*Article* **High-Stability Bi-Layer Films Incorporated with Liposomes @Anthocyanin/Carrageenan/Agar for Shrimp Freshness Monitoring**

**Junjun Zhang 1,2,3, Yan Yang 1,2, Jianing Zhang 1,3,4, Jiyong Shi 1,5,\*, Li Liu 2, Xiaowei Huang 1,2,5, Wenjun Song 1,3, Zhihua Li 1,3,5, Xiaobo Zou 1,2,3,5 and Megan Povey 6,\***


**Abstract:** High-stability bi-layer films were prepared by incorporating anthocyanin-loaded liposomes into carrageenan and agar (A-CBAL) for non-destructive shrimp freshness monitoring. The encapsulation efficiency of the anthocyanin-loaded liposomes increased from 36.06% to 46.99% with an increasing ratio of lecithin. The water vapor transmission (WVP) of the A-CBAL films, with a value of 2.32 <sup>×</sup> <sup>10</sup>−<sup>7</sup> <sup>g</sup> · <sup>m</sup>−<sup>1</sup> · <sup>h</sup>−<sup>1</sup> · pa−1, was lower than that of the film with free anthocyanins (A-CBA). The exudation rate of the A-CBA film reached 100% at pH 7 and pH 9 after 50 min, while the A-CBAL films slowed down to a value lower than 45%. The encapsulation of anthocyanins slightly decreased the ammonia sensitivity. Finally, the bi-layer films with liposomes successfully monitored shrimp freshness with visible color changes to the naked eye. These results indicated that films with anthocyanin-loaded liposomes have potential applications in high-humidity environments.

**Keywords:** liposomes; high stability; freshness; bi-layer indicator
