Gulão Eliana da S, de Souza Clitor J F, Andrade Cristina T, Garcia-Rojas Edwin E
Programa de Pós-graduação em Ciência e Tecnologia de Alimentos (PPGCTA), Universidade Federal Rural de Rio de Janeiro (UFRRJ), Rodovia BR 465, Km 7, Seropédica/RJ 23890-000, Brazil.
Instituto de Macromoléculas Professora Eloisa Mano, Universidade Federal do Rio de Janeiro, Centro de Tecnologia, Bloco J, Rio de Janeiro/RJ 21941-598, Brazil.
Food Chem. 2016 Mar 1;194:680-6. doi: 10.1016/j.foodchem.2015.08.062. Epub 2015 Aug 20.
In this study, interactions between polypeptide-leucine (0.2% w/w) and gum arabic (0.03, 0.06, 0.09, 0.12, and 0.15% w/w) were examined at concentrations of NaCl (0, 0.01, 0.25, 0.3, 0.5mol/l) and at different pH values (from 1.0 to 12.0). Formation of insoluble complex coacervates was highest at pH 4.0. At pH 2.0, which is the pKa of the gum Arabic, the dissociation of precipitate occurred. The pHØ2 positively shifted with the addition of higher concentrations of salt. Samples containing 0.2% PL and 0.03% GA and no salt had higher turbidity and increased formation of precipitates showing greater turbidity and particle sizes. The Fourier transform infrared spectroscopy confirms the complex coacervate formation of leucine and gum arabic, and rheological measurements suggest the elastic behavior of 0.2% PL and 0.03% GA complex. Overall, the study suggests that complex coacervates of PLs could be one feasible ways of incorporating amino acids in food products.
在本研究中，考察了多肽 - 亮氨酸（0.2% w/w）与阿拉伯胶（0.03%、0.06%、0.09%、0.12%和0.15% w/w）在不同氯化钠浓度（0、0.01、0.25、0.3、0.5mol/l）和不同pH值（1.0至12.0）下的相互作用。在pH 4.0时，不溶性复合凝聚层的形成量最高。在阿拉伯胶的pKa即pH 2.0时，沉淀物发生解离。随着盐浓度的增加，pHØ2呈正向移动。含有0.2% PL和0.03% GA且无盐的样品具有更高的浊度，沉淀物形成增加，表现出更大的浊度和颗粒尺寸。傅里叶变换红外光谱证实了亮氨酸和阿拉伯胶形成了复合凝聚层，流变学测量表明0.2% PL和0.03% GA复合物具有弹性行为。总体而言，该研究表明PLs的复合凝聚层可能是将氨基酸纳入食品的一种可行方法。
