The reduction of patulin in apple juice by three different types of activated carbon

Three types of activated carbon (NORIT SA 4, NORIT SX 4 and NORIT CA 1) were investigated for their ability to reduce patulin levels in apple juice at various Brix levels and temperatures. The steam-activated carbons (NORIT SA 4 and NORIT SX 4) exhibited similar adsorption isotherms at a dosage level of 1 g/l. They achieved patulin reductions of 80% and 70% respectively in 12(o) Brix juice at 55 degrees C. The similarity in performance between the steam-activated carbons implies that the purity and the surface acidity does not influence the adsorption of patulin. Chemically-activated carbon (NORIT CA 1) was less effective in removing patulin and achieved only a 45% reduction at a dose of 1 g/l. Patulin removal was influenced by juice Brix in that higher carbon doses were required at higher Brix levels for equivalent removal efficiency. At a dose of 1 g/l, NORIT SA 4 removed only 45% patulin from a 20(o) Brix juice. The removal of patulin from either 12 or 20(o) Brix juice by NORIT SA 4 at 1 g/l was not influenced by temperature changes in the range 30 to 65 degrees C.