A method for determination of tomatine in tomatoes and tomato products was developed using LC-MS/MS. Tomatine was extracted from these samples with 20% methanol aqueous solution containing 1% acetic acid. Cleanup was performed on sample solutions using a polymer-based OASIS HLB cartridge column. LC separations were performed using an Inertsil ODS-3 column and a linear gradient elution using 0.1% formic acid aqueous solution and 0.1% formic acid in acetonitrile as the mobile phase. Detection of MS was performed in positive ion electrospray ionization mode. The range of average recoveries of tomatine from 4 fresh tomatoes and 7 processed tomato products added with 0.01 mg/100 g were 80.3-94.8% and 76.8-95.5%, respectively. The limit of quantitation was estimated to be 0.01 mg/100 g, considering the limit of bitter stimulus. Using the present method, results of tomatine content in two tomatoes tasted bitter by consumers, were 1.04 mg/100 g and 1.54 mg/100 g. Further, results of a field survey of tomatine content in commercially available fresh tomatoes and processed tomato products were in the range of 0.01 mg/100 g to 3.05 mg/100 g. In addition, when tomatine was added to tomato and then heat-treated, no significant change of tomatine amount was observed by heating.

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Trigonella foenum-graecum seeds (TF) (Fabaceae) is a well-known plant traditionally used as food and medicinal herb. A variety of pharmacological effects of TF extract were shown against diabetic, cancer and dementia in animal models. Concerning anti-dementia effects of TF extract, it has not been evaluated in Alzheimer’s disease models. In addition, those previous studies, active constituents in TF extract for memory function were not identified. We aimed to clarify effects of 30% ethanol TF extract on Alzheimer’s disease model, 5XFAD mouse, and determine a major active compound in the brain after oral intake of TF extract. Trigonelline content in TF extract and trigonelline penetration in the brain after oral administration of TF extract (5000 mg/kg, once) were quantified by LCMS/ MS analysis. Memory recovery by TF extract (100, 500 mg/kg/day for 17 days) was evaluated by object location memory test. Expression level of neurofilament light in the cerebral cortex was quantified by western blotting. Trigonelline was detected in the cerebral cortex of 5XFAD mice 24 h after oral administration of TF extract. Oral administration of TF extract (500 mg/kg/day) for 17 days improved object location memory. TF extract increased dose-dependently the level of axonal protein, neurofilament light in 5XFAD mice. These results suggest that TF extract could be an expected therapeutic candidate for Alzheimer’s disease, and supposed one of active compounds transferred in the brain is trigonelline. This study is the first report to determine trigonelline penetration in the brain after oral administration of TF extract.

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In April 2015, “Foods with Functional Claims (FFCs)” was established as a new category of voluntary labeling in health food products sold in Japan. Several products comprising piperine as a functional substance, which is found in plants such as pepper, long pepper, and Java long pepper, have been categorized as FFCs. Health food products such as dietary supplements and spices derived from the above-mentioned peppers have also been sold commercially. Although piperine has been reported to improve blood flow and induce other positive effects, some reports showed that it exhibits acute toxicity values that are equivalent to those of powerful drugs. Therefore, ensuring the quality of piperine-containing food products is important. In this study, a quantitative analysis using HPLC was conducted for 28 piperine-containing products belonging to three product categories (FFCs, health food products, and spices) with a commercially available piperine reagent that was determined its absolute purity via quantitative NMR analysis. Four health food products and seven spices contained piperine at daily intake levels fifty times greater than those of FFCs. Conversely, piperine was not detected in two spice products; these products might have been made using different ingredients than those on the labels. We will continue to pay attention to the market trends of piperine-containing food products.

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Supercritical fluid extraction was used to extract pesticides from cereals. Each sample was homogenized with water, celite, and water-absorbent polymer. The obtained mixture was extracted using supercritical carbon dioxide. Each pesticide trapped in ODS column was eluted by acetonitrile and was analyzed using LC-MS/MS. The validation study (2 samples per day on 5 days) was conducted for 114 compounds at 0.01 and 0.05 μg/g for 5 samples. Results demonstrated that 47–71 compounds in each sample met target values for trueness, repeatability, and within-laboratory reproducibility. This assay can be used as a method for analysis of pesticide residues in cereals.

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To check the authenticity of the food labeling regarding genetically modified organisms (GMOs), we need to detect recombinant DNA remaining in processed foods. In this study, we investigated on the detection of corn starch-derived recombinant DNA in beer. We made beer samples from identity preserved corn starch (low GMO content) and non-identity preserved corn starch (high GMO content). Recombinant DNA was detected only from start material, and not detected from the other intermediates and final products irrespective of GMO contents in starch. Real-time PCR analysis detecting 18S rDNA and internal positive control proved that the impossible detection of recombinant DNA was caused not by PCR inhibitors but by extremely small DNA amounts in beer.

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A rapid and simple method was developed for the determination of emetic toxin (CER; cereulide) produced by Bacillus cereus in processed foods. CER was extracted using 70% hydrated acetonitrile and n-hexane. The n-hexane layer was separated and evaporated. The residue was redissolved in acetonitrile and defatted with n-hexane saturated with acetonitrile, and The acetonitrile layer was then analyzed using LC-MS/MS. To validate this method, foods that cause food poisoning by B. cereus, including cooked rice, fried rice, pilaf, and pasta, were spiked with 1 ng/g or 100 ng/g CER, and recovery test were performed. CER recovery rates from these 4 processed foods were 75%–92% at 1 ng/g, and 70%–91% at 100 ng/g with satisfactory repeatability and all other parameters. It was possible to detect CER in fried rice about 6 hours after inoculation with B. cereus.

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