DEVELOPMENT OF PLANT-BASED BEVERAGE MADE OF CASSAVA (Manihot Esculenta) AND SWEET POTATO (Ipomoea Batatas) USING RESPONSE SURFACE METHODOLOGY

The industry of plant-based beverages (PBB) is expanding rapidly due to rising consumer demand for sustainable, ethical food options, and restrictions such as lactose intolerance and hypercholesterolemia. This study aims to optimize the production of PBB made from underutilized crops using robust experimental designs in overcoming issues with product quality and consumer acceptance. A Response Surface Methodology (RSM) was used to improve stability and sensory acceptability of PBB by testing different combinations of ingredients and processing methods. This included adjusting the amount of cassava (Manihot esculenta) [0.5%, 1.0%], inclusion of other root crops [0%, 0.5%], homogenization pressure [2, 20 MPa], cassava-to-water ratio [1:2, 1:5], and using flavors like sweet potato (Ipomoea batatas) and purple yam (Dioscorea alata). The effects and correlation between the factors and responses (physicochemical and sensory properties) were evaluated using Analysis of Variance (ANOVA), diagnostic tests, equations, and model graphs. Results showed that the significant models (p <0.05) are color b* coordinate, chromaticity, sensory taste, and overall acceptability, with R² values from 0.7445 to 0.8769, non-significant lack-of-fit (p >0.05), and adequate precision ratios of more than 4.0. While the numerical optimization using the desirability function identified optimal parameters— 1:5 dilution ratio for the extraction of cassava using water, then preparation of PBB composed of 0.5% cassava and 0.5% sweet potato (w/w), and homogenization at 20 MPa for producing consumer acceptable beverage with viscosity of 2.19- 8.39 mPa.s, 7.57-9.55 °Bx, pH of 6.40-6.56, 286.89 - 355.11 color hue values and sensory rating of “like slightly” to “like moderately”. This highlights how local crops can be used as raw materials in PBB, offering more choices for people with dietary restrictions. Future research should investigate the addition of stabilizers, nutrient strategies, and comprehensive microbiological shelf-life testing to meet commercial safety standards.