Five tips for "calcium preservation" in cooking

Calcium supplementation is an eternal topic, and food is the best choice for calcium supplementation. After choosing the right food, cooking is also important. So what are some tips for preserving calcium when cooking?

The first trick: Be good at eating vinegar to help dissolve calcium

Most calcium in food exists in complex form, but after entering the stomach it needs to become soluble and ionic in order to be absorbed. This is one of the daily duties of gastric acid.

In addition to stomach acid, which is the main force, adding some vinegar when cooking can also promote the insoluble calcium in food to become ionic state. This is a good trick especially for friends with low stomach acid.

For example, many green vegetables (carrot tops, mustard greens, kale, rapeseed, Chinese cabbage, water spinach, fennel, etc.) have low oxalic acid content but great calcium content. Adding some vinegar when frying can not only help protect vitamin C and most B vitamins, but also facilitate the dissolution of calcium, killing two birds with one stone.

For example, many meats and fish are actually potential calcium masters, such as goat meat, Wuchang fish, sea bass, anchovies, sea bream, flounder, yellow croaker, hairtail, shrimp, river shrimp, scallops, oysters, etc. The calcium content is above 100mg/100g. Adding some vinegar when cooking can not only remove the fishy smell, but also promote the dissolution and absorption of calcium.

Tip 2: Take one more step before cooking to remove bad molecules

There are some bad molecules in food that tend to fight with calcium. At this time, some cooking treatments can just break up the enemies.

For example, some vegetables with a distinct astringent taste (including amaranth, purslane, spinach, bamboo shoots, and a few others) have high oxalic acid content, which will react with calcium to form calcium oxalate, thus affecting calcium absorption.

When cooking these vegetables, you can blanch them in water before proceeding with the subsequent operations. This is because most of the oxalic acid in vegetables exists in the form of potassium oxalate, which is easily soluble in water. For example, if you blanch spinach in boiling water for 1 minute and then remove it, more than 80% of the oxalic acid can be removed.

For example, phytic acid in grains and beans will form calcium phytate in the intestines and affect calcium absorption. Soaking grains and beans for 4 to 12 hours before cooking will not only make the rice more tender, but also help activate phytase and promote the degradation of phytic acid.

Tip 3: Change your cooking method

Making tofu from soybeans can remove most of the oxalic acid and phytic acid. At the same time, calcium-containing coagulants are added to northern tofu and southern tofu, achieving a "win-win" improvement in calcium supplementation.

Soybean fermentation can also remove oxalic acid and phytic acid. Although the calcium content of fermented soy products and non-fermented soy products is similar, the bioavailability of phytic acid and oxalic acid is improved because they are destroyed by external aid-microorganisms. For example, natto, fermented black beans, and fermented bean curd are all fermented soy products.

Similarly, grain fermentation also helps to improve the bioavailability of calcium. For example, multi-grain steamed buns are more conducive to calcium absorption and utilization than multi-grain rice.

Fine grinding is also effective. For example, grinding dried shrimp into powder is equivalent to using it to help teeth gain strength, reducing the blind spot of calcium absorption caused by insufficient chewing. Dried shrimp can be blanched in water, dried, and then ground into powder, which can be used directly as a seasoning when cooking.

Tip 4: Use "Yiyou" to promote calcium absorption

In the nutrition circle, calcium has several good friends, such as vitamin D, mineral potassium, magnesium, vitamin K, vitamin C, etc., which can promote calcium absorption very well. When matching meals, you have to find some such "old friends" for calcium.

For example, stewing fish with tofu is a good match. The vitamin D in fish can promote the absorption of calcium in tofu. If you add some dried mushrooms, it will be the icing on the cake, because dried mushrooms are not only rich in umami substances, but also contain vitamin D that promotes calcium absorption.

Braised Chinese cabbage with tofu is also a good pair. Chinese cabbage has a low oxalic acid content and excellent minerals such as magnesium, potassium, vitamin K, and vitamin C, which are all helpful in improving the utilization rate of calcium. Of course, it doesn’t matter if you don’t make it into one dish. Remember to have a balanced combination in one meal. It’s OK to have both high-calcium foods and some green leafy vegetables, mushrooms, and algae rich in the above “good friends” elements.

The fifth tip is to keep a distance from “bad friends” when cooking.

First, use less salt when cooking. A high-sodium diet has a great impact on calcium loss, because sodium competes with calcium in the reabsorption process in the renal tubules. When sodium intake is high, calcium reabsorption is reduced and calcium excretion is increased. It is best not to exceed 5 grams of salt per day, including hidden salt.

Secondly, don't use too much fat. Fat is a double-faced person. A moderate amount of fat can prolong the contact time between calcium and mucous membrane, thus facilitating calcium absorption. But if there is too much fat, undigested fatty acids will combine with calcium to form calcium soap, affecting calcium absorption. Generally, 1 to 2 porcelain spoons of cooking oil are enough for one dish, and no more than 25 to 30 grams per day.