Sensory Evaluation of Carbonated Soykunun-Zaki Beverage Using Response Surface Analysis

Abstract

Carbonated Soykunun-zaki is a modern adaptation of the traditional kunun-zaki, a beverage made from fermented sorghum or millet, water, and other ingredients. This carbonated version aims to appeal to a wider range of consumers by introducing carbonation, stabilizers, and preservatives. In order to optimize the production and enhance the sensory appeal of carbonated Soykunun-zaki, this study applies response surface analysis to evaluate various factors such as volume of sample, stabilizer concentration, preservative concentration, and volume of carbon dioxide. The study identified optimal production parameters for a beverage with enhanced sensory characteristics and overall consumer acceptance. Adequate and significant (p<0.05) regression models describing the effects of production conditions on the sensory qualities with Lack of fit, F-values obtained showing the models that can be used to navigate the design space were reported. Results obtained showed that the sensory panelist’s scores ranged between 6.00 and 7.00 for taste, 5.77 and 6.90 for color, 6.00 and 7.50 for mouthfeel, 5.71 and 8.00 for consistency, 5.88 and 7.65 for aroma and 6.02 and 6.97 for overall acceptability. In all samples analysis of variance showed that preservative concentration, volume of CO2 injected in samples, and interactions between volume of sample and stabilizer concentration had significant effects on the taste, while the color was significantly affected by the preservative concentration, and interactions between volume of sample and volume of CO2 injected. Mouthfeel, aroma, consistency and overall acceptance were all significantly affected by the stabilizer concentration. The study identified optimal conditions based on desirability concept indicated that 287.242ml for volume of sample, 1.639% for stabilizer concentration, 0.100% for preservative concentration and 2.500g/L of CO2 for balancing various factors will produce a beverage with enhanced sensory attributes and overall consumer satisfaction.