L-glycine is a white to cream crystalline powder, odorless and non-toxic. Soluble in water, almost insoluble in ethanol or ether. It is used in pharmaceutical industry, biochemical testing and organic synthesis. It is an amino acid with the simplest structure in the amino acid series and is not essential for the human body. It has both acidic and alkaline functional groups in the molecule.

Natamycin is a cream or cream yellow crystalline powder. It is an odorless and tasteless, low-dose and highly safe food preservative. Natamycin is a white to milky white, odourless and tasteless crystalline powder produced by controlled fermentation of Streptomyces nata, usually in the form of an enol structure.

The food additive Nisin is a kind of polypeptide substance produced by Streptococcus lactis, which consists of 34 amino acid residues and has a molecular weight of about 3500 Da. Because Nisin can inhibit most gram-positive bacteria and has a strong inhibitory effect on the spores of Bacillus, it is widely used in the food industry as a food preservative.

The mechanism of action of Natamycin is to combine with ergosterol and other sterol groups in fungi to inhibit the biosynthesis of ergosterol, thereby distorting the cell membrane, ultimately leading to leakage and cell death. Surface treatment of dough with Natamycin in baked goods can obviously extend shelf life.