A study was carried out to determine the effect of enzyme concentration, temperature and incubation time of bromelain on nitrogen content (NC) and degree of hydrolysis (DH) of hydrolysate from cockle (Anadara granosa) meat wash water. Protein precipitation of cockle meat wash water was conducted at pH 4. The precipitate was then hydrolyzed using bromelain at concentrations of 0.5, 1.5 and 2.5% (enzyme/substrate). The best enzyme concentration was subsequently used to study the effect of incubation temperature at 30, 45 and 60°C. The best temperature was then used to determine the effect of incubation time at 0, 24 and 48 hours. Increasing bromelain concentration from 0 to 2.5% produced an increase in NC and DH. Similarly, increasing the incubation time from 0 to 48 hours also increased the value of NC and DH. However, while the increasing of incubation temperature from 30 to 60°C produced an increase in NC, no significant difference was observed for DH.
Cockle (Anadara granosa) meat wash water precipitate was hydrolyzed using bromelain. Experiments were carried out to determine optimum conditions for temperature, enzyme concentration and hydrolysis time using response surface methodology (RSM) based on a central composite rotatable design (CCRD) to obtain the highest value of nitrogen content (NC) and degree of hydrolysis (DH). Results revealed that the optimum conditions for temperature, enzyme concentration and hydrolysis time were 33.7°C, 1.45% (E/S) and 28.42 hrs, respectively. At the optimum condition, hydrolysis of cockle meat wash water precipitate using bromelain resulted in a NC of 0.6% and DH of 48%. The NC and DH were significantly influenced by temperature, enzyme concentration and hydrolysis time. When the bromelain concentration, hydrolysis time and temperature were increased, the values of NC and DH also increased. The hydrolysate produced contained flavor compounds found in clam and oyster which were 3-methylbutanol and 1-pentanol. The compound 3-MCPD was not found in the hydrolysate.