豌豆蛋白乳液的模拟口腔摩擦学特性

Simulated Oral Tribological Properties of Pea Protein-Stabilized Emulsion

食品乳液在口腔加工过程中的脂肪感知属性主要来自于其乳液液滴与口腔软表面及唾液之间的复杂相互作用,乳滴在舌头表面的黏附、润湿、铺展等一系列界面行为影响乳液在口腔中的摩擦特性和润滑作用。采用高压微射流处理后的豌豆分离蛋白(pea protein isolate,PPI)作为乳化剂制备具有不同油滴粒径的水包油(O/W)乳液,研究油滴粒径变化及施加法向载荷、唾液添加等对PPI稳定的O/W乳液摩擦学特性的影响。结果表明:随着施加法向荷载的增大(0.5~2.0 N),乳液的摩擦系数明显下降,同时,随着乳液粒径的减小,更多乳滴会夹带到接触面之间,从而导致乳液摩擦系数下降(10%~30%),边界层区范围减小15%~20%,能在较低的滑动速率下实现润滑;在模拟口腔加工过程中,唾液的添加会使乳滴发生絮凝,粒径增大,不易夹带到接触面之间,进而导致PPI乳液摩擦系数增大。本研究可为调控豌豆蛋白乳液的口腔质构感官特性及产品研发提供一定技术支持。

The perception of fat-related sensory attributes in food emulsions during oral processing mainly depends on the complex interactions between the emulsion droplets and the oral soft surface as well as saliva.A range of surface behaviors including adhesion,wetting,and spreading of emulsion droplets on the tongue surface influence the frictional and lubricative properties of emulsions.In this study,the effect of oil droplet size,applied normal load,and saliva addition on the tribological properties of an oil-in-water(O/W)emulsion prepared using microfluidized pea protein isolate(PPI)as an emulsifier.The results showed that with increasing applied normal load(0.5-2.0 N),the friction coefficient of the emulsion decreased obviously.With the decrease in droplet size,the number of droplets available for entrainment increased,resulting in a decrease in friction coefficient(10%-30%)and a decrease in boundary regime range of 15%-20%and thus enabling lubrication at lower entrainment speeds.During simulated oral processing,addition of saliva induced the flocculation of droplets,increasing droplet size,preventing droplets from being entrained into the oral surface,and ultimately resulting in a higher friction coefficient for the emulsion.This study can provide technical support for regulating the oral texture sensory properties of pea protein-based emulsion and the development of plant-based products.