苹果渣中结合酚不同提取方法的研究

Study of different extraction methods on bound phenols in apple pomace

在最优条件下,以结合态酚类物质的种类和含量为指标,比较碱法、酶法和酸法对苹果渣中结合态酚类物质的提取效果。采用单因素实验对提取条件进行优化,HPLC-DAD法分别检测游离态酚和结合态酚中单体酚的种类和含量。结果表明:在温度为40℃下,选择碱降解时间为4 h,Na OH浓度为3 mol/L;酸降解时间为15 h,甲醇/浓硫酸浓度为13∶1(v/v);酶降解时间为24 h,单宁酶酶活为1000 U。苹果渣中酚类物质主要是金丝桃苷、绿原酸、根皮苷、儿茶素、槲皮素、根皮素、没食子酸、原儿茶酸和咖啡酸。儿茶素、槲皮素、根皮素、没食子酸、原儿茶酸和咖啡酸主要以结合态的形式存在,没食子酸、原儿茶酸、咖啡酸和根皮素通过酶法提取的含量最高,分别为16.122、18.574、13.030、69.934μg/g;儿茶素和槲皮素通过酸法提取的含量最高,分别为148.909、66.396μg/g。酶法水解和酸法水解比碱法水解更适用于提取苹果渣中的结合态酚类物质。

The bound phenols in the apple pomace were released by alkaline degradation, acid degradation, and enzymatic hydrolysis respectively,and the degradation conditions were optimized using single factor experiment. The HPLC-DAD method was applied to detect the types and contents of individual phenolic in free phenol and three kinds of bound phenols.The optimum alkaline degradation time was 4 h,and the NaOH concentration was 3 mol/L, and the optimum acid degradation time was 15 h, and the methanol/concentrated sulfuric acid concentration was 13：1 （v/v） ,and the optimum enzymatic degradation time was 24 h,and the tannase activity was 1000 U. Hyperoside, chlorogenic acid, phlorizin, catechin, quercetin, phloretin and gallic acid were the major polyphenols of apple pomace.Catechin,quercetin, phloretin, gallic acid, protocatechuic acid and caffeic acid were mainly in bound form. The highest content of gallic acid, protocatechuic acid, caffeic acid and phloretin by enzymatic hydrolysis were 16.122,18.574,13.030 and 69.934 μg/g respectively,and the highest content of catechin and quercetin by acid degradation were 148.909 μg/g and 66.396 μg/g respectively. Acid degradation and enzymatic hydrolysis were more suitable than alkaline hydrolysis for the extraction of bound phenols of apple pomace.