Effect of ultrasound on survival and growth of Escherichia coli in cactus pear juice during storage

• Published in: Brazilian journal of microbiology 2016-04, Vol.47 (2), p.431-437
• Main Authors: Cruz-Cansino, Nelly del Socorro, Reyes-Hernández, Isidro, Delgado-Olivares, Luis, Jaramillo-Bustos, Diana Pamela, Ariza-Ortega, José Alberto, Ramírez-Moreno, Esther
• Format: Article
• Language: English
• Subjects: bacteria; Cactaceae - chemistry; Cactaceae - microbiology; Cactus pear juice; cactus pears; E coli; Escherichia coli; Escherichia coli - growth & development; Food Microbiology; Food Preservation - instrumentation; Food Preservation - methods; Food Storage; Fruit - chemistry; Fruit - microbiology; Fruit and Vegetable Juices - analysis; Fruit and Vegetable Juices - microbiology; Fruit juices; Growth; Microbial Viability; MICROBIOLOGY; pear juice; Storage; storage time; titratable acidity; total soluble solids; Ultrasonic imaging; ultrasonic treatment; Ultrasonics - instrumentation; Ultrasonics - methods; Ultrasound
• ISSN: 1517-8382; 1678-4405; 1678-4405
• DOI: 10.1016/j.bjm.2016.01.014

The aim of this study was to investigate the effectiveness of ultrasound as a conservation method for the inactivation of Escherichia coli inoculated into cactus pear juices (green and purple). Total soluble solids, pH, titratable acidity, and the kinetics of E. coli in cactus pear juices treated by ultrasound (60%, 70%, 80% and 90% amplitude levels for 1, 3 and 5min) were evaluated over 5 days. Total inactivation was observed in both fruit juices after 5min of ultrasound treatment at most amplitude levels (with the exception of 60% and 80%). After one and two days of storage, the recovery of bacteria counts was observed in all cactus pear juices. Ultrasound treatment at 90% amplitude for 5min resulted in non-detectable levels of E. coli in cactus pear juice for 2 days. The parameters of pH, titratable acidity and soluble solids were unaffected.