Extraction And Characters Of Dietary Fiber From Bamboo Shoots And Their Dregs

Dietary fiber is a mixture including cellulose,hemicellulose and lignin,pectin and soluble polysaccharide,and other components.As an extremely important functional food, dietary fibe has gained the concern of the nutritionist at home and abroad very much.In the development of functional food,dietary fibe has been payed more and more attention. Bamboo shoots and their dregs are rich in dietary fiber,which has not been fully utilized. In this paper,bamboo shoots and their dregs mainly producted in Sichuan were used as raw materials to extract dietary fiber by fermentation and enzymatic method,and the extracted dietary fiber's physical and chemical characteristics was studied too.The aim of this study was to find a new way to comprehensively utilize bamboo shoots and their dregs and to increase the bamboo products' additional value,to improve the economic benefits of bamboo shoots,and to reduce waste and environmental pollution.For optimizing the best extraction conditions of dietary fiber,the qucdratic rotational regression combination design was used.And the results were as follows:The best fermentation conditions to extract dietary fiber from bamboo shoots were that 18%volume of the Trichoderma viride fermented liquor was inoculated,and acidity was adjusted to pH 7.3,and fermention period was 56 h at 36℃.The TDF content of products was 68.52%,and the IDF content was 56.51%,and the SDF content was 12.01%.The best fermentation conditions to extract dietary fiber from bamboo shoots' dregs were that 10%volume of the Trichoderma viride fermented liquor was inoculated,and acidity was adjusted to pH 6.8,and fermention period was 44 h at 32℃.The TDF content of products was 61.02%,and the IDF content was 50.23%,and the SDF content was 10.79%.The best conditions to extract dietary fiber by mixed enzyme from bamboo shoots were that 0.2%mixed enzyme[amylase(room temperature) and cellulose 1:1]was added, and enzymolysis conditions were 60℃,pH 6.0,1h.Then 0.1%neutral protease was added and acidity was adjusted to pH 7.5,and enzymolysis period was 2.5 h at 50℃.The TDF content of products was 69.79%,and the IDF content was 57.18%,and the SDF content was 12.79%.The best conditions to extract dietary fiber by mixed enzyme from bamboo shoots' dregs were that 0.2%mixed enzyme[amylase(room temperature) and cellulose 1:1]was added,and enzymolysis conditions were 60℃.pH 6.0,1h.Then 0.2%neutral protease was added and acidity was adjusted to pH 6.0,and enzymolysis period was 1.5 h at 40℃. The TDF content of products was 70.22%,and the IDF content was 60.10%,and the SDF content was 10.13%.The physical and chemical characteristics study of dietary fiber extracted under optimal conditions indecated that: The expansion capacities of dietary fiber extracted from bamboo shoots and their dregs by fermentation and enzymolysis were bigger than that of their material,as well as the water holding capacities.And enzymolysis was better than fermentation.Dietary fiber's adsorption capacity on cholesterol was depended on acidity.At pH 7, the value was bigger than that at pH 2.And enzymolysis had more effects than fermentation on bamboo shoots.The adsorption capacity on NO₂^- was still depended on acidity.The value at pH2.0 was bigger than the value at pH7.0.And the capacity of enzymolysis products was absolutely bigger than that of fermentation products.The adsorption on Cu²⁺,Cd²⁺ and Pb²⁺ was improved by fermentation and enzymolysis.And the adsorption value on Cu²⁺ of enzymolysis products was bigger than the value of fermentation products,which extracted from bamboo shoots.The adsorption value on Cd²⁺ of enzymolysis products was bigger than the value of fermentation products, which extracted from bamboo shoots dregs.But there were no difference between fermentation products' adsorption capacity and enzymolysis products capacity on Pb²⁺.Dietary fiber extracted from bamboo shoots and their dregs by enzymatic and fermentation method had significantly effected the digestive of protein and fat in the rats. Four kinds of dietary fiber had made the rats' digestibility on fat reduce significantly when above 2.5%dosage.When the dosage was 5%it also had decreased the protein digestibility significantly.Through the comparison of the TDF content,SDF content and its physical and chemical characteristics of the four products,the purity of dietary fibe extracted from bamboo shoots and their dregs by mixed enzymatic method was higher than the products extracted by Trichoderma viride fermention,and the quality was better,and the process period was shorter too.The environmental requirement of the process was less than fermentation,and the operation was more simple.All the above had made the mixed enzymatic method easier for the actual production.