Study On Extraction Dietary Fiber From Grape Skin Residue By Enzyme Technology

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℃.