Yield and some physicochemical properties of starch from four Nigerian varieties of bambara groundnut (Vigna subterranea): part I

 
                                  *Barimalaa, I. S., Achinewhu, S. C. and Osondu, F. C.
                                   Department of Food Science and Technology,
                                   Rivers State University of Science and Technology,
                                   P. M. B. 5080, Port Harcourt, Nigeria.
                                   e-mail: barimalaa@yahoo.com    

ABSTRACT

Starch was isolated from four Nigerian varieties (identified by seed coat colour) of bambara groundnut (Vigna subterranea).  Starch yields were high with an average of 47.08g/100g seed weight.  No significant difference (P > 0.5) was observed in the starch content of the bambara groundnut varieties with white hilum.  There was no intercultivar difference in the shape of the starch granules.  They were all oval to kidney- shaped.  Bulk densities of starches obtained ranged from 0.26 g/ml in black seed coat – white hilum (BSWH) seeds to 0.33 g/ml in cream seed coat – cream hilum (CSCH) seeds, and were higher than 0.09 and 0.20 g/ml for cassava starch (CS) and standard corn starch (SCS) respectively.  The average gelatinization temperature for the starches (75 – 83^oC) was similar for the bean seeds with white hilum, while total available starches ranged from 79.40 – 81.20g/100g dry starch.  Viscosities of gelatinized starches (1g /100ml starch gels) at 300rpm, ranged from 3.0cP in cream seed coat – cream hilum (CSCH) seed starch to 4.2cP in purple speckles on cream seed coat – white hilum (PSWH) seed starch, and gels were all stable.