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

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(2alpha) 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(2alpha), 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(2alpha) 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(2alpha) 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(2alpha) concentrations in healthy humans.