Effect of acid ensiling on the stability of visceral waste proteases of Indian major carp Labeo rohita

The effect of acid ensiling on the stability of different classes of proteases present in the visceral wastes of a major freshwater carp is presented. The changes in moisture, fat and ash content were not significant (P >= 0.05) during the storage period of 4 weeks at ambient temperature of 27 +/- 2 degrees C. Fresh visceral waste of the freshwater major carp Labeo rohita had considerable protease activity and buffer extractable proteins (2.7% w/w). There was a significant reduction in buffer extractable proteins (BEP) immediately after acidification (P <= 0.05), which later increased in the first two weeks before decreasing further during storage. Marked decreases (P <= 0.05) in specific activity (U mg(-1) protein) of acidic, neutral and alkaline proteases were observed during storage. The stability of proteases was negatively affected by acid ensiling, even with the use of weak acids like propionic and formic acid.