Production and characteristics of protein hydrolysate from tra fish (Pangasius hypophthalmus)

The goal of this study was investigate effects of pH and temperature on the production of tra fish protein hydrolysate (FPH) fish protein concentrate (FPC) using alcalase and characterization of FPHs. Temperature of 55 o C and pH 8.5 were the best condition for highest degree of hydrolysis (around 55%) after 60 min of reaction. Under hydrolysis, protein solubility was significantly increased from 4% to >90%. FPC contained fractions of 50, 40, 37, 15, 12, and 11×10 3 g/mol. After 15 or 120 min of enzymatic reaction, molecular weight was degraded to 4.86 and 4.31 (x10 3 g/mol) of FPH15 or FPH120 samples. Due to the increasing of protein solubility during the hydrolysis, water holding capacity reduced from 2.81 ml/g (FPC) to FPH120>FPC and FPH120>FPH15>FPC. Furthermore, foam activity index and foam stability index of samples were arranged as FPH15>FPH120> FPC. At pH 4.0, all these indexes were lowest. Generally, under enzymatic hydrolysis, FPH could be possessed of different molecular weights and physico-chemical properties. Thus, FPH could reach various demand of industrial applications.