Comparing the impact of high pressure high temperature and thermal sterilization on the volatile fingerprint of onion, potato, pumpkin and red beet

Abstract

This work reports the effect of high pressure high temperature (HPHT) processing as compared to thermal processing on the volatile fraction of four, industrially-relevant, vegetables: onion, potato, pumpkin and red beet. The vegetables were selected from different botanical families, edible plant parts and color groups, aiming for investigation of a wide range of chemical reactions. Despite the difference in chemical composition among these vegetables, some remarkable general trends could be found. Firstly, in all vegetables, Strecker degradation products (such as 2- and 3-methylbutanal) were detected at higher levels after HPHT sterilization in comparison to thermally sterilized counterparts. Secondly, HPHT sterilization enhanced oxidative degradation reactions (e.g. unsaturated fatty acids (in pumpkin, red beet and onion) and carotenoids (in pumpkin)). This work demonstrated the power of the untargeted multi-variate fingerprinting approach as a fast screening tool to zoom into relevant reaction pathways out of a complex network of chemical changes and to determine discriminative volatiles which can serve as potential markers.