School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu 212013, China; Institute of Food Physical Processing, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu 212013, China.
Department of Agricultural and Biosystems Engineering, Faculty of Agriculture, Benha University, P.O. Box 13736, Moshtohor, Qaluobia, Egypt.
Int J Biol Macromol. 2024 Jan;256(Pt 1):128120. doi: 10.1016/j.ijbiomac.2023.128120. Epub 2023 Nov 16.
We added three different carbohydrates (Xylose/Xyl, Maltose/Mal, and Sodium alginate/Sal) to pH-shifted silkworm pupa protein isolates (SPPI), and examined the influence of multi-frequency ultrasound (US) on them, with reference to lysinoalanine (LAL) formation, changes in conformational characteristics and functionality. Results showed that, the LAL content of the glycoconjugates - SPPI-Xyl, SPPI-Mal, and SPPI-Sal decreased by 1.47, 1.39, and 1.54 times, respectively, compared with the control. Notably, ultrasonication further reduced the LAL content by 45.85 % and brought SPPI-Xyl highest graft degree (57.14 %). SPPI-Xyl and SPPI-Mal were polymerized by different non-covalent bonds, and SPPI-Sal were polymerized through ionic, hydrogen, and disulfide (covalent/non-covalent) bonds. Significant increase in turbidity, Maillard reaction products and the formation of new hydroxyl groups was detected in grafted SPPI (p < 0.05). US and glycation altered the structure and surface topography of SPPI, in which sugars with high molecular weight were more likely to aggregate with SPPI into enormous nanoparticles with high steric hindrance. Compared to control, the solubility at pH 7.0, emulsifying capacity and stability, and foaming capacity of SPPI-US-Xyl were respectively increased by 244.33 %, 86.5 %, 414.67 %, and 31.58 %. Thus, combined US and xylose-glycation could be an effective approach for minimizing LAL content and optimizing functionality of SPPI.
我们向 pH 移位的蚕蛹蛋白分离物（SPPI）中添加了三种不同的碳水化合物（木糖/Xyl、麦芽糖/Mal 和海藻酸钠/Sal），并参考赖氨酰（LAL）的形成、构象特征和功能的变化，研究了多频超声（US）对它们的影响。结果表明，糖缀合物 - SPPI-Xyl、SPPI-Mal 和 SPPI-Sal 的 LAL 含量分别比对照降低了 1.47、1.39 和 1.54 倍。值得注意的是，超声进一步将 LAL 含量降低了 45.85%，并使 SPPI-Xyl 的接枝程度最高（57.14%）。SPPI-Xyl 和 SPPI-Mal 是通过不同的非共价键聚合的，而 SPPI-Sal 则是通过离子、氢键和二硫键（共价/非共价）聚合的。接枝后的 SPPI 中浊度、美拉德反应产物和新羟基的形成显著增加（p<0.05）。超声和糖化改变了 SPPI 的结构和表面形貌，其中高分子量的糖更有可能与 SPPI 聚集形成具有高空间位阻的巨大纳米颗粒。与对照相比，SPPI-US-Xyl 的 pH 7.0 时的溶解度、乳化能力和稳定性以及泡沫能力分别提高了 244.33%、86.5%、414.67%和 31.58%。因此，结合超声和木糖糖化可能是一种有效方法，可以最大限度地减少 SPPI 中的 LAL 含量并优化其功能。
