A chemometrics approach to compare volatile changes during shelf life of Pulsed Electric Fields, High Pressure and thermal pasteurized apple juice

Abstract

High Pressure Processing (HPP) and Pulsed Electric Fields (PEF) processing technologies 17 are being used increasingly on a commercial basis, with high quality-labelled fruit juices being as 18 one of the most important promotion strategies. Quality-related enzymes, which might still be 19 active after HPP and PEF pasteurizations, can cause undesirable aroma changes during storage. 20 This study investigated volatile changes during shelf life of PEF (15.5 kV/cm and specific energy of 21 158 kJ/L), HPP (600 MPa for 3 min) and thermally (72°C for 15 s) pasteurized Jazz apple juices, up 22 to 5 weeks. To have an increased insight into the volatile changes, an integrated instrumental (GC-23 MS) and data analysis (chemometrics) approach was implemented. Immediately after 24 pasteurization, PEF processing resulted a better retention of odor active volatiles, such as (E)-2-25 hexenal and hexyl acetate, whereas thermal processing lowered their amount. During refrigerated 26 storage, these volatiles have gradually decreased in all processed juices. By the end of storage, the 27 amount of these aroma relevant volatiles appears to be still higher in PEF and HPP pasteurized 28 juices compared to their conventional counterparts. This study demonstrated the potential of 29 advanced chemometric approaches to obtain an increased insight into complex shelf life changes.