酒花有益物质对人体健康的作用

本文简要介绍了人类某些疾病的病理现象与起因,阐明了啤酒生产用酒花内含有如8-含异戊二烯基的4’,5,7-三羟黄烷酮、3,4、,5,7-五羟黄酮、黄腐酚等化学物质,其对预防和治疗某些疾病的机理及对人体健康的积极作用。     

捷克酒花和啤酒中的类黄酮

类黄酮是酒花中的天然物质。由于其显著的生物活性作用,最近已经成为医疗和制药研究的课题。酒花中最重要的类黄酮类物质是黄腐酚（X）,其同类物质中其它代表性物质是去甲黄腐酚（DMX）,异黄腐酚（IX）和8-异戊二烯基黄烷酮（8-PN）。这几种物质已被证实具有抗癌、消炎、雌激素和抗菌的作用。根据分类,类黄酮类属于查耳酮（chalcon）类的多酚,它和树脂、香精油一起组成了蛇麻腺。黄腐酚和蓰草酮能抑制骨骼里钙的流失,目前,8-PN被认为是最有效的雌激素之一。     

黄腐酚的研究现状及啤酒酿造应用前景

黄腐酚是由酒花所分泌产生的,属于异戊烯类黄酮化合物（Xanthohumol,简称Xn）。黄腐酚具有抗癌、预防和治疗糖尿病、抗氧化等多种生理活性。黄腐酚的提取方法主要有：有机溶剂提取、大孔树脂吸附、超声技术提取、高速逆流色谱提取法。饮用啤酒是人体吸收黄腐酚的唯一方法,通过提高啤酒中黄腐酚的含量,可提高人体对黄腐酚的摄入量,可采用在啤酒酿造工艺过程提高啤酒的黄腐酚含量。（孙悟）     

酒花中"黄腐酚"的最新研究进展与开发前景

啤酒花中特有的一种名叫黄腐酚的物质被越来越多的人们所关注,该物质属异戊烯类黄酮化合物(Xantho-humol,简称Xn),经科学家研究表明:黄腐酚具有明显的抗癌等功效.重点介绍了国内外学者对啤酒中所含黄腐酚的最新研究进展,进一步论述了今后对富含黄腐酚等因子的功能性保健啤酒的开发前景.     

富含黄腐酚啤酒的研究与制备

酒花中的黄腐酚具有多种有利于人类的生物活性.文中通过在啤酒中添加高纯度的黄腐酚粉末来提高啤酒中的黄腐酚含量,并对其利用情况及啤酒老化情况进行了研究.最终选用在成品啤酒中添加黄腐酚的工艺,这一添加方法能够保证黄腐酚含量在0.35mg/L～3.5mg/L,并且能够抑制啤酒的老化.     

在啤酒物理稳定性和风味稳定性方面对多酚的讨论

一般来说,啤酒中的多酚、类黄酮（如黄烷-3-醇及它们的聚合物）和原花色素表现出很强的氧化能力,这样就可以阻止啤酒中其它物质的氧化。在其它食品中已经有用黄烷-3-醇和原花色素来改善氧化稳定性,这些抗氧化剂作为潜在的啤酒风味修饰剂和（或）稳定剂已经被大家接受。它们在啤酒中存在二元性,就是多酚与蛋白质结合形成暂时性混浊和永久性混浊。由于多酚-蛋白质交联产生的物理不稳定性物质能够通过树脂（如PVPP）吸附来解决。多酚的去除提高了啤酒货架期内的物理稳定性,但是,去除多酚仍然没有解决啤酒风味稳定性的问题。本文将讨论多酚的来源、含量,以及它们的存在和去除对啤酒物理稳定性和风味稳定性的影响。     

啤酒花中黄腐酚提取和纯化的研究进展

黄腐酚(xanthohumol,简称XN)是啤酒花中主要的异戊二烯基黄酮类物质,目前发现它仅存在于酒花中,其含量约占啤酒花干重的0.1%¹.2%。研究发现黄腐酚具有多种生理功效作用如抗癌、抗氧化、抗艾滋病毒等,因此从啤酒花中提取和纯化黄腐酚的研究备受关注。本文概述了近年来国内外对啤酒花中黄腐酚提取和纯化的研究进展,总结出了黄腐酚的提取纯化流程,重点介绍了多步溶剂法,色谱法,柱层析法,硅藻土吸附法,钠盐沉淀法以及重结晶法分离纯化黄腐酚的工艺,并简要分析其特点,以期为建立高效低廉的黄腐酚提取工业化生产工艺提供理论依据。     

