| At present, major orange estates in our country mainly make use of their pulp, just little of them make use of their skin, as a result, about 15-25% orange skin are abandon as rubbish. Orange skin rotted very quickly and emit a bad smell, which is harmful for people and plants and has become one of the most important pollution source. For this reason, orange skin must be utilized synthetically, it is also the need persistant development for mankind.In this thesis, newly-rising methods as ultrasonic-assisted extraction was researched for extraction of essential oil and hesperidin and macroporous adsorption resins were applied to purification of hesperidin. UV, IR and HPLC were used for analysis of hesperidin. In view of the functionality and market prospects of hesperetin and hesperetin-glucosidase, the acid catalyzed degradation of hesperidin into hesperetin and hesperetin-7-β-D-glucoside were studied, too.First, the effect of various factors on stream distillation of the orange peel were studied in detail, and the optimum extractions schemes were obtained. The content and compositions of orange peel essential oil through different pretreatment methods were studied. The result revealed that add neutral salt and ultrasonic treatment can improve the yield of essential oils. According to experiment, the optimistic combination of ultrasound-assisted extraction of essential oils was: the ratio of water to orange peel 13:1(v/w), ultrasonic processing power of 80 percent, ultrasonic treatment temperature 50℃, ultrasonic processing time 40min. Under this condition the yield of orange peel reached 3.18%, which can also reach 2.77% when adding 3% NaCl neutral salt. So the overall situation into consideration, adding NaCl neutral salt is a cost-effective way, and it had not much impact on the essential oil components by GC-MS analysisSecond, the orange peel residue after extraction essential oils as raw materials, the efficient factors of extraction field of hesperidin by experiment of the single factor and orthogonal experiments were optimized. The optimum conditions of extraction as follows: extraction temperature 40℃, extraction time 30min, pH 10.5, concentration of Ca(OH)2 4g/L and the mass ratio of Ca(OH)2 solution to orange peel residue 30:1. The better reproducibility of several times of the experiment at the optimum extraction condition was revealed. In the process of purification, the macro porous resins as the adsorption was used. Choices of categories of resins, parameters of static and dynamic adsorption was studied, the purification technology of extracting hesperidin was established. The results shown that DA201-B was a good resin for purification of hesperidin. It can be used for preparation of a pure hesperidin, and hesperidin purity was 95.7%.At last, by the single factor test the optimum conditions for hesperidin were hydrolyzed into hesperetin or hesperetin-glucosidase were found respectively. The optimal reaction conditions of acid hydrolysis of hesperidin into hesperetin were concentration of hesperidin 10mg/mL, 5%(V/V) sulfuric acid for 2 hours, reaction temperature 75℃;The optimal reaction conditions of acid hydrolysis of hesperidin into hesperetin-glucosidase were concentration of hesperidin 5mg/mL, 1%(V/V) sulfuric acid for 2 hours, reaction temperature 75℃. At the best conditions, hesperidin acid hydrolysis generation of hesperidin or hesperetin-glucosidase conversion rates reached to 90% or 60%. The reaction products of hesperidin acid hydrolysis were separated through chemical extraction and silica gel column chromatography. The products were identified by HPLC-MS, their purity reached 95%.
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