19-08-2014, 10:33 AM
Dry solid formulations are often developed to provide acceptable protein and enzyme shelf lives. Spraydrying is the most common method for drying of liquids. The quality of final product very much depends on how the latex is dried, thus the method of drying is the main factor that determines the final quality of papain. Traditionally latex is sun dried or oven dried but it causes a considerable loss of enzyme activity and the papain turns brown. Spray dried papain has a higher enzyme activity than other papain and it is completely soluble in water.
Dry solid formulations are often developed to provide acceptable protein and enzyme shelf lives. Spraydrying is the most common method for drying of liquids. The quality of final product very much depends on how the latex is dried, thus the method of drying is the main factor that determines the final quality of papain. Traditionally latex is sun dried or oven dried but it causes a considerable loss of enzyme activity and the papain turns brown. Spray dried papain has a higher enzyme activity than other papain and it is completely soluble in water.
Papain was obtained by cutting the skin of the unripe but almost mature papaya and then collecting and drying the latex which flows from the cuts. Tapping of the fruit was done early in the morning and finished by mid-late morning (i.e. during periods of high humidity). Four to five vertical cuts, 1-2 mm deep were made, meeting at the base of the fruit. The incisions were made using a stainless steel razor blade set. Fruits were tapped at intervals of about 4-7 days. The wet latex were subjected to sun drying, freeze drying, spray drying and vacuum oven drying .The initial and final bound water was measured using water activity meter . Protein content was estimated by Folin-Lowry method and activity was expressed in terms of CDU i.e. Casein Digesting Units.
Freeze Drying and Spray Drying: The sample was subjected to freezing at temperature below -25ºC for a period of 6 hrs. Then the sample was subjected to freeze drying in a freeze dryer (M/s. Ref – Vac Consultancy). The dimensions of the chamber were 0.4 m x 0.4 m. The sample was also subjected to the spray drying (1 lit/hr evaporation capacity spray dryer, M/s Labultima). The spray dryer operates in a co-current manner and is equipped with a two fluid nozzle.