FORMATION OF CHAIN-LIKE STRUCTURES IN APPLE JUICE HAZE

Red Delicious apple juice made by exclusion of oxygen (anaerobic juice ) was stored in the presence of air at 21 degrees C for 67 d. During t his period a haze developed in the juice and partially sedimented at t he bottom of the glass container. This haze/deposit contained 12 g/kg protein and the remainder was butanol-HCl and/or vanillin reactive mat erial. Electron microscopic examination using negative staining with u ranyl acetate showed that the haze/deposit preparations consisted of b ranched chain-like aggregates of globular particles of variable size. The particles had sufficient electron density to be examined in detail without staining. Their three-dimensional structure was confirmed by shadow casting. A mechanism of formation of these particles is propose d and discussed and a model for formation and aggregation suggested (C ) 1998 Academic Press Limited.