Improved emulsification performance of corn fibre gum following maturation treatment

Corn fibre gum (CFG) in the solid state (milled powder form) was subjected to a maturation treatment by heating under atmospheric pressure at 110 degrees C for 5 (CFG5) and 24 h (CFG24). The treatment reduced the solubility and aggregation of the proteinaceous component increased with heating time. The protein content of CFG is comparable to that of gum arabic but has a different amino acids profile. Glutamine and proline are the most abundant in CFG compared with hydroxyproline and serine in gum arabic. The control and matured CFG samples have been characterized by gel permeation chromatography coupled on line to a multi angle laser light, refractive index and UV detectors. The weight average molecular weight (M-w) values for control, CFG5 and CFG24 were 4.2, 5.8 and 5.7 x 10(5) g/mol respectively with corresponding Rg values of 29, 44 and 41 nm. High pressure homogenization treatment of the control gum did not show significant changes whereas the matured samples were disaggregated. The emulsification performance and stability of the matured samples were greatly improved in comparison with the control gum. A three times increase in the proportion of the adsorbed fraction on to the oilewater interface accounts for the improved emulsification. A model to describe the changes following maturation and the improved emulsion stability is proposed. (C) 2013 Elsevier Ltd. All rights reserved.