Optimization of sauce formulation from sea grape (Caulerpa racemosa) protein hydrolysate using response surface methodology

Sea grape (Caulerpa racemosa) is an edible green alga which contains a high amount of protein with a seafood flavor, which can be released via protein hydrolysis. Our present work was designed to determine the optimal concentration of palm sugar and carboxymethylcellulose (CMC) in sea grape protein hydrolysate sauce. The process optimization was performed to evaluate multiple parameters such as viscosity, color properties, and hedonic score. Five different levels of palm sugar and CMC were designed using a central composite design to yield sauce with a maximum hedonic score. We developed different mathematical models in this work, where viscosity, color properties (L*, a*, b*), and hedonic score were modeled using 2FI (two-factor interaction), quadratic, and linear models, respectively. The numerical optimization revealed that the predicted optimal solution was palm sugar and CMC concentration with generated viscosity, L*, a*, b*, and hedonic score of 0.893 poise, 23.296, 7.300, 19.565, and 3.522, respectively, and a desirability value of 0.839. GC-MS data associated with referred information represented that sea grape sauce had four compounds with a typical seafood flavor, namely, nonanal, hexanal, (E)-2-octenal, and octanoic acid; some native palm sugar flavors; and Maillard reaction products (MRP). Our study suggests that sauce is a potential value-added product from sea grape protein hydrolysate.