| Chitosan film is a kind of high molecular polymer which can be completely degraded by biological means.It has certain mechanical properties and good barrier performance to various small molecules.It is a kind of green environmental protection film packaging material with wide development prospects.As a new natural preservative,anthocyanins have been widely used in Japan,the United States and other countries.They not only have good antibacterial effect,but also have high safety compared with other natural preservatives.At the same time,the results showed that adding anthocyanins to chitosan can improve the antibacterial ability of chitosan,but the mechanical properties of the film need to be improved.In this paper,the anthocyanins with concentration of 0%,5%,10% and 15% were added into chitosan solution by tape casting method to mix with chitosan.The effects of different anthocyanins concentration on the transmittance,mechanical properties,oxygen permeability,moisture permeability and UV spectrum of chitosan composite film were studied.The results showed that the addition of anthocyanins improved the light transmittance and elongation at break of the composite film,improved its oxygen permeability,improved the moisture permeability and antibacterial properties of the composite film.In addition,in order to investigate the effect of different anthocyanin extracts on the freshness indication of chitosan / anthocyanin composite film,the aseptic test of fresh soybean milk was carried out by using different concentrations of chitosan / tomato anthocyanin composite film and chitosan / Black wolfberry anthocyanin composite film.The changes of appearance color and p H value of the experimental samples were monitored The results showed that as an intelligent indicator,anthocyanins indicated food spoilage by color at different pH values. |
PDF Full Text Request