A Screening Study of the Spray Drying Process for the Microencapsulation of Phenolic Compounds from Sarcocephalus latifolius (Sm.) Bruce Root Extracts Using a Two-level Factorial Design

The stability of bioactive molecules is improved with microencapsulation by spray drying, providing protection against oxygen, water, or any agent. Sarcocephalus latifolius (sm.) Bruce is a medicinal plant widely used in traditional herbal medicine to treat several diseases such as fever, pains, dental caries and malaria. In this research, various spray drying process operational parameters such as encapsulating agent to extract ratio (5 – 20 g/ g of extracts), feed suspension flow rate (200–800 mL/h), inlet air temperature (110 – 180°C), and inlet air flow rate (50 - 90 m3/h) were evaluated by screening process using two level factorial design (TLFD). Design-Expert software has been used to find out the significant variables in terms of obtaining high spray drying process yield, Encapsulation efficiency (EE) of polyphenols from S. latifolius roots and least moisture content of spray dried powders. The screening process indicated that encapsulating agent to extract ratio was the most significant and contributing factor affecting the results of spray drying process yield together with encapsulation efficiency of polyphenolic compounds (p < 0.05), while feed suspension flow rate exhibited the least significance and contribution (p > 0.05). Most interactions between the studied parameters were insignificant. The Process yield of 78.44%, Moisture content of 2.21% and EE of polyphenols of 72.93% have been obtained at encapsulating agent to extract ratio (20 g/ g of extracts), feed suspension flow rate (200 mL/h), inlet air temperature (180°C), and inlet air flow rate of 90 m3/h and 50 m3/h (for moisture content).