【作者】 熊皓平；

【导师】 何国庆；

【作者基本信息】 浙江大学 ， 食品科学， 2005， 博士

【摘要】 啤酒花(Humunus Lupulus L)是桑科葎草属多年生草质蔓生藤本,雌雄异株,花单性,雌性球穗花序简称酒花。酒花主要用于啤酒酿造工业,赋予啤酒苦味和香味。酒花亦作为一种植物药被国内外广泛使用。国外将其用于治疗消化不良、不安、失眠等;我国药典上记载酒花的乙醇浸膏用于治疗麻风病、肺结核病和细菌性痢疾等症。本研究主要着眼于酒花的综合利用,比较系统地分析了酒花的化学成分并着重对其多酚类化合物、黄酮类化合物、挥发性化学成分等进行了研究。主要结果如下: (1) 采用中药化学中系统预实验法对啤酒花中各种类型的化学成分进行了定性检识。结果表明:酒花中含有黄酮类化合物、多酚类化合物、氨基酸及肽类化合物、有机酸、强心甙、甾体皂甙、还可能含有蒽醌类化合物、生物碱等具有生物活性的化合物。 (2) 对比分析了香型和苦型啤酒花中水浸出物、水溶性糖、水溶性蛋白质、氨基酸总量、多酚类物质总量、黄酮类物质总量、总蛋白、总灰分及α-酸和β-酸含量等。结果表明:苦型酒花除在树脂(α-酸和β-酸)含量上明显高于香型酒花,其它各方面的指标一般较低。水溶性有效成分如水溶性糖、水溶性黄酮、水溶性灰分、游离氨基酸在苦型与香型啤酒花中均有较高的含量。由此说明啤酒花还可作为一种集营养、保健和药用功能为一体的资源加以开发利用。 (3) 从提取溶剂及提取条件等方面对啤酒花多酚提取工艺进行了优化研究。用单因子实验对提取溶剂进行了筛选,结果表明丙酮和水组成的复合体系是理想的提取溶剂。用析因实验对提取条件进行了分析研究,结果表明丙酮浓度、提取温度、提取时间、料液比都对啤酒花多酚提取产生一定的影响,其中丙酮浓度和提取温度的影响最为显著。通过最陡爬坡实验和中心组合设计实验,优化得到最佳的多酚类化合物提取条件为:丙酮浓度为62%,提取温度为47℃,在此条件下啤酒花中多酚的最大提取量为47.44mg·g-1。更多还原

【Abstract】 The hop plant (Humulus lupulus L., Cannabinaceae) is a dioecious twining perennial. The inflorescences (hops or hop cones) are used in the breweries to give beer its characteristics such as flavor and aroma and also as herbs. On abroad, it has been used to aid digestion and as a mild sedative to treat insomnia. Chinese pharmacopoeia recorded that alcoholic extracts of hops have been used clinically in treating numerous forms of leprosy, pulmonary tuberculosis and acute bacterial dysentery. This paper aimed on the comprehensive utilization of hops. Biochemical constituents of hops were studied, especially for the polyphenols, flavonoids and volatile compounds. The main results were as follows:(1) The compounds of hops were tested qualitatively by the methods from Chinese herb chemistry. Results showed that hops contained many bioactivity compounds such as flavonoids, polyphenols, amino acids, polypetide, organic acids, saponins, anthraquinones and alkaloids.(2) Aroma and bitter hops were analyzed for the contents of water extracts, water soluble sugars, water soluble proteins, total amino acids, total polyphenols, total flavonoids , total proteins, total ashes and α -acids, β -acids . The results were as follows: the content of active constituents were higher in aroma hops than in bitter hops except for resins ( α -acids and β -acids); there were high content of water soluble active constituents such as water soluble sugars, flavanoids , ashes and amino acids both in aroma hops and bitter hops . Therefore, hops is a multifunctional resource that can be exploited and utilized in nutrition, health-protection and medicine.(3) Extraction of polyphenols from hops was optimized from extracting solvents and other extracting conditions. The results indicated that the mixture of acetone and water was the best solvent. The results of fractional factorial design experiment showed thatfactors such as acetone concentration, extracting temperature, material and solvent ratio, extracting time had significant effect on the extracting rate. Acetone concentration and extracting temperature were the most significant for extracting rate compared with the other factors. The optimal condition described as that acetone concentration was 62% and extracting temperature was 47 by the steepest accent experiment and the central composite design. Under the optimized condition, the extracting effect of polyphenols from hops was 47.44mg-g~-1.(4) extracting process of flavonoids with organic solvents from hops were optimized. Based on the single factors such as ethanol concentration, material and solvent ratio, extracting temperature and extracting time, orthogonal test was performed and the best combination was conformed for the four factors. Among them, ethanol concentration and extracting temperature had significant effect. Central composite design was further carried out aimed at ethanol concentration and extracting temperature by the central composite design. The results indicated that the optimal conditions were as follows: ethanol concentration was 43% , extracting temperature was 61 , material and solvent ratio was 1 : 25 and extracting time was 90min.Under the optimized condition, the maximal extracting effect of flavonoids from hops was 76.5 mg g~-1.(5) Steam distillation followed by solvent extraction (SDE), direct solvent extraction (DSE) and supercritical fluid (CO2) extraction( SFE) were used for sample preparation in volatile compound analysis in hops (qingdao flower variety). The extracts obtained from three methods were then analyzed by gas chromatography-mass spectrometry (GC - MS). Mass spectra or authentic compounds were used to identify around 70 components in various volatile fractions. 29 chemical constituents were identified in SDE, 29 chemical constituents in DSE, 29 chemical constituents in SFE. Among the volatile compounds obtained from three preparation techniques, there were 8 Compounds in common. Thechemical composition of hop volatiles were hydrocarbon components including aliphatic hydrocarbons and terpenes and oxygenated components such as alcohols, aldehydes, ketones, epoxides and esters. Caryophyllene was the primary component in volatile compounds by SDE methods.(6) Supercritical CO2 (SC- CO2) extraction of effective constituents from hops was tested based on the yield of total solids. The optimal condition described as that extraction temperature was 45 °C and extraction pressure was 20MPa. Under the optimized condition, the yield of total solids was 17.5%. The content of a -acids were 47% and the P -acids were 32% in the total solids.(7) Extraction of flavonoids from waste hops (SC-CO2 extracted hops) using supercritical fluids (ethanol was added as modifier) was investigated. Various temperatures, pressures and concentrations of ethanol and the ratio(w/w) of solvent to material were tested in this study. The results of the single factor and orthogonal experiments showed that at 50 °C, 25MPa, the ratio of solvent to material (50%), ethanol concentration 80% exhibited the maximum extraction yield of flavonoids (8.2 mg.g"1). The results of HPLC-MS analysis of the extracts indicated that some kinds of flavonoids were obtained including Xanthohumol, which was the principal prenylflavonoid in hops.(8) Flavonoids extracted by organic solvent and supercritical fluids were compared based on TLC, HPLC methods. Results showed organic solvent could extract flavanones, flavonol glycosides and prenylflavonoids (xanthohumol was the primary flavonoid ) while supercritical fluids extracted xanthohumol and other prenylflavonoids. The content of xanthohumol in supercritical fluids extracts was 5-6 fold higher than that in organic solvent extracts.(9) The results of HPLC-MS analysis of the supercritical fluids extracts indicated that Isoxanthohumol, Xanthohumol , Dehydrocycloxanthohumol and other two unknown更多还原