Development and Process Optimization of Blended Beverage from Coconut Water and Sweetpotato

Abstract

Combination of coconut water and sweetpotato are potential raw materials in making a nutritious and quality health drink. This study aimed to optimize the process and formulation of the product employing a Response Surface Methodology by Central Composite Design. Sugar (10,15, 20% w/w), calamansi (8,12,16% w/w), and sweetpotato (10,20,30% w/w) levels were identified as the significant variables. Sensory acceptability evaluation, cost analysis, and physico-chemical analysis were carried out on the different samples. Response surface regression analyses revealed that there is no significant effect on sensory acceptability except for general acceptability. Based on the superimposed contour plots, the optimum region is at 18% w/w sugar, 12% w/w calamansi, and 20% w/w sweetpotato at a cost of P 16.51/ 330 mL. Even if independent variables had significant effect on total solids, pH and Vitamin C were not affected. Free radical scavenging activity was, however, affected by calamansi and sugar levels. Total soluble solids and titratable acidity significantly increased with increasing sugar and calamansi, respectively. Either stored at room or in refrigerated condition for a month, the optimum beverage had a satisfactory acceptability with tolerable level of microbial load.