Bambara Bean Substitution Improves the Nutritional Content and Increases the Satiety Index of Purple Sweet Potato Bread

This study aimed to develop tuber bread from purple sweet potato and bambara beans with high satiety and low glycemic index (GI). Different ratios of purple sweet potato to bambara bean were used: 100:0 (F0), 80:20 (F1), 60:40 (F2), and 40:60 (F3). The satiety index (SI) was determined by assessing the consumption of a 240 kcal isocaloric food and collecting data through a visual analog scale. Blood samples were collected from 11 subjects to determine the GI of the test food. This was achieved using the finger-prick capillary blood sampling method or an EasyTouch glucometer. The results showed that tuber-bread F1 was categorized as high-fiber sources (6.92±0.03 g), whereas F2 and F3 were classified as fiber sources (5.50±0.07 and 5.14±0.11 g, respectively). Significant differences were observed among all formulas. Additionally, formula F3 showed a high SI (160.12%±18.38%) and GI (81.94±2.13), suggesting that the consumption of fiber-rich food may promote feelings of fullness and reduce food cravings. The satiety score analysis of the selected products against standard food yielded a regression equation (y=-0.257x+66.648), showing that tuber-bread F3 extended satiety by up to 95 min compared with white bread. As a result, tuber-bread F3 may help to reduce the consumption of additional food, which is frequently a significant contributor to excessive calorie intake.