The effect of high-pressure processing or thermosonication in combination with nisin on microbial inactivation and quality of green juice

摘要

The impact of high-pressure processing (HPP) or thermosonication (TS) in combination with nisin on the microbial inactivation of green juice (celery stalk, apple, cucumber, parsley) and changes in its quality was investigated. Microbial inactivation with HPP at 600 MPa resulted ≥7 log reduction of Escherichia coli, whereas 5 and 7 log reduction of Listeria innocua were attained after combining with 100 and 200 mg/L of nisin, respectively. With TS at 60°C, 7.42 log reduction of E. coli was achieved after 6 min; meanwhile, combining with 100 mg/L of nisin, 7 log reduction of L. innocua was detected after 3 min. Neither HPP nor TS did not alter pH and total soluble solids; however, significant changes were observed in color. Green juice predominantly followed Newtonian flow behavior and the viscosity did not change significantly after using both technologies. Results indicated that HPP or TS in combination with nisin is a viable option for green juice pasteurization.