Study on purification of capsaicinoids from capsicum oleoresin

A combined method of extraction and purification of capsaicinoids from capsicum oleoresin was investigated in this study. The orthogonal experiment was used to optimize the process of extraction in low concentration ethanol,and results showed that the ideal conditions were as follows:ethanol concentration 50%,the ratio of material to solvent 1∶30,extraction temperature 30℃. D201 resin was proved to be suitable to purify capsaicinoids,as the dynamic adsorption/desorption characteristic curves indicated that D201 had strong adsorption ability and a relatively high desorption rate. Further process optimization experiment demonstrated that the optimal conditions of purification by D201 resin with a desorption percentage of 70.72% were as follows:sample concentration 8.45mg/m L,sample amount 4BV,sample rate 1.5BV/h,elution concentration 70%,elution p H4,elution rate 3BV/h and elution amount 20.5BV. After purified by the D201 resin method,sample was crystallized with distilled water as crystallization solvent. And results showed that p H11.32 and temperature20℃ were the best parameters. Finally,the purification efficiency was evaluated by the GC-MS method,indicating that concentration of capsaicinoids in crystals was as 2.11 times as in raw materials,and the relative contents of capsaicin and dihydrocapsaicin were 62.00% and 34.84%,respectively. Therefore the conclusion was obtained that the combination of extraction in low concentration ethanol,purification by ion-exchange resin and recrystallization was feasible,as it achieved the purpose of low cost and high purity.