Development of PLA‐PHB‐based biodegradable active packaging and its application to salmon

Abstract

In this study, poly (lactic acid)‐poly (hydroxybutyrate) (PLA‐PHB) based films containing bioactive elements were developed and characterized. Seven formulations containing different contents of plasticizers (mono‐caprylin glycerate (GMC) or glycerol monolaurate (GML)) were initially developed. After basic mechanical property tests, the PLA‐PHB‐based films with 0.5% GMC or GML were selected as 2 formulations for further study. In the subsequent experiments, 5% cinnamaldehyde was added into each of the 2 formulations selected and EVOH copolymer (widely used nonbiodegradable packaging as control here) respectively. More mechanical and active properties were investigated. The results showed that PLA‐PHB‐based films possessed some better mechanical properties than those of EVOH‐based film, and better active properties when applied to high lipid food simulant. In a preservative test, changes in total bacterial counts, thiobarbituric acid, and total volatile basic nitrogen were carried out on salmon dices packed with films and stored at 4 ± 1°C. It was only 4.65 CFU/g on day 17 for the salmon packed with PLA‐PHB‐based film with GML as plasticizer; meanwhile, the total bacterial counts of salmon dices sealed in other 2 films reached 6.65 and 6.35 CFU/g respectively on day 15. This study showed that it could be feasible to use biodegradable active packing as an alternative to replace nonbiodegradable packaging for chilled salmon.