Xue X.F.,Chinese Academy of Agricultural Sciences |
Xue X.F.,Risk Assessment Laboratory for Bee Products Quality and Safety of Ministry of Agriculture |
Selvaraj J.N.,Chinese Academy of Agricultural Sciences |
Zhao L.,China Agricultural University |
And 5 more authors.
Food Analytical Methods | Year: 2014
A simple and sensitive method has been developed for simultaneous determination of aflatoxins (AFB1, AFB2, AFG1, and AFG2) and ochratoxin A (OTA) in bee pollen. The analytes in the sample were extracted with a mixture of acetonitrile/water (60:40, v/v), using low temperature for fat precipitation, followed by immunoaffinity column cleanup of extracts. The mycotoxins were quantified using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) with an electrospray ionization (ESI) and a triple quadrupole (QqQ) analyzer. Matrix effect, accuracy, and precision were evaluated and achieved good results calculated by matrix-matched calibration standards which reduced the influence of matrix effect. Recoveries at three levels were in the range of 74.3-96.5 % with RSD less than 10.0 %. The correlation coefficients (r 2) of the five mycotoxins were higher than 0.997. The method showed high sensitivity with LOD below 0.05 μg/kg. © 2013 Springer Science+Business Media New York. Source
Wu L.,Chinese Academy of Agricultural Sciences |
Wu L.,Risk Assessment Laboratory for Bee Products Quality and Safety of Ministry of Agriculture |
Wei Y.,Chinese Academy of Agricultural Sciences |
Du B.,Chinese Academy of Agricultural Sciences |
And 7 more authors.
LWT - Food Science and Technology | Year: 2015
Royal jelly (RJ), widely used in food products, is highly perishable. To ensure its quality, it is necessary to identify an indicator of RJ freshness. In this study, we measured the concentrations of adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine monophosphate (AMP), inosine monophosphate (IMP), inosine (HxR), hypoxanthine (Hx), adenosine (Ao), and adenine (Ai) in RJ stored at different temperatures and for different storage periods. An F-value, defined as ratio between the sum of Ao, Ai, HxR, and Hx and the sum of ATP, ADP, AMP, IMP, HxR, Hx, Ao, and Ai, was evaluated as an indicator of RJ freshness. When the F-value of an RJ sample was evaluated, the equivalent biochemical age could be determined based on linear equations. An F-value of 20%, with an equivalent biochemical age of 60.69 days when stored at 4°C or 6.82 days when stored at 30°C, was the calculated RJ freshness threshold value in this study. This novel indicator could contribute to the establishment of standardized criteria for the identification of RJ freshness and provide more rigorous standards for harvesting, packaging, and storage procedures of RJ. © 2015 Elsevier Ltd. Source
Zhang Y.-N.,Chinese Academy of Agricultural Sciences |
Zhang Y.-N.,Risk Assessment Laboratory for Bee Products Quality and Safety of Ministry of Agriculture |
Chen L.-Z.,Chinese Academy of Agricultural Sciences |
Chen L.-Z.,Risk Assessment Laboratory for Bee Products Quality and Safety of Ministry of Agriculture |
And 9 more authors.
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2015
At present, the rice syrup as a low price of the sweeteners was often adulterated into acacia honey and the adulterated honeys were sold in honey markets, while there is no suitable and fast method to identify honey adulterated with rice syrup. In this study, Near infrared spectroscopy (NIR) combined with chemometric methods were used to discriminate authenticity of honey. 20 unprocessed acacia honey samples from the different honey producing areas, mixed?with different proportion of rice syrup, were prepared of seven different concentration gradient?including 121 samples. The near infrared spectrum (NIR) instrument and spectrum processing software have been applied in the?spectrum?scanning and data conversion on adulterant samples, respectively. Then it was analyzed by Principal component analysis (PCA) and canonical discriminant analysis methods in order to discriminating adulterated honey, The results showed that after principal components analysis, the first two principal components accounted for 97.23% of total variation, but the regionalism of the score plot of the first two PCs was not obvious, so the canonical discriminant analysis was used to make the further discrimination, all samples had been discriminated correctly, the first two discriminant functions accounted for 91.6% among the six canonical discriminant functions, Then the different concentration of adulterant samples can be discriminated correctly, it illustrate that canonical discriminant analysis method combined with NIR spectroscopy is not only feasible but also practical for rapid and effective discriminate of the rice syrup adulterant of acacia honey. © 2015, Science Press. All right reserved. Source