关键词: 感应电场；生牛乳；杀菌；理化特性

Abstract: In order to investigate the efficacy of induced electric field (IEF) in sterilizing raw milk and the effect on its physicochemical properties, milk samples were treated by IEF at different excitation voltages (300, 400, and 500 V) and evaluated for Staphylococcus aureus and Escherichia coli counts and physicochemical properties. Meanwhile, changes in acidity and total bacterial count were minored during storage. Results indicated that the outlet endpoint temperature of milk increased with the increase in excitation voltage, and so did the efficacy of IEF in inactivating S. aureus and E. coli. The efficacy of reducing the microbial level in raw milk was higher than that of traditional heat treatment and high-temperature short-time pasteurization. IEF had no significant effect on the pH, fat, soluble solids, casein, or lactoferrin content of milk (P > 0.05), nor did it destroy milk nutrients. Moreover, IEF effectively delayed the increase in acidity and extended the shelf-life of milk stored at 4 ℃ by about 6 days. This study provides a new solution for high-quality sterilization and shelf-life prolongation of raw milk.

Key words: induced electric field; raw milk; sterilization; physicochemical properties