Analysis of egg yolk components that contribute to deliciousness by sensory evaluation

<p>[Objective]</p><p>Eggs are used as ingredients in a variety of foods. This is because the egg's ability to improve physical properties makes the food tastier. Another important reason is that the flavor of the egg, especially the yolk, enhances the taste. However, the components involved in the deliciousness of egg yolks have not been identified. Therefore, we fractionated egg yolks to determine the flavor characteristics of each fractionated component.</p><p>[Materials and Methods]</p><p>The egg yolk was added to distilled water and centrifuged to obtain the precipitated HDL-dominated granule fraction. The plasma fraction of the supernatant was further frozen to separate the LDL fraction, and the remainder was the water-soluble fraction. The components of each of the three fractions were lyophilized. The samples of each fraction mixed with egg white, egg liquid with different proportions of egg yolk, and egg white were prepared and mixed with 0.3% salt. 3% salad oil was used to prepare fried eggs. For the terms used in the sensory evaluation, preliminary experiments were conducted and 12 research terms were extracted to describe the egg yolk flavor. Analytical sensory evaluation of six samples was conducted by ten expert panelists using a five-point grading system. The samples were consumed at room temperature at a dose of 20 g per person. The obtained results were analyzed by principal component analysis.</p><p>[Result]</p><p>The following terms were used for scrambled eggs: "hardness," "elasticity," "roughness," "wateriness," "sulfur smell," "fish smell," "saltiness," "bitterness," "umami," "richness," and "oiliness. As a result, the LDL fraction sample and the two samples containing a large amount of egg yolk were rated as "strong" in "umami", "richness", and "fatty taste". In the water-soluble fraction samples, "salty taste" and "bitter taste" were rated as strong. These results indicate that the LDL fraction components are related to the richness and other deliciousness of the egg yolk.</p>