Microencapsulation of borage oil with blends of milk protein, β ‐glucan and maltodextrin through spray drying: physicochemical characteristics and stability of the microcapsules

BACKGROUND Borage oil is a rich commercial source of γ ‐linolenic acid (18:3 n ‐6). However, borage oil is rich in omega‐6 polyunsaturated fatty acids and vulnerable to oxidation. Thus, selecting appropriate wall materials is critical to the encapsulation of borage oil. The present study investigated the influence of wall materials on the physicochemical characteristics and stability of microencapsulated borage oil by spray drying. Blends of milk protein [sodium caseinate (CAS) or whey protein concentrate], β ‐glucan (GLU) and maltodextrin (MD) were used as the wall materials for encapsulating borage oil. RESULTS The microencapsulation of borage oil with different wall materials attained high encapsulation efficiencies. The microencapsulated borage oil prepared with CAS–MD achieved the optimal encapsulation efficiency of 96.62%. The oxidative stabilities of borage oil and microencapsulated borage oil were measured by accelerated storage test at 45 °C and 33% relative humidity for 30 days. The microencapsulated borage oil presented lower peroxide values than those of borage oil, and the microcapsules prepared with CAS–10GLU–MD (consisting of CAS 50 g kg –1 , GLU 100 g kg –1 and MD 475 g kg –1 of microencapsulation) conferred borage oil with high protection against lipid oxidation. CONCLUSION The results of the present study demonstrate that the CAS–GLU–MD blend is appropriate for microencapsulating borage oil. © 2017 Society of Chemical Industry