PARTIAL CHARACTERIZATION OF PROTEASE EXTRACTED FROM “YATSIN BIRI” GINGER (Zingiber officinale) CULTIVAR OF NORTHWESTERN NIGERIA

Résumé

enzymes for cheese making and related processes have ignited a flame of scientific enquiries on the possibility and suitability of their substitution by other enzymes of plant sources. In this study, ammonium sulphate fractionation, characterization and milk clotting activity (MCA) of protease extracted from YatsinBiri ginger rhizome cultivar of the family Zingiberaceae from northwestern Nigeria were analysed. The protease extracted showed optimum activity at 50 °C and pH value of 5.5. Relative activity of the enzyme was also observed within a broad pH range of 4.5 to 7.0 accordingly. The enzyme was completely denatured at 100 °C and alkaline pH of 11.5. The milk clotting property of the protease indicated 2.83 and 1.81 folds of MCA and MSCA respectively in relation to commercial calf rennet with MCA/PA ratio of 2.18. These properties of YatsinBiri ginger protease, especially its milk clotting activity, broad pH ranges and moderately elevated temperature of 50 °C, may favour its suitability as substitute calf rennet in the food industries, especially in
cheese making and related products