Fabrication of black pepper essential oil based nanoemulsions fortificated with ZnO and polysaccharide coating for improving the organoleptic characteristics and shelf life of chicken meat

Chicken meat is a major commodity worldwide and one of the most widely consumed protein sources due to its accessibility and high nutritional value. However, its high water activity and high nutrient content make it prone to microbial spoilage and lipid oxidation, resulting in a severe decline in organoleptic quality and raising serious food safety concerns, thereby necessitating effective food preservation strategies. This study addresses this requirement by evaluating the development of a novel antimicrobial and antioxidant solution for preserving the quality of chicken meat and improving its shelf life. The black pepper essential oil (BPEO)-based nanoemulsion (NE), enriched by the addition of zinc oxide nanoparticles (ZnO NPs) and an edible polysaccharide coating, was used as a significant strategy to maintain meat quality with extended shelf life. Black pepper essential oil contains bioactive compounds such as 3-carene, D-limonene, caryophyllene, β-pinene, and α-pinene, which exhibit influential antimicrobial and antioxidant activities. However, its high volatility and poor water solubility are the limitations for its direct application. The BPEONE was synthesized by low-energy, emulsion phase inversion emulsification process. Optimization provided a stable NE with a mean droplet size of 120±73 nm and a polydispersity index of 0.261. The incorporation of ZnO NPs along with BPEONE significantly enhanced the antimicrobial efficacy against microorganisms. Results from the preservation efficacy tests showed that the ZnO NP- and BPEONE-coated chicken samples had significantly lower microbial loads than the uncoated control sample and the samples coated with BPEONE and BPEO alone. Specifically, the total viable count (TVC) was reduced by approximately 4.77  106 CFU/g, on the 16th day of refrigerated storage as compared to the control group with 8.40  106 CFU/g. Furthermore, the nano-formulation coating was also effective in suppressing lipid oxidation, as indicated by a decrease in Thiobarbituric acid reactive substances (TBARS) values, from 2.73±0.13 mg MDA/kg (control group) to 0.68±0.09 mg MDA/kg (ZnO NP+BPEONE coating) after 16 days of storage. Crucially, the treatment preserved the organoleptic qualities (i.e., color, texture, flavor) of the chicken meat, maintaining acceptable scores until the 12th day of storage, as compared to the control group. This nano-formulation of BPEONE and ZnO NPs in a polysaccharide matrix offers a sustainable, effective, and clean-label approach to enhancing meat preservation.