Effects of processing moisture on the physical properties and in vitro digestibility of starch and protein in extruded brown rice and pinto bean composite flours.
The influence of pinto bean flour and processing moisture on the physical properties and in vitro digestibility of rice-bean extrudates has been investigated. Brown rice: pinto bean flour (0%, 15%, 30%, and 45% bean flour) were extruded under 5 moisture conditions (17.2%, 18.1%, 18.3%, 19.5%, and 20.1%). Physical properties [bulk density, unit density, radial expansion, axial expansion, overall expansion, specific volume, hardness, color, water solubility index, and water absorption index] and in vitro starch and protein digestibilities were determined. Increasing bean flour and processing moisture increased density and hardness while decreasing expansion. Rapidly digestible starch decreased and resistant starch increased as bean substitution and processing moisture increased. In vitro protein digestibility increased with increasing bean flour or with decreasing processing moisture. Incorporating bean flour into extruded snacks can negatively affect physical attributes (hardness, density, and expansion) while positively affecting in vitro starch (decrease) and protein (increase) digestibilities.
Department of Food Science & Technology, University of Nebraska, Lincoln, NE, USA.
Franklin
F
Sumargo
Department of Food Science & Technology, University of Nebraska, Lincoln, NE, USA.
Paridhi
P
Gulati
The Food Processing Center, University of Nebraska, Lincoln, NE, USA.
Steven A
SA
Weier
Department of Food Science & Technology, University of Nebraska, Lincoln, NE, USA; Department of Statistics, University of Nebraska, Lincoln, NE, USA.
Jennifer
J
Clarke
Department of Food Science & Technology, University of Nebraska, Lincoln, NE, USA; Department of Agronomy & Horticulture, University of Nebraska, Lincoln, NE, USA. Electronic address: drose3@unl.edu.
Devin J
DJ
Rose
D007887:Fabaceae / Q000378:metabolism*; D005433:Flour / Q000032:analysis*; D005511:Food Handling; D006801:Humans; D012275:Oryza / Q000378:metabolism*; D012995:Solubility; D013213:Starch / Q000378:metabolism*; D014867:Water
D014867:Water; D013213:Starch
Expansion; Health; Protein; Snacks; Starch