Principles of Fruit Wine, Fruit Vinegar, Pickle and Sufu

(1) Mucor is the main microorganism involved in making sufu. The principle of making sufu is that protease can decompose protein in tofu into small peptides and amino acids; Lipase can hydrolyze fat into glycerol and fatty acids.

(2) Acetobacter is a microorganism involved in the production of apple vinegar, and its metabolic type is heterotrophic aerobic, so the temperature should be controlled at 30 ~ 35℃ during the production of fruit vinegar.

(3) The preserved sufu soup should contain about 12% alcohol to inhibit the proliferation of bacteria.

(4) Salt water should be prepared for pickle production, in which the mass ratio of salt to water is1:4; The content of nitrite in pickles can be determined by colorimetry. Its principle is that under the condition of hydrochloric acid acidification, nitrite and sulfanilic acid undergo diazotization reaction, and then combine with N- 1- naphthylethylenediamine hydrochloride to form a rose red dye. The content of nitrite in kimchi can be roughly estimated by comparing the sample after the color reaction with the standard color solution with known concentration.

So the answer is:

(1) Mucor peptide and amino acid lipase

(2) Heterotrophic aerobic acetic acid bacteria at 30-35℃

(3) 12%

(4) 1: 4 hydrochloric acid acidified rose red