Active packaging film with functions of moisture-absorbing and antioxidant activity was developed based on poly(vinyl alcohol) (PVA) incorporated with green tea extract (GTE). The effects of GTE concentrations of 0, 0.5, 1, 1.5, and 2% on the physical, structural, and antioxidant properties of PVA films were investigated. The PVA film containing 2% GTE had lower moisture absorbing efficiency relatively and better antioxidant activity through DPPH radical-scavenging ability experiment. A packaging system of GTE-incorporated PVA films was applied to package dried eel and quality of dried eel was evaluated during storage. The result showed that dried eel packed with GTE-incorporated PVA films showed lower weight change, peroxide value and TBARS value during storage than that packed without PVA films or with PVA films but no GTE. The PVA film containing 2% GTE showed the best quality protective effectiveness to prevent the dried eel from absorbing moisture and oxidizing of lipid.
Practical applicationsPoly(vinyl alcohol) (PVA) is a synthetic polymer that is widely used in packaging applications because of its excellent film forming, biodegradability, good mechanical, and gas barrier properties.The present study evidenced that the PVA films incorporated with GTE showed good quality protective effectiveness to prevent the dried eel packed with these films from absorbing moisture and oxidizing of lipid. This active packaging film could be used as inner layer or intermediate layer in the composite packaging film system to improve the storage quality of moisture-sensitive and high-fat food. Based on this concept, the moisture-absorbing agents and antioxidant can be incorporated into the packaging structures to develop an active multifunctional food packaging material potentially to remove or reduce moisture inside the food packaging system instead of desiccants and preservative added in the food.