When brown rice germinates, an off-flavor occurs as the γ-amino butyric acid (GABA) production increases. Therefore, the temperature and germination time were studied to determine their effects on the aroma components of the germinated brown rice cultivar, ‘Koshihikari’. GABA and aroma components were quantified. Thus, increases in each aroma component in accordance with increasing germination processing times were determined. The GABA content of germinated rice, as well as the aroma components, increased as the temperature increased. However, the generation of the aroma components was controlled on the heat treatment condition of 60℃. The aroma components’ composition under each treatment condition was different. Therefore, by changing the germination process, we can improve the aroma’s properties while increasing GABA production.

View full abstract

Fifteen brands of rice harvested in four different countries in 2013 were polished at the yield rate of 90%, and then the oligosaccharide content in each cooked rice was measured. In addition, the comprehensive taste characteristics of the cooked rice were evaluated by the syokumikanteidan, and the relationship between the taste characteristics and the oligosaccharide content was examined. It was shown that the oligosaccharide content contributed to the taste and there was the negative correlation between the content and the firmness of cooked rice.

View full abstract

From the viewpoint of improving taste, we investigated the influence of heating at low temperatures (under 100ºC) on the taste compounds of cherry tomatoes. These taste compounds, sugars, organic acids, and amino acids, were analyzed by high performance liquid chromatography. Among sugars, sucrose content increased, particularly under heating at 90ºC/10 min and at 90ºC/15 min, while glucose and fructose contents decreased, but not significantly. With respect to other changes with heating, citric acid was similar to malic acid, and their minimum values were found at 70ºC. The ratio of glutamic acid content to aspartic acid content did not change significantly, which is important to the good taste of tomatoes. These results show that heating temperatures influence taste compounds, especially sugars and organic acids. Therefore, heating cherry tomatoes to different temperatures has the potential to make our perception of sweetness or sourness change when they are eaten.

View full abstract