Entity

Time filter

Source Type


Wang H.W.,Chinese Academy of Agricultural Sciences | Wang H.W.,Gansu Agricultural University | Wang J.Q.,Chinese Academy of Agricultural Sciences | Zheng B.Q.,Tangshan Livestock and Aquatic Products Quality Monitoring Center | And 4 more authors.
Food and Chemical Toxicology | Year: 2014

This study investigated the cytotoxicity of combined mycotoxins of ochratoxin A (OTA), zearalenone (ZEA), and/or α-zearalenol (α-ZOL). The cytotoxicity of two mycotoxin combinations (two two-toxin combinations and one three-toxin combination) on human Hep G2 cells was evaluated using a tetrazolium salt (MTT) assay and isobologram analysis. Our results demonstrated significant cytotoxic effects of the two-toxin combination and the three-toxin combination on Hep G2 cells in a time- and concentration-dependent manner. The combination indexes (CI) were 2.73-7.67 for the OTA+ZEA combination and 1.23-17.82 for the OTA+α-ZOL combination after 24h, 48h, and 72h of exposure at all inhibit concentration (IC) levels (IC10-IC90), indicating an antagonism. The CIs of the ZEA+α-ZOL combination were 1.29-2.55 after 24h and 72h of exposure (IC10-IC90), indicating an antagonism. The CIs of the ZEA+α-ZOL combination were 0.74-1.68 after 48h of exposure, indicating synergism (IC80-IC90), additive effects (IC50-IC70), or antagonism (IC10-IC40). For the OTA+ZEA+α-ZOL combination, the CIs were 1.41-14.65 after 24h, 48h, and 72h of exposure (IC10-IC90), indicating an antagonism. © 2014 Elsevier Ltd. Source


Huang L.C.,Chinese Academy of Agricultural Sciences | Huang L.C.,Anhui Agricultural University | Huang L.C.,Ministry of Agriculture Milk and Dairy Product Inspection Center Beijing | Zheng N.,Chinese Academy of Agricultural Sciences | And 14 more authors.
Food Chemistry | Year: 2014

In this study, a sensitive and rapid method has been developed for the simultaneous determination of aflatoxin M1, ochratoxin A, zearalenone and α-zearalenol in milk by ultra high performance liquid chromatography combined with electrospray ionisation triple quadrupole tandem mass spectrometry (UHPLC-ESI-MS/MS). The milk samples were purified using Oasis HLB cartridge. The matrix effects were evaluated by determining the signal suppression- enhancement (SSE) and corrected by external matrix-matched calibration. The limits of quantity (LOQ) of the mycotoxins were in the range of 0.003-0.015 μg kg-1. The high correlation coefficients (R2 ≥ 0.996) were obtained in the range of 0.01-1.00 μg kg-1 of the mycotoxins, along with good recovery (87.0-109%), repeatability (3.4-9.9%) and intra-laboratory reproducibility (4.0-9.9%) at the concentrations of 0.025, 0.1 and 0.5 μg kg-1. The detected rates of the mycotoxins were from 16.7% to 96.7% in raw milk, liquid milk and milk powder samples collected from the dairy farms and supermarkets in Beijing. The method proposed is suitable for the simultaneous determination of aflatoxin M1, ochratoxin A, zearalenone, and α-zearalenol, and could be performed for analysing the mycotoxins in milk. © 2013 Elsevier Ltd. All rights reserved. Source


Zhang Y.D.,Chinese Academy of Agricultural Sciences | Zhang Y.D.,Ministry of Agriculture Milk and Dairy Product Inspection Center Beijing | Zheng N.,Chinese Academy of Agricultural Sciences | Zheng N.,Ministry of Agriculture Milk and Dairy Product Inspection Center Beijing | And 11 more authors.
Food Control | Year: 2014

