Shrimp tropomyosin is one of the most important causes of shellfish allergy. The objective of this study was to develop a highly sensitive and specific immunoassay for the detection of shrimp tropomyosin in food. Ten monoclonal antibodies against shrimp tropomyosin were obtained by fusion and cell screening. We found two optimum monoclonal antibodies (mAbs); mAb 2 was used as the capture antibody, and HRP-labelled mAb 3 was used as the detection antibody. Using this pair of mAbs, a sandwich enzyme-linked immunosorbent assay (ELISA) was developed with the limit of detection (LOD) of 0.45 ng/mL. Cross-reactivity with other food allergens using this method was found to be negligible. An immunochromatographic assay strip was also developed for the rapid detection of shrimp tropomyosin with the LOD of 0.5 ng/mL. The results demonstrated that our developmental methods represent a useful tool for the detection of shrimp tropomyosin in food.

A total of 139 vegetable oils and 48 frying oils produced in China were tested for the levels of 15 Environmental Protection Agency-regulated polycyclic aromatic hydrocarbons (PAHs). The analysis was completed by high-performance liquid chromatography-fluorescence detection (HPLC-FLD). The limit of detection and limit of quantitation were ranged between 0.2–0.3 and 0.6–1 μg/kg, respectively. The average recovery was 58.6–90.6%. The highest mean of total PAHs was found in peanut oil (3.31 μg/kg), while the lowest content was found in olive oil (0.39 μg/kg). In brief, 32.4% of vegetable oils exceeded the European Union maximum levels in China. The detected level of total PAHs in vegetable oils was lower than the frying oils. The mean dietary exposure to PAH15 ranged from 0.197 to 2.051 ng BaPeq/kg bw/day. The margin of exposure values was greater than 10,000, and the cumulative probabilities of the incremental lifetime cancer risk of different age groups were less than the priority risk level (10⁻⁴). Therefore, there was no potential health concern for specific populations.

A highly sensitive and specific monoclonal antibody against bisphenol S (BPS) was prepared. The derived BPS was coupled to keyhole limpet hemocyanin as the immunogen and ovalbumin as the coating antigen. Based on monoclonal antibodies, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) was established, and the conditions of action were optimized. The half maximal inhibitory concentration (IC₅₀) of BPS was 0.228 ng/mL and the linear range was 0.064–0.810 ng/mL. In the recovery test for the milk samples, the recovery rates were in the range of 89%–95% and coefficient of variation ranged from 1.0% to 6.0% respectively. In addition, the cut-off value of the immunochromatographic strip detection method in milk samples was 5 ng/mL. Therefore, both methods are suitable for use in milk samples. Furthermore, this immunochromatographic strip detection method is suitable for on-site testing and screening of very large samples.

In this study, soymilk was fermented with Lactobacillus casei 16. The contents of aglycone isoflavones, saponins, total phenolic, and free amino acid in the fermented soymilk, and the protection for the HepG₂ cells against 2,2'‐azobis(2‐amidinopropane) dihydrochloride (ABAP) damage and the antiproliferative effects of the fermented soymilk on the HT‐29 cells and Caco‐2 cells were studied. The results showed that the levels of total phenolic, aglycone isoflavones, and free amino acids in the L. casei 16‐fermented soymilk were enhanced. The ethanol extract and the water extract of the L. casei 16‐fermented soymilk showed protection for HepG₂ cells against ABAP damage and inhibited the proliferation of the HT‐29 cells and Caco‐2 cells, which may be attributed to the enhanced level of total phenolic, aglycone isoflavones, and free amino acids in the L. casei 16‐fermented soymilk.