EFFECT OF ROASTING TIME ON THE PROXIMATE, FUNCTIONAL AND SENSORY PROPERTIES OF SOYBEAN (GLYCINE MAX) POWDER FOR BEVERAGE PRODUCTION

ABSTRACT The aim of this research work was to investigate the effect of roasting time on the proximate composition, functional and sensory properties of soybean flour for beverage production. The soybeans were purchased from Ogbete Main market and bought to the laboratory, sorted out the wholesome from the unwholesome ones, steeped in water for 12 hrs. The soaked soybean seed were divided into four equal parts and roasted in aluminium pot at 110ºC for 5, 10 and 15 minutes while the unroasted seed served as the control and labeled as sample A, B, C and D respectively. The seeds were manually dehulled after cooling, milled, sieved with 60mm mesh to obtain the soy beverage. The beverage samples were subjected to analysis of proximate composition, functional and sensory properties using standard methods and the data obtained where further subjected to statistical analysis. The result of the proximate composition of the samples showed that the moisture content ranged from 2.56 to 4.30%, fat 12.70 to 16.90%, protein 36.30 to 45. 18%, ash 2.84 to 3.20%, fibre 4.22 to 6.14% and carbohydrate 30.76 to 34.90% respectively. The functional properties of the samples showed that water absorption capacity ranged from 1.42 to 1.78ml/g, oil absorption capacity 0.45 to 0.67ml/g, swelling capacity 3.31 to 3.98ml/g, foam capacity 4.00 to 6.50ml/g and bulk density 0.56 to 0.63% respectively. The sensory properties of the soy beverage showed that appearance ranged from 6.30 to 8.50, consistency 5.80 to 7.10, taste 5.90 to 8.50, aroma 4.80 to 7.60, mouthfeel 4.80 to 7.50 and general acceptability 5.00 to 7.50 respectively. The result showed that fat content, ash, fibre and carbohydrate content are influenced positively by roasting time of the soybean while the moisture and protein content are impacted to be lower in the powder beverage and roasting were correlated with functional properties and sensory properties which shown that roasting of soy bean for a minimum of 10 minutes could improve the qualities of soybean flour for beverage production.