酸水解法提取甘薯结合酚工艺优化

Optimization of Extraction Process of Bound Phenol from Sweet Potato by Acidic Hydrolysis Method

为探明不同品种甘薯中游离酚与结合酚的含量差异,以"辽薯20"紫薯为原料,用酸水解法对提取完游离酚的紫薯渣中的结合酚进行提取,在单因素试验的基础上,采用体积分数为10%的H2SO4进行水解,利用响应面优化相关参数,在此基础上,对12个甘薯品种的游离酚和结合酚进行了提取测定。结果表明,结合酚提取最优工艺参数为水解时间22 h,水解温度62℃,液料比35∶1 mL/g,实际提取量为(0.212±0.004) g/100 g,达到预测值(0.220 g/100 g)的96.36%。不同甘薯品种间游离酚和结合酚含量存在显著差异、分布范围较宽,分别为(0.14～1.63) g/100 g和(0.05～0.28) g/100 g,且游离酚含量大于结合酚含量,平均值分别为0.61、0.15 g/100 g,其中,紫肉品种甘薯游离酚与结合酚含量均高于其它肉色品种。研究表明了结合酚提取工艺的切实可行,及紫肉品种甘薯作为游离酚和结合酚提取原料进一步开发利用的潜力,为评价不同品种甘薯多酚的总量及选取适宜甘薯品种开展结合酚的生物活性研究奠定了基础。

To investigate the content of free and bound phenol in different varieties of sweet potato,'Liaoshu 20'purple sweet potato lyophilized powder whose free phenol had been extracted adequately was used as the raw material to study the extraction of the bound phenol by acid hydrolysis. Based on the single factor test,H2SO4 with volume fraction of 10% was utilized to hydrolyze the material and the response surface analysis method were used to optimize the relevant parameters.Then,free and bound phenol in twelve variety of sweet potato were extracted and determined.The results showed that the optimal parameters for the extraction of bound phenol by acid hydrolysis were: Extracting time 22 h,temperature 62 ℃,ratio of liquid to solid 35∶ 1 mL/g,the actual extraction amount of( 0.212 ± 0.004) g/100 g,reaching the predicted value( 0.220 g/100 g) of 96.36%.The content of free phenol was more than that of bound state( average content is 0.61 and 0.15 g/100 g respectively) and both of them in these twelve varieties of sweet potato was significantly different with wide range of( 0.14~1.63) and( 0.05~0.28) g/100 g.Compared with other color fleshes of sweet potato,purple flesh varieties have more free and bound phenol.These data suggested that this bound phenol extraction technology was practical and purple flesh varieties were better material for extraction of free and bound phenol.This study laid the foundation for evaluating the total amount of polyphenols in different varieties of sweet potato and further researching the bioactivity of bound phenol from suitable sweet potato varieties.