Optimization of production of enzymatic protein hydrolysate-based flavor from sea grape (Caulerpa racemosa)

Caulerpa racemosa (sea grape) is an abundantly growing algae in Indonesia which contains high amount of protein and has a seafood-like flavor. This species is not widely used by people due to the lack of information on its functionalities. Therefore, this study was objected to optimize the production of protein hydrolysate based flavoring agent by using a response surface methodology. The ratio of bromelain enzyme to substrate of 21.72, 30, 50, 70, 78.28 %w/w and hydrolysis time of 0.17, 1, 3, 5, 5.83 h was designed using a central composite design by developing a quadratic model to yield the highest protein yield. The air-dried sea grape was preincubated and poured with bromelain enzyme, incubated at 50ºC, followed by heating at 95ºC to terminate the enzymatic reaction. The hydrolysate was collected by centrifugation, and then filtered. This study revealed that the valid optimal solution of protein hydrolysis was obtained as the ratio of bromelain enzyme to substrate of 78.28% and hydrolysis time of 3.49 h with 0.3215% (w/w) yield. The present study showed that hydrolysis could release the volatile compounds originated from air-dried seaweed and even formed new products, such as hydrocarbon, aldehyde, alcohols, ketone, and fatty acid, which were resulted by thermal degradation of fatty acid during hydrolysis and Maillard reaction. By inferring with prior studies of sea food flavor, this study suggested that sea grape protein hydrolysate enzymatically produced by bromelain was highly potential as sea food flavoring agent.