Optimization of Finger Millet, Foxnut and Kannankaya (Green Banana)-Based Premix Using Response Surface Methodology and Sensory Evaluation

Abstract

Finger millet, foxnut and Kannankaya (green banana) are traditional plant-based ingredients with potential for use in value-added food formulations. However, the proportions of these ingredients can influence the sensory characteristics and overall acceptability of composite products. Optimising their combination is therefore important for developing a sensory-acceptable premix. The present study was undertaken to optimise the levels of finger millet, foxnut and Kannankaya in a premix using response surface methodology (RSM) based on sensory characteristics. Preliminary trials were conducted to establish suitable ranges of the three formulation variables. Based on sensory acceptability, the experimental ranges were selected as 20–40% for finger millet, 15–25% for foxnut and 10–30% for Kannankaya. A three-factor response surface design comprising 20 experimental runs was employed to evaluate the effects of these variables on colour and appearance, consistency, odour, taste, mouthfeel and overall acceptability of the reconstituted premix. Quadratic regression models were fitted to each sensory response. The coefficients of determination (R) for colour and appearance, consistency, odour, taste, mouthfeel and overall acceptability were 0.9660, 0.9532, 0.9265, 0.9691, 0.9512 and 0.9787, respectively. The model F-values were significant (p<0.0001), while the lack of fit was reported to be non-significant for all responses. Numerical optimisation was performed by maximising sensory desirability within the experimental domain. The optimum formulation consisted of 20.776% finger millet, 15.00% foxnut and 10.00% Kannankaya, with a desirability of 0.907. Experimental validation of the optimised formulation yielded sensory scores of 7.60 ± 0.55 for colour and appearance, 7.00 ± 0.71 for consistency, 7.60 ± 0.55 for odour, 8.20 ± 0.45 for taste, 8.20 ± 0.45 for mouthfeel and 8.10 ± 0.55 for overall acceptability. The findings demonstrate that RSM can effectively be used to identify a sensory-acceptable combination of finger millet, foxnut and Kannankaya for premix development.