【摘要】 【目的】笋头是笋加工的主要副产物,是来源广泛且成本低廉的膳食纤维原料。传统的热水法制备的笋头膳食纤维由于纤维颗粒大,口感粗糙,在食品中添加应用易造成品质下降。为了推动笋头膳食纤维在食品加工中的应用,本文研究了复合酶法改性工艺对笋头膳食纤维的粒径及理化特性的影响。【方法】以热水法制备的笋头膳食纤维为原料,以纤维粒径为评价指标,通过单因素试验研究复合酶添加量、时间、温度和pH值对纤维粒径的影响。根据单因素结果,进行以Box-Behnken试验设计为基础的响应面优化试验。比较分析了改性前后笋头膳食纤维的理化特性变化。【结果】复合酶法改性笋头膳食纤维的最优工艺条件为:复合酶添加量0.20%（纤维素酶∶木聚糖酶=1∶1）,温度47℃,pH 5.4,时间2.0 h。以优化后的复合酶解法处理的笋头膳食纤维的纤维粒径(D₉₀)由（146.2±0.21）μm降低至（97.2±0.14）μm。相对于改性处理前的笋头膳食纤维,改性笋头膳食纤维的持水力、持油力和膨胀度分别提高1.30、2.16和1.64倍。【结论】经过工艺优化的复合酶法可显著减小笋头膳食纤维的纤维粒径,并显著提高纤维的持水力、持油力和膨胀度等理化性质。研究结果有利于推动笋头膳食纤维在功能食品加工中的应用。更多还原

【Abstract】 【Objective】Enzymatic hydrolysis was studied and optimized to modify the otherwise long and tough fibers of the bottom portion of a bamboo shoot（BDF） for a low-cost source of dietary fiber. 【Method】 Various enzymes in varying dosages at different temperatures,pHs and digestion durations were applied on hot-water cooked BDF for the experiment. Size of the fibers was measured in a single factor test followed by a Box-Behnken response surface experiment at 3 levels of each factor to optimize the process. Physical properties of the raw material and the resulting dietary fibers were compared. 【Result】The optimized hydrolysis was found to include 0.20% addition of cellulase:xylanase at 1∶1 ratio,temperature at 47℃,pH at 5.4 and digestion for 2.0 h. The BDF size(D₉₀) decreased from（146.2±0.21） μm to（97.2±0.14） μm after the enzymatic hydrolysis. The water and oil holding capacities and expansion of the hydrolyzed BDF increased by 1.30-,2.16-and 1.64-folds,respectively,over the pre-treatment samples. 【Conclusion】The optimized composite enzymatic hydrolysis significantly reduced the fiber size and improved the physical properties of BDF making it as a dietary fiber ingredient feasible.更多还原