The surface oil content or superficial oil content was calculated as per the method stated by Tan, Chan, and Heng (2005) with some slight modifications// 5 g of microencapsulated powder was weighed in a beaker, and 50 ml of hexane was added// This mixture was slightly shaken for 15 s to extort the surface vanillin// The solvent mixture was then filtered through filter paper to collect the unencapsulated vanillin via vacuum hexane evaporation// The determination of encapsulated vanillin was performed by soxhlet extraction of the same powders for 4 h// Hexane was evaporated to calculate the encapsulated vanillin and microencapsulation efficiency was calculated by Eq. (2):