Extraction And Analysis Of Fatty Acids In Rape Bee Pollen Of The Qinghai-Tibet Plateau

The study using Qinghai-Tibet Plateau rape bee pollen as raw material and the biological enzymatic wall-broken method, focused on extraction of the wall-broken and wall-unbroken Rape bee pollen oil, analysis of its physical-chemical properties and fatty acid composition. It supplied a theoretic basis and optimum processing technics for empoldering and utilizing the rich resources of rape bee pollen of the Qinghai-Tibet Plateau.The results of the study were as followings.1. The process of supercritical carbon dioxide extraction of rape bee pollen oil was practicable, its optimum condition of extraction were as follows: extraction pressure and separation I pressure were 20MPa and 8MPa respectively. Extraction temperature and separation I temperature was 35℃and 55℃respectively. CO₂ flow rate was 15L/h. The grain size of pollen was 20～40 mesh.Extraction time was 2～3h. The extraction rate of wall-broken and wall-unbroken rape bee pollen oil was 9.69% and 9.25% in the optimum condition, respectively.2. The optimum cold soak extraction conditions of fatty Acids in rape bee pollen of the Qinghai-Tibet Plateau with petroleum ether as solvent: extraction time was 36 hours. The ratio of the pollen weight and solvent volume was 1:15(g/mL). The grain size of pollen was greater than 40 mesh. The yield ratios of wall-broken and wall-unbroken rape bee pollen oil were 8.73% and 7.81% in the optimum condition, respectively.3. It was testified by determining the physical-chemical properties of wall-broken and wall-unbroken rape bee pollen oil and then comparing them that supercritical CO₂ extraction was better than petroleum ether cold soak extraction. The content of moisture and volatile, refractive index (n²⁵), acid value, saponification value, peroxide value, iodine value, the burning heat value of wall-broken rape bee pollen oil extracted by Supercritical CO₂ extraction were 0.038%, 1.4933, 10.49mgKOH/g, 148.40, 9.6meq/kg, 149.57, 41.75KJ/g, respectively. The ones of wall-unbroken rape bee pollen oil extracted by Supercritical CO₂ extraction were 0.039%, 1.4916, 13.31mg KOH/g, 101.61, 9.4 meq/kg, 147.23, 42.37KJ/g, respectively.4. The optimum chromatographic conditions were found: oven tempera -ture: temperature-programmed conditions was 110℃(3min)10℃/ min240℃(20min); detector temperature: 250℃; injector temperature: 250℃; split injection; flow ratio of H2:Air: 50:500mL/min. The better reaction conditions of the simplified method of alkaline methylesterefication were as follows: n-hexane-ether (1:2) as extractant, 0.5mol/L sodium methoxide in methanol solution as derived catalyst, reaction time for 10min. The wall-broken and wall-unbroken rape bee pollen oils which were extracted by different methods were analyzed qualitatively and quantitatively and the fatty acids compositions were compared in the optimum chromatographic and methyl -esterefication conditions.