Abstract: A new type of yacon (Smallanthus sonchifolius) juice microencapsulated oil powder was prepared by spray drying using evening primrose oil as the core material and Yacon juice as the wall material. The results showed that the optimal formula was 30% evening primrose oil, 1.7% polyglycerol ester, 14% self-made octenyl succinic anhydride-modified maize starch, 0.5% propylene glycol alginate (PGA), 0.5% xanthan gum, 0.5% sodium carboxymethyl cellulose (CMC), 25% yacon juice (dry matter basis), and 27.8% maltodextrin. The oil content on the surface of microencapsulated evening primrose oil powder was 1.20% and the embedding efficiency of evening primrose oil 96.0%. Meanwhile, microencapsulated evening primrose oil powder was rich in fructo-oligosaccharide (FOS). After dissolved, microencapsulated evening primrose oil powder became an emulsion with good stability and yacon flavor.

Key words: yacon, juice, primrose oil, powder oil, microencapsulation