Intake of Mediterranean vegetable soup treated by pulsed electric fields affects plasma vitamin C and antioxidant biomarkers in humans

Abstract

The bioavailability of vitamin C from pulsed electric fields (PEF)-treated vegetable soup in comparison with freshly made (FM) vegetable soup—gazpacho—and its impact on 8-epiPGF_2α and uric acid concentrations in a human population were assessed. For this purpose six subjects consumed 500 ml PEF-treated vegetable soup/day, and six subjects consumed 500 ml FM vegetable soup/day for 14 days. On the first day of the study, the subjects drank the vegetable soup in one dose (dose–response study), and on days 2–14 they consumed 250 ml in the morning and 250 ml in the afternoon (multiple-dose–response study). Blood was collected every hour for 6 h on the first day and again on days 7 and 14. All blood samples were analyzed for vitamin C, 8-epiPGF_2α, and uric acid. The maximum increase in plasma vitamin C occurred 3 h post-dose in both the PEF and the FM groups. Vitamin C remained significantly higher (P≤0.05) on days 7 and 14. The plasma 8-epiPGF_2α concentration was significantly lower at the end of the study in both the PEF group (P=0.002) and the FM group (P=0.05). Plasma levels of vitamin C and 8-epiPGF_2α were inversely correlated in both groups (r= − 0.549, P=0.018; and r= − 0.743, P=0.0004, respectively). To summarize, drinking two servings (500 ml) of PEF-treated or FM gazpacho daily increases plasma vitamin C and significantly decreases 8-epiPGF_2α concentrations in healthy humans.