Corn fiber gum: A potential gum arabic replacer for beverage flavor emulsification

The US food industry would benefit from a domestically produced gum with a dependable supply and consistent quality that can be used for preparing oil-in-water (O-in-W) emulsions, such as citrus oil emulsions for beverages. Corn fiber gum (CFG) is an arabinoxylan (hemicellulose) extracted from the corn kernel pericarp and/or endosperm fiber fractions that can possibly fulfill this need. In this study two different types of CFG, CFG-1 and 2, were prepared from corn fiber collected from different wet or dry corn milling facilities by (a) sequential alkaline extraction and alkaline hydrogen peroxide bleaching and (b) an additional alkaline hydrogen peroxide treatment of the alkali treated residue, respectively. CFG-1 might be linked to the cell wall matrix through ester linkages and CFG-2 by non-ester linkages and/or other strong interactions. The stabilization of O-in-W emulsions by corn fiber and acacia gums was investigated by preparing emulsions with a high pressure homogenizer and monitoring the emulsion breakage by turbidity measurements. All CFG samples were effective emulsifiers but CFG-2 extracted separately from three different corn fiber sources was determined to be a better emulsifier than the corresponding CFG-1. CFGs isolated from wet milled pericarp and endosperm fiber and wet milled pericarp fiber have a higher protein content than CFGs isolated from dry milled pericarp fiber and were determined to be better emulsifiers for the O-in-W emulsion system. The emulsifying properties of all CFGs including an industrial grade commercial CFG were determined to be better than native and modified acacia gums.