%EY =
(Total phenolics content in the powder/ Total phenolics content in the extract) × 100 (1)
The efficiency of encapsulation (EE) (%) is defined as the degree of phenolics encapsulated in the method Eq (2).
%EE = [(Mtot –Msurf)/ Mtot] × 100 (2)
Msurf = amount of phenolics on the microcapsule surface
Mtot = total phenolics in the product
For the determination of surface phenolics microcapsule, 0.1 g of phenolics microcapsule sample was washed for 5 min in 45 mL anhydrous ethanol and then filtered. After 5 min, 1 mL of distilled water was added to the filtrate and the phenolics content was determined. For determination of the total amount of phenolics microcapsule, 0.1 g of phenolics microcapsules was mixed with 1 mL distilled water and grounded to degrade the microcapsule membrane. The sample was extracted for 5 min after addition of 9 mL of anhydrous methanol and then filtered.