The effects of the extrusion process used for the production of maize snacks and pasta on the free, bound, and total B fumonisin contents

Mechanical and thermal treatments promote chemical changes in B fumonisins (FBs), mycotoxins that frequently contaminate maize. These changes, in turn, lead to the production of chemically modified or matrix-associated FBs, the so-called "bound" FBs, at the expense of the free forms. The present study has been aimed at evaluating the effects of the maize composition and the technological processes of co-extrusion, used for snack production and pasta-making, on the free and total FB contents, which were released after alkaline hydrolysis, by means of an LC-MS/MS analysis of the hydrolyzed FBs, estimating by difference the content of the bound FBs. Overall, the total content of FBs was always higher (1.1-2.3 times) than the free one, and higher values of bound FBs (2.6-4.3 times) were always reached for the maize-based products than the raw materials, thus confirming that processing promotes the binding of a part of the free FBs to the matrix. The obtained results confirm that the 'masking' phenomenon, which takes place through a matrix-association, is predominant during food processing, and is higher in pasta-making compared to co-extrusion for snack production. Moreover, results to increase in higher particle size flours than finer ones, while no clear effects are related to the starch composition.