基于生物酶法提取费约果果胶及其理化性质的研究

Effects of enzymes on extraction of pectin from feijoa and pectin physicochemical properties

以费约果果实为原料,比较纤维素酶、木聚糖酶及复合酶对费约果果胶提取率和理化性质的影响。结果表明:纤维素酶为200 U/g时,提取率为11.35%;木聚糖单酶为150 U/g时,果胶得率为7.41%;200 U/g木聚糖酶和300 U/g纤维素酶(比例1∶1.5)混合时,果胶得率最高为11.99%;复合酶的果胶得率高于单一酶的果胶得率。不同提取方法所得的果胶分子量介于600〜1200 kDa、溶解性为96.1%〜98.5%。扫描电镜结果发现纤维素酶法得到的果胶呈不规则纤维棒状结构;木聚糖酶提取的果胶呈现较厚的片状结构;而热酸法所得果胶呈疏松的片状。傅里叶光谱的结果表明,提取的费约果果胶在500〜4000 cm^(-1)范围内均具有多糖的特征峰。通过不同方法所获得的费约果果胶均具有较好的理化性质,因此可将费约果作为提取果胶的优选原料。

Feijoa fruit was used as raw material,effects of enzymes on the yield of pectin and the physicochemical properties of the pectin were compared.Enzymes including cellulase,xylanase and complex of these two enzymes were tested,and the physicochemical properties of extracted pectin were compared.The results showed that,the pectin extraction rate was 11.35%when cellulase concentration was 200 U/g,and the yield of pectin was 7.41%when xylanase was 150 U/g;and the pectin yield reached 11.99%,higher than any of these two single enzymes,when the two enzymes were mixed(150 U/g xylanase and 300 U/g cellulase)at the ratio of 1∶1.5.The molecular weight of pectin obtained by different methods was between 600〜1200 kDa,and the solubility was in the range of 96.1%〜98.5%.Scanning electron microscopy(SEM)showed that the structure of pectin obtained by cellulase was irregular fiber rod;the pectin extracted by xylanase showed a thick sheet structure;and the pectin obtained by hot acid method was a loose flake layer.FTIR spectra showed that the characteristic peaks of polysaccharides were found in the range of 500〜4000 cm^(-1).In conclusion,the feijoa pectin obtained through different methods had good physical and chemical properties,so feijoa could be used as the preferred raw material for extracting pectin.