【作者】 王文华；

【导师】 江英；

【作者基本信息】 石河子大学 ， 农产品加工及贮藏工程， 2008， 硕士

【摘要】 大量研究证明,许多慢性病如糖尿病、动脉硬化等与食物中摄入的膳食纤维含量较少有关,因此有必要开发安全高效的膳食纤维产品。葡萄皮渣是葡萄加工的副产品,最近的研究显示,葡萄皮渣中含有大量纤维素,是一种很好的膳食纤维来源,但至今都未得到很好的利用。米曲霉、黑曲霉、绿色木霉是已知产纤维素酶的菌种中应用较广泛的三种菌种,本研究应用刚果红平板初筛和DNS法复筛两种方法,对三种菌种产纤维素酶活力进行了比较,得到一株产纤维素酶活力较高菌株――绿色木霉,通对绿色木霉菌株培养条件的优化,进一步提高了其纤维素酶活力。在此基础上,对绿色木霉粗酶液应用于生产高活性葡萄皮渣膳食纤维的关键技术进行了探讨,此外,为改善其感官品质对其进行了脱色方法和条件的研究,为提高葡萄加工副产品的附加值和综合利用资源提供了理论依据,并为果渣的开发利用提供了指导作用。通过试验得到了以下结果和结论:1.采用刚果红筛选培养基筛选和DNS法测定酶活两种方法结合,得到一株适用于葡萄皮渣膳食纤维生产的菌株—绿色木霉。2.以绿色木霉菌株为实验材料,采用液体发酵方法,对其产纤维素酶条件进行了研究。结果表明:初始pH5.5的条件下,接种量为5%,六层纱布封口,32℃培养120 h,该菌株产酶效率高,外切β-1,4葡聚糖酶(C1酶)活可达0.391 IU/ml,内切β-1,4葡聚糖酶(Cx酶)活可1.387 IU/ml,这将为膳食纤维的生物改性提供理论参考依据。3.将绿色木霉在最佳产酶条件下培养,取粗酶液酶解葡萄皮渣。采用四因子二次旋转组合设计(CORD),对微生物酶法活化葡萄皮渣膳食纤维工艺进行了优化研究。分析活化温度(X1)、活化时间(X2)、酶添加量(X3)、活化pH(X4)四个变量对产品中可溶性膳食纤维含量的影响,在此基础上由试验数据推导出描述四个指标的二次回归模型,并对变量进行响应面分析(RSM),得出最佳活化葡萄皮渣膳食纤维工艺条件为:活化温度50℃;活化时间38min;酶添加量为18.41 ml;活化pH为7.682,通过验证实验得到活性膳食纤维得率达到55%。其中溶性膳食纤维膨胀力达到4.5 ml/g,持水力达到11.05 g/g,结合水力达到:3.06 g/g4.分别运用了过氧化氢、亚硫酸钠、次氯酸钠作为脱色剂,实验结果表明:采用H2O2对葡萄皮渣不溶性膳食纤维进行脱色,效果显著,最适宜的脱色条件为:H2O2浓度为3%、脱色时间为5.5 h、脱色温度为45℃、pH值为10更多还原

【Abstract】 A large number of research shows that such chronic diseases as diabetes and arteriosclerosis etc. are concerned with the deficiency of dietary fibers in food.So it is very necessary to develop safe, functional food of high quality and dietary fibers. Grape skin residue is by-product of grape wine processing ,The recent researches indicate that there are rich of cellulose in grape peel,is a good resource of dietary fibers. But it hasn’t been made good use of so far.In this paper, a mildew with relatively high cellulase activity was isolated,By primary screened with Congo red cellulose identification culture medium and subtle screened with DNS method from three mildew of produce cellulose enzyme,after the best conditions of the ferment of the Strain Trichoderma viride,as a result that enhanced its vitality of cellulose enzyme.Studies on the key technology of use Trichoderma viride original liquid enzyme on produce high activity of grape skin residue dietary fiber based on the experimental,to provide the technics evidences for utilizing the grape resource comprehensively and increasing the added value of the grape deep-processing product. This study was also to provide the instruction for exploring the residue of fruits.and through the experimentation of whiten so that improve its character of appearance.The main results and conclusions were as follows:1.A high cellulase-producing strain—Trichoderma viride was obtained by primary screened with Congo red cellulose identification culture medium and subtle screened with DNS method from three mildew of produce cellulose enzyme.2.Take the Trichoderma viride as the experimental material,liquid fermentation was used to study the production of specific cellulase. The optimum cultivating condition was as below ,initial pH 5.5,the quantity of inoculation was 5%,6 layer gauze seal,temperature 32°C, fermentation for 120h. The enzyme activity of Cellobiohydrolase exo-1,4-β-D-Glucanase was 0.391IU/ml, The enzyme activity of Endo-β-1,4-glucanase was 1.387IU/ml,This paper provided some technics bases for the modification of high quality dietary fibre.3.The Trichoderma viride was fermented in optimal liquid state ,Then further purification of original liquid enzyme by centrifuging. A central composite rotatable design (CORD) was adopted to optimize the technology of Centrifugal original enzyme degradating experiment of grape skin residue. Analyzed the temperature (X1),hydrolysis time(X2), massration(X3), optimal pH(X4)via soluble dietary fibre content.Based on the experimental date, the quadratic regression model of four indexes were deduced, then variables were analyzed with response surface methodology (RSM).,the optimal technical conditions were obtained as follows: the temperature (X1)was 50℃,hydrolysis time(X2)was 38min ,massration(X3)was 18.41ml,optimal pH(X4)was 7.682,the result of soluble dietary fibre content of Verification test was 55%. swelling capacity was 4.5 ml/g; the water holding capacity of dietary fiber was11.05 g/g;1and yield reached 3.06 g/g.4.There was better effect in decoloring IDF with H2O2,the suitable conditions for decoloring IDF were: H2O2 concentration 3%, time 5.5h, temperature 45℃.更多还原