The relative effectiveness of two filter aids in removing ochratoxin A during beer filtration

Mycotoxins originate from fungal contamination of barley (and other cereals) and can be found at low levels in beer. Filtration is an effective way to remove mycotoxins. This work – at a laboratory scale – assesses the effectiveness of a commercial filter aid in the removal of mycotoxins in beer. Kieselguhr (Celite 577) and rice hull ash (Pattern II type), an emerging alternative filter aid to DE, were evaluated for the removal of ochratoxin A during beer filtration. The adsorption isotherm was conducted for the filter aids adsorptive capacity against ochratoxin A (100 μg/mL). Residual ochratoxin A in beer was analysed using an immunoaffinity column and high-performance liquid chromatography. The results showed that rice hull ash (72%) was more effective in the removal of ochratoxin A in beer than Celite 577 (38%). Adsorption was the major form of ochratoxin A removal using rice hull ash, whereas with Celite 577 it was entrapment.