An in vitro dose-response
analysis was performed to determine the optimal dose of a variety of extracts (baobab fruit
extract, green tea extract, grape seed extract, and resveratrol) for reducing rapidly digestible
starch in white bread. The 2 extracts with the greatest sugar reducing potential were then
used for the human study in which 13 volunteers (9 female and 4 male) were recruited for a
crossover trial of 3 different meals. On separate days, participants consumed a control
white bread, white bread with green tea extract (0.4%), and white bread with baobab fruit
extract (1.88%) Glycemic response, insulin response, and satiety were measured 3 hours
postprandially. Although enriched breads did not reduce glycemic response or hunger,
white bread with added baobab fruit extract significantly (P < .05) reduced the total (0-180
minutes) and segmental insulin area under the curve at 0 to 90, 0 to 120, and 0 to 150
minutes, and therefore reduced the amount of insulin needed for a given blood glucose
response.