Some properties of white and yellow plantain (Musa paradisiaca, Normalis) starches

Starch obtained from yellow and white plantain varieties were subjected to proximate analysis, physicochemical and rheological characterization in order to evaluate their properties. Yellow plantain variety gave higher yield of starch than the white variety. The two varieties differed in the purity of starch extract; white plantain starch contained: ash (1.09%), protein (0.640%) and fat (0.276%) while yellow plantain starch contained: ash (0.95%), protein (0.325%) and fat (0.403%). The amylose content of yellow plantain starch (24.36% (apparent), 26.13% (total)) was similar to that of white plantain starch (24.24% (apparent), 26.01% (total)). Scanning electron microscopy revealed bimodal irregular shaped granules (3.74–7.00 and 10.00–33.00 μm) in white plantain starch and elliptical granules (11.22–41.00 μm) in yellow plantain starch. Both starches differed markedly in their physicochemical properties. Their differences in gelatinization temperature (yellow plantain, 64.99–73.90 °C; white plantain, 68.08–77.15 °C), swelling and solubility patterns, and pasting characteristics indicated that yellow plantain starch had weaker granule architecture compared with white plantain starch. Further evidence of differences in properties was obtained from flow and viscoelastic properties of the starch gels, paste clarity and freeze–thaw stability.