INSTRUMENTAL AND SENSORY ANALYSIS OF VOLATILE AROMA OF COOKED RICE

The objective of this study was to compare the differences in aroma of cooked rice samples. The rice aroma of four popular rice varieties in Taiwan (TC 189, TNu 70, TNu 67 and TC Sen 10) at different temperatures (18C, 25C and 60C) were analyzed by GC‐MS system (using headspace capture collection) and evaluated by trained and naive panels. The GC‐MS results indicated that the composition of the volatile components of rice was complicated and no single volatile compound contributed to the characteristics of rice aroma. Fourteen attributes were developed using modified quantitative descriptive analysis and evaluated with line scaling method. The 60C samples were higher in hot‐steam‐bread aroma, corn aroma, corn‐leaf aroma and brown‐rice aroma, while the 18C samples were higher in cold‐steam‐bread aroma and fermented‐sour aroma. Compared to the other varieties, the TC Sen 10 was uniquely higher in plastic aroma, sulfur aroma and gasoline aroma. As expected, hedonic results showed that naive panelists preferred the overall aroma perception of the 60C samples. The relationship between the volatile compounds and descriptive attributes is discussed.