Mycotoxins in malting and brewing by-products used for animal feed

Abstract

Malting and brewing by-products (germ/rootlets, spent grains and spent yeast) represent a valuable and nutritious source of food for the livestock. The incidence of mycotoxins in animal feed is not an unusual phenomenon, and for that reason, feed obtained from malting and brewing process is subjected to mycotoxicological anyalysis. Objectives of this study were to establish the impact of the initial F. culmorum contamination and fungicide treatment on trichothecenes, namely deoxynivalenol (DON), 3-acetyl deoxynivelanol (3-ADON), nivalenol (NIV), diacetoxyscirpenol (DAS), fusarenon X (FUS X), HT-2 and T-2 . Their concentrations were measured in water after steeping, germ/rootlets, spent grains and spent yeast. Two wheat genotypes (A and B) were treated in four different ways in the field: control (a), treated with fungicide (b), inoculated with F. culmorum spores and treated with fungicide (c), and inoculated with F. culmorum spores (d). Standard malting procedure for wheat malt was implemented, followed by degermination process and brewing procedure. Mycotoxins were determined using multi- mycotoxin LC-MS/MS method. DON proved to be the most occurring mycotoxin in all of the samples and the highest concentration was found in steeping water of sample A(d) where detected concentration of DON was 20326 µgL-1. Germ/rootlets contained DON, 1384 μg/L in B(d) and 5636 μg/L in A(d) sample. Spent grains showed elevated DON value (1178 μg/L) for B(b) sample. Spent yeast showed increased DON values for A(d) sample (705 μg/L) but also for B(d) sample (1180 μg/L).