Combination of DNA barcoding, targeted metabolite profiling and multispectral imaging to identify mold species and metabolites in sliced bread
Nicole Ollinger,
Alexandra Malachova,
Michael Sulyok,
Lisa Schütz-Kapl,
Nicole Wiesinger,
Rudolf Krska,
Julian Weghuber
Affiliations
Nicole Ollinger
FFoQSI – Austrian Competence Centre for Feed and Food Quality, Safety & Innovation, Stelzhamerstr. 23, 4600 Wels, Austria; Corresponding authors at: Julian Weghuber, University of Applied Sciences Upper Austria, Stelzhamerstrasse 23, A-4600 Wels, Austria. Nicole Ollinger, FFoQSI – Austrian Competence Centre for Feed and Food Quality, Safety & Innovation, Stelzhamerstr. 23, 4600 Wels, Austria.
Alexandra Malachova
FFoQSI – Austrian Competence Centre for Feed and Food Quality, Safety & Innovation, Konrad Lorenz Str. 20, 3430 Tulln, Austria
Michael Sulyok
Department for Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad Lorenz Str. 20, 3430 Tulln, Austria
Lisa Schütz-Kapl
FFoQSI – Austrian Competence Centre for Feed and Food Quality, Safety & Innovation, Stelzhamerstr. 23, 4600 Wels, Austria
Nicole Wiesinger
FFoQSI – Austrian Competence Centre for Feed and Food Quality, Safety & Innovation, Stelzhamerstr. 23, 4600 Wels, Austria
Rudolf Krska
FFoQSI – Austrian Competence Centre for Feed and Food Quality, Safety & Innovation, Konrad Lorenz Str. 20, 3430 Tulln, Austria; Department for Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad Lorenz Str. 20, 3430 Tulln, Austria
Julian Weghuber
FFoQSI – Austrian Competence Centre for Feed and Food Quality, Safety & Innovation, Stelzhamerstr. 23, 4600 Wels, Austria; University of Applied Sciences Upper Austria, Stelzhamerstrasse 23, 4600 Wels, Austria; Corresponding authors at: Julian Weghuber, University of Applied Sciences Upper Austria, Stelzhamerstrasse 23, A-4600 Wels, Austria. Nicole Ollinger, FFoQSI – Austrian Competence Centre for Feed and Food Quality, Safety & Innovation, Stelzhamerstr. 23, 4600 Wels, Austria.
Mould is a ubiquitous threat to safe food. In this work, a combination of three reliable methods to identify mould present in food at the species level is presented, to estimate the safety of the apparently non-moldy slices of bread and therefore contribute to the prevention of food waste. In overstored sliced bread, three mould species on the first slice of the stack (Chaetomium globosum, Penicillium chrysogenum and Scopulariopsis brevicaulis) were identified by DNA barcoding. The obtained sequences of the PCR products matched 100% in BLAST alignments with an e-value of 0. Targeted metabolite profiling confirmed the presence of the mycotoxin producers Chaetomium globosum and Penicillium chrysogenum. Known mycotoxins from these moulds (chaetoglobosin A and meleangrin, respectively) were quantitated (8.2 µg/g chaetoglobosin A and 2.2 µg/g meleangrin) in bread spot A. The second slice was less infected, which was revealed by only two mouldy spots, the lower amounts of determined mould metabolites and by normalized canonical discriminant analysis (nCDA) after multispectral imaging. On the third slice of the stack, no mould traces were detected by either metabolite profiling, or comparative multispectral imaging. These results suggest that it might be safe to consume bread slices in lower layers of bread stacks, even if mould growth is visible on the outer slices.
