Spray drying of Gentiana asclepiadea L. root extract: Successful encapsulation into powders with preserved stability of bioactive compounds

Abstract

Willow gentian as a source of bitter compounds is traditionally used for digestive disorders. Gentiana root extract was spray dried using five different carriers (maltodextrin, whey protein, pectin, starch, gelatine) at various concentrations. Powders were characterized in terms of physical properties and encapsulation efficiency of bioactive compounds. The moisture content of all powders was between 1.78 and 3.46 %, and bulk density from 0.23 to 0.32 g/mL. Powders produced with maltodextrin and whey protein provided the highest yield (around 75 and 70 %, respectively) and the lowest hygroscopicity (6 and 7%, respectively). Gelatin and pectin provided powders with the highest encapsulation efficiency of total phenolic as well as the individual compounds. The stability of encapsulated bioactive compounds was studied after 6 months, and the most stable in all samples were gentiopicrin and sweroside with their content decreased by 10 % only. This study has shown that spray drying of gentian root extract produces powders with good physical properties and encapsulation of bioactives.