Evidences have been accumulated that the taste organ is involved in the detection of fats since ~2000, because several molecules have been found to detect fatty acids in taste systems. The authors reported expression and function of GPR40 (FFAR1) and GPR120 (FFAR4) in mouse tongue to transmit fatty acid information to the brain. Particularly, GPR120 is involved in neural information pathway that plays role in distinguishing fatty acid taste from other primary tastes. The function of GPR120 was first reported to be involved in appetite and feeding control in the intestine through secretion of intestinal peptides, GLP-1. Recently, GPR120 is also reported in gastric ghrelin-expressing cells to suppress ghrelin secretion by fatty-acid stimulation. Taste information of fatty acids is suggested to be induce cephalic phase responses before food has reached the digestion, priming the body for an incoming fats or oils. As for the relationship between taste and disease, due to poor taste sensitivity, obese and/or diabetic patients have a risk of taking too much lipids and seasonings. In conclusion, it is important to elucidate mechanisms for the pleasant and unpleasant taste of fats because taste is closely related to feeding behavior connecting to lifestyle-related diseases.

One of the factors that contributes to the deliciousness of fats and oils in foods is the ability to adsorb aroma components. We investigated the difference in the ability to adsorb aroma components in various fats and oils and some trace components. As a result, it was suggested that fats and oils with a small amount of solid fat generally have a higher ability to adsorb aroma components. It was also clarified that the ability to adsorb aroma components was further increased by adding a small amount of glycerin and plant sterol. In these studies, it was found that the fats and oils may contribute to the deliciousness and “koku” by acting as a solvent for the aroma components.

Fat blooming problems are the main causes of deterioration of surface roughness and internal textures of chocolate, leading to the decrease in the quality of chocolate products such as fine melting and flavor release. The fat bloom occurs during the long-period storage after production processes and its detailed features diversely vary in accordance with the structures of chocolate items and the confectionery fat materials employed. This review summarizes in the first the basic mechanisms of the fat bloom formation and modern techniques to monitor the occurrence of the fat bloom. Then, the novel techniques of fat bloom monitoring using laser scanning confocal microscopy, and the ideas and methods to prevent the fat blooming of chocolate using cocoa butter alternatives, all of which have recently been investigated by the authors.