Physicochemical characterization and polyphenol oxidase inactivation of Ataulfo mango pulp pasteurized by conventional and ohmic heating processes

Abstract

Ohmic heating (OH) is an emerging technology with potential for pasteurization and enzyme inactivation in mango pulp. This research aimed to investigate the effect of OH and conventional boiling treatment (CT) at moderate pasteurization conditions (72 °C, 2 min) on the physicochemical characteristics and the polyphenol oxidase (PPO) residual activity in Ataulfo mango pulp. Pulp's physical features, such as titratable acidity (TA) and pH did not show differences (p > 0.05) between treatments, whereas OH increased the apparent viscosity of mango pulp (10.26–15.64%). This effect was associated to a higher release of insoluble fiber. Both thermal treatments affected the color (ΔE values > 5) of mango pulp. PPO inactivation reached 95.7 ± 5.9% after 15 s with both thermal treatments. In silico molecular dynamics suggested that temperature and pH contributed to the PPO inactivation by inducing modifications in its catalytic site and altering the protein-substrate interaction. Our results indicate that OH is an effective technology to inactivate PPO at moderate pasteurization conditions (72 °C, 15 s), with minimal modifications on the physicochemical properties of Ataulfo mango pulp.