Determinación analítica e incidencia de aflatoxina m1 en leche cruda y sus derivados

Resumen

Mycotoxins are toxic compounds produced in the secondary metabolism of a high number of fungal species; within this group, aflatoxins appear as the products of certain Apergillus species. Dairy cows consuming feedstuffs contaminated with aflatoxin B1, metabolize it to AFM1 to some extent. The objective of the present doctoral work is to optimize and validate quantitative methods to analyze the incidence of AFM1 in three different matrices produced or commercialised in Navarra (Northern Spain): raw cow¿s milk, infant formulae and dairy products. Most of these methods are based on the international standard 14501:1998 (immunoaffinity extraction followed by chromatographic analysis coupled with fluorescence detection); but also immunoenzymatic manufactured fast kits were used when handling a high number of samples. Regardless of the technique, all methods fulfilled current European regulations to prove their fitness-for-purpose. Fortunately, median and maximum contents in each matrix were always far below the legal limit and so, estimated intakes reveal that AFM1 is not actually a serious hazard for consumers of this Spanish region. Main results: 1.Raw cow¿s milk. Local dairy farms were sampled one year long to evaluate the AFM1 presence in milk (477 samples), together with meteorological and quality routine parameters. Factorial analysis applied to the data pool revealed a great seasonal and physiological influence on AFM1 contents, whereas geographical emplacement of farms and cattle healthiness played a minor role. 2.Infant formulae. This survey shows the results of AFM1 incidence in infant formula are closely related to the industrial processing of milk proteins. 3.Dairy products. AFM1 presence was investigated by a sampling 200 different dairy products, representative to the local consumption and shopping patterns, in summer and winter. For these products, no seasonal effect was observed, neither an influence dependent on manufacturing process (mainly due to very low contents found in all the study), but a lower significant incidence was commented in white label products.