DOI: 10.1094/CC-82-0479 |  VIEW ARTICLE

Chemical Composition and Starch Hydrolysis of Acacia colei and Acacia tumida Seeds.

Muyiwa S. Falade (1), O. Owoyomi (1), C. E. Harwood (2), and Steve R. A. Adewusi (1,3). (1) Department of Chemistry, Obafemi Awolowo University, Ile-Ife, Nigeria. (2) CSIRO Forestry and Forest Products, P.O. Box E4008, Kingston, A.C.T. 4008, Australia. (3) Corresponding author. E-mail: <sadewusi@oauife.edu.ng> Cereal Chem. 82(5):479-484. Accepted March 15, 2005. Copyright 2005 AACC International, Inc.

Acacia seed is a promising famine food due to its ability to thrive in dry zones of the world. In this study, some chemical compounds of nutritional importance as well as starch hydrolysis in three cultivars of Acacia tumida and A. colei were determined. The crude protein was 20.6–23.0%, while extractable protein was 11.5–17.5%. Total dietary fiber (TDF) (28.5–32.7%) and soluble dietary fiber (SDF) (2.2–5.8%) were higher than values reported for most legumes. Reducing sugar range was 31.0–54.5 mg/g, while total sugar range was 137–161 mg/g. The starch content of the seed was 25.6–32.3%. The samples did not contain any alkaloid but did contain saponins. Phytate and trypsin inhibitor contents were low; oxalate was fairly high (2.2–2.6 g/100 g), but tannin was on the high side (66.0–86.7 mg/g) compared with legumes. In vitro starch digestibility was highest in A. tumida (III). Using a first-order kinetic equation, A. colei showed the highest initial rate of starch hydrolysis (t(1/2) = 411.56 and 1,893.4 min), followed by A. tumida (III) (539.25 and 1,738.1 min); the lowest vales were for A. tumida (II) (1,764.99 and 4,249.8 min) for both methods of starch digestion.