Variations in the phytochemical contents and antioxidant capacity of organically and conventionally grown Italian cauliflower (Brassica oleracea L. subsp. botrytis): results from a three-year field study.

A three-year field study (2009-2011) was performed to evaluate phytochemicals and antioxidant capacities of two genotypes (HF1 Emeraude and the local variety, Velox) of green cauliflower grown under organic and conventional management. The conventional system increased yield, but had little effect on the dry matter, whereas the organic system increased the soluble solids. Phytochemicals and antioxidant capacity showed significant year-to-year variability. During the third year, the scarce rainfall determined a significant increase of total glucosinolates and a general decrease of antioxidants in all samples. Interestingly, in the same year organic plants were less affected by the unfavorable climatic conditions, as they increased ascorbic acid, polyphenols, and carotenoids with respect to conventional ones. The overall results for the three years showed that the two genotypes responded differently. Compared to the conventional system, Velox showed 24, 21, 13, 48, and 44% higher content of ascorbic acid, polyphenols, carotenoids, volatiles, and antioxidant capacity, respectively. In contrast, no significant increase in the phytochemicals or the antioxidant potential was found in organic Emeraude, with the exception of total volatiles (+41%). These findings suggest that organic cultivation may be highly effective for particular cauliflower genotypes.

Effects of organic farming and genotype on alimentary and nutraceutical parameters in tomato fruits.

BACKGROUND: In recent years there has been growing interest in the influence of sustainable cultivation systems on the biochemical quality of vegetables. In this study, two genotypes of tomato, Giulianova and Perbruzzo, were grown in both organic (Or) and conventional (Conv) systems for three years and harvested at commercial ripening in each year. The Conv system was established according to traditional techniques and the Or system according to current EU regulations. Samples were evaluated for volatile substances, sugars, organic acids, dry matter, pH and lycopene. RESULTS: During the three years, volatile substances increased in Or samples of Giulianova, while this response was less evident in Perbruzzo. Other parameters of both genotypes were not influenced by Or cultivation. Lycopene content in both Conv-cultivated genotypes was constant during the whole experimental period. In Or samples, lycopene content was lower than in Conv samples during the first and second years. In the last year, lycopene content in Or samples of Giulianova was similar to that in Conv samples, while lycopene content in Or samples of Perbruzzo was higher than that in Conv samples. CONCLUSION: Changes in biochemical parameters of tomato fruits could be affected by both cultivation system and genotype, with a significant increase in both volatile substances and lycopene in the 2010 crop.