Abstract: Sorbic acid nanoparticles (SAN), an edible coating made from chitosan, sorbic acid and sodium tripolyphosphate by ionic gelation process, were investigated for their antimicrobial and antioxidant effects on chilled pork in comparison with chitosan nanoparticles, potassium sorbate and blank control. Results showed that the changes in total volatile basic nitrogen (TVB-N), pH and thiobarbituric acid (TBA) value were effectively controlled by SAN. The total numbers of bacteria, and molds and yeasts in chilled pork samples treated with SAN was significantly lower (P < 0.05) than those in the blank control group during the whole storage period, and those in the chitosan nanoparticle group at the late stage of storage. At 7 days of storage, a value (redness) in chilled pork treated with SAN was significantly higher (P < 0.05) than the other groups. Compared with the blank control, SAN extended the shelf life of chilled pork by 5 days. Thus it can be concluded that SAN could inhibit microbial growth and lipid oxidation and prolong the shelf life of chilled pork.

Key words: sorbic acid, nanoparticle, chilled pork, antimicrobial effect, preservation