Isolation, Characterization and Emulsifying Properties of wattle See (Acacia victoriae Bentham) Extracts

Extracts from either ground whole wattle seeds or uncoated cotyledons were obtained using water, alkali or ethanol. These extracts were then analysed for their protein molecular weight and electrophoretic profiles using sodium dodecyl sulphate-poly acrylamide gel electrophoresis (SDS-PAGE) and capillary electrophoresis (CE) respectively. Water extracts and those from the cotyledons gave higher material yield and contained significantly more proteins than other extracts. Furthermore, the proteins ranged in molecular weight from 6 kDa to 92 kDa with the highest concentration between 27 kDa to 61 kDa. Water extracts, even at very low protein concentrations (0.17-1.12 %), formed stable emulsions containing up to 50 % canola oil and these emulsions were affected by pH (4-9), ionic strength (0.25 to 1 % NaCl) and retorting (115º C for 30 min). The study showed that water-soluble wattle extracts have great potential as emulsifiers and stabilisers for the food industry, especially at low pH levels.