Purification and drying of bromelain

The present work deals with the purification and drying of bromelain, one of the vegetal proteases. The purification of the enzyme from fruit Ananas comosus was carried out by precipitation and by chromatography. Further, the drying of chromatographically purified fraction was carried out in freeze dryer and spray dryer. The activity was expressed in terms of casein digesting units (CDU). The bromelain extract of higher purity was obtained from the fruit using ion exchange chromatography. The elution efficiency in chromatographic purification was obtained in the range of 80–90%. The fold purity obtained by chromatography was 3.3 times as compared to that obtained by precipitation. Bromelain thus obtained was subjected to spray and freeze drying. It was observed that the yield obtained in spray dryer at an outlet temperature of 40–50 °C was almost 50–70% and in case of freeze dryer the yield obtained was 96%. The resulting residual activity and the specific activity was compared between spray-dried and freeze-dried powder. The purity of enzyme obtained in the present study was found to be 2.8 times more than that of a commercial sample.