Suppressing Effect of Japanese Pepper on the Odor of Niboshi Soup Stock

Abstract

The suppressing effect of the leaf or fruit of Japanese pepper Zanthoxylum piperitum DC, on niboshi odor was studied by a combination sensory analysis testing, gas chromatography, and gas chromatograph-y-mass spectrometry.
In sensory tests it was found that the niboshi odor was distinctly suppressed by the addition of Japanese pepper leaf and fruit, respectively. Eight carbonyls and one alcohol identified in niboshi soup stock were also detected in the niboshi soup stock to which Japanese pepper leaf or fruit was added. On the other hand, five compounds (a-pinene, myrcene, limonene, citronellal, and 2-undecanone) identified as main components in leaf and four compounds (myrcene, limonene, citronellal, and geranyl acetate) identified as main components in fruit were also detected in the niboshi soup stock to which Japanese pepper leaf and fruit was added, respectively. The effect of the addition of the above four or five authentic compounds on niboshi odor was then examined using sensory tests.
It was concluded that the above five compounds and geranyl acetate of the above four compounds greatly contributed to masking the odor of niboshi in cases where the Japanese pepper leaf and fruit were respectively added.