Fried eggs are healthy? Boiled vegetables are not healthy?
Is fried egg really better than scrambled eggs? Can boiled vegetables really lose vitamins? This is too subversive.
In fact, I am very supportive of the balanced diet concept advocated by the BBC. However, the reason why these details are true is because the media is good or the consumers are very good. There is always a huge misunderstanding about the evaluation of the nutritional value of food.
Because each food contains too many ingredients, and the effect on each ingredient is different during cooking and processing. Good or not, depending on what angle you are evaluating. For people with different goals, the results of the evaluation may be completely different.
1 Comparison of fried and scrambled eggs
Compared with scrambled eggs, the maximum oil absorption potential is different. This is true.
If you use a non-stick pan, be careful not to break the egg yolk, then put a little bit of oil to fry an egg. However, if the yellow of the egg is broken, the oil will be inhaled.
This is because the protein part is only water and protein, and the lipophilic ability is weak. Egg yolk is not only fat, but also a large amount of lecithin, an emulsifier that binds a lot of oil and protein very quickly. Therefore, the protein has poor ability to absorb oil and has strong egg yolk ability.
When scrambled eggs, the egg yolk protein is mixed together, and the oil absorption capacity is super strong.
However, if you use a non-stick pan and do not put a little oil, avoid stirring, wait for the egg to solidify and then gently turn it over to make it into a Japanese-style quiche state. In fact, there is very little oil inhaled.
If you follow the cooking method of most people, put a lot of oil, and then vigorously stir the egg liquid, so that the oil is fully absorbed, even a big bubble, the fried eggs can really be high in fat. Such scrambled eggs are not suitable for weight control, and are not suitable for patients with gallbladder disease.
On the other hand, the health of the fried egg is also related to its frying power and time.
The color of the tender omelette is basically unchanged, the protein utilization rate is affected to a small extent, the Maillard reaction is not high, and the content of AGEs (the end product of the Maillard reaction) is low. If the egg yolk is not broken, the degree of cholesterol oxidation is also low.
However, if the protein is already yellow and crisp, it will be different. Protein utilization decreased and AGEs increased significantly. If the egg yolk membrane is broken and the cholesterol in the egg yolk is directly exposed to the hot oil, the cholesterol oxidation product will also increase greatly. AGEs and cholesterol oxidation products are not conducive to the prevention of chronic diseases, and are not conducive to the prevention of aging.
(About egg cooking, AGEs, and oxidized cholesterol, I wrote a related science article in 2012: How to eat the most unhealthy eggs)
Therefore, whether the omelet is healthy or not depends on how it is fried. Complete saute is better.
In contrast, I recommend tender boiled eggs and steamed egg tarts. They don't need to be refueled at all, they only need to be heated to 70 degrees Celsius, and the degree of oxidation is very low.
This program is estimated to be eye-catching, deliberately ignoring other healthier cooking methods, specifically comparing scrambled eggs and fried eggs. This is not the fault of the expert, but the careful machine of the producer.
2 boiled broccoli and microwave cooking broccoli
In fact, I have been in science for a few years, and the water-soluble vitamins in boiled vegetables are more lost.
Because vitamin C, vitamin B2, folic acid, potassium, flavonoids, etc. in vegetables, including health care ingredients of glucosinolates, are easily soluble in water. When you use a large pot of water to leek, about half of these ingredients will dissolve into the water, and then the leek water will be thrown away and will not be served on the table. Therefore, the loss ratio is considerable.
At the same time, the natural flavor of vegetables will also be dissolved into a large amount of water and lost, affecting the taste of vegetables. Vegetables contain a small amount of soluble sugar. If you don't put too much condiment, you will find them have a sweet taste and a unique aroma when you taste it carefully.
(So, the key to the oil-cooked dish/water-oil method I advocate is to put less water! Less water release not only reduces nutrient loss, but also makes the sweet taste not diluted and lost!)
If it is a bitter, astringent vegetable, it makes sense to do so, because at the same time losing so much nutrients, at least most of the oxalic acid and alkaloids can be removed.
However, for vegetables that are neither bitter nor uncomfortable, such as cabbage, rapeseed, kale, etc., it is not necessary to put it in a large pot of water or boil, the benefits are not much.
Of course, if it is microwave cooking with little or no water release, the nutrient loss will be even smaller. On the one hand, when the vegetables reach the same central temperature, the microwave cooking time is shorter, the nutrient heating time is short, and the loss is small. At the same time, microwave cooking can help the flavonoids and other components in the bound state to be freed, so the content will even increase after microwave cooking.
