This study examined the optimal mixing amount of carrot juice, sugar, and agar powder for the preparation of Yanggaeng. The experiment was designed according to the central composite design of response surface methodology (RSM). To develop the Yanggeng using RSM, carrot juice (A), sugar (B), and agar powder (C) were set as the independent variables. The experimental data on physicochemical properties and sensory evaluation were fitted to various models. Among the responses, water content (P<0.001), sugar content (P<0.001), L-value (P<0.001), a-value (P<0.001), b-value (P<0.05), hardness (P<0.001), adhesiveness (P<0.05), resilience (P<0.01), cohesiveness (P<0.01), springiness (P<0.001), gumminess (P<0.001), chewiness (P<0.001), and sensory properties of appearance (P<0.001), flavor (P<0.001), taste (P<0.001), texture (P<0.05), and overall acceptability (P<0.001) showed significant correlations with carrot juice, sugar, and agar powder. From these results, the optimal formulations, which was calculated by numerical and graphical methods, was carrot juice 58.06 g, sugar 39.01 g, and agar powder 5.03 g.

Keywords: carrot juice, sugar, agar powder, Yanggaeng, response surface methodology (RSM)