The effect of calcium chloride and calcium lactate pretreatment concentration on peach cell integrity after highpressure processing

The objective of this study was to determine the effect of calcium chloride and calcium lactate pretreatments at different concentrations (1, 1.5 and 2% w/v) on enzymatic browning of clingstone and freestone peaches following high-pressure processing (HPP) at 200 MPa for 10 min. Proton nuclear magnetic resonance (H-NMR) relaxometry indicated that following calcium pretreatment and HPP, both peach types had lower percentages of water in the vacuole compartment and a simultaneous increase in the percentage of water in the cytoplasm compartment. Calcium pretreatment of freestone peaches did not affect the development of browning, regardless of the form of calcium or the concentration, whereas calcium lactate pretreatment undesirably enhanced clingstone peach discoloration. Calcium pretreatments have the potential to reduce the loss of cell integrity that results from HPP; however, in this study, the effect was not sufficient to inhibit the interaction between the polyphenol oxidase enzyme that catalyses browning and its substrates.