Preparation of safflower oil microcapsules with gelatin and a novel exopolysaccharide as wall matrix

Abstract

Gelatin and exopolysaccharide (EPS) as wall matrix were investigated for safflower oil microcapsules using complex coacervation. The EPS from Pseudomonas PT-8 was negatively charged, which can react with positive charge of gelatin electrostatic to yield polymer rich phases. Single factor and orthogonal tests were carried out to determine optimal preparation conditions, mixing gelatin (30 g/L) and EPS (30 g/L) with a ratio of 5:4 at pH3.6 firstly, then coating safflower oil with 50 g/L gelatin-EPS, 60 g/L Tween 80, and Span 80 (1:1) as emulsifier and 3‰ transglutaminase (TG) as cross-linking agent, encapsulation efficiency of microcapsules reached 81.27% by cross-linking for 120 min at 20,000 rpm. Free flowing spherical microcapsules were made up of small round particles whose diameters were between 1 and 20 µm. When microcapsule powder dissolved in water, it can be dyed well by safranin due to its good dispersivity. Evaluation of endotoxin suggested that gelatin–EPS was not contaminated by endotoxin. Practical applications Gelatin and a novel microbial polysaccharide as shell matrix are used in safflower oil microcapsules. It can be easily digested by the body and effectively decrease undesirable taste and odor. It also can keep the ability of reducing blood viscosity, improving blood circulation and enhancing memory, due to the special shell.