PROCESSING OF PEACH NECTAR BY PULSED ELECTRIC FIELDS WITH RESPECT TO PHYSICAL AND CHEMICAL PROPERTIES AND MICROBIAL INACTIVATION

摘要

Applicability of pulsed electric fields (PEFs) to process peach nectar as a function of electric field strength and treatment time with respect to microbial inactivation and measurement of physical and chemical properties of peach nectar was evaluated. No significant difference was detected in terms of pH, °Brix, titration acidity (TA), conductivity, color (L*, a* and b*), nonenzymatic browning index (NBI), metal ion concentration, ascorbic acid content and beta carotene concentration between control and PEF-treated peach nectar samples (P > 0.05). On the other hand, Escherichia coli O157:H7, Staphylococcus aureus, Listeria monocytogenes, Erwinia carotowora, Pseudomonas syringae, Botrytis cinerea and Penicillum expansum were significantly inactivated (P ≤ 0.05). PEF can successfully be applied to peach nectar with significant amount of microbial inactivation without a significant adverse effect on physical and chemical properties.