Construction of a biprotein based highly stable CEO encapsulation system: Application to fish preservation

Aquatic products are susceptible to spoilage by enzymatic hydrolysis and microbial action during storage. In this study, a biprotein nanocomplex was prepared using Zein and WPI, which was assembled by non-covalent bonds such as hydrogen bonding and electrostatic interactions, and possessed excellent affinity, dispersibility and emulsification ability. An encapsulation system of cinnamon essential oil (bip-IC) was prepared using this complex. Different concentrations of CEO would greatly affect the performance of bip-IC. At a CEO concentration of 2.5%, the particle size of bip-IC was minimized and environmental stability was enhanced. The antioxidant and antimicrobial evaluations showed that bip-IC achieved 81.4% and 72.4% of DPPH radical scavenging activity and OH· scavenging activity, respectively, and effectively inhibited E. coli , S. aureus , and P. aeruginosa . Finally, bip-IC was successfully coated on grass carp fillets and stored at 4°C for 10 d. At 10 d, the total colony viable count of the bip-IC-coated grass carp fillets was 1.08 lg (CFU/g) lower than that of the control group, the drip loss was 27.48% lower than that of the control group, and the TVB-N was 53.45% lower than that of the control group. The muscle texture, color and flavor of grass carp were well maintained. In conclusion, bip-IC prepared based on Zein/WPI nanocomplexes, as a promising material, is expected to provide new ideas for aquatic products preservation. • Zein and WPI combine through non-covalent bonds to form biprotein nanocomplexes. • Biprotein nanocomplexes form cinnamon essential oil inclusion complexes (bip-IC). • Bip-IC with 2.5% concentration of CEO showed the best environmental stability. • Bip-IC exhibits good antioxidant and antimicrobial properties. • Bip-IC has been successfully used as coating material for grass carp preservation.