The Effect of Maltodextrin Concentration and Inlet Air Temperature on Spray Dried Centella Asiatica L. Powder

Abstract It is a common practice for the medicinal herbs which contain valuable bioactive compounds to be preserved by converting it into dry powder through various drying technology such as oven, freeze and spray drying. However, the number of study for the production of Centella asiatica L. (CAL) powder through spray drying process has been very limited and most of the work only focused on the chemical properties of the herbs. Therefore, the purpose of this study is to investigate the feasibility of spray dried CAL powder at different maltodextrin concentrations (0–10 %w/w) and inlet air temperatures (130–170°C). The spray dried CAL powders were analysed for the percentage of yield, outlet temperature, appearance and moisture content while the reconstituted powders were assessed for its colour and radical scavenging activity (RSA). The findings showed that the increased of maltodextrin concentration resulted in higher percentage of yield (12.60 ± 0.14 to 51.05 ± 1.68 g), decreased in the moisture content (13.58 ± 0.42 to 7.43 ± 0.99 %) and more lighter green colour of CAL powder produced, L* (20.27 ± 0.12 - 23.77 ± 0.69). Besides that, the increased in both inlet air temperature and maltodextrin concentration reduced the RSA of the spray dried powder. From the study, it can be concluded that the production of spray dried CAL powder is feasible and the addition of maltodextrin as the drying agent has provided a greater impact to the physicochemical properties of the powder.