Quantification of bisphenols in Korean urine using online solid-phase extraction-high-performance liquid chromatography-tandem mass spectrometry.

Bisphenol A (BPA), an endocrine-disrupting chemical, has been used as a basic raw material for the production of polycarbonate plastics. As concern over the toxic effects of BPA grows, it is gradually being replaced in many consumer products with compounds such as bisphenol F (BPF) and bisphenol S (BPS). In this study, online solid-phase extraction-high-performance liquid chromatography-tandem mass spectrometry was used to analyze the urinary concentrations of BPA, BPF, and BPS in 2487 Korean urine samples collected between 2017 and 2018. The detection rates and geometric mean (GM) concentrations were as follows: BPA (82.1 %; 0.65 µg/L), BPF (11.1 %; not calculated), and BPS (63.6 %; 0.20 µg/L), respectively. The mean daily intake based on urinary BPA concentrations was 0.013 µg/kg bw/day (95th percentile, 0.089 µg/kg bw/day), which is lower than the tolerable daily intake. This is the first study observing urinary BPA, BPF, and BPS concentrations based on a nationally representative Korean population and could contribute to the evaluation of bisphenol analogue exposure levels in risk assessments.

Assessment of microbial contaminations in commercial frozen duck meats and the application of electron beam irradiation to improve their hygienic quality.

BACKGROUND: High microbial load is a serious concern in terms of the health-related safety of products of animal origin. In this study, the microbial loads of commercial frozen duck-meat products, including bone-in whole raw, boneless sliced raw, and boneless whole smoked, were investigated for pathogenic contamination. The application of electron beam irradiation was also investigated. RESULTS: The samples revealed a serious microbial threat (102 -105 CFU g-1 for total aerobic bacteria and positive for foodborne pathogens), which required effective decontamination technology. Electron-beam irradiation (0, 1, 3, and 7 kGy) could potentially improve the hygienic quality of duck-meat samples. The D10 values for Listeria monocytogenes and Salmonella Typhi were 0.47 and 0.51 kGy, respectively. A direct epifluorescent filter technique and aerobic plate count (DEFT/APC) method was used for screening, while electron-spin resonance (ESR) spectroscopy and gas chromatography with mass spectrometry were effective as confirmatory techniques to identify radiation-induced markers in frozen duck meat. CONCLUSION: Electron-beam irradiation has the potential to ensure the microbial safety and hygienic quality of commercial duck meats. Identification of the samples for their irradiation history was also possible using radiation-induced detection markers, including the DEFT/APC, hydroxyapatite ESR radicals, and hydrocarbons. © 2018 Society of Chemical Industry.

Assessment of Microbial and Radioactive Contaminations in Korean Cold Duck Meats and Electron-Beam Application for Quality Improvement.

Animal-origin food products pose serious threat to public food safety due to high microbial loads. The microbial and radioactive contaminations in commercial cold duck meat products were evaluated. Ten different lots of commercial samples (C1-C10) were classified based on type and smoking process. All samples were highly contaminated (< 4-7 Log CFU/g) with total aerobic bacteria (TAB), yeasts and molds (Y&M), and 7 samples (C1-C7) were positive for coliforms. Furthermore, three samples were contaminated with Listeria monocytogenes (C4-C6) and one with Salmonella typhimurium (C6). No radionuclides (131I, 137Cs, and 134Cs) were detected in any sample. The results of DEFT (direct epifluorescent filter technique)/APC (aerobic plate count), employed to screen pre-pasteurization treatments of products, indicated that smoked samples were positive showing DEFT/APC ratios higher than 4. Notably, the samples showed a serious threat to microbial safety, thus were irradiated with electron-beam (e-beam). The D10 values for S. typhimurium and L. monocytogenes were 0.65 and 0.42 kGy, respectively. E-beam application at 3 and 7 kGy resulted in reduction of initial TAB, Y&M, and coliform populations by 3 and 6 log cycles, respectively. Thus, e-beam was proven to be a good decontamination approach to improve the hygiene of cold duck meat.

E-Beam Irradiation for Improving the Microbiological Quality of Smoked Duck Meat with Minimum Effects on Physicochemical Properties During Storage.

This study was performed to evaluate the effect of different doses (0, 1.5, 3, and 4.5 kGy) of e-beam irradiation on the quality parameters (pH, Hunter's parameter, and heme pigment) and stability qualifiers (peroxide value [POV], thiobarbituric acid reactive substances [TBARSs], and total volatile basic nitrogen [TVBN]) of smoked duck meat during 40 d of storage under vacuum packaging at 4 °C. The initial populations of total bacteria (7.81 log CFU/g) and coliforms (5.68 log CFU/g) were reduced by approximately 2 to 5 log cycles with respect to irradiation doses. The results showed that pH, myoglobin, met-myoglobin, L* , a* , and b* showed significant differences with respect to different doses and storage intervals; a* and b* did not vary significantly because of storage. Higher pH was found in samples treated with 4.5 kGy at 40 d, while the minimum was observed in nonirradiated samples at day 0 of storage. Higher POV (2.31 ± 0.03 meq peroxide/kg) and TBARS (5.24 ± 0.03 mg MDA/kg) values were found in 4.5 kGy-treated smoked meat at 40 d and the lowest was reported in 0 kGy-treated meat at initiation of storage (0 d). However, irradiation suppressed TVBN during storage and higher TVBN (7.09 ± 0.32 mg/100 mL) was found in duck meat treated with 0 kGy at 40 d. The electronic nose (e-nose) effectively distinguished flavor profiles during the different storage intervals. The results showed that different sensory attributes did not vary significantly with respect to the dose of irradiation. We conclude that low dose of e-beam irradiation and vacuum packaging is beneficial for safety and shelf life extension without affecting the sensory characteristics of smoked duck meat.