A comparative research of flavor characteristics in different methods of broccoli (Brassica oleracea var. Italica) extracts using electronic sensors

Abstract

This study compared flavor and taste patterns in various broccoli extracts using the electronic nose and electronic tongue. The electronic nose analysis identified a total of 41 volatiles, including 9 acids and esters, 8 alcohols, 6 aldehydes, 6 heterocyclics, 7 hydrocarbons, 5 sulfur-containing compounds, and 2 ketones. The principal component analysis for volatiles demonstrated that principal component 1 (PC1) showed 37.67%, PC2 showed 28.69% and PC3 showed 19.94% variances, respectively. Hot-brewed extracts and espresso extracts were separated by the PC1 and hot-brewed extracts were located on the negative PC1 axis. However, espresso extracts were located on the positive PC1 axis. the cold-brewed extracts of stem and floret were separated by PC2. In the electronic tongue analysis, the sensor values of sourness (SRS) and sweetness (SWS) showed the highest value in the cold-brewed extracts, followed by hot-brewed extracts and espresso extracts, regardless of the broccoli parts. However, the sensor value of umami taste (UMS) showed the highest in the hot-brewed extracts, followed by the cold-brewed extracts and espresso extracts. The sensor value of bitterness (BRS) was high in the hot-brewed extracts and espresso extracts. However, cold-brewed extracts showed low BRS. In the principal component analysis for tastes, PC1 showed a 60.03% variance and PC2 showed a 20.49% variance. Cold-brewed extracts were located on the positive PC1 axis by the SRS and SWS. However, hot-brewed and espresso extracts were mainly affected by the BRS. Copyright ? 2021 by The Korean Society of Food Science and Nutrition. All rights Reserved.