Assessment of processing impacts and type of clarifier on the concentration of ochratoxin A in pekmez as a conventional grape-based product

Abstract

Pekmez can be considered as one of the most favored traditional grape's products, however, it can be contaminated with ochratoxin A (OTA). In this regard, for the first time, the effects of unit operations including washing, juicing (crushing and pressing), clarification with the aid of various clarifier (bentonite, white soil, and gelation) and boiling on the concentration of OTA in artificially spiked pekmez samples were investigated. According to findings, all unit operations utilized in pekmez production led to OTA reduction while the range - mean of OTA reduction in washing, juicing (crushing and pressing), clarification and boiling stages were recorded as 7.36–16.53%-12.19 ± 4.60%, 2.51–8.32%-6.13 ± 3.16%, 4.24–16.55%-16.38 ± 10.25%, and 1.54–37.43%-10.44 ± 3.85%, respectively. Among the clarifiers used, the highest (23.76 ± 7.90%) and lowest (11.48 ± 9.37%) mean reduction of OTA was attributed to gelatin and bentonite, respectively. Therefore, the utilization of gelatin could remove higher levels of OTA. Generally speaking, the OTA overall reduction range and mean during the pekmez production process was 25.84–54.67 and 37.52 ± 6.54%, respectively, which depended on the initial concentration of OTA and unit operations, the type and concentration of clarifier. The optimum condition of OTA reduction was obtained in samples containing initial OTA content of 5 μg kg−1 which were clarified with 3% of gelatin.