Development of micronutrient enriched composite flour with selected grains, pulses, and herbs

Abstract

Most of the non-communicable diseases are directly related to the consumption of purified wheat flour. Therefore, composite flour mixtures can be introduced as a remedy. This study aimed to formulate a composite flour mixture comprising rice (Oryza sativa, variety Bg352), cowpea (Vigna unguiculata), horse gram (Macrotyloma uniflorum), black cumin (Nigella sativa), and ash plantain (Musa paradisiaca) pseudo stem. All the raw materials were cleaned and transformed into flour forms, and eight different composite flour mixtures were prepared according to Taguchi’s L8 orthogonal design. Eight samples of String hoppers, hoppers and pittu were prepared with eight different formulations. The sensory properties of prepared samples were evaluated using the five-point hedonic scale with thirty semi-trained panelists. The proximate composition, mineral profile, total phenolic content and antioxidant activity of the selected formulae were determined using standard analytical techniques. The colour, swelling index, initial water absorption capacity and bulk density of the final formulae were also evaluated. The highest rank for all the tested sensory attributes was obtained by the formula consisting of 82.93% O. sativa, 10.73% V. unguiculata, 3.90% M. paradisiaca pseudo stem, 1.95% M. uniflorum, and 4.88% N. sativa flour. The proximate results revealed that the sample with highest overall acceptability contains moisture (9.83%), ash (1.25%), total fat (1.28%), crude protein (10.55%), crude fiber (2.40%) and carbohydrate (70.25%). The results of the mineral profile of the sample with the highest overall acceptability for all sensory attributes revealed that sodium (1879.85 ppm), potassium (1276.20 ppm), calcium (2911.67 ppm), magnesium (8923.68 ppm), zinc (2.57 ppm), manganese(0.32 ppm), and iron (2.19 ppm). DPPH radical scavenging activity (0.0688 mg mL-1 ) and gallic acid equivalent phenolic content (37.02 µg/mL) of the composite flour mixture were analyzed. The initial water absorption capacity (150.83), oil absorption capacity (1.99 g/g), swelling index (4.99 mL/g), bulk density (0.50 g/ mL), and color (L*87.03, a*0.8, b*7.9, h 84.27) were recorded. The total plate count, yeast & mold count, coliform count, peroxide value and moisture content confirmed the product's safe consumption for two months. The developed composite flour mixture meets micronutrient requirements, and it can be used as a substitute for purified wheat flour for making string hoppers, hoppers, roti and pittu.