Starch retrogradation and its impact on nutritional starch fractions in plantain (Musa AAB) foods

Starch retrogradation in plantain starch was studied by an enzymatic method and X-ray diffraction analysis. The enzymatic method and X-ray diffraction gave comparable results. Retrograded starch (RS3) and physically trapped starch (RS1) contents of plantain foods were subsequently determined by the enzymatic method. RS3 content of 5.0 +/- 0.9 to 13.2 +/- 3.0 g/100 g dry weight basis was obtained for unripe samples while a value ranging from 0.9 +/- 0.4 to 2.5 +/- 0.9 g/100 g was obtained for ripe samples. Retrogradation increased slowly digestible starch (SDS) and physically inaccessible starch (RS1) portions in some of the samples but not in others. Retrogradation resulted in an increase in the quantity of SDS for ripe plantain samples. In unripe plantain samples cooked without salt, there was a significant increase (p aecurrency sign 0.05) in the value of RS1 from 4.6 +/- 3.6 to 7.7 +/- 2.0 g/100 g after 48 h of cold storage but no significant change for samples cooked with salt.