Impact of resistant starch in three plantain (Musa AAB) products on glycaemic response of healthy volunteers

Background and aim of the study: Plantains can be eaten in various forms providing a good opportunity to study the effect of starch type on glycaemic response, and so three products differing in their types of available carbohydrate and contents of resistant starch were tested. Methods: Boiled unripe plantain (BUP), boiled unripe plantain crisps (BUPC), ripe raw plantain (RRP) and white bread as reference (all 25 g available carbohydrate portion) were given to ten pre-screened healthy individuals. Postprandial glycaemic responses and glycaemic indices (GI) were measured. Results: Peak blood glucose for BUP, BUPC and RRP was at 45, 45 and 30 min post-meal time, respectively. The peak blood glucose concentrations for BUP, BUPC and RRP (1.8 ± 0.8, 2.3 ± 0.8, 1.9 ± 0.7 mmol/L, n = 10, respectively) reflected the in vitro quantities/types of rapidly available glucose (RAG) in the samples. On the other hand, mean GI ± SEM values obtained for the test products (BUP = 44.9 ± 3.6, BUPC = 55.0 ± 4.2, RRP = 38 ± 4.4, n = 10) were neither significantly different nor directly correlated with RAG. Conclusions: The results show a potential link between RAG and GI, but the correlation is confounded by the presence of other constituents in the plantains