Grapes were packaged by different Poly (L-lactic acid)-based packaging films (PLTL-PLEL) and stored at 5 °C for 35 days to investigate the effects of equilibrium modified atmosphere packaging on the quality of “Kyoho” grapes during storage. Changes in physiochemical quality, antioxidant content and senescence of grapes were studied. Furthermore, UPLC-Q-TOF-MS/MS was used to observe and identify key factors influencing the variation of grape anthocyanins under different atmosphere conditions. Alterations in gas components and enzyme activities significantly impacted anthocyanin levels, highlighting oxygen concentration as the primary influence on total anthocyanin levels. The PLTL-PLEL50 packaging resulted in an approximate 5.7% lower weight loss and increased soluble solids by approximately 14.4%, vitamin C, total phenols and flavonoids reaching 60.2 mg/100 g, 8.4 mg/100 g and 7.2 mg/100 g, respectively. This packaging also preserved higher anthocyanin levels, with malvidin-3-glucoside and peonidin-3-glucoside at 0.55 μg/mL and 1.62 μg/mL, respectively, on the 35th day of storage.

中文翻译：

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聚L-乳酸基薄膜在“巨峰”葡萄平衡气调包装中的应用及其对花青素的良好保护

采用不同的聚左旋乳酸基包装膜（PLTL-PLEL）对葡萄进行​​包装，并在5℃下贮藏35天，研究平衡气调包装对“巨峰”葡萄贮藏过程中品质的影响。研究了葡萄理化品质、抗氧化剂含量和衰老的变化。进一步采用UPLC-Q-TOF-MS/MS技术观察并鉴定了不同大气条件下影响葡萄花色苷变化的关键因素。气体成分和酶活性的变化显着影响花青素水平，突出显示氧浓度是对总花青素水平的主要影响。 PLTL-PLEL50 包装的重量损失减少约 5.7%，可溶性固形物增加约 14.4%，维生素 C、总酚和黄酮类化合物含量分别达到 60.2 毫克/100 克、8.4 毫克/100 克和 7.2 毫克/100 克。该包装还保留了较高的花青素水平，在储存第 35 天时，锦葵素-3-葡萄糖苷和芍药素-3-葡萄糖苷分别为 0.55 μg/mL 和 1.62 μg/mL。