Milk clotting activity of protease, extracted from rhizome of Taffin giwa ginger (Zingiber officinale) cultivar, from northwestern Nigeria

Abstract

The increasing prices of calf rennets, their accessibility and ethical concerns associated with the production of such enzymes for general cheese making have led to systematic investigations on the possibility and suitability of their substitution by other enzymes of plant origin. In this study, ammonium sulphate ((NH₄)₂SO₄) fractionation, characterization and milk clotting activity (MCA) of protease extracted from Taffin Giwa ginger rhizome cultivar of the family Zingiberaceae from northwestern Nigeria were carried out. The protease extracted showed optimum activity at temperatures near 60 °C and pH value of 6.5 with a relative activity in a broad pH range of 5.0 to 8.0 accordingly. The enzyme was completely denatured at higher temperature of 100 °C and higher pH range of 12.0. The milk clotting property of the protease indicated 3.1 and 2.2 folds of MCA and MSCA respectively in relation to the commercial calf rennet with MCA/PA ratio of 2.52. The properties of Taffin Giwa protease shown in this study, especially its milk clotting activity, make it a potential candidate for substituting calf rennet in the food industries, particularly in cheese making processes.

Keywords: Ginger Protease, Milk Clotting Activity, Calf rennet, Characterization, Extraction