【作者】 张洁；

【导师】 杨晓萍；

【作者基本信息】 华中农业大学 ， 茶学， 2009， 硕士

【摘要】 以粗老茶叶渣为原料,分别采用化学法和酶法制备茶叶膳食纤维（DF）,探讨了茶叶水溶性膳食纤维（SDF）和非水溶性膳食纤维（IDF）的制备工艺及技术参数,并对茶叶膳食纤维产品的组成成分和理化性质进行了研究,这不仅为综合利用茶叶资源提供了新的思路,也为茶叶膳食纤维在食品上的应用提供了理论依据。主要研究结果如下:1、化学法制备茶叶DF:在单因素试验基础上,分别通过二次回归正交旋转组合试验和四因素三水平（L₉3⁴）正交试验优化茶叶膳食纤维制备工艺,结果表明茶叶SDF最佳制备工艺为:温度79℃、料液比1:35、时间2.2 h、盐酸浓度1.5 mol/L,提取率达49.72%;茶叶IDF最佳制备工艺为:温度55℃、氢氧化钠浓度0.5 mol/L、时间30 min、料液比1:15,提取率达69.89%。2、酶法制备茶叶DF:在单因素试验基础上,通过五因素四水平(L₁₆4⁵)正交试验优化茶叶膳食纤维制备工艺,结果表明茶叶SDF最佳制备工艺为:温度60℃、酶添加量0.08g/g、pH值9.0、时间2.0 h、料液比1:20,提取率达53.72%;茶叶IDF最佳制备工艺为:温度65℃、酶添加量0.004g/g、pH值4.0、时间2.0 h、料液比1:10,提取率达94.12%。3、茶叶DF产品理化性质:茶叶DF具有良好的持水力、膨胀力、结合水力、阳离子交换力及吸附脂肪、胆固醇、胆酸钠的能力,SDF溶解度良好,IDF对Fe²⁺、Mg²⁺、Cu²⁺、Pb²⁺、Hg²⁺等金属离子和NO₂^-也有一定吸附能力。相对而言,两种方法制备的IDF持水力、膨胀力、结合水力、阳离子交换力均明显高于SDF,但堆积密度和对脂肪、胆固醇、胆酸钠的吸附能力SDF明显高于IDF;酶法制备DF各项理化性质指标均明显优于化学法制备DF。4、通过研究不同因素对茶叶DF理化性质的影响发现,两种方法制备SDF的溶解度均随温度升高而增加,随pH值增大呈先升后降趋势;温度、pH值对化学法制备IDF持水力无明显影响,但不同浓度盐溶液明显使两种IDF持水力降低;两种IDF对NO₂^-的吸附能力随温度升高、时间延长均呈增加趋势,但随pH值增加反而降低;时间、pH值对两种IDF吸附金属离子能力也有明显影响,pH 7.0时对Cu²⁺、Pb²⁺、Hg²⁺的吸附率较高,分别达Cu²⁺（86.15%、85.37%）、Pb²⁺（87.39%、81.72%）和Hg²⁺（93.79%、90.30%）。总体上来说,酶法制备DF的理化性质在不同条件下均明显优于化学法制备DF。更多还原

【Abstract】 Tea dietary fibers （DF） were extracted from tea residue respectively throughchemical and enzyme extraction method. The preparation technology, component andphysicochemical characteristics of soluble dietary fiber （SDF） and insoluble dietary fiber（IDF） of tea were studied. The aim of this study was to provide a new thought for thecomprehensive utilization of tea and a theoretical basis for the application of tea dietaryfiber in food industry. Main results are as follows:1. Tea dietary fiber extracted by chemical method: on the base of single-factor test,the preparation technology of tea dietary fibers was studied respectively through quadraticregression of orthogonal rotation test and the method four factors three levers oforthogonal design test （L₉3⁴）. The results showed that the optimum technologicalparameters of SDF was temperature 79℃, solid-liquid ratio 1:35, time 2.2 h, hydrochloricacid concentrate 1.5 mol/L and the extraction rate was 49.72% on the optimum condition.The optimum technological parameters of IDF was temperature 55℃, solid-liquid ratio1:15, time 0.5 h, sodium hydroxide concentrate 0.5 mol/L and the extraction rate was69.89%.2. Tea dietary fiber extracted by enzyme method: on the base of single-factor test, thepreparation technology of tea dietary fibers was studied through five factors four levers oforthogonal design test (L₁₆4⁵). The results showed that the optimum technologicalparameters of SDF was temperature 60℃, enzyme added 0.08g/g, pH 9.0, time 2.0 h,solid-liquid ratio 1:20 and the extraction rate was 53.72% on the optimum condition. Theoptimum technological parameters of IDF was temperature 65℃, enzyme added 0.004g/g,pH 4.0, time 2.0 h, solid-liquid ratio 1:10 and the extraction rate was 94.12%.3. Physicochemical characteristics of tea dietary fiber: tea dietary fiber had goodphysicochemical characteristics. SDF had good water solubility. IDF could adsorb NO₂^-and metal ions such as Fe²⁺、Mg²⁺、Cu²⁺、Pb²⁺、Hg²⁺. The swelling capacity （SWC）, thewater holding capacity （WHC）, the water binding capacity （WBC）, cation exchangecapacity （CEC） of IDF were better than that of SDF, but the deposition density and theadsorption capacity of fat, cholesterol and sodium cholate of SDF were better than IDF.Physicochemical characteristics of tea dietary fiber extracted by enzyme method werebetter than that by chemical method.4. The effect of different factors on physicochemical characteristics of tea dietaryfiber was studied. The water solubility of SDF by two kinds of extraction method improved with the increase of temperature, and tended to rise first and then fall with theincrease of pH. The change of temperature and pH had no significantly effect on WHC ofIDF extracted by chemical method, but salt solution significantly decreased WHC of thetwo IDF. The adsorption capacity of the two IDF to NO2" increased with the increase oftemperature and time, but decreased with the increase of pH. The time and pH hadsignificant effects on the adsorption capacity to metal ions of the two IDF. At pH of 7.0,the adsorption rate to Cu²⁺ were 86.15%、85.37% respectively, the adsorption rate to Pb²⁺were 87.39%、81.72%, the adsorption rate to Hg²⁺ were 93.79%、90.30%. In general,physicochemical characteristics of tea dietary fiber extracted by enzyme method werebetter than that extracted by chemical method.更多还原