Moderate and High Intensity Pulsed Electric Fields. Effect on microbial inactivation, shelf life and quality of fruit juices

PhD defence

Moderate and High Intensity Pulsed Electric Fields. Effect on microbial inactivation, shelf life and quality of fruit juices

PhD candidate dr. RAH (Rian) Timmermans
Promotor prof.dr.ir. MAJS (Tiny) van Boekel
Co-promotor dr.ir. MN (Masja) Nierop Groot
Co-promotor dr. HC Mastwijk
Organisation Wageningen University, Wageningen Food & Biobased Research
Date

Fri 19 January 2018 13:30 to 15:00

Venue Auditorium, building number 362
Generaal Foulkesweg 1
362
6703 BG Wageningen
0317-483592

Summary

Pulsed Electric Field (PEF) processing can be used as a mild preservation technology that uses electrical pulses to extend the shelf life of liquid food products, such as fruit juices; it is a mild alternative to thermal pasteurisation of high acid products, because it extends the shelf life of the product with retention of the fresh characteristics. Micro-organisms are inactivated by electric pulses of a certain strength and duration that damage their cell membranes.

This PhD research investigated how PEF processing conditions, product characteristics and characteristics of the micro-organisms affect microbial inactivation, shelf life, enzyme activity and quality of the fruit juice. The work resulted in a new combination of moderate intensity process parameters that are easy to scale and interesting for industrial application, because the effectivity of the process is less dependent on microbial characteristics as found for the – usual - high intensity pulses and can be used for both high acid and low-acid food products.