Comprehensive changes in volatile/nonvolatile compounds and flavor and physicochemical characteristics in Angelica gigas Nakai roots by thermal processing

This study investigated the changes of physicochemical and flavor characteristics of Angelica gigas Nakai roots during roasting. Glutamic acid and arginine were higher in constituent amino acids. In the taste value, glutamic acid was highest in constituent and free amino acids. Total phenol contents were highest in 0 min and lowest in 3 min. Hundred twenty-six volatile compounds were detected by GC/MS during roasting. α-pinene, eudesmol, nonane, and limonene were detected as major volatile compounds. For antioxidant ability, 1,1-diphenyl-2-picrylhydrazyl did not change during roasting, and 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid showed the highest value in 3 min. Browning intensity showed a slight decrease over time. In Electronic nose, fragrance increased by roasting, and strength, NH3, and H2S decreased significantly. In Electronic tongue, sweetness, bitterness, and umami taste increased by roasting, and this was related to amino acid composition. The results provide basic data on the physicochemical and flavor characteristics of A. gigas Nakai according to the roasting process. Practical applications: Angelica gigas Nakai has been known as a medicinal herb in Asian countries and usually consumed in powder, tea, and snacks. In order to produce the powder, tea, or snacks with A. gigas Nakai, thermal treatment is an essential and critical process. Despite that existing studies reported many physiological benefits and functional properties of A. gigas Nakai, studies have rarely discovered how the nutritional properties and volatile compounds of A. gigas Nakai alter when it undergoes thermal treatment. Therefore, this study will be utilized as basic data to optimize the thermal processing conditions (e.g., roasting time) for the production of food products with A. gigas Nakai such as tea and snacks. This study further provides objective chemical measures of sensory profiles of A. gigas Nakai using electronic tongue and electronic nose during the thermal processing.