Food can sometimes contain odors not normally associated with that food. These odors are called off-flavors, and cow milk is known to contain off-flavors such as hexanal depending on the feed or physical condition of the cows. We previously discovered and revealed the structure of 2-Iodo-4-methylphenol (2I4MP), an off-flavor component in commercially available cow milk. We were the first group to discover 2I4MP is an off-flavor component in cow milk.

This study investigated the following three questions. First, what compounds serve as the starting materials in generating 2I4MP? Organic synthesis techniques were used to identify p-cresol as a candidate starting material. Second, how is 2I4MP generated in the cowshed? Using cow dung, we confirmed that 2I4MP was generated by the effects of iodine on cow dung. Based on these findings, measures were proposed to prevent contamination of cow milk by 2I4MP. Third, how is 2I4MP transferred to raw milk? 2I4MP movement was estimated by creating a desiccator-based model that showed 2I4MP is potentially transferred to raw milk in the cowshed. These involve that the iodine-based disinfectants, used to disinfect teats during milking, should not be used excessively. Furthermore, ensuring the disinfectants do not fall onto cow dung or bedding. Adopting these measures is vital for preventing contamination of cow milk by 2I4MP.

Species-specific endogenous reference sequences are indispensable in the development of methods to detect genetically modified (GM) crops for food and feed. We analyzed a partial sequence derived from the β-fructosidase gene among several solanaceous species and developed a new eggplant specific detection method using loop-mediated isothermal amplification (LAMP). LAMP is a rapid, specific, and cost-effective technique. The species-specificity and stability of the developed method were evaluated using 18 eggplant cultivars and other crops including solanaceous plants. The limit of detection was also evaluated. The developed method showed high specificity for eggplants and stability among the eggplant cultivars tested. These results suggested that the developed method would be useful as a positive control for the detection of GM eggplants with LAMP.

To promote and raise the awareness of accurate knowledge on pesticide residues, the symposium program on risk communication on pesticide residues was held by the broadcasted online style. The risk communication program was statistically evaluated using a pre- and post-program online questionnaire survey. We had the questionnaire answers of the 105 valid participants. The analysis of post-program questionnaires shows that the risk communication program was effective in terms of levels of understanding and interest. Pre-program risk perception or awareness of safety assessments was significantly and positively correlated with awareness for establishing standard values of pesticide residues by the analysis of pre-program questionnaires. Risk perception after the program was significantly higher than before the program, suggesting that risk perception increased due to the program by analysis the same question between pre- and post-program questionnaires. Multiple regression analysis suggests that the participants with higher pre-program awareness of safety assessments or pre-program awareness for establishing standard values appeared to have higher levels of understanding and post-program risk perception.

We examined the effects of cooking and processing on the quantitation of soy protein in various soy-based foods. For the phosphate-buffered saline (PBS) extraction, the total protein content was measured by bicinchoninic acid assay, and the buffer extraction containing sodium dodecyl sulfate (SDS) and 2-mercaptoethanol (ME) was measured by the 2-D Quant Kit, and SDS-polyacrylamide gel electrophoresis analysis (SDS-PAGE) of each extraction was performed. Furthermore, measurements were performed by various ELISAs. During the tofu cooking process, the protein concentrations of soaked soybeans and Seigo (soybean homogenized with water) fluctuated- the change in protein solubility due to the amount of water during sample homogenization was considered to be a factor. It was thought that the decrease in protein concentration due to heating of Seigo during soymilk production was considered to indicate thermal denaturation of the protein, and that SDS and ME extraction in tofu may affect the measurement system. In cooking excluding roasted beans, proteins with a mass of 50 kDa or above and around 20 kDa were denatured, and in twice-fried tofu, proteins around 40 kDa were denatured, but the protein concentration excluding boiled soybeans did not decreased. Furthermore, the protein concentration from roasted beans, yuba, roasted okara and fried tofu increased with the cooking time, suggesting that the denaturation temperature of the protein shifted to a high temperature as the water content decreased. Both of the two types of ELISAs that comply with the official labeling system of foods containing allergenic substances were useful for detecting soybean protein by detecting proteins and peptides in processed soybean products, fermented foods excluding natto, and health foods.

Tetramine (tetramethyl ammonium ion), a neurotoxin, is present at high levels in the salivary glands of buccinid gastropods and is responsible for human intoxication due to consumption of the gastropods. We used LC-MS/MS to examine the tetramine contents of salivary glands from 16 species of carnivorous gastropods collected along Japanese coasts. Tetramine was detected in all specimens except for Babylonia japonica. High levels of tetramine were detected in whelks, Neptunea lamellosa (1,380–9,410 μg/g of salivary gland) and N. purpurea (1,190–7,400 μg/g of salivary gland). Although consumption of N. lamellosa is well-known cause of foodborne tetramine poisoning, it was newly discovered that N. purpurea has tetramine. In addition, we found 7 other species of gastropods containing tetramine: Siphonalia cassidariaeformis (117–135 μg/g), S. fusoides (204 μg/g), Buccinum inclytum (2.94–3.40 μg/g), and B. aniwanum (0.700 μg/g) of the family Buccinidae, and Fusinus perplexus (397 μg/g), F. ferrugineus (105 μg/g), and F. forceps salisburyi (67.5 μg/g) of the family Fasciolariidae. The present study, together with previous studies, shows that gastropods with salivary glands containing more than 1,000 μg tetramine/g of salivary gland, including the genus Neptunea as well as Fusitriton oregonesis and Hemifusus tuba, carry a high risk of tetramine poisoning, and their salivary glands should be removed before consumption to prevent food poisoning.