The purpose of this study was to investigate the flavor characteristics of Gondre (Cirsium setidens Nakai) essential oil. The essential oil was isolated from the aerial parts of the plant by the hydrodistillation extraction method and analyzed by gas chromatography (GC) and GC-mass spectroscopy (MS). Seventy-eight (90.28%) volatile flavor components were identified in the essential oil from Gondre harvested in May. The major compounds were hexadecanoic acid (44.84%), phytol (15.57%), 6,10,14-trimethyl-2- pentadecanone (5.62%), and tertadecanoic acid (4.77%). Seventy (90.72%) volatile flavor components were identified in the essential oil from Gondre harvested in September. The major compounds were phytol (24.18%), 6,10,14-trimethyl-2-pentadecanone (15.59%), tetracosane (8.87%), 2-methyl eicosane (3.55%), 6,10,14-trimethyl-5,9,13-pentadecatrien-2-one (3.12%), dibuthyl phthalate (2.35%), and viridiflorol (2.33%). The flavor components of the essential oil from Gondre harvested in May and September were characterized by higher proportions of aliphatic fatty acids and terpene compounds, respectively.

This study examined the quality characteristics of Gondre tofu containing 0, 0.1, 0.2, and 0.3% Cirsium setidens powder. Quality and sensory tests of Gondre tofu were performed. The yield rate of tofu decreased with the addition of Cirsium setidens powder. The pH of tofu decreased after the addition of Cirsium setidens powder. During 8 days storage, the addition of Cirsium setidens powder to tofu did not effectively inhibit the number of total aerobic bacteria. The L, a and b values of tofu decreased with increasing amount of Cirsium setidens powder added. In the texture properties, the hardness, cohesiveness, gumminess and brittleness increased, whereas the springiness decreased. The results of sensory evaluation showed that tofu containing 0, 0.1, and 0.2% Cirsium setidens powder had a higher taste, texture preference and overall acceptability than 0.3% Cirsium setidens powder. Therefore, the addition up to 0.2% Cirsium setidens powder positively affects the sensory evaluation of Gondre tofu. The addition 0.2% Cirsium setidens powder might be considered the most appropriate choice for manufacturing Gondre tofu.