The effects of spray drying process parameters on the characteristic process indices and rheological powder properties of microencapsulated plant (Gypsophila) extract powder

Gypsophila Saponaria afficinalis, is in the family Caryophyllaceae, native to southern Europe and southwest Asia, and commonly known as the soapworts. The aqueous extract was obtained by sequential extraction of soapwort plant roots and prior to spray drying operation maltodextrin was added as a carrier material to adjust the soluble solid content (°Bx) of the soapwort extract (15°Bx, 22.5°Bx, 30°Bx). Powder properties of the product and the characteristic process indices were determined after spray drying of soapwort extracts with different air inlet (110 °C, 135 °C, 160 °C) and outlet temperatures (50 °C, 65 °C, 80 °C) with the other process parameters being constant. The moisture content of the powders changed between 6.35% and 0.44% being mostly affected by increasing outlet temperatures. Productivity and drying rate showed a decreasing tendency as air outlet temperature increased since high outlet temperatures required low feed flow rates. Dissolution time and tapped density were determined as powder characteristics combined with foam producing capacity, color and morphological properties. In general, results showed that spray drying can satisfactorily be used for spray drying of soapwort root extracts with acceptable moisture and water activity of the powders and functional properties of the reconstituted powders.