Emulsification and microencapsulation properties of sodium caseinate/carbohydrate blends

Emulsions of soya oil in mixed solutions of sodium caseinate (Na Cas) and carbohydrates of various dextrose equivalence (DE) were prepared and subsequently spray-dried to yield powders with 20-75% oil. Effects of DE (0-50), core/wall and Na Cas/carbohydrate ratios and total solids concentration on emulsion oil droplet size and microencapsulation efficiency (ME) and redispersion behaviour of spray-dried emulsions were examined. Emulsion oil droplet size was not affected by DE in most cases but was dependent on Na Cas/carbohydrate and core/wall ratio. ME of dried emulsions increased with increasing DE and decreased at Na Cas/carbohydrate ratios < I : 19 and at high core/wall ratios. ME was negatively correlated with particle size of redispersed dried emulsions (R = -0.81). A wall material combining mixtures of Na Cas and DE 28 at ratios greater than or equal to I : 19, offered the best encapsulating properties. (C) 2001 Published by Elsevier Science Ltd.