高含低聚糖豆渣膳食纤维制备工艺研究

Study on Preparation Processing of Okara Dietary Fiber with Oligosaccharides Content

以豆渣为原料,研究了β-甘露聚糖酶酶解法与纤维素酶酶解法提高豆渣可溶性膳食纤维(SDF)含量的工艺。结果表明,纤维素酶酶解法进一步提高挤压后豆渣SDF含量的最优工艺为:酶解温度50℃,酶解时间3 h,酶与底物质量比1∶500,此条件下豆渣SDF含量为(30.10±0.17)%。β-甘露聚糖酶酶解法制得高含低聚糖SDF的最佳工艺参数:酶解温度60℃,酶解时间4 h,酶与底物质量比1:50。将酶解产物经中空纤维超滤膜进行超滤,将滤出液浓缩干燥后得到的低聚糖粗品得率为37.67%。高效液相色谱(HPLC)分析结果表明该低聚糖粗品中有4种不同聚合度的低聚糖存在,总含量40.31%,其中含量最高的组分为分子量1 349 Da,其含量为27.65%,根据其分子量进行推测,这可能是一种聚合度为8的低聚糖。通过葡聚糖凝胶Sephadex G25分离低聚糖粗品,分离得到一种主要组分,通过Sephadex G15验证纯度,证明分离得到的组分是单一组分的低聚糖。经计算,得到的豆渣低聚糖含量为3.7 g/100 g(以干豆渣计)。温下整个试验贮藏期间果汁透光率都大于90%,试验还表明壳聚糖对柚子汁的澄清不影响果汁的营养价值。

Okara was used as materials to determine the optimum parameters to improve the soluble dietary fiber（SDF）content in okara of β-mannanase enzymatic method and its composition were determined.The results showed that the optimum parameters of further improved the SDF content of extruded okara with cellulase enzymatic method were：enzymatic temperature 50 ℃,enzymatic time 3 h,enzyme amount（the mass ratio of enzyme and the substrates）1 ∶ 500.In this condition,the SDF content of enzymolysis okara was（30.10±0.17）%.The optimum parameters of preparation of high oligosaccharides content SDF according to β-mannanase enzymatic method were：enzymatic temperature 60 ℃,enzymatic time 4 h,enzyme amount（the mass ratio of enzyme and the substrates）1 ∶ 50.After enzymatic hydrolysis,the mixture was subjected to ultrafiltration by Hollow fiber ultrafiltration membrane.The filtrate was concentrated and lyophilized,the yield of crude oligosaccharide was 37.67 %.High performance liquid chromatography（HPLC）analyze showed that the crude oligosaccharide had four kinds of oligosaccharide with different degree of polymerization,total amount was40.31 %.The content of the best group is divided into molecular weight 1 349 Da,its content is 27.65 %.The degree of the oligosaccharide may be eight when speculated based on the molecular weight.A major oligosaccharide component was obtained when separated the oligosaccharide fractions with dextran gel Sephadex G25.The purity of the main component was verified by Sephadex G15,the results showed that the separated component was a single component oligosaccharide.After calculation,the okara oligosaccharides content obtained through this research was 3.7 g/100 g（in dry okara）.