Influence of annealing flours from raw and pre-cooked plantain fruit on cooked starch digestion rates

While native plantain starch is resistant to digestive enzymes, gelatinization increases its digestion rate and may be negatively associated with glycemia-related health issues. It is known that thermal treatments can be used to reduce starch digestibility. In this study, precooking of plantain fruit was used along with thermal treatment of its derived flours, with and without storage, to decrease the susceptibility of its starch in the final cooked product to α-amylase hydrolysis. Plantain flours from raw and pre-cooked fruits were annealed at 65°C and stored at 4°C for 7 days. Starches were isolated from treated samples, and were then cooked and treated with α-amylase. With annealing, hydrolysis of starch from pre-cooked plantain fruit decreased from 62.3 to 44.9% in the final cooked product. Storage had only a minor effect of promoting retrogradation of leached molecules. In conclusion, a combination of thermal treatments applied at various levels on both fruit and flour, affected starch organization and decreased susceptibility of the final cooked starch to α-amylase, for potential use in processed products.