LC-MS/MS Analysis Reveals Insecticide Residues in Japanese Sake

Hydrophilic systemic insecticides translocating within plant tissues have created emerging dietary exposure pathways via alcoholic beverages which were produced from treated crops. Although such insecticides have been detected in wines and beers, their occurrence in sake, a traditional Japanese rice-based beverage, has been unstudied. In response to this gap in information, researchers analyzed 52 sake samples from five prefectures in Japan for seven neonicotinoids and six metabolites, chlorantraniliprole, ethiprole, sulfoxaflor, and triflumezopyrim using liquid chromatography-tandem mass spectrometry (LC-MS/MS). A paper based on this research was published in Food Additives & Contaminants: Part A.¹

Sake is a traditional Japanese fermented drink produced from rice, water, koji mold, and yeast. As global appreciation for Japanese cuisine has risen, the international demand for sake has grown substantially; exports of the beverage have increased from 22 million yen in 2018 to 47 million yen in 2022.² The production of sake involves a meticulous series of steps, including rice polishing, washing, steaming, fermentation, maturation, and filtration. Systemic insecticides have been intensively used in Japan for the cultivation of rice, which has resulted in their presence being found in rice grains, as well as their persisting through the food processing process, which makes it possible for their entering the human diet.³

The researchers found that systemic insecticides occurred in 88% of the 52 samples analyzed (maximum 68.2 μg/L), with dinotefuran as the most frequently detected compound. Contamination levels were comparable to Asian red wines but exceeded those reported for EU red wines, which are subject to stricter regulations. Although concentrations were below Japan's tap water limits and contributed <0.2% of Japanese ADIs (HQs, HIs < 1), 81% of samples and eight compounds exceeded EU drinking water thresholds.¹

“The intensive use of persistent systemic insecticides in the cultivation of raw materials for alcoholic beverage production has resulted in their presence in the final products, including sake,” state the authors of the study.¹ “This suggests that processing and fermentation steps may not effectively eliminate these contaminants completely. Concentration levels in the beverage likely reflect the contamination in raw materials, further influenced by regional variations in pesticide regulation and agricultural practices. For instance, contamination in sakes (with a maximum total concentration of 68.2 μg/L) was observed to be higher than in Asian red wines and, most notably, in EU red wines, where stricter regulatory controls are implemented.”¹

The data indicated to the research team that the HQs and HIs of detected compounds in sakes showed no appreciable health risks. The co-occurrence of alcohol and insecticide residues raised concern, however, as combined toxicological interactions may intensify negative health outcomes in those who partake. The lack of specific regulatory limits for pesticide residues in alcoholic beverages, in the minds of the researchers, presents an additional safety gap. To protect public health, they are of the opinion that is crucial to consider establishing stricter maximum residue limits applicable to both domestic and imported alcoholic beverages, agricultural products, and drinking water, alongside stricter regulation of pesticide applications on relevant agricultural crops. Further studies on systematic toxicology and epidemiology are also recommended for clarification of the potential health effects of chronic, low-level exposure to systemic insecticides contained within alcoholic beverages.¹

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References

1. Putri, Z. S.; Kondoh, T.; Ikenaka, Y. et al. Potential Human Exposure to Systemic Insecticides via Alcoholic Beverages: First Report on Japanese Sakes. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2026, 1-14. DOI: 10.1080/19440049.2026.2622323
2. NTA. 2025. Alcoholic Beverage Export Trends. National Tax Agency of Japan website. https://www.nta.go.jp/taxes/sake/yushutsu/yushutsu_tokei/index.htm
3. Watanabe, M.; Ueyama, J.; Ueno, E. et al. Effects of Processing and Cooking on the Reduction of Dinotefuran Concentration in Japanese Rice Samples. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2018, 35 (7), 1316-1323. DOI: 10.1080/19440049.2018.1451659