Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
Food Chem. 2020 Nov 30;331:127349. doi: 10.1016/j.foodchem.2020.127349. Epub 2020 Jun 20.
Atomic force microscopy was applied to characterize the self-assembling behaviors of α-zein molecules in 70% (v/v) aqueous ethanol solution under different parameters including α-zein concentration (0.001%-0.1%, w/v), pH (2.0-8.0) and the thermal treatment (90 ℃, 2-24 h). α-Zein (0.1% and 0.01%, w/v) at pH 7.0 formed globules while α-zein assemblies (0.001%, w/v) exhibited the co-existence of worm-like strings, bundles of fibers, and rod-like fibers. Heating the aqueous ethanol solutions containing 0.001% (w/v) α-zein at 90 °C and pH 4.0 converted the irregular aggregates into regular spherical particles (100-120 nm), followed by fibrils (15-50 nm) at a prolonged times (8 h). Besides, fibrils were formed after heating aqueous ethanol solutions containing α-zein (0.001%, w/v) at pH 2.0 for 8 h. A two-step mechanism was proposed to explain such findings, which involved the aggregation of α-zein molecules to form aggregates, and followed by the rearrangement of α-zein molecules to form fibrils.
原子力显微镜被应用于研究α-玉米醇溶蛋白在不同参数下（包括α-玉米醇溶蛋白浓度（0.001%-0.1%，w/v）、pH 值（2.0-8.0）和热处理（90℃，2-24 小时））在 70%（v/v）乙醇水溶液中的自组装行为。在 pH 值为 7.0 时，α-玉米醇溶蛋白（0.1%和 0.01%，w/v）形成小球，而 α-玉米醇溶蛋白组装体（0.001%，w/v）则表现出蠕虫状线、纤维束和棒状纤维的共存。将含有 0.001%（w/v）α-玉米醇溶蛋白的乙醇水溶液在 90℃和 pH 值为 4.0 的条件下加热，会将不规则的聚集物转化为规则的球形颗粒（100-120nm），然后在较长时间（8 小时）内转化为纤维（15-50nm）。此外，在 pH 值为 2.0 的条件下将含有α-玉米醇溶蛋白（0.001%，w/v）的乙醇水溶液加热 8 小时后也会形成纤维。提出了一种两步机制来解释这些发现，涉及α-玉米醇溶蛋白分子的聚集形成聚集物，然后α-玉米醇溶蛋白分子的重排形成纤维。
