MgSO_4处理对西兰花芽苗菜生理活性物质和抗氧化能力的影响

Effect of MgSO_4 Treatment on Bioactive Compounds and Antioxidant Activity in Broccoli Sprouts

本实验研究了外源喷施0、25、50、75 mmol/L的Mg SO4对西兰花芽苗菜生长状况、生理活性物质含量和抗氧化能力的影响。结果表明:Mg SO4处理对西兰花芽苗菜造成了生长胁迫效应;叶绿素和总酚含量随着Mg SO4浓度的增大而增加,抗坏血酸含量却随着Mg SO4浓度的增加而降低。发芽5 d的西兰花芽苗菜中总硫代葡萄糖苷(简称硫苷)和萝卜硫素含量显著高于发芽8 d的,但发芽8 d的黑芥子酶活力高于发芽5 d的;Mg SO4处理后,总硫苷和萝卜硫素含量及黑芥子酶活力显著提高,但50 mmol/L和75 mmol/L Mg SO4处理组之间差异不显著。Mg SO4处理显著提高了西兰花芽苗菜的抗氧化能力,但1,1-二苯基-2-三硝基苯肼自由基清除率在50 mmol/L和75 mmol/L处理组之间无显著差异,H2O2清除率随Mg SO4浓度的增加逐渐增强。因此,综合考虑,50 mmol/L Mg SO4对于提高西兰花芽苗菜的营养价值和保健功能是较适合的浓度。

The growth, bioactive compound contents and antioxidant activity of broccoli sprouts sprayed with exogenous Mg SO4 at 0, 25, 50 and 75 mmol/L were studied in this investigation. The results showed that MgSO4 inhibited the growth of broccoli sprouts. The contents of chlorophyll and total phenolics increased with the increase of MgSO4 concentration; however, ascorbic acid content continuously reduced. In addition, 5-day-old sprouts contained more glucosinolates and sulforaphane than 8-day-old sprouts, whereas the opposite was observed for myrosinase activity. MgSO4 treatment significantly enhanced the contents of glucosinolates and sulforaphane as well as myrosinase activity, but no significant difference was found between 50 and 75 mmol/L treatments. Antioxidant ability was significantly promoted by MgSO4 treatment. Specially, no significant difference in 1,1-diphenyl-2-picrylhydrazyl radical scavenging capacity was observed between 50 and 75 mmol/L MgSO4 groups. Nevertheless, H2O2 scavenging capacity was gradually enhanced with the increase of MgSO4 concentration. These results suggest that 50 mmol/L MgSO4 treatment could be useful to improve the nutritional value and health-promoting function of broccoli sprouts.