MALDI-TOF/TOF mass spectrometry for determination of yeast diversity in traditional cornelian cherry tarhana produced with different cereal/pseudocereal flours

Abstract

This study is to determine the dynamics in the microflora of cornelian cherry tarhana (CCT), a traditional food of Turkey, by MALDI-TOF/TOF MS. Non-fermented and fermented CCT productions were performed by using flours of bread wheat, wholegrain hull-less barley, buckwheat, and clear flour. Identification of the isolates obtained from raw materials and various production steps of the CCT was performed by MALDI-TOF/TOF MS. Dendograms were prepared by cluster analysis and the distances between the strains isolated during production stages and from cornelian cherry puree were determined. Totally, 231 isolates were obtained and 45.5% of them were identified at species level, 30.3% at genus level while 24.2% of the isolates could not be identified. It was found that microflora of cornelian cherry tarhana is mainly composed of yeasts. Thirty-two percent of the identified yeast isolates were Hanseniaspora uvarum and the others were Saccharomycescerevisiae (19.6%), Torulaspora delbrueckii (18.6%), Candida krusei (11.3%), Candida lusitaniae (9.3%), Metschnikowia pulcherrima (3.1%), Wickerhamomyces anomalus (2.1%), Candida kefyr (2.1%), Cyberlindnera fabianii (1%), and Candida parapsilosis (1%). Only two lactic acid bacteria could be isolated, which were Lactobacillus reuteri and Enterococcus spp., originating from buckwheat flour and clear flour, respectively. Dendograms revealed that some of the yeast strains isolated during production were originating from cornelian cherry. Microflora of CCT was investigated for the first time. This is one of the few studies using MALDI-TOF/TOF MS for identification of food originated yeasts. Novel species–identified, endogenic yeasts which could have potential technological characteristics were introduced.