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• Excessive oven-roasting of pomegranate seeds breaks down the innate carotenoid pigments and reduces the a* (redness) value. • Oven roasting increases the total phenolic and flavonoid content of pomegranate seeds, which improves their antioxidant capacities. • Proper roasting conditions increase antioxidant properties and positive flavors such as furan derivatives, pyrazines. • Higher temperatures and a long roasting time increase the amounts of off-flavor such as sulfur compounds and amines. This study investigated the effects of oven-roasting temperature (160, 180, and 200 ℃) and time (5, 10, 15, and 20 min) on pomegranate seeds. Physicochemical properties, such as color (L*, a*, and b* values), browning index (BI), total phenolic and flavonoid contents, 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity, and chemosensory properties, including taste and volatile compounds, were analyzed. The L* and a* values, and level of sourness, umami, sweetness, and terpenes decreased, whereas the b* value, BI, and level of saltiness, bitterness, furan derivatives, pyrazines, and sulfur-containing compounds, increased with roasting time. The findings of this study showed that the positive roasting conditions for pomegranate seeds were 10–20 min at 160 ℃ and, 5–10 min at 180 ℃. This study is expected to be used as a primary reference for selecting the optimal oven-roasting conditions in which positive effects appear and for developing products utilizing pomegranate seeds. [ABSTRACT FROM AUTHOR]

In this study, the chemosensory components of microwave- or oven-roasted Coffea arabica L. were compared using high-performance liquid chromatography and electronic sensors. The contents of caffeine and chlorogenic acid were the highest in green bean extract and were decreased with micro- and oven-roasting time. The decreases in the content of the two components were observed more in oven roasting. In electronic tongue analysis, green bean extract had a relatively higher bitterness, sweetness, and sourness than others. After the roasting process, the bitterness decreased at 10 min, however, increased after 15 min. In addition, sourness tended to decrease over time. Microwave-roasted extracts were lower shifted than those of oven-roasted extracts during each roasting process. Accordingly, higher changes of taste patterns were represented during oven-roasting processes. In electronic nose analysis, volatile alcohols and esters were abundant in the green bean extract, and thus, these components were considered as the main volatiles in the green bean. Through the roasting process, the number of volatiles has increased. In particular, pyrazines were generated in those of roasted samples, and the amounts of furans increased. These results provide basic data regarding the chemosensory components of Yellow Bourbon and may be utilized to optimize the roasting conditions. • Chemical sensory properties of microwave- or oven-roasted coffee were studied. • Electronic tongue quantified five basic tastes in coffees roasted by microwave and oven. • Total 75 volatile compounds were identified using electronic nose. • Principal component analysis segregated coffee sample clusters with different thermal processing. [ABSTRACT FROM AUTHOR]