Improved method for the determination of hydroxymethylfurfural in baby foods using liquid chromatography-mass spectrometry     

Gökmen V  Senyuva HZ 《Journal of agricultural and food chemistry》2006,54(8):2845-2849

An improved analytical method for the rapid, reliable, and sensitive determination of hydroxymethylfurfural (HMF) in baby foods is described. It entailed aqueous extraction from food matrix with simultaneous clarification using Carrez I and II reagents, solid-phase extraction cleanup using Oasis HLB, and analysis by liquid chromatography-mass spectrometry. A narrow-bore column allowed fast chromatographic separation with good resolution of HMF and matrix coextractives. In positive atmospheric pressure chemical ionization conditions, precursor and compound-specific ions were sensitively detected in selected ion monitoring mode. Sample preparation with efficient cleanup followed by fast chromatographic analysis allowed the analysis to be completed in <20 min. Recovery ranged between 91.8 and 94.7% for spiking levels of 0.25, 1.0, and 5.0 mg/kg HMF in cereal-based baby foods. The method was shown to be successful when using liquid chromatography coupled to ultraviolet detection at 285 nm.  相似文献   

Changes in free amino acid and sugar levels of dried figs during aflatoxin B1 production by Aspergillus flavus and Aspergillus parasiticus     

Senyuva HZ  Gilbert J  Oztürkoglu S  Ozcan S  Gürel N 《Journal of agricultural and food chemistry》2008,56(20):9661-9666

An aqueous slurry of gamma-irradiated sterilized dried figs was inoculated with toxigenic strains of Aspergillus flavus and Aspergillus parasiticus. During incubation at 28 degrees C, pH, fructose, glucose, and free amino acids were determined by high-performance liquid chromatography and liquid chromatography (LC)/mass spectrometry, respectively, over 13 time points (1-20 days). At the same 13 time points using a LC/time-of-flight mass spectrometry screening method, aflatoxin B 1 and other secondary metabolites were simultaneously monitored. During the course of incubation, the pH significantly decreased and aflatoxin B 1 formation correlated with a reduction in proline content for both fungi. Of the 22 free amino acids that were monitored, only proline and cystine were found to be critical in supporting aflatoxin production. Levels of fructose and glucose steadily declined during incubation, until glucose was almost exhausted after 21 days. These time-course experiments confirmed the need for carbon and nitrogen sources for aflatoxin production in dried figs, and the favorable composition of figs as a fungal growth medium.  相似文献