The chemical composition and in vitro digestibility of yambean starch

The chemical composition and in vitro digestibility of starch extracted from yambean, Sphenostylis stenocarpa, were determined. The white, powdery starch was fibre-free and was characterized by low crude nitrogen, lipid and ash values but very high polysaccharide (nitrogen-free extract), 98.37%. Yambean starch (YBS) amylose was 34%. The reducing sugar yield from its acid digestion was 103 mg 100 mg−1 sample. Only 20.8% of 1% gelatinized YBS was reduced to reducing sugars by 1% salivary amylose extract in 80 min when the achromic stage was attained using a qualitative iodine test. Except for Mg, Ca and Fe ions, the mineral content of yambean starch was very low.