Study on the encapsulation technique of high purity γ-linolenic acid, part 1 ——saponification reaction and saponification value Study on the encapsulation technique of high purity γ-linolen ic acid, part 1 -single factor, and two-factor tests for encapsulation process Prepared evening primrose oil microspheres by spay drying Separation of gamma linolenic acid from evening primrose oil with ureainclusion—orthogonal experiment of optimizing technological parameters and observation of urea inclusion compoundⅠ