The fact that chitosan has strong antifungal properties is well known. Alen et al. found that chitosan has inhibitory effect on 32 kinds of fungi, such as Leptomyces, Neurospora, and Ostrachomyces, in their antibacterial experiments on 46 kinds of fungi. Generally, when the concentration of chitosan reaches 100 μ At g/mL, antifungal activity can be demonstrated, and the antifungal activity is inversely proportional to the size of chitosan particles. The degree of polymerization of chitosan has a significant impact on its antifungal properties. When the degree of polymerization decreases, the types of fungi that chitosan can inhibit decrease, but the degree of inhibition increases. Kendra et al. also found that chitosan with heptamer has the strongest antifungal activity.
Chitosan has a good inhibitory effect on Escherichia coli, Pseudomonas fluorescens, Staphylococcus aureus, Bacillus subtilis, etc., and can also inhibit the physiological changes of fresh food. Chitosan is naturally non-toxic and suitable for preserving acidic and low protein foods. It can agglutinate when encountering polymers and ionic complexes. For example, for the preservation and preservation of fruits, the dosage is 0.1% acetic acid+0.05% -0.1% chitosan.
Chitosan derivatives also have good antibacterial properties, even stronger than chitosan.