The purpose of this study was to determine the influence of proportion and ratio of the following main ingredients comprising Pathum Thani fragrance rice powder, soy protein and milk powder on physicochemical properties and sensory characteristics of instant functional beverage powder. The experimental procedures consisted of prerequisite processing steps of cooking, drying, crushing and mixing all ingredients. The design was used to produce a total of ten samples of powdered beverage products. Whereas, dry samples and complete dissolution samples were analyzed for their physicochemical properties and sensory characteristics. Results indicated that the prepared beverage powder with various ratios of ingredient combinations delivered significant impact on their physical chemical and sensory characteristics. Principal component analysis (PCA) was implemented to group the attributes into three key dimensions that explained 76.51% of the total variance. Furthermore, Partial least squares regression (PLSR) was employed as a multivariate statistical tool to accurately determine carbohydrate, fiber, L* (dissolve), a* (dissolve) and b* (dissolve) as key drivers of liking. Having the highest consumer satisfaction levels and highest average liking scores of all sensory characteristics, the optimum formulation for instant functional beverage powder was formula 10 containing 23.34% of Pathum Thani fragrance rice powder, 13.33% of soy protein and 13.33% of milk powder, 20% of sugar, 10% of cocoa powder, 10% of malt powder, 5% of non-dairy cream powder and 5% inulin powder. More importantly, these research findings may influence decisions at many levels in increasing consumer acceptance of the product, manufacturing healthier products for people, and adding value to products of agriculture.