Role of sodium hydrosulphite and pressure on the reduction of aflatoxins and ochratoxin A in black pepper

The aim of this study was to assay a chemical method for the reduction of aflatoxins B1 (AFB1), B2 (AFB2), G1 (AFG1), G2 (AFG2) and ochratoxin A (OTA) in black pepper. The efficiency of AF and OTA reduction by sodium hydrosulphite (Na2S2O4) at different concentrations (0.25, 0.5, 1, 1.5 and 2%) in artificially contaminated black pepper was investigated under atmospheric and high pressure. The first treatment was performed under atmospheric pressure in boiling water at 100 °C for 30 min, and the second treatment was performed under high pressure (1.5 bar) at 121 °C for 15 s. The concentrations of the AFs and OTA were determined by high performance liquid chromatography (HPLC) using fluorescence detection (FD). Maximal respective reductions of 96.0%, 96.1%, 77.7%, 100% and 100% for OTA, AFB1, AFB2, AFG1 and AFG2, respectively, were achieved by treatment with 2% Na2S2O4 under high pressure. These findings suggest that AFs and OTA can be degraded by treatment with Na2S2O4 and heat under pressure.

► Na2S2O4 was used to reduce mycotoxins in black pepper under atmospheric and high pressure.
► The maximum reduction was found by applying high pressure.
► AFB2 showed to be the most resistance mycotoxin to the applied treatments.
► The method was fast and economic.