Changes in aflatoxins content during processing of pekmez as a traditional product of grape

The current study was aimed to investigate the changes in aflatoxins (AFs) content during the production of pekmez. In this context, the artificially spiked grape samples in levels of 2.5, 5, and 7.5 mu g/kg of aflatoxin B-1 (AFB(1)), and 0.5, 1 and 1.5 mu g/kg of aflatoxin B-2 (AFB(2)), G(1) (AFG(1)) and G(2) (AFG(2)) were processed by the conventional procedure and after each step, AFs levels were measured using HPLC-FD. Among different unit operations, the lowest reduction in AFs (8.2, 14.8, 12.4, and 22.7% for AFB(1) and AFB(2), AFG(1), and AFG(2), respectively) was obtained for crushing and pressing stages. The corresponded values for reduction average of AFB(1), AFB(2), AFG(1), and AFG(2) during washing step was measured as 19.3%, 22.2%, 23.7%, and 34.3%, respectively. Clarification stage was identified as the most effective step in the reduction (63.6%) of AFs. However, the reduction strongly depended on the type and concentration of clarifier as well as initial aflatoxin level. A significant difference between the assessed clarifiers (gelatin, bentonite and white soil) was observed, while the highest efficiency was demonstrated by gelatin. In general, levels of AFB(1), AFB(2), AFG(1), and AFG(2) during pekmez production were decreased about 60.4, 76.7, 76.3, and 86.7%, respectively.