Nutrition Experts Discuss the Scientific Use of Alkali in Cooking
When it comes to adding alkali to cooking, many people might be indifferent, thinking it has nothing to do with them. In fact, that's not the case—you might often eat dishes and dim sum made with alkali in restaurants!
I estimate that chefs in large and small restaurants are all too familiar with and fond of using baking soda.
Use 1: When cooking rice porridge, millet porridge, or corn porridge, add baking soda. For mung bean porridge, it's a must.
Theory: Why add alkali to porridge? This is because alkali promotes the water absorption and gelatinization of starch, and it helps dissolve the glutenin on the outer layer of the starch granules into the water. As a result, the porridge cooks faster and has a thicker, stickier texture.
Identification: Alkali will cause the small amount of flavonoids in grains to turn from colorless to yellow. Therefore, porridge with added alkali will become more or less pale yellow or pale yellow-green. If too much is added, it will have an alkaline taste, destroying the natural aroma of the porridge.
Is it bad to add alkali to rice porridge? I've heard that adding alkali to corn porridge is actually beneficial for vitamin utilization?
The reason people in northern regions add alkali to porridge lies in a special property of alkali—it can increase the affinity of most proteins for water. For example, when rehydrating various types of seafood, if you add a little alkali, they absorb more water and become plump after rehydration. For various grains, adding a little alkali makes their proteins more easily absorb water and dissolve into the soup. This allows the starch granules to disperse more easily, resulting in a thicker texture after cooking the porridge.
However, for most vitamins, alkali is a terrifying enemy. Vitamins like C, B1, B2, and folic acid are all very sensitive to alkali. The loss is even more severe when heated in an alkaline environment. Adding alkali and then simmering the porridge for a long time is tantamount to completely destroying its vitamins B1 and B2. Too much alkali also creates an unpleasant alkaline and slimy mouthfeel and destroys the original aroma of fresh grains.
Thinking about it this way, adding alkali to cook porridge is simply not worth the loss.
The reason given for adding alkali to corn porridge is that the niacin (also known as nicotinic acid) in corn—a B vitamin—is in a bound state and not easily absorbed by the human body. Adding alkali can release it. In the past, when people's diets consisted only of corn and nothing else, they were more prone to niacin deficiency, so in some regions, it was recommended to add a little alkali to corn porridge. This way, the niacin levels were sufficient, but vitamins B1 and B2 were sacrificed. Because corn contains a fair amount of B1 and B2, people could replenish these by eating unleavened corn cakes.
However, times have changed, and so should the advice. How many people today eat nothing but corn porridge and corn cakes every day? Fish, meat, and poultry are all quite rich in niacin, and so are flour-based foods. Nutritional surveys have found that the average person's niacin intake is generally sufficient, while vitamin B2 is commonly deficient, and some people also lack vitamin B1. In this situation, adding alkali to corn porridge will do nothing beneficial for the balance of dietary nutrients.
As for many people adding alkali to mung bean porridge, that is an even greater waste. The B vitamin content in bean porridge is much higher than in rice porridge to begin with, and adding alkali will destroy this benefit. The bean skins are also rich in polyphenols, which will have their structure altered by the alkali.
So, many people will ask: If I don't add alkali, how can the porridge be thick and delicious? There are actually many methods. You can add a handful of glutinous rice, a spoonful of oats, or a bit of soapberry seeds to increase the thickness. This way, you not only don't lose nutrients but can also better enjoy the natural aroma and beauty of the grains.
Finally, it should be noted that whether food becomes acidic or alkaline after human metabolism has nothing to do with whether it was cooked with vinegar or alkali.
Use 2: Making various pastries and dim sum requires adding baking soda to make them fluffy, soft, and delicious. From self-rising flour to cake flour, from youtiao (fried dough sticks) to soda crackers, from cakes to corn cakes, most of them contain alkali.
Principle: Baking soda reacts with acid salts to produce carbon dioxide gas, which makes the pastry porous. At the same time, alkali also makes the starch easier to bake or steam, for the same reason as cooking porridge.
Identification: Pastries with added alkali are fluffy and porous but lack the aroma produced by fermentation, or only have the aroma of artificial flavorings. When too much alkali is added, the pastry will turn slightly yellow, which is more noticeable if the alkali is not evenly distributed.
Use 3: Making various meats requires adding baking soda, from beef in spicy broth to boiled meat and meatballs, this technique is very popular. It can also be used for seafood like shrimp and fish balls.
Principle: Because the isoelectric point of meat protein is generally under weakly acidic conditions, the meat's water absorption is at its worst at this point. If you add alkali, it allows the meat protein to carry more charge, strengthening the affinity between the meat and water. This way, a pound of meat can absorb three ounces of water, naturally becoming more tender. The meat expands, and the cost is also reduced.
Identification: Meat with added alkali is so tender that you can barely distinguish the muscle fibers; you can hardly tell what kind of meat it is. It's extremely tender to the point of saving you the effort of chewing.
Analysis of Nutritional Pros and Cons:
Many people revere the practice of adding alkali in cooking as a classic, a national tradition, and a culinary masterstroke. Others argue that adding alkali destroys the precious vitamins in grains—whether it's B1 or B2, both vitamins that are often deficient, are severely depleted or even completely destroyed in an alkaline environment.
Some people argue that even if you lose the vitamins by eating a bowl of alkali-added porridge or a piece of alkali-added pastry, so what? Because alkali cooking makes porridge thicker and softer, and pastries fluffier, it is beneficial for people with stomach problems, especially those with excessive stomach acid. But another group believes that such staple foods not only cause excessive loss of vitamins but are also easily digested, causing blood sugar to rise too quickly, making them unsuitable for diabetics and people with high blood lipids.
Therefore, it seems whether to add alkali to staple foods depends on an individual's physical condition and cannot be generalized. The same principle applies to pastries. It's good for people with stomach problems to eat some soda crackers, but it may not be so good for diabetics.
The same goes for meat. Alkali will destroy the rich variety of B vitamins in meat. However, if this technique allows people to use water as a bulking agent and eat less meat in a meal, it might not be a bad thing.
In the final analysis, whether you eat these alkali-added dishes is up to you. If you value vitamins, eat less of them. If you prefer a soft texture and have a chronic stomach condition, you might as well have some. But in any case, eat with your eyes open. Don't eat water-injected meat, alkali-added noodles, and alkali porridge without knowing it.
Adding alkali to porridge is of no help in preventing chronic diseases. It only makes the porridge raise blood sugar faster, which is bad for diabetics. It also significantly increases the sodium content of the porridge, which is also detrimental to preventing high blood pressure.