Natural plant food supplements and food coloring agents derived from Vitis Vinifera: a new source of human exposure to ochratoxin A

Objectives Red grape pomaces are rich in natural polyphenols that comprise numerous pigments. Thanks to their antioxidant properties, they maintain and promote health and reduce the risk of cardiovascular diseases. Grape pomaces are increasingly being used as starting material to produce plant food supplements (PFS), food coloring agents and tartrates. But these byproducts could be naturally contaminated by ochratoxin A (OTA), a mycotoxin with nephrotoxic and carcinogenic effects. In this study, we analyzed 24 commercial PFS, 13 food coloring samples, and 4 leavening agents derived from Vitis vinifera using an improved HPLC-FLD method for OTA determination.1 Materials and methods Commercially products derived from Vitis vinifera were purchased from retail stores in South Italy or from e-commerce for a total of 41 samples. Each sample was extracted with organic solvents, purified with immunoaffinity column and analysed by HPLC/FLD.1 The identity and concentration of OTA in the purified extracts of two food supplements containing low levels of OTA were confirmed by LC-MS/MS. The method was robust, precise, accurate and applicable to all tested samples. Results of recovery and repeatability experiments were in the range of 87-102% and 2-4%, respectively; the values of limit of detection (LOD) and limit of quantitation (LOQ), calculated as signal-to-noise ratios of 3:1 and 6:1, were 0.50 ?g/kg and 1.16 ?g/kg, respectively.1 Results OTA was found in 75% of PFS samples at levels of <1.16-20.23 ?g/kg and in 69% of food coloring samples at levels of <1.16-32.00 ?g/kg. The four commercial leavening agents containing tartrates were negative for OTA.1 Conclusions In Europe the maximum levels of OTA in several food commodities are in force2 but not for PFS and food coloring agents derived from Vitis vinifera. The high incidence of OTA contamination in these products suggests an amendment of the regulation to include them. We previously reported that OTA can occur at high levels (up to 849.10 µg/kg) in grape pomaces.3 These findings makes imperative to control for OTA contamination all grape pomaces destined to the preparation of edible products. References 1Solfrizzo et al. J. Agric. Food Chem.2015, DOI: 10.1021/acs.jafc.5b00326. 2EC No.1881/2006 of 19 December 2006 and subsequent amendments. 3Solfrizzo et al. J. Agric. Food Chem. 2008, 56, 11081-11086.