【作者】 邓安彬；

【导师】 蒲彪；

【作者基本信息】 四川农业大学 ， 农产品加工及贮藏工程， 2008， 硕士

【摘要】 膳食纤维是一种包含纤维素、半纤维素、木质素、果胶及可溶性多糖等多种成分的混合物,它作为一种极其重要的功能食品,引起了国内外营养学家的高度关注,在功能性食品的开发中也越来越被重视。竹笋及笋渣含有丰富的膳食纤维成分,目前一直未被很好的开发利用。本文以四川主产的麻竹笋及其笋渣为原料,通过发酵法和酶法提取膳食纤维并研究其理化特性,为竹笋及笋渣的综合利用寻找一条新的途径,达到增加竹笋产品的附加值,提高竹笋的经济效益,减小浪费和环境污染的目的。试验采用四因素二次回归通用旋转组合设计,优化出膳食纤维的最佳提取条件,结果如下:发酵法提取竹笋膳食纤维的最佳工艺为:接种18%的绿色木霉发酵母液,调整pH到7.3,在36℃条件下发酵56h,产品的总膳食纤维（TDF）含量为68.52%,不溶性膳食纤维（IDF）为56.51%,可溶性膳食纤维（SDF）为12.01%。发酵法提取笋渣膳食纤维的最佳工艺为:接种10%的绿色木霉发酵母液,调整pH到6.8,在32℃条件下发酵44h,产品的TDF含量为61.02%,IDF为50.23%,SDF为10.79%。混合酶法提取竹笋膳食纤维的最佳工艺为:用0.2%混合酶[淀粉酶（常温）加纤维素酶1:1]进行水解,条件是60℃、pH 6.0、1h。再添加0.1%的中性蛋白酶,调整pH到7.5,在50℃条件下酶解2.5h,产品的TDF含量为69.97%,IDF为57.18%,SDF为12.79%。混合酶法提取笋渣膳食纤维的最佳工艺为:用0.2%混合酶[淀粉酶（常温）加纤维素酶1:1]进行水解,条件是60℃、pH 6.0、1h。再添加0.2%的中性蛋白酶,调整pH到6.0,在40℃条件下酶解1.5h,产品的TDF含量为70.22%,IDF为60.10%,SDF为10.13%。最佳工艺条件下提取的膳食纤维产品的理化特性研究表明:发酵产品和酶法产品的持水力和溶胀性都有很大提高,并且酶法产品高于发酵产品;对胆固醇的吸附能力与环境pH有关,pH7.0时大于pH2.0时的值,并且都远大于原料吸附力,酶法获得的竹笋膳食纤维产品吸附力远大于相应发酵法产品,但两种笋渣膳食纤维产品间区别不明显;四种膳食纤维在pH2.0时对NO₂^-的吸附力大于pH7.0时的吸附能力,酶法产品大于发酵产品,且都比原料有明显提高。四种膳食纤维对Cu²⁺、Pb²⁺、Cd²⁺的束缚量较之原料有很大提高。竹笋的酶法产品对Cu²⁺的束缚量显著高于发酵产品;笋渣的酶法产品对Pb²⁺的束缚量显著大于发酵产品;对Cd²⁺的束缚量测定结果表明酶法产品与发酵产品间没有显著差异。酶法和发酵法提取的竹笋膳食纤维和笋渣膳食纤维对大白鼠在蛋白质和脂肪的消化率方面有显著影响。四种膳食纤维在2.5%以上的剂量能使脂肪的消化率显著降低;在5%剂量下蛋白质的消化率显著降低。综合比较产品中TDF含量、SDF含量及其理化特性得出,混合酶法提取的竹笋和笋渣膳食纤维纯度更高,品质也优于绿色木霉发酵法的产品,而且此法周期短,对生产环境要求也没有发酵法高,操作简便,是一种较易用于实际生产的方法。更多还原

【Abstract】 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.更多还原