Cooperativa de Ensino Superior Egas Moniz. Núcleo de Investigação e Formação em Segurança e Qualidade Alimentar (NISQA)
Abstract
Aflatoxins are a group of naturally occurring toxins, which are secondary
metabolites of some Aspergillus spp. When lactating animals ingest aflatoxin B1
(AFB1) contaminated feedstuffs, aflatoxin M1 (AFM1) may be excreted to milk.
Thus, AFM1 represents a potential hazardous to humans via consumption of
milk and milk products. AFM1 is less mutagenic and carcinogenic than AFB1
but it exhibits high genotoxic activity. The maximum admissible level of this
mycotoxin in raw milk, heat-treated milk and milk for manufacture of milkbased
products was set at 0.05 μg/Kg by the EC.
In cheese production, high amount of a by product – cheese whey – products
is obtained. Cheese represents about 10 % of the initial mass of milk. This
cheese whey may be further processed when whey is to be turned into more
valuable products than animal feed or whey powder. One way is the use of
ultra filtration, yielding a protein rich fraction (retentate) and a lactose rich
fraction (permeate). Since whey proteins have a number of useful nutritional
and functional properties, whey proteins can be used in a wide range of
commercial products such as food additives or may be fractionated into
individual whey proteins.
The aim of this work was to study the distribution of aflatoxin M1 through the
retentate and permeate when whey ultra filtration is carried out. To perform
this study, cheese whey was spiked with AFM1 at a level of 0.1 μg l-1. Under the
used experimental conditions it was found that AFM1 has a higher affinity for
the rich protein fraction (retentate). These data will be presented and discussed
