High Pressure Processing causes enzymatic browning and cell damage in peaches

Peach cultivars contribute to unique product characteristics and may affect the degree of browning after high-pressure processing (HPP). Nine peach cultivars were subjected to HPP at 0, 100, and 400 MPa for 10 min. Proton nuclear magnetic resonance (1H NMR) relaxometry, light microscopy, color, polyphenol oxidase (PPO) activity, and total phenols were evaluated. The development of enzymatic browning during refrigerated storage occurred because of damage during HPP that triggered loss of cell integrity, allowing substrates to interact with enzymes. Increasing pressure levels resulted in greater damage, as determined by shifts in transverse relaxation time?and by light micrographs. Discoloration was triggered by membrane decompartmentalization but limited by PPO activity, which was found to correlate to cultivar harvest time (early, mid, and late season). Outcomes from the microstructure,?1H NMR ,and PPO activity evaluation were an effective means of determining membrane decompartmentalization and allowed for prediction of browning scenarios. ? Chukwan Techakanon??,?Thomas M. Gradziel?, and?Diane M. Barrett? ?Department of Food Science and Technology and??Department of Pomology,?University of California, Davis, One Shields Avenue, Davis, California 95616,?United States ??Faculty of Science and Industrial Technology,?Prince of Songkla University, Surat Thani Campus, 31 Makham Tia, Muang Surat Thani, Suratthani 84000,?Thailand J. Agric. Food Chem.,?2016,?64?(40), pp 7606?7614 DOI:?10.1021/acs.jafc.6b01879 Publication Date (Web): September 14, 2016 Copyright ? 2016 American Chemical Society