• Korean Journal of Food Science and Technology
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• v.41 no.2
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• pp.141-145
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• 2009

Cheongyukjang, a Banga food, is a heavy soy-soup prepared by boiling cheonggukjang, sea foods, and meats. Soybeans roasted at 140$^{\circ}C$ for 21.0 min and 220$^{\circ}C$ for 6.0 min, respectively, were used for cheonggukjang preparation. Distributions of isoflavones in raw soybeans, roasted soybeans, cheonggukjang, and cheongyukjang were analyzed by high performance liquid chromatography. The total isoflavones in roasted soybeans, cheonggukjang and cheongyukjang were about 79-80, 56-65, and 47-50% of those in raw soybeans, respectively. Roasting caused significant increases in acetyl derivatives and ${\beta}$-glucoside isoflavones, and significant decreases in malonyl derivatives (p < 0.05). The major isoflavones in cheonggukjang and cheongyukjang were ${\beta}$-glucosides. Succinyl-${\beta}$-daidzin and succinyl-${\beta}$-genistin, which are recognized as new metabolites of isoflavones, were not detected in raw and roasted soybeans. Peak areas of succinyl-${\beta}$-genistin were higher than thse of succinyl-${\beta}$-daidzin, in both cheongyukjang and cheonggukjang.

• Journal of the Korean Society of Food Culture
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• v.31 no.6
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• pp.643-651
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• 2016

This study was investigated the difference in the quality characteristics of the fermented soybean roasted with different conditions for making chungyukjang. Roasted condition of soybean was decided by pre-test, which was on $140^{\circ}C$ for 21 min, $180^{\circ}C$ 9.5 min, and $220^{\circ}C$ 6 min. Fermented soybean with different roasted condition and conventionally made cheonggukjang were measured for proximate composition, color, pH, amino nitrogen, ammonia nitrogen, free sugar and amino acids. The lightness and yellowness of soybean fermented by conventional method was higher than those of the fermented soybean with roasted soybean. The contents of free sugar of fermented soybean roasted on $220^{\circ}C$ for 6 min (FS220) was the highest among the group and followed by fermented soybean roasted on $180^{\circ}C$ for 9.5 min (FS180), $140^{\circ}C$ 21 min (FS140) and conventional cheonggukjang (FS0). The contents of total free amino acid was highest on fermented soybean roasted on $140^{\circ}C$ for 21 min (FS140) and followed by fermented soybean roasted on $180^{\circ}C$ for 9.5 min (FS180), $220^{\circ}C$ 6 min (FS220) and conventional cheonggukjang (FS0).