THE GLUCOSINOLATES AND VARIATION OF ANTIOXIDANT COMPOUNDS IN SEEDS AND SPROUTS OF BROCCOLI (BRASSICA OLERACEA L. VAR. ITALIC) AND ROCKET (ERUCA SATIVA L.) IN RELATION TO TEMPERATURE AND GERMINATIVE STAGE

In this study we investigated the variation of glucosinolate profile and the amount of antioxidant compounds (total phenols, ascorbic acid and carotenoids) during germination from seed to sprout at 10°C, 20°C and 30°C in two species, broccoli (Brassica oleracea var. italic) and rocket (Eruca sativa L.). The percentage of germination varied in relation to the species and the growth temperature: it was greatest in rocket and the better results were obtained at 20°C. The glucosinolate profile was different between broccoli and rocket, with glucoraphanin as the main component in broccoli and glucoerucin in rocket. The temperature of germination had a significant influence on their total amount, with the maximum at 30°C. Broccoli showed the highest antioxidant response at 10°C and 20°C, while rocket at 10°C. Seed extracts showed the lowest response. Simple linear regression analysis has been performed and the highest correlation was found between the two antioxidant assays. A significant correlation was also found between the two antioxidant assays and the total phenol content. On the other hand, the glucosinolate content and the antioxidant indexes were not significantly correlated.