Abstract
Breakfast cereals was formulated from blends of acha and fermented okara (soybean residue). Acha grains were cleaned, winnowed, washed, dried (at 50 °C for 4 h) and milled into flour. Okara was processed from soybean seed through the stepwise procedure of cleaning, soaking, washing, milling and sieving. The residue was divided into five portions, fermented differently for 0, 12, 24, 36, and 48 h and then dried at 50 °C for 6 h. Acha flour (UFAC) was milled and blended at 50, 60, 70, 80, 90, 100 % ratio with milled okara flour. Functional properties (bulk density, water absorption capacity, swelling capacity, wettability, viscosity and particle size distribution, microbial load, and proximate composition were carried out on the individual flour samples. The blended flours were conditioned, partially heat treated (for 10 min), aged (4 °C for 6 h), cut, toasted (120 °C for 1 h), cooled and packaged. The different toasted breakfast cereals, TBFC, were subjected to sensory evaluation, proximate composition, micronutrient composition (vitamin A, B1, B2, B3, calcium, iron, phosphorus, and zinc) and microbial analyses (mould count and total viable count). The proximate composition of the unfermented okara (UFOK) and fermented okara (FEOK 1, 2, 3, and 4 fermented at 12, 24, 36, 48 h respectively) flour samples showed that fermentation increased moisture from 4.71 ± 0.06 to 6.11 ± 0.05, crude fibre from 36.62 ± 0.01 to 46.18 ± 0.55, and carbohydrate from 2.50 ± 0.18 to 2.71 ± 0.34 contents. There was a decrease in the fat content from 16.29 ± 0.04 to 13.27 ± 0.22, ash from 1.41 ± 0.17 to 6.36 ± 0.17 and crude protein from 30.32 ± 0.21 to 33.53 ± 0.11 contents. From the sensory evaluation, the result showed that 70:30 acha-unfermented okara TBFC, FEOK 1D 60:40 acha-12 h FEOK TBFC, 70:30 acha-24 h FEOK TBFC, 50:50 acha-36 h FEOK TBFC, and 70:30 acha-48 h FEOK TBFC had the best overall acceptability for the different fermentation times. The functional properties, proximate and sensory evaluation were the basis for selection of the best products which were UFAC (control), UFOK C (70:30 acha UFOK TBFC) and FEOK 4C (70:30 acha 48 h FEOK TBFC) which were further subjected to proximate, micronutrient, and microbial analyses. There was an increase in the protein, fat, ash, crude fibre content whereas the moisture and carbohydrate contents decreased. A considerable decrease was found in vitamin A and B1 contents of the products, whereas vitamin B2 and B3 increased. Also the mineral contents of all the products were improved as indicated in the increase in ash content.