蒸汽爆破预处理对紫甘薯花色苷抗氧化性及抑菌性的影响

Effect of Steam Explosion Pretreatment on Antioxidation and Antibacterial Activity of Anthocyanins from Purple Sweet Potato

对紫甘薯原料进行蒸汽爆破预处理,采用溶剂提取法制备紫甘薯花色苷并采用大孔树脂进行纯化,全波长扫描结果表明,蒸汽爆破处理后紫甘薯花色苷的最大吸收波长由531nm变为527nm。高效液相色谱检测结果表明,对爆破和未爆破处理的紫甘薯提取所得的均为花色苷,但各组分的相对含量不同。紫甘薯花色苷的体外抗氧化试验结果表明,一定范围内花色苷的抗氧化性与质量浓度呈正比。蒸汽爆破预处理后,紫甘薯花色苷的DPPH自由基清除能力和羟自由基清除能力有一定的提升,而还原力基本不变。采用牛津杯法检测紫甘薯花色苷的抑菌性,结果表明紫甘薯花色苷对于金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌和沙门氏菌均具有较强的抑制作用,其最小抑菌质量浓度(MIC)分别为0.125,0.25,0.25,0.0625mg/mL。

Steam blasting pretreatment of purple sweet potato raw materials.Anthocyanins were purified from ethanol extracts of purple sweet potato with macroporous resin.After full-wavelength scanning,it was found that the maximum absorption wavelength was 527 nm of steam-pretreated anthocyanin and was 531 nm of untreated one.HPLC analysis showed that the peaks of both ethanol extracts are anthocyanins,but the relative content of their components were different.The antioxidant activity of anthocyanins was proportional to its concentration in a certain range.The ability to remove DPPH free radicals and hydroxyl radicals was enhanced by steam explosion but no significant improvement of reducing power.The results of the Oxford Cup assay showed that purple sweet potato anthocyanin had strong inhibitory effects on Staphylococcus aureus,Escherichia coli,Bacillus subtilis and Salmonella.The minimum inhibitory concentration(MIC)was 0.125,0.25,0.25,0.062 5 mg/mL,respectively.