Abstract:

ε-polylysine, nisin, natamycin and R-polysaccharide were added to fresh kiwi fruit slurry for inhibiting the growth of microorganisms in it. In order to minimize the total bacterial count in kiwi fruit slurry, the amounts of these compounds were optimized using central composite design and response surface methodology. The results showed that the optimum amounts of ε-polylysine, nisin, natamycin and R-polysaccharide were 0.009514%, 0.010812%, 0.002968% and 0.140249%, respectively. Fresh kiwi fruit slurry with these compounds added at the optimum amounts was stored at 0－4 ℃ without sterilization, and after 12-month storage, the total bacterial count, mold count and coliform count were measured to be 130 CFU/g, 10 CFU/g and less than 3 MPN/100 g, respectively, no pathogenic bacteria were detected, and the titratable acidity and the contents of sugar and vitamin C were 1.14%, 8.9%, and 68 mg/100 g, respectively, indicating a good fresh-keeping effect.

Key words: kiwi fruit, fresh fruit slurry, preservative, response surface methodology, optimality