Traditional yeast-leavened steamed buns are prone to excessive virus counts; yeast-leavened buns are the way to go
Introduction: Steamed buns are like the Chinese hamburger, one of the staple foods in our daily lives. With the emergence of yeast-leavened buns, traditional yeast-leavened buns have gradually been forgotten in a corner. In fact, traditional yeast-leavened buns have obvious drawbacks. The traditional fermentation method can easily lead to excessive bacteria and viruses, and many nutrients are also lost!
Steamed buns are one of the staple foods in our daily lives. With the emergence of yeast-leavened buns, traditional yeast-leavened buns have gradually been forgotten in a corner. Today, the editor will tell you about the knowledge of yeast-leavened buns and traditional yeast-leavened buns.
Yeast-leavened buns are healthier than traditional yeast-leavened buns
Since ancient times, traditional yeast-leavened buns have been a staple food for residents in northern China, especially Shandong buns, which are famous for their long history. It is widely believed that traditional yeast-leavened buns are made using a traditional fermentation method, making them more flavorful and effectively preserving various nutrients.
However, relevant experts point out that traditional food production methods with a long history are not necessarily safe and scientific. Traditional yeast-leavened buns have obvious drawbacks. The traditional fermentation method can easily lead to excessive bacteria and viruses, and many nutrients are also lost.
Yeast-leavened buns are more nutritious than traditional yeast-leavened buns and are more beneficial to human health.
Traditional yeast-leavened buns can easily lead to excessive harmful substances
The so-called traditional fermentation method refers to leaving a small fermented dough when making steamed buns. Because it contains a large amount of yeast, it is used as a starter culture. When fermenting the next time, it is added to the new dough as a starter to quickly ferment the entire new dough. Because the fermented dough is exposed to the air, it can easily lead to a large number of bacteria breeding and secreting toxic substances.
A survey of traditional yeast-leavened bun workshops in Shanxi and Shandong by an authoritative institution found that in the sampled fermented dough, mold reached up to 2.8×10^7 CFU/g, coliform bacteria reached up to 110 MPN/g, and the content of aflatoxin B1 reached up to 5.2 ug/kg.
The European Union's food hygiene standards stipulate that the content of aflatoxin B1 must not exceed 2 ug/kg. Although high-temperature cooking can kill harmful bacteria such as mold and E. coli, it cannot eliminate the secreted toxic substances. The long-term accumulation of aflatoxin in the human body can cause cancer.
When making buns using the traditional fermentation method, a large amount of acid-producing bacteria such as Lactobacillus and Acetobacter are produced. Lactic acid, acetic acid, and other organic acids will give the dough an unpleasant sour taste, so alkali must be added to neutralize it. Adding alkali can relieve the sour taste, but it is difficult to control in actual operation.
This is because the acidity of the dough is determined by many factors such as fermentation time and fermentation temperature, making it difficult to master the amount of alkali added. If too little alkali is added, the buns will become sour; if too much is added, the alkali will combine with the isoflavone pigments in the flour, making the buns turn yellow.
Whole-wheat buns are not better the whiter they are
When consumers choose wheat flour buns, they do not need to choose very white buns; a slightly yellowish color is normal.
If the color of a wheat flour bun is particularly white, it is likely that a whitening agent has been added. When choosing other varieties of buns, if the color is particularly uniform, it is likely to be a dyed bun. Because coarse grain foods always show the fine particles of the coarse grains, the color cannot be evenly distributed.
The pigment in purple rice foods comes from anthocyanin, which turns red in acid and blue in alkali. If you break it open and add a drop of vinegar, the color will turn red; if you add baking soda, the color will turn blue-violet. The color of green foods comes from chlorophyll. If you crush it and add vinegar, the color will darken and become olive green.
Whole-wheat buns are more nutritious than white flour buns. For an adult woman, eating 300 grams of buns made from refined white flour will only provide 28% of the daily requirement of vitamin B1 and 24% of niacin.
However, eating 300 grams of buns made from whole-wheat flour can provide 93% of the daily requirement of vitamin B1 and 92% of niacin. Although the starch content of the two is not much different, the vitamin and mineral content differs by 3 to 4 times.
Yeast-leavened buns are more nutritious than traditional yeast-leavened buns
Compared with traditional fermentation, yeast-leavened buns have more advantages. Steamed buns are a product made from wheat flour and water as raw materials, steamed with yeast as the main leavening agent. Yeast is a food, not a food additive.
Yeast is divided into fresh yeast and dry yeast. It is a nutrient-rich single-cell microorganism, which is called an "inexhaustible source of nutrition" in nutrition. In addition to being rich in protein, carbohydrates, and lipids, yeast is also rich in various vitamins, minerals, and enzymes.
The protein content in 1000 grams of dry yeast is equivalent to the protein content in 5000 grams of rice, 2000 grams of soybeans, or 2500 grams of pork. Therefore, the nutrient content in buns and bread is 3 to 4 times higher than that in pancakes and noodles.
Yeast has strong antioxidant properties, can protect the liver, and has a detoxifying effect. Yeast extract (YE) extracted from yeast is a very ideal umami substance and microbial nutrient source.
Because yeast is rich in various nutrients, it can produce high-quality nutritional supplements such as yeast protein powder and instant yeast powder. Yeast can convert inorganic trace elements into organic forms, such as yeast zinc, yeast selenium, and yeast chromium, which are the best sources of trace element supplementation for the human body.
After fermentation, phytic acid in flour, which affects the absorption of elements such as calcium, magnesium, and iron, can be decomposed, thereby improving the human body's absorption and utilization of nutrients. In addition, it is also rich in a polysaccharide substance called yeast beta-glucan, which is an effective immune enhancer.
A nutrient comparison experiment between traditional and yeast-leavened dough by an authoritative institution showed that using traditional fermentation, vitamin B2 loss was 6.14%, pantothenic acid loss was 37.5%, vitamin B5 loss was 51.88%, and water-soluble protein loss was 94.5%.
Generally speaking, making buns using the traditional fermentation method takes 5 to 8 hours, while using the yeast fermentation method only takes a little over an hour, which can greatly improve efficiency. When using yeast to ferment dough, a small amount of sugar can be added to allow the yeast to fully function, but it should not be excessive, otherwise it will inhibit the reproduction of yeast.
The general ratio of sugar to yeast is 1:1, and the best fermentation effect is achieved when the amount of yeast used is 1.5% to 2% of the weight of the flour.