Effects of high hydrostatic pressure on physico-chemical and structural properties of two pumpkin species.

Graphical abstract Highlights • Effects of high pressure on pumpkin cubes was compared with thermal treatment. • The effect of three different pressures was evaluated on two pumpkin species. • After high pressure treatment parenchyma cells exhibited collapses and separations. • Treatment at 400 MPa and at 85 °C resulted the most effective on pectin methylesterase. • High pressure treatment decreased antioxidant activity that increased during storage. Abstract The effects of high pressure treatments (200, 400, 600 MPa for 5 min) and a thermal treatment (85 °C for 5 min) were evaluated on cubes of two pumpkin species (Cucurbita maxima L. var. Delica and Cucurbita moschata Duchesne var. Butternut) up to 2 months of refrigerated storage. Increasing the pressure, small parenchyma cells from the pumpkin tissue exhibited collapses and separations, especially for Butternut. This species showed a lower hardness than Delica at time 0. For both species, 400 MPa and thermal treatment were the most effective in the inactivation of pectinmethylesterase, which reactivated after 2 months, especially for Butternut. Colorimetric parameters decreased after all treatments. Antioxidant activity resulted affected by pressure, showing a significant increase during storage especially for the samples treated at 200 MPa after 2 months, comparable to the thermal treated ones. Among the tested treatments, 400 MPa may be considered as the best option for the quality retention during storage. [ABSTRACT FROM AUTHOR]