Synergistic stabilization of garlic essential oil nanoemulsions by carboxymethyl chitosan/Tween 80 and application for coating preservation of chilled fresh pork

Abstract

Garlic essential oil (GEO) is a potential natural antioxidant and antimicrobial agent for food preservation, but its intrinsic low water-solubility, high volatility and poor stability severely limit its application and promotion. In this work, we investigated the synergistic stabilization of the GEO-in-water nanoemulsion using carboxymethyl chitosan (CCS) and Tween 80 (TW 80). Additionally, the nanoemulsion was fabricated through high-pressure microfluidization and utilized for the coating-mediated preservation of chilled pork. The garlic essential oil nanoemulsion (GEON) with 3.0 % CCS and 3.0 % TW 80 exhibited more homogeneous droplet size (around 150 nm) and narrower size distribution, while maintained long-term stability with no significant change in size during 30 d storage. Compared with free GEO, the GEONs exhibited a higher scavenging capacity to DPPH and ABTS free radicals as well as higher inhibitory effects against Escherichia coli and Staphylococcus aureus, suggesting that the encapsulation of GEO in nanoemulsion considerably improved its antioxidant and antibacterial activities. Furthermore, the results of coating preservation experiments showed that the GEON coating effectively expanded the shelf-life of chilled fresh pork for approximately one week. Altogether, this study would guide the development of GEO-loaded nanoemulsions, and promote GEON as a promising alternative for coating preservation of chilled fresh meat.

Keywords: Coating preservation; Garlic essential oil; Nanoemulsion.