Sensory Features of Partially Hydrogenated Oil and Their Connection with Melting and Crystalline Characteristics

Although partially hydrogenated oil (PHO) provides foods with outstanding thick tastes and pronounced "creamy" flavor, the high level of artificial trans-fatty acids (TFA; about 30%) limits its usages around the world in the near future. It is necessary to produce trans-free alternatives with similar tastes to PHO. The relationship between sensory attributes and physicochemical characteristics of PHO and four typical specialty fats were therefore analyzed in the present study. PHO exhibited the highest greasiness score (8.19), accompanying by mild creaminess and aftertaste as well as a weak coolness during swallow, which were resulted from the close-packed arrangements of TFA, its cis-counterparts and other long chain fatty acids. None of artificial trans-fats, mainly anhydrous milk fat, cocoa butter, and coconut oil and its fully hydrogenated counterpart, were similar to PHO in terms of these sensory attributes. The unique fatty acid species of PHO and their arrangements contributed to the relatively smooth solid fat content profile and melting-crystallization curve, as well as forming uniform and dense β' crystal-structures (D_b=1.80). The Pearson correlation analyses relevelled that long chain fatty acids, e.g., t-C18:1 and C18:1, and melting final temperatures were generally positive correlated with greasiness, creaminess and aftertaste; whereas these indices were negatively correlated with coolness. The melting enthalpy was highly connected with coolness, which reflected the endothermic effectiveness during the melting process of fats in the mouth. These indices screened by correlation analyses that were strongly correlated with sensory attributes could provide references for producing trans-free alternatives.