Levels of antioxidants and nutraceuticals in basil grown in hydroponics and soil

Owing to the traditional phytotherapeutic use of basil and its importance as a basic component of the Mediterranean diet, this research aimed to study the nutraceutical properties of basil (Ocimum basilicum cv. Genova) grown in hydroponics in comparison with that grown in soil. The antioxidant activities of aqueous and lipid extracts of basil leaves were evaluated both by spectrophotometric detection with the 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) radical cation (ABTS+) and by electron paramagnetic resonance (EPR) detection with the stable radicals peroxylamine disulphonate (Fremy’s salt, hydrophilic) and 1,1-diphenyl-2-picrylhydrazyl (DPPH, lipophilic). From EPR decay kinetics analysis, it was possible to distinguish (in the lipid extract) a fast rate constant and a slow rate constant, likely attributable to two different kinds of lipophilic antioxidants. Hydroponic cultivation improved antioxidant activity of both aqueous and lipid extracts, increasing the contents of vitamin C, vitamin E, lipoic acid, total phenols and rosmarinic acid.