As a type of staple food, steamed buns and bread are more nutritious than non-fermented foods like pancakes and noodles.
Research has shown that yeast not only alters the structure of the dough, making it softer and more delicious, but also significantly enhances the nutritional value of steamed buns and bread.
Yeast can protect the liver.
There are many ways to ferment flour, such as using baking soda, a starter dough, or yeast.
The principle behind these methods is the same: the leavening agent produces a large amount of carbon dioxide gas in the dough. During the steaming process, the carbon dioxide expands with heat, making the food soft and tasty.
However, the first two methods have their drawbacks. Baking soda can severely destroy B vitamins in the flour, and a starter dough can make the dough taste sour. Only yeast fermentation not only makes the food taste good but also improves its nutritional value.
Yeast is divided into fresh yeast and dry yeast. It is an edible, nutritious single-celled microorganism, which nutritionists call "an inexhaustible source of nutrition." In addition to protein, carbohydrates, and lipids, yeast is also rich in various vitamins, minerals, and enzymes. Experiments have shown that the protein content in 1 kg of dry yeast is equivalent to the protein in 5 kg of rice, 2 kg of soybeans, or 2.5 kg of pork. Therefore, the nutritional content in steamed buns and bread is 3-4 times higher than in pancakes and noodles, with protein increasing by nearly 2 times.
Fermented yeast is also a powerful antioxidant that can protect the liver and has a certain detoxifying effect. Minerals in yeast, such as selenium and chromium, can combat aging, tumors, and arteriosclerosis, and improve the body's immunity. After fermentation, phytic acid in flour, which interferes with the absorption of elements like calcium, magnesium, and iron, can be broken down, thereby improving the human body's absorption and utilization of these nutrients.
Those with weak digestion should eat more.
Fermented bread and buns are beneficial for digestion and absorption because the enzymes in yeast promote the breakdown of nutrients. Therefore, people with weaker digestive functions, such as those who are underweight, children, and the elderly, are more suited to eat this type of food. Similarly, it's best to eat fermented foods like bread for breakfast, as the energy is released quickly, keeping you energetic all morning; however, for those trying to lose weight, it's best to eat fewer buns for dinner to avoid weight gain.
Self-rising flour does not increase nutritional value.
To make yeast fully effective during fermentation, a small amount of sugar can be added, but it's best not to overdo it, as this will inhibit the growth and reproduction of yeast. Generally, the ratio of sugar to yeast is 1:1, and the best fermentation effect is achieved when the amount of yeast used is 1.5%—2% of the flour's weight.
Many people like to buy self-rising flour or baking powder instead of yeast, which is more convenient but results in much greater nutritional loss. Because they use baking soda for fermentation, they not only fail to increase nutritional value but also destroy the B vitamins in the flour.