Wpływ parametrów suszenia rozpyłowego na aktywność ektynometyloesterazy i właściwości fizyczne suchych preparatów

Suszeniu rozpyłowemu poddawano, z zastosowaniem maltodekstryny DE15 jako nośnika, preparat pektynometyloesterazy (PME) pochodzącej z Aspergillus aculeatus. Stosowano temperaturę powietrza wlotowego 160, 180 i 200°C oraz prędkość obrotową dysku 34 000, 35 000 i 36 000 obr./min. Po suszeniu oznaczano aktywność enzymu oraz właściwości fi zyczne proszków: zawartość wody, rozkład wielkości cząstek, gęstość nasypową luźną i utrzęsioną, rozpuszczalność i higroskopijność. Stwierdzono, że suszenie rozpyłowe jest dobrą metodą utrwalania preparatu PME, ponieważ względna aktywność enzymu po suszeniu wynosiła od 67,8 do 81,0%. Otrzymane proszki miały dobrą rozpuszczalność oraz sypkość, a parametry fi zyczne preparatów uzależnione były od parametrów suszenia. Po przechowywaniu przez 12 tygodni proszki odznaczały się wysoką aktywnością względną PME.

Drying is the method of enzyme preparations preservation. Dried preparations are characterized by high stability and long shelf life, are easy to transport and storage, and their use facilitates the automation and mechanization of the production process. The selection of appropriate parameters of the drying process determines the fi nal enzyme activity and its utility in the process. During drying, the enzyme molecule can claim to numerous adverse changes in biochemical, chemical and physical properties, that cause the loss of their biological activity. The aim of the study was the selection of appropriate parameters (drying temperature and atomisation speed) for pectin methylesterase (PME) from Aspergillus aculeatus preparation spray drying capable of producing a powder of high enzyme activity and favourable physical properties. Liquid preparation of PME was spray dried with the use of maltodextrin DE15 as a carrier at inlet temperature 160, 180 and 200°C, and atomisation speed 34 000, 35 000 and 36 000 rpm. After drying PME activity was determined as well as the physical properties of powder: water content, particle size distribution, bulk density, solubility, and hygroscopicity. It was found that spray drying is a good method for the PME preparation preservation, because the relative activity of the enzyme after drying ranged from 67.8 to 81.0%. Spray drying allows to maintain the high enzyme activity due to short drying time (few seconds) and the relatively low temperature of particles during drying. Moreover, this behaviour of the enzymatic activity during spray drying is the result of the characteristic properties of the enzymes as protein substances: increased thermal resistance under reduced content and water activity. After storage for 12 weeks powders still had high relative PME activity. Powder particles obtained during spray drying had a spherical shape and smooth surface, which is characteristic of the powders obtained by this method. The resulting powders had good solubility and fl ow properties. The physical parameters of preparations were dependent on drying parameters. Inlet air temperature and the atomisation speed affected the solubility, density, hygroscopicity and Hausner ratio of the powders. The optimum parameters, of the tested variants, for the spray drying of PME preparaton, ensuring high activity of the enzyme and good physical properties of powders were: inlet air temperature 160°C and the atomisation speed 36 000 rpm.