Changes in ochratoxin A and type B trichothecenes contained in wheat flour during dough fermentation and bread-baking

Abstract

Ochratoxin A (OTA) and type B trichothecenes are mycotoxins that occur frequently in cereals and thus can be found in cereal by-products such as bread. The aim of this work was to study the variation of the levels of OTA, deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-ADON) and nivalenol (NIV) during the bread-making process. This was done by using wheat flour spiked with different levels of toxins. Mycotoxin levels were controlled after fermentation of the dough with yeasts (Saccharomyces cerevisiae) and after further baking at different temperature–time combinations. Analysis of variance (ANOVA) of the results showed a significant reduction in OTA level (p < 0.05) during fermentation of the dough. The reduction ranged between 29.8% and 33.5%, depending on the initial concentration of toxin in the flour. During this period, the level of the other mycotoxins studied was not modified. By contrast, in the baking phase there were significant changes in the levels of the four mycotoxins, although the reduction was similar under all the baking conditions. Considering all the temperature–time conditions tested, it can be concluded that during the baking period the average reduction of OTA, NIV, 3-ADON, and DON was 32.9%, 76.9%, 65.6%, and 47.9%, respectively.

Keywords:

• fermented dough
• wheat flour
• mycotoxin reduction
• baking process

Acknowledgements

The authors wish to thank the Spanish Government Ministerio de Educación y Ciencia (Project Numbers AGL-2004-07549-C05-02/ALI and AGL2007-66416-C05-01/ALI and for two research grants) and the Valencian Government (Conselleria d’Empresa, Universitat i Ciencia, Project Number ACOMP/2007/155) for financial support. The authors also thank Ms Esther Gamero, Ms Teresa Liberia, Ms Gema Garcia, Ms Maria Jose Aparisi, Ms Carmen Garcia, and Ms Elena Sanchis for technical assistance.