Regulate Effect of High Temperature and Its Na₂SeO₃ Combination on the Physiology and Metabolism of Isothiocyanates in Broccoli Sprouts

Effects of high temperature stress and its Na₂SeO₃(0.1 mmol/L)combination on the main physiology,biochemistry and metabolism of isothiocyanate of broccoli sprouts during germination were investigated. The results showed that,compared with the water treatment,the growth of broccoli sprouts was suppressed during germination under high temperature stress and combined with Na₂SeO₃ treatment. And the sprout length was significantly reduced to 79.39% and 57.45% of the respectively control group after 4 and 6 d germination(P<0.05). After 4 d germination,MDA content increased significantly to 1.67 times of the water treatment(P<0.05),and the total antioxidant capacity of the sprouts increased significantly to 1.56 times of the water treatment(P<0.05). The content of isothiocyanate in broccoli sprouts treated with high temperature and Na₂SeO₃ were significantly increased(P<0.05). And the content of isothiocyanate was 2.36 times and 3.35 times of the control after 4 d germination. The content of isothiocyanate decreased significantly with the germination time(P<0.05). Meanwhile,the glucosinolates content in 4d-sprouts under high temperature combined with Na₂SeO₃ treatment was significantly higher than that of the water treatment(P<0.05),while there was no significant change in myrosinase activity(P>0.05). Germination for 4 d under the high temperature combined with Na₂SeO₃ treatment is confirmed as an effective way to accumulate isothiocyanate content in broccoli sprouts.