绿茶提取物对聚乙烯醇/微晶纤维素薄膜性能的影响

为了研究绿茶提取物不同含量对聚乙烯醇/微晶纤维素薄膜性能的影响,通过流延法制备得到绿茶提取物不同含量的聚乙烯醇/微晶纤维素薄膜,测定分析不同含量绿茶提取物对薄膜的颜色、透明性、力学性能、疏水性能和气体阻隔性能的影响。结果表明:随着绿茶提取物含量的增加,薄膜亮度稍有变暗,颜色趋于红色、黄色;透明性显著降低;薄膜抗拉强度显著增加,断裂伸长率显著降低;薄膜的疏水性能提高,薄膜的溶胀率、持水率降低;薄膜的水蒸气透过率和氧气透过率降低。因此,绿茶提取物的加入,提高了薄膜的力学性能、疏水性和气体阻隔性,为薄膜在食品包装中的应用提供了基础。

Effects of Green Tea Extract on Properties of Poly-(Vinyl Alcohol)/Microcrystalline Cellulose Film

In order to investigate the effects of green tea extract (GTE) with different contents on the properties of poly-(vinyl alcohol)/microcrystalline cellulose (PVA/MCC) film, PVA/MCC films containing GTE were prepared by solution casting method. The effects of GTE on the properties of the films were evaluated, including color, optical property, mechanical property, water resistant and gas barrier property. The results showed that with the increasing content of GTE, the film became a little darker and its color tended to change toward redness and yellowness, with the light transmittance of the films decreased significantly. The tensile strength of the films increased greatly and the percentage of elongation at break decreased significantly. The swelling ratio and water vapor uptake ratio of the films reduced notably, which suggested that the water resistant property was improved. The water vapor transmission rate coefficient and oxygen transmission rate coefficient of the films decreased as well. With the incorporation of GTE, the mechanical property, water resistant and gas barrier property of the PVA/MCC films were improved, which provided foundation for application of the films in food packaging.