Undaria pinnatifida insoluble dietary fibre (UIDF) was modified by alkali (NaOH solution) and complex enzyme (xylanase and cellulase) to improve the physicochemical properties. Scanning electron microscopy revealed that the surface structure after modification was rough and loose. The characteristic absorption peaks in Fourier transfer infrared spectrometry and X‐ray diffraction patterns showed that enzymes can further hydrolyse the UIDF than alkali mainly in amorphous region, and increased the soluble dietary fibre content to 16.31%. The alkaline and complex enzymatic modification both resulted in higher water retention capacity, water swelling capacity, oil absorption capacity, glucose adsorption capacity and the inhibition ability towards α‐amylase. The complex enzymatic modification exhibited better features in almost all properties, and the modification did not change the inhibiting mechanism on α‐amylase (non‐competitive type). Overall, both two modifications could effectively improve the properties of UIDF, which may promote its use in food applications.

中文翻译：

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裙带菜碱和酶改性不溶性膳食纤维的表征

裙带菜用碱（NaOH溶液）和复合酶（木聚糖酶和纤维素酶）对不溶性膳食纤维（UIDF）进行了改性，以改善其理化性质。扫描电子显微镜显示，改性后的表面结构粗糙且疏松。傅立叶转移红外光谱和X射线衍射图谱中的特征吸收峰表明，酶可以比碱性区域中的碱进一步水解UIDF，而碱性膳食中的可溶性膳食纤维含量则增加了16.31％。碱性和复杂的酶促修饰均导致更高的保水能力，水溶胀能力，吸油能力，葡萄糖吸附能力和对α-淀粉酶的抑制能力。复杂的酶促修饰几乎在所有特性中都表现出更好的功能，修饰并没有改变对α-淀粉酶（非竞争性类型）的抑制机制。总体而言，这两种修改都可以有效改善UIDF的性能，从而可以促进其在食品应用中的使用。