4hw.com.cn: soy sauce is an essential condiment in life. Many people see that soy sauce is black. Why is soy sauce the color? Will soy sauce expire? Let's have a look.
Why is soy sauce black
The protein tyrosine in soy sauce is oxidized to melanin and the classic amylase is hydrolyzed to glucose and amino acid to form melanin, which makes soy sauce produce bright and shiny red brown. During the fermentation, a series of extremely complex biochemical changes produce the flavor, sweetness, acidity, wine flavor, ester flavor mixed with salt water, and finally form the soy sauce with unique color, flavor and flavor.
How to tell if soy sauce is out of date
Appearance identification: see the white substance floating on the soy sauce, or smell the flavor different from the soy sauce, that is, it has gone bad.
Will soy sauce expire
Soy sauce has a shelf life. If it is stored too long, it will go bad.
According to scientific experiments, typhoid bacteria can survive for 20 days in soy sauce, Shigella bacteria can survive for 2 days in soy sauce. After expiration, there is a kind of film-forming yeast in soy sauce that pollutes soy sauce and causes soy sauce to mildew. It is harmful to human body after eating, so you can't eat expired soy sauce.
Soy sauce knowledge
Soy sauce, commonly known as soy sauce, is mainly brewed from soybeans, wheat and salt through the processes of oil production and fermentation. The composition of soy sauce is complex. In addition to salt, there are many kinds of amino acids, sugars, organic acids, pigments and spices. It is mainly salty, but also fresh and fragrant. It can increase and improve the taste of dishes, but also add or change the color of dishes. The ancient working people of China had mastered brewing technology thousands of years ago. Soy sauce generally has two kinds of soy sauce: old soy sauce and raw soy sauce: raw soy sauce is salty and used for freshness; old soy sauce is light and used for color.