啤酒花中黄腐酚的生理活性作用的研究进展

黄腐酚为酒花中主要的异戊二烯基黄酮类物质。目前被发现仅存在于酒花中,其含量占酒花干重的0.1%～1%,它的结构赋予它多重生理活性。本文综述了近年来对酒花中黄腐酚的提取、分离纯化、结构鉴定、以及抗癌、抗病毒、预防动脉样硬化和糖尿病、雌性激素、抗氧化等生理活性及其作用机理的研究进展。     

氧化·疾病·抗氧化(二十八)

<正>6 食品类黄酮物质抗氧化作用 6．1概述 6．1．1类黄酮分类和结构 类黄酮(flavonoids;亦称黄酮类化合物)广泛存在 于植物组织中,几乎所有植物的所有组织均含有类黄 酮物质。类黄酮基本化学结构骨架为由15个碳以A、 B、c三个环和脂链形式组成黄烷结构及其衍生物,即 以C6-C3-C6结成多酚类化合物,如图1[1]。     

浊点萃取与液相色谱联用检测啤酒中的黄腐酚

本研究建立了一种浊点萃取（CPE）与高效液相色谱紫外检测联用检测啤酒中黄腐酚的方法。选择非离子表面活性剂Triton X-114作为萃取媒介。对影响CPE的参数进行了评价和优化。当Triton X-114（v／v）浓度为2．5％,pH5．0,NaCl浓度15％（w／v）,平衡温度70℃,平衡时间10min时,黄腐酚的萃取率最高。在此条件下,黄腐酚的检测限为0．003mg／L。日内和日间精密度均以相对标准偏差表示,分别为4．6％和6．3％。此方法可成功用于检测各种啤酒样品中的黄腐酚含量。啤酒样品中的黄腐酚含量变化范围为0．052～0．628mg／L,回收率范围为90．7％～101．9％。此种萃取和检测啤酒中黄腐酚的方法效率高、经济环保、成本较低。     

New approach to the production of xanthohumol‐enriched beers

Xanthohumol is a hop polyphenol with proven positive effects on human health. The aim of this work was to use special malts (roasted malt and melanoidin malt) for the preparation of high‐gravity sweet worts with an extremely high xanthohumol content. The solubility of xanthohumol was higher in sweet worts prepared from roasted malts than from Pilsen or melanoidin malts. This sweet wort (xanthohumol ~20 mg L^?1) was used for the preparation of xanthohumol‐rich beer. The importance of melanoidins in xanthohumol solubility was also examined. Isomerization reactions occurring at increased temperatures is one of the main reasons for the loss of xanthohumol in the brewing process and therefore the most appropriate temperature for addition of xanthohumol products to sweet worts was determined. The influence of filtration and stabilization materials (diatomaceous earth, polyamide sorbents and tannic acid) on the concentration of xanthohumol in enriched beer was also examined. Only a small effect of these materials was shown in xanthohumol‐rich dark beers, with the exception of tannic acid, which removed a significant amount of this polyphenol. Copyright © 2013 The Institute of Brewing & Distilling.     

Binding of the hop (Humulus lupulus L.) chalcone xanthohumol to cytosolic proteins in Caco-2 intestinal epithelial cells

