摘要
【目的】研究麦麸多糖对金线鱼糜凝胶物性和结构的影响,并阐释麦麸多糖对于鱼糜凝胶特性的浓度效应机制,为利用麦麸类副产物改善鱼糜凝胶特性提供理论支持。【方法】提取麦麸多糖加入金线鱼糜中,制备多糖-鱼糜蛋白复合凝胶,并利用物性学、流变学、分子间作用力、傅里叶红外光谱、SDS-PAGE电泳、扫描电镜等技术,探究不同添加量的麦麸多糖对金线鱼糜凝胶特性与微结构的影响。【结果】麦麸多糖对鱼糜凝胶宏观物性和微观结构的影响具有明显的浓度依赖性。共混体系的流变学参数G'值和G"值、持水性、质构特性(TPA)、凝胶强度、水分分布状态均随着麦麸多糖添加量的增加,呈现先增加后降低的趋势,并在麦麸多糖添加量为1.0%时达到最大改善效果。傅里叶红外光谱图显示,在热诱导鱼糜凝胶化过程中,蛋白质的二级结构与多糖添加量密切相关:随着多糖含量增加,α-螺旋含量逐渐下降,β-转角与β-折叠含量持续增加(P<0.05),但麦麸多糖含量超过1.0%时,α-螺旋含量逐渐回升,而β-转角与β-折叠含量反而降低。这可能是由于多糖对蛋白凝胶内二硫键和静电相互作用为主要分子间作用力的影响具有浓度依赖,导致其二级结构变化。SDS-PAGE电泳显示,麦麸多糖添加量>1.0%后,肌动蛋白(actin,AC)条带和肌球蛋白重链(myosin heavy chain,MHC)条带颜色明显变浅,同时在浓缩胶的上端有深色条带累积。扫描电镜观察鱼糜凝胶的微观结构发现,随着多糖的添加量增加,鱼糜凝胶网络结构孔隙逐渐减小,当多糖的添加量为1.0%时,鱼糜凝胶网络结构最致密,分形维数Df达到最大值2.8657;继续添加麦麸多糖导致凝胶体系出现相分离,多糖大量自我聚集会破坏鱼糜蛋白凝胶网络,从而分形维数Df下降。【结论】在金线鱼鱼糜中添加1.0%的麦麸多糖,可作为鱼糜蛋白三维网络结构中的填充剂与保水剂,诱导形成更加均匀致密的凝胶基质,有效改善鱼糜凝胶品质。
【Objective】This study aimed to investigate the impact of wheat bran polysaccharide on the physical properties and microstructure of surimi gel,and to elucidate the mechanism by which the concentration of wheat bran polysaccharide affects surimi gel characteristics,so as to provide the theoretical support for enhancing surimi gel quality through the utilization of wheat bran by-products.【Method】Different concentrations of wheat bran polysaccharide were added to threadfin bream(Nemipterus virgatus)surimi to prepare composite gels.The effects of wheat bran polysaccharide on the characteristics and structures of surimi gel were investigated using texture analysis,rheological test,molecular interaction measurement,Fourier transform infrared(FTIR)spectroscopy,and scanning electron microscopy(SEM).【Result】The impact of wheat bran polysaccharide on the macroscopic physical properties and microstructures of surimi gel exhibited a pronounced concentration dependence.As the amount of wheat bran polysaccharide increased,the rheological parameters(G'and G"values),water holding capacity,texture profile analysis(TPA)values,gel strength,and water distributions of the blended system were all initially elevated and then declined,achieving the maximum improvement at the addition level of 1.0%.FTIR revealed that the secondary structure of proteins during the heat-induced gelation of surimi was closely related to the polysaccharide content:with increasing polysaccharide content,theα-helix content gradually decreased,whileβ-turn andβ-sheet content showed an upward trend(P<0.05).However,when the polysaccharide addition exceeded 1.0%,theα-helix content gradually increased again,whileβ-turn andβ-sheet content exhibited downtrends.This may be due to the concentration-dependent effect of polysaccharides on the disulfide bonds and electrostatic interactions,which were the primary intermolecular forces within the protein gel,leading to the changes in its secondary structure.SDS-PAGE electrophoresis showed that when the polysaccharide addition was over 1.0%,the actin(AC)and myosin heavy chain(MHC)bands became significantly lighter,with dark bands accumulating at the top of the stacking gel.SEM observations of the microstructure of surimi gels revealed that as the polysaccharide added,the pore size within the surimi gel network gradually reduced.When the polysaccharide addition reached 1.0%,the surimi gel network structure was the most compact,with the fractal dimension(Df)reaching a maximum value of 2.8657.Further addition of the polysaccharide leaded to phase separation in the gel system,and extensive self-aggregation of polysaccharides disrupted the surimi protein gel network,resulting in a decrease of Df.【Conclusion】Wheat bran polysaccharide with the concentration of 1.0%to the surimi could be used as a filler as well we water retention agent in the three-dimensional network structure of surimi protein,and induce the formation of a more uniform and dense gel matrix,which could effectively improve the gel quality of surimi.
作者
张涛
王缓
谢宏凯
陈银基
ZHANG Tao;WANG Huan;XIE HongKai;CHEN YinJi(College of Food Science and Engineering,Nanjing University of Finance and Economics/Collaborative Innovation Center for Modern Grain Circulation and Safety of Jiangsu Province,Nanjing 210023)
出处
《中国农业科学》
北大核心
2025年第5期1004-1016,共13页
Scientia Agricultura Sinica
基金
国家自然科学基金(32372264,32302124)
江苏省自然科学基金(BK20210674)
江苏高校优势学科建设工程资助项目(PAPD)。
关键词
麦麸多糖
鱼糜
凝胶特性
水分状态
二级结构
微观结构
wheat bran polysaccharide
surimi
gel characteristics
water status
secondary structure
microstructure
