Mycotoxins in kvass: Characterization of the contamination profile of a traditional cereal-based fermented beverage

Kvass is a traditional fermented grain-based beverage widely consumed in the Russian Federation and Eastern European countries. Despite the use of malt, grain, and bread raw materials, there is no information on the mycotoxin content of kvass in the available scientific literature. The aim of this study was to assess the content of regulated, modified, and emerging mycotoxins in kvass samples available on the Russian market.

The study included 34 industrially produced kvass samples. Thirty-two mycotoxins were determined using high-performance liquid chromatography with tandem mass spectrometric detection (HPLC-MS/MS). The list of mycotoxins studied included toxins regulated in food products (aflatoxins, ochratoxin, trichothecenes (deoxynivalenol, T-2 toxin), fumonisins, zearalenone), their derivatives, emergent toxins (enniatins, beauvericin, Alternaria toxins), and a modified form of deoxynivalenol (DON) – DON-3-glucoside (DON-3-g).

Ten mycotoxins of 32 analytes were detected in kvass samples. The most frequently detected were Alternaria toxins tenuazonic acid (TeA, 35 % of samples), tentoxin (TEN, 36 % of samples), and the fusariotoxin deoxynivalenol (DON, 33 % of samples). Enniatin B (ENN B) was detected less frequently, in 21 % of kvass samples. Maximum concentrations were 96.0 μg/L for ENN B, 75.3 μg/L for TeA, and 26.2 μg/L for DON. Mycophenolic acid, ochratoxin B, and trace amounts of ochratoxin A and aflatoxin B2 were detected in some samples. DON-3-g was not detected in the tested samples. Co-contamination of kvass with mycotoxins was detected in half of the tested samples.

These results indicate a mixed contamination pattern in kvass and demonstrate that mycotoxins from fungi of the genera Alternaria and Fusarium play an important role in formation of its mycotoxin profile. This study addresses the existing lack of data on kvass contamination and confirms the need to include this beverage and its raw materials in food safety monitoring programs.