High-pressure processing of pumpkin (Cucurbita moschata ex Poir. Cv. Violina) cubes: effect of pressure level and time combinations on quality parameters

Abstract High-pressure processing (HPP) is one of the established innovative technologies applied to food materials to retain the highest quality. This study aimed to evaluate the influence of selective pressures (200, 400 and 600 MPa) and time (1, 3 and 5 min) on pumpkin cubes. HPP treatment decreased all color parameters values compared to untreated (UNTR) samples. The treatments 400_3, 600_1, and 600 _3 had a minor impact on them. Pressure-treated samples at 400_3 and 600_5 had lower hardness (155.3 and 161.1 ± 3 N) than untreated ones (313.0 ± 46.3 N). The combined effect of pressure and holding time altered pumpkin cubes microstructure, cell morphology, and increased antioxidant activity by releasing active compounds from damaged tissues. Samples treated at 400_1 showed the highest total polyphenol content while those treated at 600_5, 600_3 and 400_1_3 and _5 showed an increase in total carotenoid content, in particular α-carotene and β-carotene. A 2-way ANOVA showed that all volatile compounds (except 2-pentylfuran) were significantly affected by both pressure levels and holding time. Additionally, samples treated at 400_5 had a higher total sugar content than untreated samples. In conclusion, HPP at 400 and 600 MPa under holding times 1, 3, and 5 min led to the detection of various compounds in pumpkin cubes due to the textural and structural changes induced.