STRUCTURE AND COMPOSITION OF APPLE JUICE HAZE

Haze obtained from commercial apple juice over the 1991 season contain ed from 11.4 to 29.0% protein (w/w), trace quantities of both metal ca tions and polymeric carbohydrate, and gave strong responses to tests f or phenolic compounds indicating a protein-phenol haze. SDS-PAGE of th e 2-mercaptoethanol reduced, guanidinium hydrochloride dissaggregated haze particles gave a continuous smear indicating a population of mole cules ranging from 29K to greater than 205K daltons. Transmission elec tron microscopy of negatively stained preparations revealed the presen ce of spherical bodies only partially penetrable by stain and possessi ng a subunit structure. These particles were embedded in a material pr esumably polymerized in such a way as to form chain-like aggregates. P rotein-phenol haze particles consist of two structural components: sph erical particles, probably protein, embedded in polymerized phenolics.