Effect of Ensilaging and Organic Solvent Treatment on Activity of Proteases from Chicken Intestine

Abstract

Studies were carried out to assess the extractability of proteins from chicken intestine and to determine the activity of proteases in crude extract. Further, the activity of proteases was evaluated in acid and fermented chicken intestinal silage as well as in organic solvent-treated intestinal samples. Extractability of proteins was in the range of 3.85–4.06 mg/ml and was not affected (p ≥ 0.05) by the four different extractants, viz., distilled water, phosphate buffer, and 1% potassium chloride with or without 0.1 M Na2EDTA. The specific activity of acidic and alkaline proteases were in the range of 4.78–7.26 and 19.31–24.07 units, respectively, and was not affected (p ≥ 0.05) by the type of extractant used. The pH profile for activity showed higher activity in the alkaline pH range. Addition of acid or ingredients for fermentation reduced the extractability of protein significantly (p ≤ 0.05). During storage of silage, the reduction in enzyme activity was higher in acid silage compared with fermented silage. Treatment of chicken intestine with organic solvents enhanced the enzyme activity and higher increase was observed with isopropyl alcohol-treated intestine. During storage of solvent-treated powders up to 3 months, the activity of proteases reduced in all the solvent-treated samples highest being in acetone-treated powder.