Research On Aqueous Enzymatic Extraction Of Acer Truncatum Bunge Seed Oil

Acer truncatum Bunge is endemic oil tree in China. Its seeds rich in protein and fats and oil containing rare feature substance- nerve acid, are protein and nerve acid new resource species. The unique advantages of A.truncatum Bunge provide broad development prospects for its development and utilization.This paper carried out preliminary explore on aqueous enzymatic extraction of A.truncatum Bunge seed oil as a starting point to extraction of A.truncatum Bunge seed oil. In order to obtain an aqueous enzymatic extraction optimum conditions on the basis of single factor tests using L9(34) orthogonal test; at the same time, using aqueous enzymatic extraction, Soxhlet extraction, solvent-extraction, ultrasonic-assisted extraction and mechanical compression prepared A.truncatum Bunge seed oil, so as to research different extraction methods on oil yield, physical and chemical properties of oil and fatty acid composition; screening suitable extraction methods by comparing production costs, oil quality and suitability of different methods of A.truncatum seed Bunge.The main research findings are as follows:1. Alkaline protease is the optimal enzyme for aqueous enzymatic extraction of A.truncatum Bunge seed oil.Comparative analysis of the influence of cellulase, pectinase, neutral and alkaline protease extraction of A.truncatum Bunge seed oil on free oil yield. The results show that: the alkaline protease extract the best, before the process is not optimized, its free oil yield the highest, reaching 52.93%.2. Use single factor and orthogonal experiments, in order to obtain the optimum conditions of enzymatic hydrolysis of A.truncatum Bunge oilSelect the alkaline protease as hydrolytic enzyme. Study the influence of different hydrolysis conditions(PH, temperature, time, enzyme dosage, solid-liquid ratio) on oil yield through single factor experimental. Use L9(34) orthogonal experiment to obtain the optimum conditions of aqueous enzymatic extraction of A.truncatum Bunge seed oil: enzyme PH = 10, reaction time 5h, hydrolysis temperature 45 ℃, enzyme dosage 3.5%, solid-liquid ratio 1 : 4. Under this condition, free oil rate is up to 60.51%.3. Compared the influence of aqueous enzymatic extraction, Soxhlet extraction, solvent-extraction, ultrasonic-assisted extraction and mechanical compression on fatty acid composition physical and chemical properties of A.truncatum Bunge oil.Result indicates that the fatty acid composition and content of seed oil by five different methods have little difference, mainly concluding oleic acid, linoleic acid, 11-eicosanoids, erucic acid and nervonic acid in an amount accounting for 22.58%, 31.74%, 7.64%, 20.62% and 7.24%. The content of unsaturated fatty acid is over 90%.The accurate determination of the test sample nerve acid content is 7.24%(higher than that reported 5.8% in the literature).Oil extraction rate of Soxhlet is signally higher than the other four methods. Otherwise, the comprehensive physiochemical index of aqueous enzymatic extraction was superior to the other four methods. The acid value(0.68±0.02) and peroxide value(1.47±0.22) of were the lowest. And the oil of aqueous enzymatic extraction has light color, strong fragrance, and good sensory quality.4. Compared the characteristics of aqueous enzymatic extraction, Soxhlet extraction, solvent-extraction, ultrasonic-assisted extraction and mechanical compression on oil yield, production cost,advantages and disadvantagesof A.truncatum Bunge oil.The oil extraction rate from high to low was Soxhlet extraction(99.96±0.04%), solvent-extraction method(93.03±0.17%), ultrasonic-assisted extraction(90.43±0.31%), mechanical compression method(83.72±0.00%) and aqueous enzymatic extraction(60.44±0.21%). Among the five methods, aqueous enzymatic extraction has low production cost relatively. Comparing the effect of different methodsoil extraction comprehensively, solvent-extraction method, Soxhlet extraction methodand ultrasonic-assisted extraction all have solvent residue. Aqueous enzymatic extraction and mechanical compression method are more suitable for industrial continuous production. But mechanical compression heat damage the nutrition component of seeds. Aqueous enzymatic extraction use mild conditions to protect the nutrients from be destroyed, and has small production cost. In conclusion, aqueous enzymatic extraction can be used as a promising method oil technology of A.truncatum Bunge seed oil.