Microencapsulation of vitamin C and gallic acid in whey protein concentrate by spray and freeze drying

Abstract

Vitamin C and gallic acid were chosen as model antioxidants to be used as core material and whey protein concentrate (WPC) was selected as wall materials for microencapsulation. Microencapsulation methods used were spray and freeze drying. Vitamin C: WPC (w/w) ratios and gallic acid: WPC ratios (w/w) were 1:4.0, 1:5.3, 1:8.0, and 1:16.0 for both spray and freeze drying process. 1:4.0 ratio resulted in highest microencapsulation efficiency for both vitamin C and gallic acid and therefore chosen for accelerated storage study. The various factors selected for accelerated storage were temperature (25 and 45 ûC), relative humidity (22, 44, 66, 85% RH), UV light and dark, type of microencapsulation method (freeze and spray drying). Maximum degradation was found at intermediate humidity level (66%) in vitamin C as well as gallic acid powder. Microcapsules produced were characterized using scanning electron microscopy (SEM) and particle size analysis (PSD). SEM revealed outer morphology and structure of capsules and PSD determined average diameters and modal distribution.