Antioxidant, functional and rheological properties of optimized composite flour, consisting wheat and amaranth seed, brewers' spent grain and apple pomace.

Consumer's interest in functional food has continued to increase due to its potential health benefits. This study therefore is aimed at developing a functional wheat based flour comprising, amaranth (Amaranthus hypochondriacus) seed, brewers' spent grain and apple pomace. The statistical analyses were carried out using response surface methodology (RSM). For the experimental design, the composite flour components were the variables while the proximate and mineral compositions were the responses. After the statistical optimisation process, the best three blends were chosen for further analyses; determination of antioxidant, functional and rheological properties. From the results, the best blends were Runs 11, 13 and 19, with percentages composition of wheat, amaranth seed, brewers, spent grain and apple pomace of 65 %, 30 %, 2 %, 3 %; 60.43 %, 29.68 %, 4.1 %, 5.79 % and 81.94 %, 6.75 %, 3.39 %, 7.92 % respectively. The ANOVA, R(2) and R(2) adjusted values for the proximate and mineral compositions showed that the composite flours were statistically satisfactory. The results also indicated that the antioxidant, functional and rheological properties of the three best blends showed good and acceptable nutritional and rheological properties. Composite flours with acceptable and excellent nutritional composition, functional properties and rheological behaviour can be obtained from composite blends consisting wheat, amaranth seed, brewers, spent grain and apple pomace flours.