Stability of the phenolic and carotenoid profile of gazpachos during storage

Gazpacho is a ready-to-use vegetable soup containing tomato, cucumber, pepper, olive oil, and other minor constituents such as onion, garlic, wine vinegar, sea salt, and water. In this work, changes in individual phenolic and carotenoid compounds of commercial gazpachos, as well as in their hydrophilic and lipophilic antioxidant capacities (measured through ABTS+ and DPPH radicals), were assessed for 3 months at 4 °C. The storage of gazpachos at 4 °C for 3 months results in a slight decrease in their polyphenol and carotenoid content and also in the hydrophilic and lipophilic antioxidant capacities, but the levels achieved could not be construed as a nutritional drawback. The main degradation was quercetin oxidation because the hydroxy function at the C-ring of the flavonoid is not blocked by a sugar moiety as it is in the case of rutin and kaempferol-3-O-rutinoside and glycosylated caffeic and ferulic acids. Lycopene underwent significant losses throughout storage as 11 conjugated double bonds are present in its structure and should be more reactive than trans-lutein and trans-β-carotene. cis-Lycopene isomers slightly decreased. However, 5-cis-lycopene underwent a slight increase. This phenomenon could be explained by cis-isomerization increasing the proportion of cis-isomers.