摘要
Incorporating natural antimicrobial agents,such as plant extracts obtained using organic solvents,may pose some toxicity risks in packaging films.Therefore,Betel leaves(Piper betle)hydrolysates(BH)were obtained through subcritical water treatment at temperatures ranging from 150℃ to 210℃ and 3 MPa for 20 min.The total phenolic compounds(TPC),and total flavonoid compounds(TFC)ranged from 120.10±1.96 to 184.99±3.55 mg GAE/g powder and 32.10±4.96 to 56.50±0.72 mg RE/g powder,respectively.BH also showed excellent inhibitory effects against Gram-positive bacteria(Bacillus cereus and Staphylococcus aureus)and Gramnegative bacteria(Salmonella enterica and Escherichia coli).Packaging films were then fabricated using chitosan with varying concentrations of freeze-dried BH(5 wt%-20 wt%).The tensile strength decreased with increasing BH levels,while surface hydrophobicity and thermal properties increased.Although the films maintained a good microstructure and high tensile strength with up to 10%BH incorporation,15%BH-enriched films appear to be the ideal concentration for food safety and packaging applications,given their superior antioxidant activity and tensile strength.Films with BH demonstrated extended shelf life for yellow corvina fish,as evidenced by total volatile basic nitrogen(TVB-N)and total plate count(TPC)measurements.The preservation capacity of the chitosan-based films is attributed to their effective antimicrobial properties,ability to retard lipid oxidation,and inhibition of spoilage bacteria growth.These films,incorporating betel leaf phenolic extract,hold potential for commercial use as active packaging for seafood preservation.
基金
supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(2023R1A2C1005569).
