title: Roles of reversible and irreversible aggregation in sugar processing.
abstract: Colloids (1-1000-nm particles) in sugarcane/beet juice originate from non-sucrose impurities (polyphenolic colorants, residual soil, polysaccharides) of the plant materials; additional colloids form during the high temperature processing. Colloids are reactive toward aggregation, sorption, desorption, and redox/hydrolysis/thermal transformation reactions. Both Derjaguin-Landau-Verwey-Overbeek (DLVO; van der Waals and electrostatic forces) and non-DLVO (involving hydrophilic colloids) interactions control the stability of colloids in juice. Heteroaggregation causes a range of feedstock and end product problems, including turbidity, viscosity, color, gelling, crystallization, starch ghost, and heat transfer problems. Even after intensive clarification and refining, trace colloidal impurities on white (refined) sugar remain to cause a problem known as acid beverage floc. Acid beverage floc is an example of DLVO-type aggregation of oppositely charged particles at decreased pH. Examples of irreversible aggregates include starch ghost and recalcitrant organomineral composites formed at elevated temperature that resist heat transfer. Fundamental knowledge in aggregation kinetics is necessary to predict the occurrence of undesirable aggregates, as pH, ionic strength, temperature, and sucrose concentration change during the processing of sugarcane/beet juice.
authors.affiliation: a USDA-ARS Southern Regional Research Center , New Orleans , Louisiana , USA.
authors.forename: Minori
authors.initials: M
authors.lastname: Uchimiya
mesh_terms: D027461:Beta vulgaris / Q000737:chemistry*; D003102:Colloids / Q000032:analysis*; D005511:Food Handling; D000067030:Fruit and Vegetable Juices / Q000032:analysis*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D059808:Polyphenols / Q000032:analysis; D011134:Polysaccharides / Q000032:analysis; D031786:Saccharum / Q000737:chemistry*; D055672:Static Electricity; D013395:Sucrose / Q000737:chemistry
chemical_list: D003102:Colloids; D059808:Polyphenols; D011134:Polysaccharides; D013395:Sucrose
keywords: Polyphenol; aquasol; bioenergy; fermentable sugar; macromolecule