In Vitro Digestibility And Qualities Of Gluten-free Cookies Made From Germinated Unpolished Red Rice Flour With And Without Heat Moisture Treatment

Abstract

This study was aimed to investigate the effect of germinated red rice with and without heat-moisture treatment in cookie production on physicochemical, in vitro digestibility and sensorial properties. Ten kinds of cookie were prepared from wheat flour (reference), native rice flour (control), only germinated in 6,12,18,24 hours (G6, G12,G18, G24), and germinated in 6,12,18,24 hours with heat-moisture treatment afterwards (G6H, G12H, G18H, G24H) flour. The results exhibited insignificant differences in chemical composition of rice-based products except the moisture content, protein and ash of native rice compared with wheat-based cookies. Germination decreased the spread ratio of cookies; however, heat-moisture treatment could recover it. Changes in hardness were entirely dependent on germination time and heat-moisture treatment, with 562g force requirement to break after 24-hour germination. Although there were no significant changes for digestive rate during germination, resistant starch content saw a decline trend from 12% to 7%, significantly decreasing after the 18th hour. After Heat-moisture treatment, no significant difference or trend can be obtained. G12 was chosen as the best improvement compared to the G0, with impressive sensorial scores. However, considering the high RS content, G6H or G18H should be the optimal final products having improved both texture and dietary management.