Optimisation of ultrasound-assisted enzymatic extraction conditions of umami compounds from fish by-products using the combination of fractional factorial design and central composite design.

In this work, ultrasound-assisted enzymatic extraction (UAEE) conditions of umami compounds from Labeo rohita head (LRH) was optimised using the combination of fractional factorial design (FFD) and central composite design (CCD). Six factors that can potentially influence the degree of hydrolysis (DH), equivalent umami concentration (EUC), and extraction yield (EY) of umami extract were screened through FFD. The three most significant variables were further optimised using the CCD.