Effect of thermosonication on pathogenic bacteria, quality attributes and stability of soursop nectar during cold storage

Abstract

© 2017 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. In this work, the effect of the thermosonication (TS) on the inactivation of Escherichia coli and Staphylococcus aureus in soursop nectar was evaluated, as well as the quality and stability of the nectar during its storage at 4°C. A reduction of 4.5–5 log CFU/mL was achieved with the TS treatment (24 kHz, average temperature of 50–51°C, acoustic energy density of 1.3–1.4 W/mL for 10 min) in both pathogens. Likewise, thermosonicated nectar retained 85% of ascorbic acid, polyphenol oxidase inactivation and microbiological and physicochemical stability during 30 days at 4°C. Sensorially, the thermosonicated nectar was predominantly preferred over a commercial one. TS is a viable alternative to extend the shelf life of minimally processed soursop nectar.