Title : Processing, evaluation and optimization of gluten-free snack bars from malted-sorghum and sprouted-mung bean flour blends fortified with date-fruit powder using response surface methodology
Abstract:
D-optimal design expert was employed in the formulation of the composite flour blends for the production of high-quality snack bars. Fourteen (14) formulations were generated from malted sorghum (60-80 %), sprouted mung bean (10-30 %) and date fruit (5-10 %) which were the independent variables. They functional snack bars were subjected to proximate composition, mineral composition, amino acid profile and organoleptic attributes which were the dependent variables. The results of analysis showed that sprouted mung bean flour and date fruit powder significantly (p<0.05) increased the protein, fibre, amino acid, minerals and vitamin content of the snack bars. Additional, Response Surface 3D plot for the effects of mixture components (malted sorghum flour, sprouted mung bean flour and date fruit powder) on the individual responses revealed that increase inclusion of mung-bean flour and date-fruit powder in the formulation resulted in increased nutritional compositions, but decreased the values of sensory attributes evaluated. The models (linear, cubic, quartic, quadratic) showed significance for all the responses statistically tested except for aroma and texture which showed non-significant models. F-value at (P<0.05), coefficient of determination (R2), Adjusted R2, predicted R2, lack of fit, adequate precision and Coefficient of Variation (CV) were in reasonable agreement with each other. Numerical optimization was conducted on the basic research goals for the desired quality attributes. Six (6) optimization solutions with desirability of 0.541, 0.528, 0.477, 0.451, 0.451 and 0.440 respectively were generated by the Response Surface Methodology software. The software after considering all the desired goals, suggested that the Optimum snack bar contained 61.69 % malted sorghum flour, 28.70 % sprouted mung bean flour and 9.61 % date fruit powder with desirability of 0.54. The optimize snack bar was compared with the snack bar produced with the optimum flour formulation to validate the design. The experimental value of the snack bar from the optimum formulation was compared with the predicted value of optimized snack bar using Student T-test. Design validation showed a close relationship between the predicted and experimental values of the snack bar.
