Insight into the mystery of Pheretima smells worse exposed to water: Identification, type, and volatility of stenchy odor
Hui Ye,
Hongyan Ma,
Li Han,
Hong Fan,
Xiaoming Bao,
Yuhua Liu,
Jiabao Liao,
Runchun Xu,
Dingkun Zhang
Affiliations
Hui Ye
State Key Laboratory of Southwestern Chinese Medicine Resources, Pharmacy School, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, PR China
Hongyan Ma
State Key Laboratory of Southwestern Chinese Medicine Resources, Pharmacy School, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, PR China
Li Han
State Key Laboratory of Southwestern Chinese Medicine Resources, Pharmacy School, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, PR China
Hong Fan
State Key Laboratory of Southwestern Chinese Medicine Resources, Pharmacy School, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, PR China
Xiaoming Bao
Shimadzu (China) Co., Ltd, Chengdu, 610063, PR China
Yuhua Liu
China Resources Sanjiu Modern Chinese Medicine Pharmaceutical Co., Ltd., Huizhou, 516007, PR China
Jiabao Liao
China Resources Sanjiu Modern Chinese Medicine Pharmaceutical Co., Ltd., Huizhou, 516007, PR China; Corresponding author.
Runchun Xu
State Key Laboratory of Southwestern Chinese Medicine Resources, Pharmacy School, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, PR China; Corresponding author.
Dingkun Zhang
State Key Laboratory of Southwestern Chinese Medicine Resources, Pharmacy School, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, PR China; Sichuan Provincial Engineering Research Center of Innovative Re-development of Famous Classical Formulas, Tianfu TCM Innovation Harbour, Chengdu University of Traditional Chinese Medicine, Chengdu, 611930, PR China; Corresponding author. State Key Laboratory of Southwestern Chinese Medicine Resources, Pharmacy School, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, PR China.
Pheretima is a popular healthy food, but Pheretima and related foods have specific stenchy odor, especially after decocting or warm soaking, the odor is intense, resulting in nausea and vomiting. This indicates that the release of stenchy odor components is intensified when Pheretima was exposed to hot water. It is urgent to study the composition and release pattern of the stenchy odor components of Pheretima. In this study, a series of samples with different odors were prepared by the combination of SFE-CO2 and warm soaking. The results showed that the fishy and smoky odor of Pheretima were heavier, attributed to the components such as dimethyl trisulfide, TMA, and guaiacol. When Pheretima was exposed to hot water, the fishy odor increased sharply. Dimethyl trisulfide and TMA were the key odor components, especially the exposure of TMA increased by 2∼3 times after warm soaking. The volatilization rate of n-hexanal, TMA, dimethyl trisulfide and other components was found to be highly volatile, and the volatilization rate at 75 °C was 2.5 times that at room temperature. This study proved for the first time that stenchy odor substances include two categories: water-soluble and liposoluble. And found that the water-soluble odor components accelerate their exposure and volatilization in warm water, which is the scientific principle of “Pheretima smells worse exposed to water”.