Composite films produced from upcycling of tropical fruit seeds are capable of monitoring shrimp freshness

Many tropical fruit seeds are disposed of as waste but have high values for food applications. We developed intelligent pH-sensing films containing avocado seed extract (ASE), alginate, and starch derived from jackfruit seed or durian seed and use them to monitor the freshness of shrimps during 6-day storage at 4 ℃. The water resistance and tensile strength of films were increased after being crosslinked with Calcium cation. This reaction also altered the chemical structure and enhanced the thermal resilience of the film. The addition of ASE assisted in the antibacterial properties and pH sensitivity of the film. The results indicated that the designed colorimetric film could produce different colors indicative of shrimp freshness, which were significantly connected with the degradation indices of total volatile basic nitrogen (TVB-N), and pH values of shrimp. Therefore, it holds promise as a smart packaging material for real-time monitoring of shrimp’s freshness and can contribute to the sustainability of the packaging industry.