Composition analysis and microencapsulation of Eucommia ulmoides seed oil

BACKGROUND: Eucommia ulmoides seed oil is a functional health oil with a high content of unsaturated fatty acids. However, excessively high content of unsaturated fatty acids can cause E. ulmoides seed oil to easily spoil. Microencapsulation technology can effectively encapsulate substances, thereby prolonging the spoilage time of oil products. METHODS: In the present study, E. ulmoides seed oil from different manufacturers were analyzed by Agilent 7890B-5977A gas chromatography–mass spectrometry. Encapsulation efficiency, yield rate, and scanning electron microscopy results between microcapsules prepared use different wall materials and different methods (spray drying and complex coagulation) were compared to determine the best preparation process for microcapsules. The Wantong 892 professional oil oxidation stability tester was used to measure the induced oxidation time of the E. ulmoides seed oil and microcapsules. CONCLUSION: E. ulmoides seed oil comprises > 80% unsaturated fatty acids with a high α-linolenic acid content, followed by linoleic acid. The most promising combination was chitosan:gum arabic at 1:8 as the wall material and complex coagulation. The best preparation had a wall material concentration, stirring speed, aggregation pH, and core-to-wall ratio of 2.5%, 500 rpm, 4.2, and 1:4, respectively. Microcapsules prepared under these conditions exhibited higher yield and encapsulation efficiency (94.0% and 73.3%, respectively). The induced oxidation time of the E. ulmoides seed oil and microcapsules were 3.8 h and 13.9 h, respectively, indicating that microencapsulation can increase the oxidation induction time of this oil.