Comparison of physical and chemical properties of wheat flour, fermented yam flour, and unfermented yam flour

摘要

Yam is a root and tuber climbing plant and main calorie source in some tropical regionsof Africa. In this study, properties of fermented (brown) yam flour (FYF) andunfermented (white) yam flour (UYF) were compared with refined wheat flour (RWF).The yam flours were lower in protein (3.3%–5.9%), arabinoxylans (0.93%–1.40%),phytic acid (0.17–0.53 mg/g), phenolic acids (0.57–2.28 mg FAE/g), amylose (17.3%–22.6%), and fat (0.2%–0.4%) but higher in potassium 119–845 mg/100 g), ash(1.70%–2.21%), total starch (73.8%–74.2%) and fiber contents (6.8%–7.0%). All thesamples exhibited high (>90) estimated glycemic index (eGI) values. However, FYFand UFY had significantly (p < 0.05) lower eGI than RWF. Thermal studies showedthat FYF and UYF required more energy for gelatinization than RWF. Compared toRWF, FYF swelled more rapidly and retrograded faster. FYF had significantly(p < 0.05) higher gel firmness than RWF and UYF. Overall, the flours exhibited differentcharacteristics which will impact functional and nutritional properties.