Abstract: Protein isolate was prepared from African yam bean (Sphenostylis sternocarpa Hochst. Ex A. Rich.) Harms). This was modified by acetylated using acetic anhydride and succinylated with succinic anhydrides. Proximate analysis revealed that moisture and ash content increased following acetylation and succinylation. On the other hand, both acetylation and succinylation reduced percentage crude fat and protein. Acetylation and succinylation reduced protein solubility in the acidic pH range below the isoelectric point (4.5) of the protein concentrate, but improved the solubility of the unmodified protein concentrate at the isoelectric point and pH range alkaline to the isoelectric point. Both acetylation and succinylation increased the water absorption capacity of native protein isolates at all levels of ionic strength investigated (0.1-1.0 mol LG1). Acetylation improved oil absorption capacity but reduced on succinylation. Maximal emulsifying activity of native and modified proteins were obtained at pH 10. Emulsion stability of acetylated and succinylated proteins were higher than those of native proteins in the range of pH 4-10, but lower when the pH was 2. Foam capacity and stability of both native and modified proteins increased with increase in protein concentration. Foam capacity of modified proteins also, increased progressively with increase in pH from 2-10. Gelation capacity of both native and modified proteins was maximal at the region of isoelectric point (pH 2.0-4.0) and at ionic strength between 0.2-0.5 mol LG1.
Y.A. Adebowale, T. Henle and U. Schwarzenbolz, 2009. Acetylated and Succinylated Derivatives of African Yam Bean (Sphenostylis sternocarpa Hochst. Ex A. Rich.) Harms) Protein Isolates. Journal of Mobile Communication, 3: 34-46.