Influence of Temperature on the Stability of M. rosenbergii and P. monodon Muscle Protein under Various Storage Conditions
Md. Moshiur Rahman,
The influence of temperature on the changes in Ca2+-ATPase activity and solubility of M. rosenbergii and P. monodon muscle myofibrils were studied in a wide range of temperature from 20 to 55 ° C for 30 min. Both ATPase activity and solubility almost remain unchanged up to 25 ° C while both ATPase activity and solubility decreased with the raise of temperature. The decreasing of ATPase activity and solubility after 25 ° C clearly indicates the influence of temperature on the denaturation of M. rosenbergii muscle myofibrils. The influence of temperature on the inactivation rate of Ca2+-ATPase at 30 and 35 ° C on myofibrillar proteins of M. rosenbergii and P. monodon were investigated at various pH values. The inactivation rate of M. rosenbergii was low at pH 7.8 to 8.5 where the rate was quite high both in acidic and alkaline pH region irrespective of incubation temperature. The Kd value at 35 ° C was markedly higher than at 30 ° C throughout all the pH ranges. Similar studies were also conducted on P. monodon muscle myofibrils. The results obtained from P. monodon muscle myofibrils were more or less similar to that of Kd value obtained from M. rosenbergii muscle myofibrils where the myofibrils were found more stable at neutral pH ranges form 7.1 to 8.8. However, with the progress of acidic and alkaline pH value the Kd value gradually increased. The result also shows that higher temperature of 35 ° C accelerated the Kd value in myofibrils compared to that of incubated at 30 ° C throughout the pH ranges used.. Studies were also conducted to evaluate the effect of temperature on the coagulation time of sarcoplasmic protein of M.rosenbergii and P. monodon. At 40 ° C coagulation of M. rosenbergii sarcoplasmic protein was started in 8 min and coagulation time decreased gradually with the increase of temperature and at 60 ° C the coagulation of sarcoplasmic protein was started in 3 min. On the other hand, at 40 ° C coagulation of P. monodon sarcoplasmic protein started in 5 min and the coagulation time decreased with the raise of incubation temperature and it was found that at 60 ° C, coagulation was started within 1.7 min. The results obtained from present studies also shows that sarcoplasmic protein of P. monodon denature more quickly than that of M. rosenbergii sarcoplasmic protein at higher temperature.
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