In this study, a bilayer film (BIF) was fabricated to improve the stability of an anthocyanin-based freshness indicator film. The sensor layer consists of gellan gum (GG) and mulberry anthocyanin (MAE) for freshness indication. The oxygen barrier layer was constructed from chitosan (CS), polyvinyl alcohol (PVA), sodium alginate (SA), and pullulan (Pu) to the protection of MAE from oxidation. The highest antioxidant activity of BIF was 91.28%. BIF was used to monitor the Chinese mitten crab freshness. The total volatile basic nitrogen (TVB-N) level was increased to 31.23 mg/100g on day 8, and the color of the indicator presented a visible change from pink to dark green. The acquired results revealed a good correlation between TVB-N, pH, and color change of the indicator. The research indicated that the BIF was applied for freshness monitoring of Chinese mitten crab and displayed significant color changes that would be effective in commercial environments.

在这项研究中，制造了双层膜 (BIF) 以提高基于花青素的新鲜度指示膜的稳定性。传感器层由结冷胶 (GG) 和桑葚花青素 (MAE) 组成，用于指示新鲜度。氧气屏障层由壳聚糖 (CS)、聚乙烯醇 (PVA)、海藻酸钠 (SA) 和支链淀粉 (Pu) 构成，以保护 MAE 免受氧化。BIF的最高抗氧化活性为91.28%。BIF 用于监测中华绒螯蟹的新鲜度。总挥发性碱氮（TVB-N）水平在第8天增加到31.23 mg/100g，指示剂的颜色呈现出从粉红色到深绿色的可见变化。获得的结果揭示了 TVB-N、pH 和指示剂颜色变化之间的良好相关性。