Encapsulation of Alcohol Dehydrogenase in Mannitol by Spray Drying

The retention of the enzyme activity of alcohol dehydrogenase (ADH) has been studied in various drying processes such as spray drying. The aim of this study is to encapsulate ADH in mannitol, either with or without additive in order to limit the thermal denaturation of the enzyme during the drying process. The retention of ADH activity was investigated at different drying temperatures. When mannitol was used, the encapsulated ADH was found inactive in all the dried powders. This is presumably due to the quick crystallization of mannitol during spray drying that resulted in the impairment of enzyme protection ability in comparison to its amorphous form. Maltodextin (dextrose equivalent = 11) was used to reduce the crystallization of mannitol. The addition of maltodextrin increased ADH activity and drastically changed the powder X-ray diffractogram of the spray-dried powders.