This study examines 94 samples of ultra high temperature (UHT) milk and 26 samples of pasteurized milk from China's top dairy brands (I, II, III, IV), using the ELISA method to assess their contamination with tetracyclines, sulfonamides, sulfamethazine and quinolones. All of the samples were collected from China's market in September 2010. The percentage of UHT milk samples containing detectable levels of tetracyclines, sulfonamides, sulfamethazine and quinolones were 0%, 20.2%, 7.4% and 95.7%, respectively, and 7.7%, 15.4%, 0% and 61.5%, respectively, in pasteurized milk samples. The maximum concentrations ofthe tetracyclines, sulfonamides, sulfamethazine and quinolones in all liquid milk samples were 47.7μgkg-1, 20.24μgkg-1, 14.62μgkg-1 and 20.49μgkg-1, respectively. None of the samples exceeded the maximum residue levels (MRLs) set by China, the European Union (EU) and the Codex Alimentarius Commission (CAC). However, because of the high detection rates of some veterinary drug residues in the liquid milk, stringent control measurements for these residues need to remain in effect, in order to guarantee that the milk is safe for people to drink. © 2013 Elsevier Ltd. Source


Qu X.,Chinese Academy of Agricultural Sciences | Zheng B.,Tangshan Livestock and Aquatic Products Quality Monitoring Center | Zheng N.,Chinese Academy of Agricultural Sciences | Wang J.,Chinese Academy of Agricultural Sciences | And 4 more authors.
Journal of Food, Agriculture and Environment | Year: 2013

The aim of this study was to assess the level of lead, chromium, cadmium, mercury and arsenic in 192 raw milk samples collected from Tangshan City of China using inductively coupled plasma-mass spectrometry (ICP-MS). The detectable rate and concentration ranges of the five metals as follows: lead 3.1%, 31.15-39.60 μg kg-1; chromium 65.6%, 15.50-87.50 μg kg-1; cadmium 3.1%, 8.30-74.40 μg kg-1; mercury 1.6%, 0.00-9.50 μg kg-1; arsenic 3.1%, 74.70-117.00 μg kg-1. The occurrence of lead, chromium, mercury and arsenic in all positive samples was below China's national legal limit of lead 50 μg kg-1, chromium 300 μg kg-1, mercury 10 μg kg-1 and arsenic 50 μg kg-1. However, the lead content in positive milk samples exceeds the European Union (EU) and Codex Alimentarius Commission (CAC)'s legal limit of 20 μg kg-1. Source


Zhao L.,Gansu Agricultural University | Zhao L.,Chinese Academy of Agricultural Sciences | Zheng B.,Tangshan Livestock and Aquatic Products Quality Monitoring Center | Zheng N.,Chinese Academy of Agricultural Sciences | And 9 more authors.
Journal of Food, Agriculture and Environment | Year: 2014

The objective of this study was to investigate raw milk quality by measuring somatic cell count (SCC), total bacterial count (TBC), and milk protein. In addition, we compared raw milk quality between the milk stations of dairy farms and dairy cooperatives, respectively, in Tangshan city, which is the second-largest dairy-producing city in China. A total of 128 raw milk samples, comprising 70 samples from dairy farm milk stations and 58 samples from dairy cooperative milk stations, were collected in July 2011. The SCC ranged between 27.1×104 and 110.3×104 cells/ml, with 73.4% of the 128 samples being in accordance with the standards of United States Grade A Pasteurized Milk Ordinance of 75×104 cells/ml (2011). The TBC ranged between 0.55×104 and 40×104 CFU/ml, and was in compliance with the Chinese national standard (GB19301-2010) of 200×104 CFU/ml. A total of 73.5% of samples reached 10×104 CFU/ml, which is the standard of both the European Union and the United States. The protein content in the 128 samples was in the range of 2.82 -3.23 g/100 g, reaching the Chinese national standard (GB19301-2010) of 2.80 g/100 g. The SCC, TBC, and protein content values obtained showed that the quality of raw milk in Tangshan city was much higher than that stipulated in the Chinese legal limit. Further, the quality of the raw milk from the dairy farm milk stations was similar to that of the dairy cooperative milk stations, as indicated by the similar SCC, TBC and protein content values obtained (p>0.05). Source

Discover hidden collaborations