Estimation of glycaemic index of peach palm (Bactris gasipaes) cooked fruits and chips, and pitahaya (Hylocereus spp.) pulp

The glycaemic index (GI) is a physiological measure of a food's potential to increase postprandial blood glucose, as compared to the effect produced by food taken as reference, such as glucose or white bread. Currently researchers and consumers are interested in low GI foods, since their consumption is associated with better weight control and reduced risk of incidence of chronic diseases, like diabetes. In the present study, the GI value for peach palm cooked fruit, peach palm chips and pitahaya pulp was estimated. The methodology established by the FAO/WHO for determining the GI of food was used. A total of 12 healthy, non-smoking volunteers were selected and they ingested the fore mentioned foods on different occasions, in 25 g portions of available carbohydrates, after 12-14 h overnight fast. Blood glucose levels were measured in 30 min intervals up to 120 min after ingestion. Average GI value was 48 +/- 11 for the pitahaya pulp and 35 +/- 6 for the peach palm cooked fruit, which may be classified as low glyceamic index foods. The GI of peach palm chips was 60 +/- 7, corresponding to a food with a moderate GI. The processing for producing the chips caused an increase in the GI value when compared to the cooked fruit, probably because the stages of miIling, moulding and baking promote availability of starch during hydrolysis by the digestive enzymes.