Study On Extraction And Refining Technology Of Hesperidine From Citrus Peel

Hesperidin, as an important natural flavonoid, is widely used in chemical, medicine and food area. But now, various kinds of extraction methods in the literatures such as hot water extraction, alcohol solvent extraction method, ultrasonic extraction, microwave extraction method have a lot of shortcomings. Therefore, it is necessary to develop a highly efficient extraction and refining process for improving product yield and purity and reducing the product cost.Hesperidin was extracted from mandarin and orange peel by alkali leaching and acidic precipitation method. The optimum process conditions were studied with the amount of base, ratio of feed and liquid, time of extraction, pH value and temperature. The best process conditions for mandarin was that extraction proceed at30℃,25g mandarin peel with50g distilled water,1.75g calcium hydroxide was used and the time for extraction was0.5h at pH=3, the extraction yield for crude product was4.2%. The best process conditions for orange was that extraction proceed at30℃,25g orange peel with1000g distilled water and1.75g calcium hydroxide was used and the time for extraction was0.5h at pH=3, the extraction yield for crude product was2.1%.The purification of crude hesperidin was studied in this paper. The optimum purification process was researched with solvent, base, pH value and the ratio of feed and liquid. The best process conditions for purification of crude hesperidin from mandarin were that0.5g crude hesperidin was added into30mL methanol, and the pH value was adjusted to9with NaOH and the purification time was0.5h at30℃. After that, the pH value of the solution was adjusted to4and the yield was56%and the purity was up to82%. The best process conditions for for purification of crude hesperidin from orange was that0.5g crude hesperidin was added into30mL methanol, and the pH value was adjusted to11with NaOH and the purification time was0.5h at30℃. After that, the pH value of the solution was adjusted to5with0.1M HCl and the yield of purification was74%and the purity was up to80.3%.The refining product structure had been charactered by FT-IR spectra, ultraviolet spectrum, and high performance liquid chromatography.It had shown that the structure of the refining product is correct, and it is the hesperidin.