【作者】 张杰良； 谢顺歆； 黄雪松；

【Author】 Cheong Kit Leong, XIE Shun-xin, HUANG Xue-song* (Department of Food Science and Engineering, Jinan University, Guangzhou 510632, China)

【机构】 暨南大学食品科学与工程系；

【摘要】 大蒜(Allium sativum L.)果聚糖占大蒜干重的75%以上,其果聚糖水解酶(FEH)能抑制大蒜发芽和生产高质量大蒜果聚糖。采用硫酸铵分级沉淀确定FEH沉淀组分,采用薄板层析和离子色谱法研究酶解产物,通过DNS法测定还原糖的变化量计算酶活力,进而研究FEH的酶切位点,研究温度、pH、离子强度、底物浓度对FEH活力的影响。结果表明:大蒜FEH存在于0%～20%硫酸铵饱和度组分,根据酶解产物判断该酶属于外切酶,最适反应温度为45℃,最适反应pH为5.5,最适离子强度为1.5mol/L氯化钠,最适反应浓度为4mg/mL大蒜果聚糖。为大蒜果聚糖产品的开发和抑制大蒜发芽提供科学依据。更多还原

【Abstract】 Fructans occupy more than 75% of the dry weight of garlic (Allium sativum L.). Understanding of the enzymologic characteristics of garlic fructan exohydrolase (FEH) provides the theoretical basis on inhibition of garlic germination and mass production of high quality garlic fructans. In this experiment, localization of FEH was done by ammonium sulfate precipitation, degradations of enzyme was studied by TLC and ion chromatography, while enzyme activity was determined by calculating the variance of reducing sugar via DNS assay. Further study of locus of action of FEH and effects of temperature, pH level, ionic strength, and substrate concentration on FEH activity also included. The results have shown that FEH was present in 0%~20% saturated ammonium sulphate. Through the analysis of enzyme degradations, FEH was confirmed as kind of excision enzyme, the optimum temperature of reaction was 45 ℃, optimum pH was 5.5, optimum ionic strength was 1.5 mol/L, optimum concentration of reaction was 4 mg/mL. These findings were of significance in mass production of garlic fructan and in term of inhibition of its germination.更多还原