葡萄糖糖基化对蓝圆鲹分离蛋白限制性酶解产物结构及功能特性的影响

Effects of glucose glycation on structural and functional properties of limited enzymatic hydrolysates from brown-striped mackerel scad(Decapterus maruadsi)protein isolate

为拓展蓝圆鲹(Decapterus maruadsi)分离蛋白的应用范围,促进其高值化利用,以蓝圆鲹分离蛋白限制性酶解产物(Brown-striped mackerel scad protein isolate limited enzymatic hydrolysate,BPILH)为原料,采用葡萄糖对其进行糖基化反应,考察不同反应时间对BPILH结构与功能特性的影响。结果表明,葡萄糖与BPILH的糖基化反应程度与反应时间和色度呈正相关。结构表征结果显示,糖基化反应使α螺旋和无规则卷曲含量减少,并降低糖基化产物的内源荧光强度。此外,长时间的高温使蛋白质分子内部的疏水基团暴露,使其表面疏水性增加。溶解度在酸性、碱性条件下随着反应时间的延长呈现先升高后降低的趋势,其中,第8小时糖基化产物的溶解度在pH 10时达到最高值(90.49±0.01)%。乳化性随着反应时间的延长而增加,与第0小时相比,第12小时糖基化产物的乳化性提升了24.28%,乳化稳定性和持油性均随着反应时间的延长呈现先增加后减少的趋势,在第1小时乳化稳定性达到最高值(17.51±0.13)min,在第2小时持油性达到最高值(2.19±0.21)g·g^(-1)。因此,反应时间过长会对功能特性产生一定的负面影响,研究结果可为蓝圆鲹分离蛋白在食品配料蛋白中的应用提供一定的理论参考。

In order to explore the extended application of fish proteins and promote the high value utilization of brown-striped mackerel scad(Decapterus maruadsi),taking the brown-striped mackerel scad protein isolate limited enzymatic hydrolysate(BPILH)as raw material,we used glucose to conduct a glycation reaction to investigate the effects of different reaction time on the structural and functional properties of BPILH.The results show that glucose underwent glycation reaction with BPILH,and the degree of glycation reaction was positively correlated with reaction time and chromaticity.Structural properties results show that the glycation reaction reduced theα-helix and irregular coil content of BPILH and decreased its endogenous fluorescence intensity.In addition,high temperature treatment with long time during glycation reaction exposed the hydrophobic groups in-side the protein molecules and increased their surface hydrophobicity.The solubility of glycation BPILH firstly increased and then decreased with the reaction time under acidic and alkaline conditions,in which the glycation solubility of product reached the highest value of(90.49±0.01)%at pH of 10 after 8-hour reaction.The emulsification of glycosylated BPILH increased with the reaction time.Comparied with the original mixture before reaction,the emulsification of the glycation product after 12-hour reaction increased by 24.28%,and both emulsification stability and oil-holding capacity showed an increase-decrease tendency with the reaction time,with the highest value of emulsification stability of(17.51±0.13)min at 1st hour and oil-holding capacity of(2.19±0.21)g·g^(-1) at 2nd hour.The emulsification stability of glycation product increased by 24.28%with the reaction time.Therefore,long reaction time may have some negative effects on the functional properties,and this study provides theoretical references for the application of brown-striped mackerel scad protein isolate in food industry.