Food Processing Research Group, Food Convergence Research Division, Korea Food Research Institute, Wanju-gun, Republic of Korea.
Department of Food Science and Nutrition, The Catholic University of Korea, Bucheon-si, Republic of Korea.
J Texture Stud. 2024 Aug;55(4):e12857. doi: 10.1111/jtxs.12857.
The tribological properties of 19 commercial food products, grouped into six categories (yogurt, dressings, spreads, porridges, emulsified sauces, and syrups) were investigated in relation to their rheological (dynamic oscillatory shear test) and nutritional properties (fat, carbohydrate, and protein). A tribological system (a glass ball and three polydimethylsiloxane pins) generated the extended Stribeck curve, monitoring friction factors (f) over an extended range of sliding speed (v) (10 to 10 m/s). Tribological parameters (f, v) at four inflection points dividing the frictional regimes (X, breakaway point between the static and kinetic regimes; X-X, boundary; X-X, mixed; X-X, hydrodynamic regimes) and the slope between X and X (s) were subjected to principal component analysis and hierarchical clustering on principal components, using rheological and nutritional parameters as quantitative supplementary variables. Tribological patterns were predominantly influenced by viscosity, viscoelasticity, yield stress, fat content, and the presence of particles (e.g., sugar, proteins, and fibers) and pasting materials (e.g., starches and modified starches). The 19 tribological patterns were classified into 3 clusters: low f and s for fat- and/or viscoelastic-dominant foods (Cluster 1), low f and high s for food emulsions and/or those with low extent of shear-thinning (Cluster 2), and high f at the boundary regime either for the most viscous foods or for those in the presence of particulates (Cluster 3). These results suggest that the compositional and rheological properties have a more profound impact on the classification of complex tribological patterns than the categories of food products.
研究了 19 种商业食品（分为六类：酸奶、调味料、涂抹酱、粥、乳化酱和糖浆）的摩擦学特性与其流变学（动态振荡剪切测试）和营养特性（脂肪、碳水化合物和蛋白质）之间的关系。摩擦学系统（一个玻璃球和三个聚二甲基硅氧烷销）产生了扩展的 Stribeck 曲线，在较宽的滑动速度（v）范围内（10 到 10 m/s）监测摩擦系数（f）。在将摩擦状态分为四个拐点的四个参数（f、v）（X，静动状态之间的转折点；X-X，边界；X-X，混合；X-X，流体动力状态）以及 X 和 X 之间的斜率（s），使用流变学和营养参数作为定量补充变量，对摩擦学参数进行主成分分析和主成分聚类。摩擦学模式主要受粘度、粘弹性、屈服应力、脂肪含量以及颗粒（例如糖、蛋白质和纤维）和糊化材料（例如淀粉和改性淀粉）的存在影响。19 种摩擦学模式分为 3 个聚类：低 f 和 s 适用于脂肪和/或粘弹性占主导地位的食品（聚类 1），低 f 和高 s 适用于食品乳液和/或剪切稀化程度较低的食品（聚类 2），边界状态下的高 f 适用于最粘稠的食品或存在颗粒的食品（聚类 3）。这些结果表明，与食品类别相比，组成和流变学特性对复杂摩擦学模式的分类具有更深远的影响。
