Influence of pulsed light treatment on the aggregation of whey protein isolate
Influence of pulsed light treatment on the aggregation of whey protein isolate
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DOI：
10.1016/j.foodres.2017.06.003
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发表时间：
2017-09-01
影响因子：
8.1
通讯作者：
Ferrari, Giovanna
中科院分区：
文献类型：
--
作者：
Siddique, Md Abu Bakar;Maresca, Paola;Ferrari, Giovanna
研究了脉冲光（PL）对乳清分离蛋白（WPI）溶液聚集的影响。使用4至16 J/cm（2）的PL通量值处理磷酸钠缓冲液（pH = 7.5）中的WPI（1% w/v）溶液。通过测定游离SH基团和紫外吸收光谱来评估乳清蛋白的结构修饰和聚集。此外，通过浊度、聚集指数、粒度分布和SDS-PAGE的测量，鉴定了共价和非共价连接的蛋白质-蛋白质相互作用。PL处理后的WPI显示出结构变化，这通过游离SH基团含量的立即增加来证明（解折叠）和随后形成一小部分解折叠蛋白质的聚集，这是由于疏水相互作用和二硫键的形成。在PL能量密度从4 J/cm（2）到16 J/cm（2）处理的样品中，湍流度、平均粒径和聚集指数增加。此外，在较高能量密度下处理的样品的粒度分布分析表明，可能发生WPI二聚体解离和形成较大颗粒。在凝胶电泳分析中还观察到中间和较大蛋白质分子的缔合以及β-乳球蛋白和α-乳白蛋白之间可溶性聚集体的形成。总之，本研究的结果证明了PL处理诱导蛋白质变性的潜力，其中可溶性蛋白质聚集体的形成最小。
The effect of pulsed light (PL) on the aggregation of whey protein isolate (WPI) solutions was investigated. PL fluence values from 4 to 16 J/cm(2) were used to treat WPI (1% w/v) solutions in sodium phosphate buffer (pH = 7.5). Whey protein structural modification and aggregation were assessed through the determination of free SH-groups and UV -absorption spectra. Additionally, covalent and non-covalently linked protein -protein interactions were identified through the measurement of turbidity, aggregation index, particle size distribution, and SDS-PAGE.WPI upon PL treatment showed structural changes as demonstrated 'by the immediate increase of free SHgroup content (unfolding) and the subsequent formation of a small fraction of aggregation of unfolded proteins, due to both hydrophobic interactions and the formation of disulphide bonds. Turbidity, mean particle size, and aggregation index increased in samples treated at PL fluence from 4 to 16 J/cm(2). Furthermore, particle size distribution analysis of samples treated at higher fluence indicated that WPI dimer dissociation and formation of larger particles were likely to occur. The association of intermediate and larger protein molecules as well as the formation of soluble aggregates between beta-lactoglobulin and alpha-lactalbumin were also observed in gel electrophoresis analysis. In conclusion, the results of this investigation demonstrated the potential of PL treatments to induce protein denaturation, with a minimal formation of soluble protein aggregates.