preferences. Since free range eggs also have a high cholesterol content, for people who need to limit cholesterol intake, ordinary eggs can be used on a daily basis.

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Does a darker egg yolk mean it is more nutritious?

First of all, we need to understand that the color substances (mainly carotenoids) in egg yolks almost all come from a part of the total carotenoids obtained by the hen through food during the period of egg cell development (about ten days). After the hen absorbs the pigments in daily intake, part of these pigments are deposited in the yolk, and the yolk has color. In fact, if some pigments are added to the feed during artificial feeding, the color of the yolk will also become darker. The "Sudan Red" incident that occurred a few years ago was due to the fact that illegal merchants added Sudan Red to the feed, which was deposited in the duck eggs after the ducks ate it, making the yolk color red. Professor Yang Ning, who is engaged in poultry quality research and quality inspection, said that the color of the yolk can be determined by the feed, but from the perspective of chemical analysis, the color of the yolk has no direct relationship with the nutritional quality of the egg, and the protein and fatty acids contained are the same.

Image source: pixabay

Do microwaves really destroy nutrients?

In fact, almost all methods of heating food will destroy the nutrients in it, and microwave ovens are relatively good. The working principle of microwave ovens is a mechanism that converts electrical energy into short-wave energy. It selectively targets water molecules in food, causing them to vibrate and release heat quickly. A study found that boiling and pressure cooking (pressure cooker) are the culprits that cause the greatest loss of nutrients. Dry cooking methods such as microwaving and baking, on the contrary, retain more nutrients. In other words, the culprit for the low nutritional level of microwaved food is water, not microwaves.

Have you ever been fooled by these rumors about food nutrition? In fact, when eating, we don’t need to over-examine which cooking method can better preserve the nutritional value, which ingredients are more nutritious, the most important thing is to form a reasonable and healthy eating habit, drink enough water, match coarse and fine food, eat more fruits and vegetables, and eat meat and eggs in moderation. A reasonable diet is the starting point of a healthy life~

Source: Tadpole Music Website, Science Popularization China, Science Squirrel Society, Agricultural Products Market Weekly

Author: Tadpole Musical Notation