Abstract：
This study investigated the effects of ultrasound-assisted phosphorylation on gelling properties of fish gelatin (FG). Ultrasound-assisted phosphorylation (UP) for 60, 90, and 120 min resulted in >6.54% increase of phosphorylation degree and decreased zeta potential of FG. Atomic force microscopy revealed that UP-FGs showed larger aggregates than P-FGs (normal phosphorylation FGs). Low frequent-NMR and microstructure analysis revealed that phosphorylation enhanced water-binding capability of FG and improved the gel networks. However, UP60 had the highest gel strength (340 g), gelling (17.96 °C) and melting (26.54 °C) temperature while UP90 and UP120 showed slightly lower of them. FTIR analysis indicated thatβ-sheet and triple helix content increased but random coil content decreased in phosphorylated FGs. Mass spectrometry demonstrated phosphate groups mainly bound to serine, threonine and tyrosine residues of FG and UP-FG exhibited more phosphorylation sites. The study showed that mild phosphorylation (UP60) could be applied to improve FG gel properties.
摘要：
本研究调查了超声辅助磷酸化对鱼胶（FG）胶凝特性的影响。超声辅助磷酸化（UP）60、90和120min导致FG磷酸化程度增加>6.54％，ζ电位降低。原子力显微镜显示UP-FG比P-FG(正常磷酸化FG)显示更大的聚集体。低频NMR和微观结构分析表明，磷酸化增强了FG的水结合能力并改善了凝胶网络。然而,UP60具有最高的凝胶强度（340克），胶凝温度(17.96°C)和熔融温度(26.54°C),而UP90和UP120显示它们略低。FTIR分析表明，磷酸化FGs的β-折叠和三螺旋含量增加，但无规卷曲含量降低。质谱显示磷酸基团主要与丝氨酸结合，FG和UP-FG的苏氨酸和酪氨酸残基表现出更多的磷酸化位点。研究表明，轻度磷酸化（UP60）可以改善FG凝胶的性质。
