Potential of antimicrobial active packaging ‘containing natamycin, nisin, pomegranate and grape seed extract in chitosan coating’ to extend shelf life of fresh strawberry

• CH coatings as carrier of NS, NT, PE and GE were applied to fresh strawberry.
• All coating treatments preserved quality of strawberry compared to untreated ones.
• CH + NT was the best coating on delaying chemical and microbiological changes.

In this study, chitosan (CH) coatings as carrier of nisin (NS), natamycin (NT), pomegranate (PE) and grape seed extract (GE) were used to maintain quality and extend shelf life of fresh strawberry. The samples were analyzed in terms of gas composition inside packaging, pH, total soluble solid content, water activity, color, texture, FT-NIR and microbial counts for up to 40 days at 4 ̊C. The experiments showed that all coating materials preserved the quality of fresh strawberry compared to untreated ones. Among the treatments, incorporation of the natamycin in the chitosan coating (CH + NT) reduced the O2 consumption of the fruit and showed better effects on delaying changes of pH, total soluble solid content, water activity and microbial counts. The incorporation of different antimicrobial agents into chitosan matrix did not reveal any significant effect on lightness (L*) and redness (a*) of strawberry. Among the treatments, CH + PE and CH + NT showed significantly higher antimicrobial effect against the mesophilic bacteria and yeast and mold. As a general result, antimicrobial active packaging based on the combination of chitosan coating with antimicrobial agents increased the shelf life of fresh strawberry compared to uncoated fruit.