Ochratoxin [BSA]

Mycotoxins are secondary metabolites produced by fungi. These contaminate dried seafoods during processing and storage and represent a potential health hazard for consumers. A sensitive, selective and accurate liquid chromatography/tandem mass spectrometry (LC-MS/MS) method was established for simultaneous quantification of four common mycotoxins (aflatoxin B-1(AFB(1)), T-2 toxin (T-2), ochratoxin A (OTA) and deoxynivalenol (DON)) in dried shrimp, dried fish and dried mussel products. Mycotoxins were extracted from dried seafood samples by acetonitrile/water (85/15,v/v), subjected to ultrasound for 60 min at 20 degrees C and cleaned up by defatting with n-hexane. The sample matrix affected the linearity of detection (R-2 >= 0.9974). The limit of detection (LOD) and limit of quantification (LOQ) in dried seafood products varied from 0.1 to 2.0 mu g center dot kg(-1)and 0.3 to 5.0 mu g center dot kg(-1), respectively. The method was validated by spiking samples with specific mycotoxin levels, and the recoveries, intra-relative standard deviation (RSDs) and inter-RSDs ranged between 72.2-98.4%, 2.8-10.6%, and 5.5-15.4%, respectively. This method was used to analyze 40 dried seafood products purchased from the Zhanjiang seafood market. Results of this product sampling showed that while no DON was detected, AFB(1), T-2 and OTA were detected in 30.8%, 17.5% and 33.3% of the samples, respectively. AFB(1), T-2 and OTA concentrations varied at 0.58-0.89, 0.55-1.34 and 0.36-1.51 mu g center dot kg(-1), respectively. Relatively high frequency of contamination and the presence of AFB(1), OTA and T-2 residues indicate the need to monitor mycotoxins in dried seafood products.

The mycotoxin ochratoxin A (OTA) is a secondary metabolite derived from multiple Aspergillus and Penicillium strains. The development of a rapid, sensitive, and simple method for OTA detection is important to ensure food biosafety and safeguard public health. In this study, we designed a highly specific and sensitive assay for the detection of OTA using copper monosulfide (CuS) nanoparticles conjugated to an anti-OTA antibody (CuS-Ab NPs) and a fluorescent probe for Cu2+. When OTA is present in the solution, the OTA antigen, bound to the microplate, is competed off by the soluble OTA for binding to CuS-Ab NPs. After washing, the CuS-Ab NPs and bound OTA are removed. Subsequently, HCl is added to dissolve the CuS-Ab NPs bound to the OTA antigen, releasing Cu2+ and activating the Cu2+ fluorescent probe. Thus, the resultant fluorescence emission is inversely proportional to the OTA content in the solution. Under optimal conditions, this method detected 0.1-100 ng mL(-1) OTA with a limit of detection of 0.01 ng mL(-1). The assay was tested using corn, soybean, and coffee samples, with recoveries ranging from 94% to 110%. This strategy provides a new approach for the detection of mycotoxins and other small-molecule analytes with broad application potential in food safety and quality control.