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Enzymatically converted chicken bile (CB), prepared by converting taurine deoxycholic acid (TCDCA) to taurine ursodeoxycholic acid (TUDCA) in CB, possesses various functional activities. But their nutrient composition and safety assessment have not been fully investigated yet. CB was mainly composed of proteins and steroids. CB did not show genotoxic effects based on Ames test, mammalian erythrocyte micronucleus test, and in vitro mammalian chromosomal aberration test. There were no growth abnormalities or deaths in the acute toxicity test for mice, indicating that CB is nontoxic with an LD50 > 10 g/kg·body weight (BW). Subchronic toxicity test and genotoxicity test were performed based on intake of 0.5 g CB per person daily at expanded doses of 33.3, 100, and 300 times (278, 833, and 2500 mg/kg·BW). The result indicated that CB at 833 mg/kg·BW showed no toxicity on BW, body weight gain, food intake, hematological, serum biochemistry, absolute/relative organ weights, urinalysis, and pathological features of rats in the subchronic toxicity test, while CB at 833 mg/kg·BW induced maternal toxicity with no fetus teratogenicity or embryotoxicity in the teratogenicity test. In conclusion, CB did not show toxic effects and a long‐term daily intake of CB at 0.5 g per person is considered safe, but pregnant women should avoid it. These findings could provide a reference for the safe use of CB in functional food. [ABSTRACT FROM AUTHOR]

The integration of surface-enhanced Raman scattering (SERS) spectroscopy with magnetic fluid provides significant utility in point-of-care (POC) testing applications. Bifunctional magnetic–plasmonic composites have been widely employed as SERS substrates. In this study, a simple and cost-effective approach was developed to synthesize magnetic–plasmonic SERS substrates by decorating silver nanoparticles onto magnetic Fe3O4 nanoparticles (AgMNPs), which function both as SERS-active substrates and magnetic fluid particles. The strong magnetic responsivity from AgMNPs can isolate, concentrate, and detect target analytes from the irregular surface of fish skin rapidly. We fabricate a microfluid chip with three sample reservoirs that confine AgMNPs into ever smaller volumes under an applied magnetic field, which enhances the SERS signal and improves the detection limit by two orders of magnitude. The magnetic fluid POC sensor successfully detected malachite green from fish with excellent selectivity and high sensitivity down to the picomolar level. This work achieves a label-free, non-destructive optical sensing approach with promising potential for the detection of various harmful ingredients in food or the environment. [ABSTRACT FROM AUTHOR]