(When microwave cooking, the center temperature of the food material rises much faster than when cooking in a pot. Therefore, it is unfair to compare the same heating time. It is necessary to use the nutrient content at the same temperature to achieve microwave cooking. Rapid advantage, otherwise it will be difficult to eat after overheating...)
Regarding microwave cooking, it is harmless and healthy, does not produce carcinogens, and does not reduce the nutritional value. I have been in science for ten years, and I have talked on TV many times. A lot of literature data. However, many people have to believe in rumors such as "no microwave in foreign countries", and then throw away the microwave oven in their home... I really want to thank the BBC for helping.
Some people may ask: China's national conditions are not as mentioned in the program, boiled, or do not put oil in the microwave cooking. Who can eat it? What we eat every day is boiled broccoli, or fried broccoli, or fried broccoli with garlic. If you choose one of three, which one do you choose?
(1) Boiling broccoli, throw the broccoli into the boiling water with a little salt, and cook it out, then put some oil in the pot to heat it, add the seasoning, and pour the salty soup on the broccoli. . White candied kale, white cabbage heart... all done this.
(2) Garlic broccoli, put the oil in the pan, saute the garlic, and then add the broccoli (worried or not) to stir fry, then smash it a little, then add salt and Season the freshener and put it in the pan.
(3) Fried broccoli can be fried in the way of garlic broccoli above, but not garlic. Most of the time, the chef first throws the broccoli into the boiling water pot, and then simmers it into a semi-cooked state, then throws it into the frying pan and stirs it, then seasons with salt, and perhaps uses a starch to smear it.
I am afraid this is even more complicated.
In terms of the preservation rate of vitamins and minerals, the oil cooking with shorter heating time, the loss of vitamin C, folic acid and flavonoids will be much less. Because the cooking will evaporate water, the vegetables will shrink, the volume and weight will decrease, and the nutrient will have a "concentration effect".
(For researchers, when evaluating measurement data, it must be compared according to "raw material weight" or "dry matter weight", otherwise it will lead to the absurd conclusion that "cooking does not cause vitamin loss or even increase nutrients". .)
So, can we say that garlic broccoli is healthier than boiled broccoli?
Does not. It depends on what you value, and everything has a price.
If you are a person who cares about weight and is controlling calories, then boiled broccoli may be more beneficial. Although it loses some vitamins, it does not increase the cooking oil. The fat content of the dishes is low and the calories are low.
For broccoli and most green leafy vegetables, their calories are usually between 10 and 30 kcal/100 g, but if 10 g of cooking oil is inhaled, it adds 90 kcal of calories. Stir a plate of vegetables with 20 grams of oil, it is normal again, it will increase the heat of 180 kcal! This still does not see the oil oozing out of the plate. If it is a state of oil, there will be 30 to 50 grams of oil in one dish.
Would you like to eat so much calories in order to reduce the loss of vitamin C by 30%?
If you are a thin person, or have a lot of exercise, then there is no problem, enjoy the delicious food of garlic.
If you are a person who wants to lose weight, I am afraid I have to think about it. We can make up for it from other sources, or eat more vegetables with less oil, and we can make up for the lack of preservation rate by the amount of intake.
The analysis of these two cases is to let everyone understand that the "healthy" or "unhealthy" cooking methods are not so absolute.
Many times, cooking is a multi-objective decision. In the BBC program, I did not explain these things to everyone, but continued to use an absolute "subversion" to boast eyeballs. This is a big mistake.
- Want to get rid of the bitter taste of oxalic acid, phytic acid, and alkaloids? Drowning is better.
- Want to save water-soluble nutrients? It is better not to drown.
- Want to reduce nutrient loss? Put more oil, fire is better.
- Want to avoid heat rise? Do not put the oil and stir fry, cook it directly or mix it well. When mixing it, put less salad dressing or sesame sauce.
- Want to taste delicious? Stir-fry, or add more salad dressing / sesame sauce.
——I don’t want nutrients to lose at all? Raw food is better, zero loss.
- Want to eat a little more? It is better to cook well. The amount that can be eaten raw is too small.
——I want to be safer, and the bacteria and eggs are all killed? It is better to cook well.
——Do not produce soot pollution when cooking, do not hurt the skin? Don't stir-fry, simmer, cook, steam, and cold.
Is it difficult to make decisions now?
Therefore, we can only evaluate which target is more important for each person's needs, and then choose the cooking method that is most suitable for a person's situation and the easiest to operate.
For example, I chose the cooking method of oil cooking (water oil). Because it tastes good, it has good safety, there is no soot, it can eat more, the oil is placed relatively less, the nutrient loss is relatively small, and it is easy to operate. It is a comprehensively high-quality vegetable cooking method suitable for a variety of green leafy vegetables, as well as broccoli and white cauliflower.