Determination of patulin in vegetables and evaluation of its Cytotoxicity on mammalian cells

Abstract

Monitoring mycotoxin contamination in foods and feeds is important in both human's and animals' health and it is of concern in the regulation of mycotoxins in foods and feeds worldwide. Out of all the contaminants found in food and feeds, mycotoxins are one of the extensively studied contaminants. Mycotoxins are secondary metabolites produced by a wide range of filamentous fungi. Mycotoxins are commonly found in agricultural commodities and derivate. Exposure to high concentrations of mycotoxins may have a toxicological effect on both animals and humans. As mentioned, the major sources of mycotoxin contamination are agricultural commodities and derivative products. For this reason, an ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) method was optimised and validated for the simultaneous determination of patulin, aflatoxins B1, B2, G1, and G2 in vegetable samples. The optimised UHPLC MS/MS method was validated by evaluating the method characteristics such as linearity, limits of detection (LODs), limits of quantification (LOQs), accuracy, and precision. The method exhibited good linearity and it was sensitive with good recoveries. The prevalence and occurrence of fungal and mycotoxin contamination on vegetables from South Africa were determined. A total of hundred and twenty-one vegetable samples such as Carrots, cucumber, onions, potatoes, and sweet potatoes were collected from five South African provinces namely Limpopo Province (LP), Gauteng Province (GP), KwaZulu-Natal (KZN), Eastern Cape Province (EC) and Western Cape Province (WC). The isolated fungal species from the vegetable samples belonged to the Aspergillus, Fusarium, and Penicillium genera. The most predominant fungal isolate in the vegetable samples was Aspergillus fumigatus. Furthermore, the vegetable samples from KZN province were the most susceptible to fungal contamination. Patulin was detected in carrots and peppers. It was found that the level of patulin in these samples was below the LOQ. The presence of patulin in vegetable samples demonstrated its prevalence in the food chain. Thus, it is important to set- Page iii up guidelines for the monitoring of mycotoxins which can be achieved by the use of robust, sensitive, and simple analytical methods. The cytotoxic effect of patulin on humans was evaluated. The results demonstrated that the decrease in the viable cancer cell is dependent on the concentration of patulin. Although the results of this study demonstrated that patulin has the potential to reduce cancer cell lines, prolonged consumption of patulin could have a negative impact on human health.