The Engineering Technological Center of Mushroom Industry, School of Biological Science and Biotechnology, Minnan Normal University, Zhangzhou 363000, PR China.
The Engineering Technological Center of Mushroom Industry, School of Biological Science and Biotechnology, Minnan Normal University, Zhangzhou 363000, PR China.
Food Res Int. 2022 Oct;160:111719. doi: 10.1016/j.foodres.2022.111719. Epub 2022 Jul 22.
In this paper, α-alanine and β-alanine were used as modifiers to prepare α-alanine amidated pectin (α-AP) and β-alanine amidated pectin (β-AP) through enzymatic method. The effects of alanine and its isomer on the amidation degree and physicochemical properties of pectin were studied. Fourier transform infrared spectrum, proton nuclear magnetic resonance analysis, X-ray photoelectron spectrum and elemental analysis indicated that the amino groups from α-C and β-C could be aminated with the carboxyl group of pectin to form the corresponding aminated pectin. The alanine grafting ratio of α-AP and β-AP were 21.99% and 18.92%, respectively. The results showed that the dynamic viscosity of β-AP was significantly higher than that of α-AP due to the influence of amino acid side chain. However, due to the higher alanine grafting ratio of α-AP, the strength of hydrogel prepared by α-AP was higher than that of β-AP, and it also has the highest elastic modulus and swelling capacity. In addition, pectin, as a carbohydrate-based fat substitute, has been widely used in the field of food to simulate the smooth and delicate taste of fat. Compared with High methoxy pectin (HMP) and β-AP, α-AP had better colloid stability and smaller hydrogel particles in the composite system. The results provide references for the application of amidated pectin in low-fat food.
本文以α-丙氨酸和β-丙氨酸为修饰剂，通过酶法制备了α-丙氨酸酰胺化果胶（α-AP）和β-丙氨酸酰胺化果胶（β-AP）。研究了丙氨酸及其异构体对果胶酯化度和理化性质的影响。傅里叶变换红外光谱、质子核磁共振分析、X 射线光电子能谱和元素分析表明，果胶的羧基可以与α-C 和β-C 的氨基发生酰胺化反应，形成相应的酰胺化果胶。α-AP 和 β-AP 的接枝率分别为 21.99%和 18.92%。结果表明，由于氨基酸侧链的影响，β-AP 的动态粘度明显高于α-AP。然而，由于α-AP 的丙氨酸接枝率较高，α-AP 制备的水凝胶强度高于β-AP，其弹性模量和溶胀能力也最高。此外，果胶作为一种基于碳水化合物的脂肪替代品，已广泛应用于食品领域，以模拟脂肪的光滑细腻口感。与高甲氧基果胶（HMP）和β-AP 相比，α-AP 在复合体系中具有更好的胶体稳定性和更小的水凝胶颗粒。研究结果为酰胺化果胶在低脂食品中的应用提供了参考。
