Electrospun film polyvinyl alcohol/chitosan loaded with cinnamon essential oil and inhibitory effects on polyphenol oxidase and dominant spoilage bacteria from Pacific white shrimp

Abstract

Pacific white shrimp (Litopenaeus vannamei) is prone to melanosis and spoilage during refrigeration. To develop an active packaging material with inhibitory effects on polyphenol oxidase (PPO) (related with melanosis) and specific spoilage organisms of refrigerated spoilage Litopenaeus vannamei (Lv-SSOs), one degradable polyvinyl alcohol-chitosan (PVA-CS) fibrous mats encapsulating cinnamon essential oil (CEO) were fabricated by electrospinning. Compared to PVA-CS, the transparency, tensile strength and water contract angle of CEO-loaded electrospun film (CEO/PVA-CS) were all significant increased. CEO molecules uniformly dispersed between PVA-CS fiber bundles without any visible gaps under scanning electron microscopy observation. Fourier transform infrared spectroscopy and X-ray diffraction analyses revealed that CEO successfully embedded into PVA-CS matrix through inter-molecular forces, thus improving the compact of CEO/PVA-CS. In simulate food systems (4 °C and 25 °C), the release patterns of CEO from CEO/PVA-CS fit well to Higuchi and Rigter-Peppas models, and could be explained by the Fickian diffusion mechanism. At refrigeration (4 °C), CEO/PVA-CS had 57.52 ± 3.33% inhibition rate on PPO, extracted from the cephalothorax of Litopenaeus vannamei, after 7 h of interaction. Moreover, CEO/PVA-CS effectively inhibited Lv-SSOs growth at 4 °C. Therefore, the electrospun film of CEO/PVA-CS should have potential application prospects in delaying melanosis and spoilage of refrigerated shrimp.