Food applications
Antimicrobial agent
Chitosan and its derivatives have good antibacterial activity, can inhibit the growth and reproduction of fungi, bacteria, and viruses. That There are three possible mechanisms: First, the chitosan polycation easy to group the role of the fungal cell surface is negatively charged, thus altering membrane fluidity and permeability of the pathogen; interfere with DNA replication and transcription; blocking pathogen metabolism. In recent years, many researchers have put forward the view of the chitosan through the induction of pathogenesis-related protein, the accumulation of secondary metabolites, and signal transduction way to achieve anti-bacterial purposes.
Papineau believes that the negative charge interactions due to the positive charge of chitosan molecules and bacterial cell membrane, intracellular proteases and other components of leakage, so as to achieve antibacterial, bactericidal effect. They study found that the dosage has a better inhibitory effect on the propagation of Escherichia coli 0.12mg/ml chitosan lactate, chitosan glutamate on the proliferation of yeast such as Saccharomyces cerevisiae also has good inhibitory effect, and, the 1mg/mL chitosan lactate make yeast activity completely lost within 17min.
Sudharshan, etc., pointed out that chitosan can penetrate the bacterial nuclear DNA and combined inhibition of mRNA synthesis, thus preventing the synthesis of mRNA and protein to achieve antibacterial effect. They studied the water-soluble chitosan such as chitosan lactate, chitosan glutamate and chitosan hydrogenated glutamate of different bacteria in the rearing of. It was found that chitosan lactate, chitosan glutamate has high antibacterial effect against Gram-positive bacteria and gram-negative bacteria. Ghaoth and other studies have shown that, The strawberry corruption caused by such as B.Cinerea or R.Stolonifer in after coated with chitosan solution significantly inhibited, extend the shelf life of strawberries.
Another study reported that the preservative effect of different molecular weight chitosan, including chitosan of about 200 000 and 10 000 for the best. In addition, most of the spices used in preservatives benzoic acid and its sodium salt, compared to the same storage conditions, the chitosan antibacterial effect is more, with less good taste, and without any side side effects, is an ideal seasoning preservatives. Yang Jisheng, who the chitosan preservative effect of soy sauce, the results showed that the 0.1% chitosan added to the soy sauce, soy sauce deterioration caused by yeast group significantly inhibited in the summer open conditions can be stored for 30d not degenerate and does not affect the taste, color, flavor and ingredients.