10th U6+ Consortium of African Universities International Conference

Plantain-based poundo is increasingly promoted as a functional food for individuals managing diabetes and metabolic disorders. Processing conditions, particularly steaming, may alter starch composition, digestibility, and glycemic response, yet cultivar-specific effects remain underexplored. This study examined the impact of steaming parameters and varietal differences (yellow vs. white fingers) on carbohydrate fractions, starch digestibility, and blood glucose response. Yellow and white plantain fingers were subjected to controlled steaming (92–94 °C, 7–8 min) or left unsteamed. Flours were prepared and analysed for starch fractions (amylose, amylopectin), reducing and non-reducing sugars, and in vitro digestibility. Blood glucose responses were assessed relative to glucose control. Steaming significantly modifies starch composition. Yellow steamed fingers (92 °C for 8 min) showed the highest starch (80.28%) and amylose (38.25%), while unsteamed yellow fingers retained the highest amylopectin (80.50%). White steamed fingers (94 °C for 7 min) exhibited lower starch (74.55%) and amylose (26.25%) but higher amylopectin (73.75%). Reducing sugars peaked in unsteamed yellow fingers (2.88%), with steaming reducing both sugar fractions. Digestibility was highest in white steamed fingers (34.46%) but lower in yellow steamed and unsteamed samples (~25%). All plantain-based poundo elicited significantly lower blood glucose responses (4.69–4.87 mg/dL) compared to glucose control (6.56 mg/dL). Resistant starch formation in yellow steamed samples likely contributed to moderated glycemic responses, while white steamed samples, despite higher digestibility, still decreased postprandial glucose relative to pure glucose. Therefore, steaming conditions and varietal differences critically influence starch composition, digestibility, and glycemic response in plantain-based poundo. Yellow steamed fingers exhibited higher amylose and resistant starch, supporting moderated glycemia, whereas white steamed fingers showed higher digestibility. These findings underscore the importance of varietal selection and processing optimisation in developing plantain-based functional foods for metabolic health management.