茶叶非水溶性膳食纤维的提取及其理化特性研究

Preparation and Physico-chemical Characterization of Tea Water-insoluble Dietary Fiber

对酶法提物茶叶非水溶性膳食纤维的工艺及其理化性能进行研究,探讨料液比、pH值、酶添加量、酶解温度及酶解时间对茶叶非水溶性膳食纤维(IDF)提取的影响,在单因素试验基础上,通过L16(45)正交试验确定最佳提取条件。结果表明:pH值对茶叶IDF的提取影响最大,其次依次为酶解时间、酶添加量、酶解温度、料液比;其最佳提取工艺为:酶解温度65℃、酶添加量0.004g/g、pH4.0、酶解时间2h、料液比1:10(g/mL),提取率达94.12%;所获茶叶IDF具有良好的持水力、膨胀力、结合水力、持油力、阳离子交换能力及对胆固醇、胆酸钠的吸附能力等特性,是一种优质膳食纤维源。

Freshly harvested old tea leaves were pretreated for the removals of lipid and water-soluble substances such as polyphenols,sugars and amino acids before sequential hydrolysis with amylase followed by papain for production of water-insoluble dietary fiber（IDF）.To maximize IDF yield,papain hydrolysis parameters such as enzyme dosage,pH,hydrolysis temperature and time and material/liquid ratio were investigated by single factor and orthogonal array design methods.Results showed that the effects of the parameters on IDF yield decreased in the following order：pHhydrolysis timeenzyme dosage hydrolysis temperaturematerial/liquid ratio.A maximum IDF yield of up to 94.12% was obtained through the extraction for 2 h at 65 ℃,pH 4.0 and a material/liquid ratio of 1：10 using an enzyme dosage of 0.004 g/g.The IDF obtained was good in water holding capacity,swelling capacity,water binding capacity,oil holding capacity,cation exchange capacity and cholesterol and sodium cholate adsorption capacity,thereby providing an excellent IDF resource.