| Polyphenols is the secondary metabolites in plant. Some polyphenols which have activity of antioxidant and hypolipidemic have broad application prospects to prevent atherosclerosis. More and more studies showed that polyphenols have varieties of biological activities and positive impacts on human health. The main active ingredients of hops for brewing beer are hop resins and hop oils. The technology of supercritical CO2 extraction can extract these components effectively. Hop condensate, preparated by the technology of supercritical CO2 extraction which consistently better guarantee quality and significantly longer stability than those of natural hops, and permit a higher utilization rate of hop compounds. But the polyphenols rich in hops can not be extracted by supercritical CO2; because they have certain polarity. Most of polyphenols in hops are retained in the supercritical CO2 extraction residue. The extraction residue is not being used effectively. Therefore, we studied the extraction separation and purification method of polyphenols from waste hops. In this study, as the supercritical CO2 extraction residue the research object, anti-oxidation and hypolipidemic of the total polyphenols from waste hops were studied for the future medicine of preventing atherosclerosis and providing a theoretical basis for its development and reuse of waste hops.The main content and the results are as follows:(1) This experiment studied the supercritical CO2 fluid extraction (SFE-CO2) technology of waste hops preparation, the condition was CO2 flow rate was 25 L/h, it's extracting temperature was 50℃,separation pressure was 10MPa, separation temperature was 60℃,and extraction time was 1.5 h.In this condition,94% polyphenols in hops were retained in the supercritical CO2 extraction residue and only 4% in hop condensate.(2) This paper compared the results of ultrasonic extraction,heat circumfluence extraction, constant temperature oscillation extraction, the amount of extraction from large to small relations as:ultrasonic> thermal circumfluence> constant temperature oscillation, so eventually the ultrasonic aided extraction, so finally chose ultrasonic wave assisted extraction. The optimal extraction condition of polyphenols was Solid-Liquid Ratio was 1:20, extracting temperature was 60℃, extractant was 50% ethanol, extraction time was 30 minutes and extracting twice. In this condition,the amount of extraction of hops polyphenols achieved 43.4 mg/g in waste hops.(3) The static adsorption and desorption were used in selecting the type of macroporous adsorption resin (SP850,HP20,HP2MGL) to purifying hops polyphenols. Eventually, it screened SP850 resin (adsorption ratio and resolution was 87.4 mg/g and 78.4 mg/g, respectively) to apply on hops polyphenols purification. The purification condition of SP850 macroporous resin was the feed concentration of sample was 7.3 mg/mL, the volume of sample was 6 BV, it's adsorption rate was 3 BV/h, and eluted with 60% ethanol from SP850 resin, it's velocity was 2 BV/h, the volume was 4 BV, eluted with water to remove impurities, it's velocity was 2 BV/h and volume was 5 BV. In this condition, contents of the total polyphenols was 75.1%.(4) We detected 75% total polyphenols and 55.18% procyanidins in the polyphenols purification and identified ten components, and the major components are rutin and Hyperoside, with the contents of 82.10 mg/g and 78.10 mg/g, and the contents in total polyphenols 10.89% and 10.36%, respectively. Following catechin and astragalin content is high, the contents in total polyphenols 4.96% and 3.51%,the content of other components are very low.(5) Through the hyperlipidemia mice test in vivo concluded that polyphenols in hop could reduced hyperlipidemia mice plasma TC,TG and LDL-C levels, increased HDL-C levels, and reduced TC and TG levels in liver, which showed that it has biological effection of hyperlipidemia The hop polyphenols can improve the activity of the mouse blood cells SOD,whole blood GSH-Px, blood serum CAT,liver SOD, liver GSH-Px, liver CAT and reduce the contents of blood serum and liver MDA, which showed that it has biological activity of antioxidantion and it is a new source to get drugs of preventing atherosclerosis. |
