本文研究了不同浓度（0%、5%、7.5%、10%和12.5%）的葡萄柚精油（GEO）对聚乳酸(PLA)/葡萄柚精油复合膜的热性能，结构性能，机械性能，气体阻隔性能和抗菌性能等方面的影响。GEO通过减少聚合物链段的分子间作用力，从而改善复合膜的柔韧性，对复合膜起到一定的增塑作用。GEO的添加降低了PLA相的结晶性。随着GEO浓度的增加，复合膜的水蒸汽阻隔性能显著降低。但是，复合膜的抗菌活性因GEO的加入得以提高。将聚乳酸/葡萄柚精油复合膜应用于双孢蘑菇保鲜。结果表明，聚乳酸/葡萄柚精油复合膜与纯聚乳酸膜、低密度聚乙烯膜相比较，更能有效地保持蘑菇的硬度，阻止微生物生长，维持较好的总体接受度。因此，聚乳酸/葡萄柚精油复合膜可作为一种有效的包装材料，用于延长双孢蘑菇的货架期。

The effect of various concentrations (0%, 5%, 7.5%, 10%, and 12.5% V/m) of grapefruit essential oil (GEO) was studied on the on thermal, structural, mechanical, gas barrier, and antimicrobial properties of polylactic acid (PLA)/GEO composite film. By reducing the intermolecular force of polymer chains, GEO improved the flexibility of the composite film and showed a certain plasticization effect on the films. The presence of GEO decreased the crystallinity of PLA phase. The water vapor barrier properties of the films significantly decreased with increasing GEO content. Additionally, the incorporation of GEO in the PLA polymer matrix improved the antimicrobial activity of packaging films. PLA packaging films with or without GEO were used for preservation of button mushroom (Agaricus bisporus). The results indicate that PLA/GEO composite film is more effective in retaining the firmness, reducing the microbial count, and maintaining a high overall acceptability of mushrooms than pure PLA and low-density polyethylene (LDPE) films. Therefore, the results suggest that PLA/GEO composite film is a useful packaging material for extending the shelf life of button mushrooms.

国家自然科学基金资助项目（21576126）