Development and characterization of a carbon-based composite material for deducing patulin levels in apple juice

Patulin, a heterocyclic lactone produced by various species of Penicillium and Aspergillus fungi, is often detected in apple juices and ciders. Previo us research has shown the effectiveness of granular activated carbon for re ducing patulin levels in aqueous solutions, apple juices, and ciders. In th is study, ultrafine activated carbon was bonded onto granular quartz to pro duce a composite carbon adsorbent (CCA) with a high carbonaceous surface ar ea, good bed porosity, and increased bulk density. CCA in fixed-bed adsorpt ion columns was evaluated for efficacy in reducing patulin levels from aque ous solutions and apple juice. Columns containing 1.0, 0.5, and 0.25 g of C CA were continuously loaded with a patulin solution (10 mu g/ml) and eluted at a how rate of 1 ml/min. Results indicated that 50% breakthrough capacit ies fax patulin on 1.0-, 0.5-, and 0.25-g CCA columns were 137.5, 38.5, and 19.9 mu g, respectively. The effectiveness of CCA to adsorb patulin and pr event toxic effects was confirmed in vitro using adult hydra in culture. Hy dra were sensitive to the effects of patulin, with a minimal affective conc entration equal to 0.7 mu g/ml; CCA adsorption prevented patulin toxicity u ntil 76% breakthrough capacity was achieved. Fixed-bed adsorption with 1.0 g of CCA was also effective in reducing patulin concentrations (20 mu g/lit er) in a naturally contaminated apple juice, and breakthrough capacities we re shown to increase with temperature. Additionally, CCA offered a higher i nitial breakthrough capacity than pelleted activated carbon when compared i n parallel experiments. This study suggests that CCA used in fixed-bed adso rption systems effectively reduced patulin levels in both aqueous solutions and naturally contaminated apple juice; however, the appearance and taste of apple juice may be affected by the treatment process.