Probe sonicator as an effective alternative to inactivate pathogens and maintain in vitro antioxidant activity and α-tocopherol content in human milk

Abstract

This study assessed the new technology of a high-intensity sonicator for processing of human milk comparing it with slow pasteurisation for effectiveness in inactivating pathogenic microorganisms and reducing the loss of antioxidant activity (AA). In the first stage, the effect of the diameter of glass vials on the effectiveness of ultrasound was evaluated and, subsequently, the effect of varying time and sonication amplitude in the inactivation of enteropathogenic Escherichia coli and Staphylococcus aureus in human milk. In the second stage, the effect of sonication on in vitro antioxidant activity was determined. Samples treated in the smaller diameter vials showed significantly greater decimal reductions. With higher amplitudes and the increase in sonication time there was a preservation of AA with the ultrasonic treatment, but with a shorter time span, which can lead to time and cost optimisation in human milk banks, in addition to significant decimal reductions in the pathogens evaluated.