摘要
为研究鱼胶原蛋白肽(CP)对α-乳白蛋白(α-La)和表没食子儿茶素没食子酸酯(EGCG)聚集行为的影响及其形成的三元复合物的热稳定性,采用浊度法、动态光散射、荧光光谱和圆二色谱四种光谱学手段。结果表明,α-La、EGCG和CP的添加顺序直接影响所形成的三元复合物的结构特性。在温度为25℃条件下,低浓度的CP促进α-LaEGCG复合物的聚集,聚集体粒径增大,粒径分布不均一,溶液浊度增加;而较高浓度的CP则抑制α-La和EGCG的聚集行为,聚集体粒径较小,粒径分布均一,溶液相对澄清。zeta电位(ζ-电位)结果表明,在澄清溶液中,溶液的ζ-电位接近于0,这可能与CP抑制α-La和EGCG聚集的机理有关。荧光结果表明,CP的加入使三元复合物中α-La的结构伸展,α-La分子中色氨酸的亲水性增强。圆二色谱分析表明,澄清溶液中,CP使三元复合物中α-La的α-螺旋结构增加,而β-折叠、β-转角和无规则卷曲结构减小。热处理能够进一步降低溶液的浊度,增加颗粒粒径,使三元复合物中的α-La结构更加伸展,但对溶液ζ-电位和α-La二级结构影响不大。
To investigate the effect of fish collagen peptide（ CP） on the aggregation behavior of α-lactalbumin（ α-La） and epigallocatechin gallate（ EGCG）,and the thermal stability of the resulting ternary complexby turbidity,dynamic light scattering,fluorescence spectroscopy and circular dichroism four spectroscopy methods. The results showed that,the addition sequence of α-La,EGCG and CP could directly affect the structural properties of the ternary complexes. At 25 ℃,CP at low concentration could enhance the formation of α-La-EGCG aggregates,with larger particle size,higher PDI and increased turbidity.CP at high concentration could inhibit the formation of α-La-EGCG aggregates,and clear solutions were formed with smaller particle size,lower PDI and decreased turbidity. The zeta potentials showed that,the zeta potentials of these clear solutions were close to 0,which would be related to the mechanism ofthe aggregation of α-La and EGCG by the inhibition of CP.Fluorescent results showed that CP decreased fluorescence emission intensities and caused increase of the polarity around tyrosine residues resulting in a partially unfolded conformation of α-La. Circular dichroism analysis showed that,in the clear solution,CP induced a progressive increase in the proportion of α-helix structure at the cost of the β-sheet and β-turn structures and unordered coil of α-La in α-La-EGCG-CP ternary aggregate.The heated ternary aggregates reduced turbidityand smaller particle size,leading to a more unfolded conformation of α-La. However,heat treatment hardly impacted theζ-potential of the ternary aggregates and α-La secondary structure.
作者
杨伟
陈如炎
徐响
赵通
李根
郝一博
王文娟
焦梦婷
张浩
李波
YANG Wei;CHEN Ru-yan;XU Xiang;ZHAO Tong;LI Gen;HAO Yi-bo;WANG Wen-juan;JIAO Meng-ting;ZHANG Hao;LI Bo(School of Food Science, Henan Institute of Science and Technology,Xinxiang 453003, China;Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100093, China)
出处
《食品工业科技》
CAS
CSCD
北大核心
2018年第14期55-60,共6页
Science and Technology of Food Industry
基金
国家自然科学基金青年科学基金项目(31601511)
国家级大学生创新训练项目(201610467026)
河南科技学院博士启动基金项目(205010616001)
河南省科技攻关项目(162102110065)
