Katarzyna Samborska

Spray-Drying of α-Amylase—The Effect of Process Variables on the Enzyme Inactivation

ABSTRACT The objective of this work was to investigate the effect of spray-drying conditions on the activity of enzyme and the process development. Several experiments were performed to determine the influence of the following variables: feed ratio speed and inlet and outlet drying air temperature. Fungal α-amylase was dissolved in a maltodextrin solution and spray-dried in a laboratory drier Anhydro. Water concentration and residual enzyme activity were determined in obtained powders as a function of the drying conditions. It was found that both temperature and feed ratio speed affected the activity retention of enzyme after drying. Higher value of feed ratio speed should be used in order to obtain high active dried α-amylase. Low outlet air temperature should be kept in order to obtain high active dried α-amylase.

Spray Drying of Honey: The Effect of Drying Agents on Powder Properties

Abstract The aim of this study was to investigate the possibility of honey spray drying with addition of maltodextrin and gum Arabic as drying agents. The influence of the concentration of the solution subjected to drying, the type and content of the drying agents upon the physical properties of obtained powders was examined. An attempt was undertaken to obtain powder with a honey content of more than 50% d.b. Spray drying of multifloral honey with the addition of maltodextrin and gum Arabic was carried out at inlet air temperature of 180°C, feed rate of 1 mL/s and rotational speed of a disc atomizer of 39,000 rpm. The properties of obtained powders were quantified in terms of moisture content, bulk density, Hausner ratio, apparent density, hygroscopicity and wettability. Using gum Arabic it was possible to obtain a product with a higher content of honey (67% solids) than in the case of maltodextrin (50% d.b.). However, the powders obtained with gum Arabic were characterised by worse physical properties: higher hygroscopicity and cohesion, and longer wetting time.

Diastase Activity Retention and Physical Properties of Honey/Arabic Gum Mixtures After Spray Drying and Storage

Abstract The effect of heat treatment (75 °C) and spray drying with the addition of Arabic gum (inlet/outlet air temperature 180/75 °C), on the diastase activity of multifloral honey (MH) and rape honey (RH) was investigated. The physical properties of the powders (particle size and morphology, water content and activity, bulk loose and tapped density, angle of repose, hygroscopicity) directly after drying and after 12 weeks of storage were studied. During heat treatment, diastase activity decreased gradually, to decline below limit values after 180 min. Diastase activity in the powders was lower than in fresh honeys, but it was concluded that temperature was not the only factor affecting this decrease. Powders were characterized by low water content and medium flowability, which was improved after storage due to particle size increase. Diastase activity in powders was stable during storage.