Abstract
In the recent years, there is an increasing demand for organic foods in Saudi Arabia, due to concerns of consumers about health and nutrition. In order to accurately draw any conclusion regarding the health benefits and nutrition superiority of organic food, the aim of the present study was to investigate the antioxidant activity, antioxidant compounds and nutritional constituents of organically and conventionally cultivated tomato and carrot samples purchased from local markets of Al-Qassim region, Saudi Arabia, throughout six months. Antioxidant capacities were evaluated based on the ability of the extracts to scavenge 1,1-diphenyl-2-picryl hydrazyl (DPPH). Antioxidant activity and antioxidant components of organically and conventionally cultivated samples varied throughout the experimental time. Organic tomatoes had higher values of antioxidant activity and antioxidant components, lycopene and phenolics than conventional tomatoes. In contrast, a lower antioxidant capacity and its contributors' phenolics and vitamin C was observed in organic carrots. Nutritional constituents in tomato and carrot varied in their response to production method. Organic tomatoes had higher values of dry matter, soluble sugars and oils and lower levels of protein and minerals than conventional ones, whereas organic carrots contained higher levels of protein, oils and minerals and lower levels of sugar content as compared with conventional cultivation: Variation in antioxidant capacity, antioxidant components and nutrient components between tomato and carrot samples as affected by production methods seemed to be associated with nitrogen and protein contents more than with production system.