PLANT FOOD SUPPLEMENTS AND FOOD COLORING AGENTS DERIVED FROM VITIS VINIFERA, A NEW SOURCE OF HUMAN EXPOSURE TO OCHRATOXIN A

Ochratoxin A (OTA) is an extremely harmful mycotoxin, having nephrotoxic, immunosuppressive, teratogenic and carcinogenic properties. Aspergillus carbonarius was identified as the main species responsible for OTA accumulation in grape and derived products. During winemaking, 95% of OTA originally present in grapes remains adherent onto pomaces, the main by-product. Grape pomaces are increasingly being used as starting material in the industrial production of plant food supplements (PFS), food colouring and tartrates. The occurrence of OTA in commercially available PFS (24 samples), food colouring (13 samples) and leavening agents containing tartrates (4 samples), all derived from Vitis vinifera was investigated in this study by using an improved HPLC-FLD method. The occurrence of OTA in 32 samples of grape pomaces collected from vineries of Apulia and Basilicata during 2013 and 2014 was also investigated. OTA was found in 75% of commercial PFS samples and 69% of food colouring samples at levels of 0.50-20.23 ?g/Kg and 0.50-32.00 µg/kg, respectively. The four commercial leavening agents containing tartrates were negative for OTA. Ninety-six percent of grape pomaces samples collected in 2013 contained OTA at levels of 3.60-140.90 µg/kg. All samples collected in 2014 contained OTA at level of 2.80-47.30 µg/kg. Higher levels of OTA (up to 849.10 µg/kg) were measured in samples of grape pomaces collected in Apulia in the past. The high incidence of positive samples as well as the high variability of OTA levels in grape pomaces makes it imperative to check the OTA level in this starting material if used for production of PFS and food colouring agents. Maximum permitted level(s) of OTA should be established in commercial PFS and food colouring agents derived from V. vinifera due to the high incidence of OTA contamination in these products.