上海騰拔質(zhì)構(gòu)儀用于測定保鮮膜的拉伸強(qiáng)度和斷裂伸長率

Xylan-based preservative films were prepared using xylan, chitosan, citric acid and Sanguisorba officinalis   L. polyphenols (SOPs) as main components. According to the trend of change in the physical properties of the films, the optimal composition was found to be: 1% xylan, 0.9% chitosan, 0.26% citric acid, and 0.15% SOPs. The effects of SOP content on the films were also determined. The results showed that incorporation of SOPs decreased the TS and EAB of the film and improved the water vapor barrier performance of the film. Scanning electron microscopy, contact angle measurements and thermogravimetric analysis showed that incorporation of SOPs enhanced the compactness, hydrophobicity and thermal stability of the films. Moreover, the films exhibited excellent antibacterial activities in the presence of SOPs. Compared to the polyethylene film, the film delayed spoilage bacteria growth during refrigerated storage of pork, effectively prolonging its shelf life to at least 10 days at 4 1C. In summary, xylan-based SOP preservative films meet the requirements for food packaging materials and have good prospects for use in this field.