Unreported Aflatoxins and Hydroxylate Metabolites in Artisanal Oaxaca Cheese from Veracruz, Mexico

Vargas Ortiz M,Ruiz Velasco S,Carvajal Moreno M,Hernandez Camarillo E,Rojo Callejas F

doi:10.4172/2161-1009.1000322

Abstract

Aflatoxins (AFs) are toxic secondary metabolites of the fungi Aspergillus flavus, A. parasiticus and A. nomius. The fungi produce these AFs in cereals, oilseeds and spices. AFs have damaging effects on all organisms, including humans, and their symptoms can be classified as acute (vomiting, hemorrhage and death) or chronic (immunodepression, Reye syndrome, Kwashiorkor, teratogenesis, hepatitis, cirrhosis, and various cancers). The common AFs (AFB1, AFB2, AFG1, AFG2) are metabolized in the liver or by microbes that produce hydroxylates (AFM1, AFM2, AFP1) and aflatoxicol (AFL), which makes them soluble in water. This means that AFs can be excreted in fluids such as milk or urine, and AFs are not destroyed in the process of making cheese. Other AFs can also be excreted in milk, but they have not been reported until now. The purpose of this study was to identify and quantify the AFs present in 30 samples of artisanal Oaxaca-type cheese sold in the City of Veracruz. The average concentrations of AFs detected in the 30 samples of artisanal cheese were AFB1 (11.2 ng g-1) in 77% (23/30); AFL (19.1 ng g-1) in 70% (21/30); AFG2 (0.2 ng g-1) in 63% (19/30); AFM1 (3.0 ng g-1) in 53% (16/30); AFP1 (0.1 ng g-1) in 50% (15/30); AFM2 (0.2 ng g-1) in 20% (6/30); AFG1 (0.03 ng g-1) in 13% (4/30); and a trace amount of AFB2 (

Highlights

IntroductionIn Mexico, 76,696 tons of Oaxaca-type cheese were produced in 2005, with a value of 2,700 million Mexican pesos [1,2]
Cheese is an economically important commodity worldwide
Most of the Oaxaca-type cheese consumed in Mexico is handmade artisanally, and there have been no reports about AFs in cheese and the quantities sold in Mexico

Summary

Introduction

In Mexico, 76,696 tons of Oaxaca-type cheese were produced in 2005, with a value of 2,700 million Mexican pesos [1,2]. Most of the Oaxaca-type cheese consumed in Mexico is handmade artisanally, and there have been no reports about AFs in cheese and the quantities sold in Mexico. One of the main artisanal cheeses produced in this region is Oaxaca-type cheese, which is made in the same way throughout the country. The whey is drained, and the curds without whey are melted when mixed with hot water (60°C). The product is stretched by hand to form threads of 3 cm to 6 cm wide and cooled with water (18°C). The cheese is left to drain, and salt is added (11 g to 50 g salt per 1 kg of threads). Ball hanks are formed with the cheese threads [5]

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Results