Chitosan, Gelatin, Aloe vera, and Carvacrol Nanoemulsion–Based Edible Coatings: Effects on Physicochemical, Microbiological, and Sensory Qualities of Vacuum-Packed Chicken Fillets

Abstract

Chicken meat contains high-quality protein and is prone to postharvest quality deterioration due to high moisture and lipid content. Thus, in this study, edible coatings were developed from natural biomaterials, that is, chitosan (CH), gelatin (GL), Aloe vera gel (AVG), and carvacrol nanoemulsion (CNE), and their effects on shelf life of unpacked and vacuum-packaged chicken fillets stored at 4°C were investigated. Five different coatings, that is, CH/GL, CH/GL/AVG, CH/GL/AVG/CNE-1 (1% CNE), CH/GL/AVG/CNE-2 (2% CNE), and CH/GL/AVG/CNE-5 (5% CNE), were developed and applied on chicken fillets. In vitro studies of the developed coating formulations showed that CH/GL/AVG/CNE-2 coating had better inhibition against the tested bacterial strains. Consequently, CH/GL/AVG/CNE-2- and CH/GL/AVG/CNE-5-coated chicken fillets had reduced mesophilic and psychrotrophic bacteria, yeast, and mold counts by 3 log CFU/g. The coatings also delayed the production of total volatile bases-nitrogen (TVB-N) and thiobarbituric acid reactive substance (TBARS) during storage. The CH/GL/AVG/CNE-2-coated chicken fillets maintained an overall sensory score above 7.5 at the end of the 20-day storage, while the uncoated control samples scored below 4. Among the five formulations, CH/GL/AVG/CNE-2 demonstrated the best performance, effectively extended shelf life of vacuum-packaged and unpacked fresh chicken fillets up to 20 and 12 days, respectively, under refrigerated (4°C) storage conditions.