Comparison of physicochemical, rheological, and digestibility properties of starch isolated from plantain ( <i>Musa paradisiaca</i> ) using different methods

Abstract The present work aimed to evaluate the effect of different isolation methods (distilled water, sodium hydroxide, and potassium metabisulfite) on the properties of plantain starch and compared with flour. It was hypothesized that chemical steeping enhanced yield, techno‐functional properties, and resistant starch without disrupting native structure. Starch isolated using NaOH exhibited the highest starch content (91.2 ± 4.34%), lightness values (95.39 ± 0.10), consistency ( K = 867.12 ± 2.59 kPa·s n ), and resistant starch content (77.04 ± 1.63). Starch isolated using potassium metabisulfite exhibited the highest amylose content (27.62 ± 0.27%), enhanced thermal stability, and lower breakdown viscosity (490.37 ± 2.88 cP), indicating the thermal resistance during processing. The starch isolated using distilled water showed the highest swelling power (10.76 ± 0.20 g/g) and yield content (10.20 ± 0.43%) obtained from whole fruit. Plantain flour showed the lowest amylose content (16.33 ± 0.26%), starch content (54.84 ± 0.27%), swelling power (8.80 ± 0.54 g/g), and pasting properties, whereas the highest solubility (21.93 ± 0.85%) was observed as compared to all starches. All starches and flour showed a B‐type polymorphic pattern. However, relative crystallinity varied markedly, with SSH demonstrating higher crystallinity than SPM and SDW, whereas flour displayed lowest crystallinity. The SEM images revealed that the granular structure of all starches was comparable; however, the flour exhibited a more compact and dense structure surrounding starch granules.