The Application Of Hurdle Technology Based On Antibacterial Packaging And Cold Sterilization During Surimi-based Product Storage

Hurdle technology is one combined method of various technologies, which aim to prevent the oxidation of fatty acid and the growth of microbiology, and prolong the shelf-life during aquatic products processing and storage. The selection of hurdle factors is very important for quality control of each food. In this study, the new hurdle technology based on antibacterial packaging and cold sterilization was applied during surimi-based product storage, which mainly contained preparations of microcaplules and antibacterial packaging films, as well as their physical-chemical proterties and mechanical property. At the same time, the combination of antibacterial package and high hydrostatic pressure was measured to select the optimal method for surimi-based product storage. The main results were as follows:(1) The nisin/chitosan antimicrobial encapsulation was prepared with the analyzing of morphology, antibacterial activity and release characteristics. The ionic gelation method was used to prepare the nanoparticles. The encapsulation efficiency of mirocapsule was 70.87% when 2% chitosan, 0.1% sodium tripolyphosphate and 0.1g/m L nisinsolution were blended by magnetic stirring with the volume ratio of 10:10:1. Each prepared encapsulation exhibited an approximate spherical shape and a smooth surface. The nisin-loaded microencapsulation demonstrated antibacterial activity toward foodborne pathogens including E. coli, V. parahaemolyticus, and especially toward L. monocytogenes. Nisin was released slowly from the CS/TPP nanoparticles in sodium phosphate buffer throughout a 72 h period; the releasing rate was faster within 48 h. Moreover, the lower p H value was, the faster the releasing rate was. This study indicates that nisin-loaded nanoparticles could be used to delay the release of nisin, and highlight their potential as antibacterial packaging films and coating applications in extending the shelf life of packaged foods.(2) The antibacteial packaging films were prepared and their mophology, antibacterial activity, release rate and tensile strength were analyzed. In this study, zein-based packaging films contained nisin-loaded CS/TPP nanoparticles were prepared with antimicrobial soliquoid of 2% chitosan and 0.1% sodium tripolyphosphate. The diameters of the nanoparticles, approximately 300-600 nm, were smoother in films than others, meanwhile, they have regular spherical structure. The nisin-loaded films also demonstrated antibacterial activity toward foodborne pathogens including E. coli, V. parahaemolyticus, and especially toward L. monocytogenes. Nisin in films was released slowly from the CS/TPP nanoparticles and films in sodium phosphate buffer throughout a 72 h period; the releasing rate was faster from 24 h to 48 h. Moreover, the lower p H value was, the faster the releasing rate was. Different concentrations of CS and TPP influenced the mechanical properties of the edible film significantly; the optimal concentration of CS and TPP was 2% and 0.1%, respectively.(3) The hurdle technology based on antimicrobial packaging and cold sterilization during fish ball storage was applied in this study. The physical-chemical properties(p H, whiteness, texture, total volatile basic nitrogen and thiobarbituric acid reactive substance) and safe indexes(total bacterial account and coli groups) were analyzed. The results demonstrated that the samples had better quality and longer shelf-life with antibacterial packaging than control packaging. At the same time, the samples had better quality with high hydrostatic pressure sterilization than thermal sterilization processing according to p H value, TVBN and whiteness. Moreover, the combination of antibacterial packaging and HHP had safe TBA, and no coli group was detected. Hence, the application of new hurdle technology based on antibacterial packaging and HHP sterilization could prolong the shelf-life of fishball to 30 days in storage temperature of 4℃.