Soybean flour is often used as a gluten-free ingredient. We aimed to compare the nutrients and the difference in satiety of soybean and wheat after ingestion. We measured the amounts of polyphenol and oxygen radical absorbance capacity (ORAC) and examined the acute appetite sensation after the ingestion of soybean powder and bread powder. Japanese women were enrolled in the meal tests. Participants were provided with 18 g of bread or soybean powder, 180 g of yogurt, and 285 mL of bottled water. Subjective satiety (hunger, appetite, satiety, and stomach fullness) was measured using a visual analog scale 120 min after sample ingestion. The polyphenol content and ORAC were 2- and 12-folds higher, respectively, in soybean powder than in bread flour. In the meal tests, the area under the curve (AUC) of satiety 60-120 min after ingestion (n = 44) was significantly higher for soybean powder than bread powder. The AUCs of hunger and appetite 60-120 min after ingestion were significantly lower for soybean powder than bread powder. The effect sizes of hunger and appetite by soybean powder were 0.341 and 0.424, respectively. Thus, these results suggest that soybean is a healthy food and soybeans maintain satiety and suppress hunger more than bread flour.
Keywords: appetite; gluten-free; satiety; soybean; visual analog scale (VAS).