Study On Preservative Function Of Pomegranate Peel Extracts And On Preparation Of Antibiofilm

The effect of chitosan(CH) coating combined with pomegranate peel extracts(PPE)on the melanosis formation and quality of Pacific white shrimp(Litopenaeus vannamei)was investigated. The CH-based antimicrobial films were developed by incorporation of PPE using a solvent casing method and their physical, mechanical and antimicrobial properties were examined in the present study. Our results will provide therocial foundation for utilization of PPE on the preservation and freshness of aquatic products.The effect of CH coating combined with PPE on the melanosis formation and quality of Pacific white shrimp(Litopenaeus vannamei) during the 10 days of iced storage was investigated. The melanosis scores and changes of ΔE values were significantly retarded,and the texture parameters and sensory scores were significantly improved in shrimp treated by CH coating, PPE and CH coating combined with PPE compared with the control.The increase in total aerobic plate count, p H and total volatile basic nitrogen content were significantly inhibited in shrimp treated with CH coating, PPE and CH coating combined with PPE. The melanosis and sensory score, total volatile basic nitrogen content, and total aerobic plate count of shrimp treated by CH coating combined with PPE was lower than that treated by CH coating or PPE alone during the later stage of iced storage, suggested there was a synergistic effect between CH coating and PPE. The CH coating combined with PPE could be used as an effective natural alternative to synthetic antimelanosic agents to inhibit postmortem melanosis and improve the quality of shrimp during iced storage.The CH-based antimicrobial films were developed by incorporation of 1% carvacrol(CR), 1%PPE and 1%CR+1%PPE using a solvent casing method and their physical,antioxidant and antimicrobial properties were investigated. The results showed that incorporation of 1%CR, 1%PPE and 1%CR+1%PPE into the film had no significant difference in thickness. The water content rate of 1%PPE or 1%CR+1%PPE incorporated-films was significantly increased, whereas the WVP of 1%PPE or1%CR+1%PPE incorporated-films was significantly decreased. The water absorbing capacities of 1%PPE, 1%CR or 1%CR+1%PPE incorporated-films were significantly decreased, with the lowest in the 1%CR+1%PPE-incorporated-film. The total phenolcontent and antioxidant activity were significantly increased after incorporation of 1%CR,1%PPE and 1%CR+1%PPE into the films. The antibacterial activity against the S. aureus was significantly increased after incorporation with the 1%PPE, 1%CR and1%CR+1%PPE. In addition, the antibacterial activity against the S. aureus in the film incorporated with 1%CR+1%PPE was significantly higher than that incorporated with1%CR or 1%PPE alone, suggesting that there was a synergistic effect between CR and PPE in the film.The CH-based antimicrobial films were developed by incorporation of 1% cinnamon oil(CEO), 1%PPE and 1% CEO +1%PPE using a solvent casing method and their physical,antioxidant and antimicrobial properties were inveistiged. The results showed that incorporation of 1%CEO, 1%PPE and 1%CEO+1%PPE into the film had no significant difference in thickness. The water content rate of 1%PPE or 1%CEO+1%PPE incorporated-films was significantly increased, whereas the WVP of 1%PPE or 1%CEO+1%PPE incorporated-films was significantly decreased. The water absorbing capacities of1%PPE, 1%CEO or 1%CEO+1%PPE incorporated-films were significantly decreased,with the lowest in the 1%CEO+1%PPE incorporated-film. The total phenol content and antioxidant activity were significantly increased after incorporation of 1%CEO, 1%PPE and 1%CEO +1%PPE into the films. The antibacterial activity against the S. aureus was significantly increased after incorporation with the 1%PPE, 1%CEO and 1%CEO +1%PPE.In addition, the antibacterial activity against the S. aureus in the film incorporated with 1%CEO+1%PPE was significantly higher than that incorporated with 1% CEO or 1%PPE alone, suggesting that there was a synergistic effect between CEO and PPE in the film.