|Functional properties and in vitro protein digestibility of untreated and thermally-treated barley-pulse flour blends|
C. CHIREMBA (1), K. Schultz (1), M. Nickerson (1) (1) University of Saskatchewan, , Canada.
Pulse and cereal flours are often blended to obtain complementary nutrition. In this research, the functional attributes and <i>in</i> <i>vitro</i> protein digestibility (IVPD) of untreated and thermally-treated (dry heat; 25min at 121oC) blends of chickpea, green pea, red lentil or faba bean flour with hull less barley flour at ratios of 50:50, 60:40 and 70:30 were examined. Oil holding capacities (OHC) for pure barley and pulse untreated flours were found to be ~1.3 g/g and ~1.0-1.1 g/g respectively. Overall, the effect of ratio and dry heat in the blended flours had little effect on OHC. Water hydration capacities (WHC) for pure barley and pulse untreated flours were ~1.3 g/g and ~1.2-1.8 g/g, respectively. Dry heat resulted in an increased WHC, with the exception of red lentil and faba bean, which were similar to the untreated flours. Foaming capacity (FC) for pure barley and pulse flours were 144% and 155-200%, respectively. Dry heat did not affect FC except of green pea flour where FC increased. FC was similar among the different blending ratios, for blends containing faba bean and red lentil flours, but varied with green pea flour. Foam stability (FS) for the pure barley and pulse untreated flours were found at ~14% and 56-78%, respectively. The addition of dry heat increased FS for barley and red lentil, but a decrease in chickpea, green pea and faba bean flours. IVPD for pure barley, chickpea, red lentil, green pea and faba bean untreated flours were found to be similar at ~72%, ~71%, 74%, ~78% and ~76%, respectively. No blending ratio effect was seen and the addition of dry heat had no effect on IVPD values with the exception of green pea and red lentil flour and their blends where the IVPD values became reduced slightly. A better understanding of the effects of processing on the functionality and digestibility blended flours is essential for product development purposes.