Northeast soybeans

Northeast soybeans

　　Soybean (scientific name: Glycine max), known as "shu" in ancient China, is a leguminous plant whose seeds are rich in protein. Soybeans are oval or spherical in shape and come in colors such as yellow, light green, and black, hence they are also called yellow beans, green beans, or black beans. Soybeans are most commonly used to make various soy products, press soybean oil, refine soy sauce, and extract protein. Soybean meal or coarsely ground soybeans are also often used as feed for poultry and livestock. In China, Japan, and Korea, tofu of varying firmness has been consumed for thousands of years. Processed soy can also be made into soy sauce or fermented bean curd. In recent times, Western countries have also begun consuming tofu, but it is generally used as a dairy substitute.

Soybean is an annual herbaceous plant of the genus Glycine in the legume family, native to China. It is a leguminous plant whose seeds are rich in protein and is the general term for pod-bearing grains; in ancient China it was called "shu," and the seal script character for "dou" (豆) depicts seeds inside a pod. The pods of the bean are called "doujia," the leaves are called "douhuo," and the stems are called "douqi."

When referring to soybeans, it usually means their seeds. Based on seed coat color and grain shape, they are classified into five categories: yellow soybeans, green soybeans, black soybeans, other soybeans (those with single-colored seed coats such as brown, tan, or red), and feed soybeans (typically smaller, flat-oval seeds with sunken round spots on both cotyledons, and seed coats that are slightly glossy or matte). Black ones are called black beans, which can be used medicinally, as food, or made into fermented black beans; yellow ones can be made into tofu, pressed for oil, or made into broad bean paste; other colors can all be roasted and eaten.

China has cultivated soybeans since ancient times, with a planting history of up to 5,000 years. Now they are grown throughout the country, with production in the Northeast, North China, Shaanxi, Sichuan, and the lower reaches of the Yangtze River. The Yangtze River basin and the southwest have higher yields, and the soybeans from the Northeast are of the highest quality. Soybeans grown around the world have been directly or indirectly introduced from China. Due to its high nutritional value, it is known as the "king of beans," "meat of the field," or "green milk," and is among the most nutritionally recommended foods out of hundreds of natural foods.

Various types of soybeans are sown around the summer solstice. When fully grown, the plants stand about 3–4 feet tall; the leaves are peach-shaped; white flowers bloom in autumn; and the mature pods are about one inch long. All soybeans are susceptible to frost, and after an autumn frost, they gradually wither. To achieve a good harvest when growing soybeans, a common method is to take several bags filled with soybeans of equal weight, bury them in a dark and damp place on the winter solstice, dig them up after fifteen days, weigh each bag, and select the beans from the heavier bags as seeds.

Soybeans can be stored for a relatively long time, up to one year, so they can be stockpiled for use when needed.

Fermented soy products, including fermented black beans, soybean milk residue, yellow soybean paste, and various types of fermented bean curd, are all made by inoculating soybeans or soy products with mold for fermentation. Through microbial action, inhibitory factors in soybeans and their products are eliminated, various aromatic substances are produced, making them easier for the human body to digest and absorb. More importantly, the vitamin B12 content is increased.