氯化钠对肌原纤维蛋白与风味物质相互作用的影响

Effect of NaCl on the Interaction of Flavor Compounds with Myofibrillar Proteins

为了阐明氯化钠浓度对肌肉蛋白风味吸附特性的影响和相关原理,选取17种典型性醇类、醛类、酮类和酯类化合物,研究0.0~1.0 mol/L氯化钠浓度对肌原纤维蛋白与上述物质的吸附关系,以及对蛋白结构的影响。结果表明,肌原纤维蛋白的表面疏水性在氯化钠浓度0.0~0.4 mol/L时显著升高,在0.4~1.0 mol/L时显著下降;氯化钠浓度在0.0~0.4 mol/L时α-螺旋和β-折叠转化为β-转角,之后无显著变化;肌原纤维蛋白对醇类吸附很弱,随氯化钠浓度升高,醇类、酮类和醛类吸附性总体降低;酯类吸附性在氯化钠浓度0.0~0.4 mol/L时趋于下降,在0.4~1.0 mol/L时趋于升高。蛋白对醛、酮吸附的下降,前期可能是由于二级结构改变导致席夫碱结合位点被屏蔽,后期可能是由于疏水作用力下降;对酯类的吸附作用变化趋势与疏水性相反,是由于静电相互作用为主要结合力。

The aim of the present work was to illustrate the effect and mechanism of action of NaCl concentration on the adsorption capacity of myofibrillar proteins(MPs)to flavor compounds.We selected17typical flavor compounds including alcohols,aldehydes,ketones and esters as flavor compounds for investigation of their adsorption properties onto MPs in theNaCl concentration range of0.0?1.0mol/L,and we also researched the effect of NaCl concentration on the structure of MPs.Our results showed that the hydrophobicity of MPs significantly increased in the NaCl concentration range of0.0?0.4mol/Lbut remarkably decreased as NaCl concentration rose further to1.0mol/L.Theα-helix andβ-sheet turned intoβ-turn at NaClconcentration of0.0?0.4mol/L and the secondary structure of MPs did not significantly change at higher NaCl concentration.MPs exhibited low adsorption efficiency for alcohols.The adsorptivity for alcohols,aldehydes and ketones in general decreased with increasing NaCl concentration,and the adsorptivity for esters tended to decrease at NaCl levels of0.0?0.4mol/Land increase with increasing NaCl level up to1.0mol/L.The decreased adsorption to aldehydes and ketones was attributed to the shielding of Schiff sites caused by the unfolding of secondary structure at low salt concentration,and the decrease of hydrophobicity at high salt concentration.The adsorption capacity to esters was negatively related to hydrophobicity,since the binding depended on electrostatic interaction.