Insight into the mystery of Pheretima smells worse exposed to water: Identification, type, and volatility of stenchy odor

• Published in: Heliyon Vol. 10; no. 18; p. e37700
• Main Authors: Ye, Hui, Ma, Hongyan, Han, Li, Fan, Hong, Bao, Xiaoming, Liu, Yuhua, Liao, Jiabao, Xu, Runchun, Zhang, Dingkun
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 30.09.2024; Elsevier
• Subjects: Evaporation rate; HS-SPME-GC-MS; Pheretima; Sensory evaluation; Stenchy odor; Volatile component; Pheretima; HS-SPME-GC-MS; Volatile component; Stenchy odor; Sensory evaluation; Evaporation rate
• ISSN: 2405-8440; 2405-8440
• DOI: 10.1016/j.heliyon.2024.e37700

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”. By adopting a subjective and objective analysis and evaluation method, the scientific mechanism of the peculiar change of “Pheretima smells worse exposed to water” was explored, providing data support and research ideas for the deodorization of Pheretima and its related products. [Display omitted] •Extract Pheretima grease and prepare different samples such as grease and residue.•The stenchy odor of Pheretima was obviously enhanced after exposure to water.•The key odor components were characterized by HS-SPME-GC-MS combined with OAV.•Comparative study on volatilization rate of key odor components.