Studies on the rheological properties and functional potentials of achi (Brachystegea eurycoma) and ogbono (Irvingia gabonesis) seed gums

Water soluble gums were extracted from seeds of achi (Brachystegea eurycoma) and Ogbono (Irvingia gabonesis). The rheological properties of each gum were studied at temperatures from between 10–70°C at 1.0, 1.5, 2.0, and 2.5% concentrations. The effects of small quantities of the gums on some of the quality characteristics of an ice cream mix were investigated. These characteristics were compared with those of some commercial food gums, carboxymethyl cellulose (CMC), Kappa carrageenan (KCA), and sodium alginate (SA). The viscosities of both gums were time-independent and Ogbono seed gum (OSG) appeared to be more pseudoplastic than Achi seed gum (ASG). The pseudoplastic nature was not affected by increasing temperature. The temperature control was more critical for OSG (Ea. 20.2 MJ mol−1) than ASG (Ea 13.9 MJ mol−1) during processing. The viscosity behaviour of ASG indicates that it may be a highly branched polysaccharide. The overrun, viscosity, shapefactor and meltdown values of the ice cream, when ASG was added as stabilizer, were 95%, 0.035 PaS, 72% and 32%, respectively. Values for OSG were 70%, 0.025 PaS, 65% and 37.7%, respectively. Only values for the ASG cream fell within the ranges of values obtained for the commercial gums. ©