Hydrophilic and Lipophilic Antioxidant Capacities of Commercial Mediterranean Vegetable Soups (Gazpachos)

Abstract

Gazpacho is a traditional cold Mediterranean soup consisting of 5 vegetables (tomato, cucumber, green pepper, onion, and garlic) and olive oil. Antioxidant activities of commercial gazpachos, processed by different technologies (traditional pasteurized [TP], slight pasteurized [SP], and frozen [F]), were assessed. Both lipophilic and hydrophilic DPPH* radical scavenging capacities (L-RSC and H-RSC, respectively) were determined in terms of EC50 and antiradical efficiency (AE). AE parameter takes into account not only antioxidant concentration but also antioxidant kinetic. L-RSC values were approximately 3-fold lower than the H-RSC values in all the gazpacho soups. Lycopene and total carotenoid concentration showed statistically significant correlation against L-RSC as follows: for lycopene, EC50 (r2= 0.4549, P = 0.0001) and AE (r2= 0.5982, P < 0.0001); for total carotenoid, EC50 (r2= 0.4381, P = 0.0002) and AE (r2= 0.5881, P< 0.0001). In the case of H-RSC, a correlation was found between EC50 values and total phenol content (r2= 0.1570, P = 0.0452) and vitamin C (r2= 0.1751, P = 0.0299). Also, a correlation was found between vitamin C and AE values (r2= 0.3485, P = 0.0012), suggesting a predominant role of vitamin C among others constituents in the kinetic of H-RSC. One serving (200 mL) of TP, SP, or F gazpacho soup corresponds to an intake of 16.4 ± 2.6 mg, 16.3 ± 2.1 mg, or 10.6 0.8 mg of vitamin C equivalents of H-RSC, respectively; and to an intake of 7.0 ± 1.0 mg, 6.9 ± 1.0 mg, or 5.3 ± 0.1 mg of lycopene equivalents of L-RSC, respectively.