Used in the brewing of beer, hops (Humulus lupulus L.) contain the prenylated chalcone xanthohumol, which is under investigation as a cancer chemoprevention agent and as a precursor for the estrogenic flavanones isoxanthohumol and 8-prenylnaringenin. The uptake, transport and accumulation of xanthohumol were studied using the human intestinal epithelial cell line Caco-2 to help understand the poor bioavailability of this chalcone. Studies were carried out using Caco-2 cell monolayers 18-21 days after seeding. The apparent K(m) and V(max) values of xanthohumol accumulation in Caco-2 cells were determined, and the protein binding of xanthohumol in sub-cellular fractions of Caco-2 cells was investigated. Approximately 70% of xanthohumol added to the apical side of Caco-2 cells accumulated inside the cells, while 93% of the intracellular xanthohumol was localized in the cytosol. Xanthohumol accumulation was temperature dependent and saturable with an apparent K(m )value of 26.5 +/- 4.66 muM and an apparent V(max) of 0.215 +/- 0.018 nmol/mg protein/min. Facilitated transport was not responsible for the uptake of xanthohumol, instead, accumulation inside the Caco-2 cells was apparently the result of specific binding to cytosolic proteins. These data suggest that specific binding of xanthohumol to cytosolic proteins in intestinal epithelial cells contributes to the poor oral bioavailability observed previously in vivo.     

American India Pale Ale matrix rich in xanthohumol is potent in suppressing proliferation and elevating apoptosis of human colon cancer cells

American India Pale Ales (IPAs) with and without addition of dark/roasted malts (DRM) and dry hopping (DP) were analysed to determine whether these processes will increase total phenolic content (TP), antioxidant capacity (AA) and the levels of bioactive compounds (xanthohumol, XN and isoxanthohumol, IX). In addition, bioactivity of whole beer matrices, that is, the ‘phytochemical team approach,’ was compared to isolated compounds, the ‘silver bullet approach,’ by measuring antiproliferative and pro‐apoptotic properties using HCT 116 human colon cancer cells. DP and addition of DRM elevated the XN, IX, TP and AA. Dark malts reduced losses in XN and TP due to filtration. Xanthohumol content positively correlated with phenolic content (r = 0.88, P = 0.0002), indicating that the processes which increased xanthohumol content also elevated other bioactive compounds in beer. However, whole extract from IPAs were more potent in suppressing proliferation and elevating apoptosis in colon cancer cells compared with xanthohumol alone.     

Preparative isolation and purification of xanthohumol from hops (Humulus lupulus L.) by high-speed counter-current chromatography

Xanthohumol (XN) and related prenylflavonoids are the main bioactive components of hops (Humulus lupulus L.). The current work is to investigate the use of high-speed counter-current chromatography (HSCCC) in search for high isolation of xanthohumol from hops. A solvent system consisted of n-hexane-ethyl acetate-methanol-water at a volume ratio of 5:5:4:3 was employed. The results demonstrated that the constructed method could be well applied for the isolation of xanthohumol from hops extract. After HSCCC isolation procedure, the purity of xanthohumol was over 95% assayed by HPLC and the yield of extraction was 93.60%. The chemical structure identification of xanthohumol was carried out by UV, ¹H NMR and ¹³C NMR. The present results demonstrated that xanthohumol could be efficiently obtained using a single HSCCC step from H. lupulus L. extract.     

Inhibitors of hyaluronan export from hops prevent osteoarthritic reactions

Scope: An early reaction in osteoarthritic chondrocytes is hyaluronan overproduction followed by proteoglycan loss and collagen degradation. We recently found that hyaluronan is exported by the ATP‐binding cassette transporter multidrug resistance associated protein 5 (MRP5) in competition with cGMP and that some phosphodiesterase 5 inhibitors also inhibited hyaluronan export. These inhibitors also prevented osteoarthritic reactions in cartilage. In an effort to identify the improved inhibitors directed primarily toward MRP5, we analyzed the flavonoids Methods and results: Prenylflavonoids from hop xanthohumol, isoxanthohumol and 8‐prenylnaringenin inhibited MRP5 export at lower concentrations than phosphodiesterase 5 activity. They were analyzed for their effect on IL‐induced osteoarthritic reactions in bovine chondrocytes. Xanthohumol was the superior compound to inhibit hyaluronan export, as well as proteoglycan and collagen loss. It also prevented the shedding of metalloproteases into the culture medium. It directly inhibited MRP5, because it reduced the export of the MRP5 substrate fluorescein immediately and did not influence the hyaluronan synthase activity. Conclusions: Xanthohumol may be a natural compound to prevent hyaluronan overproduction and subsequent reactions in osteoarthritis.     

The Impact of Xanthohumol on a Brewing Yeast's Viability,Vitality and Metabolite Formation

In order to understand how xanthohumol affects a brewing yeast's metabolism, yeast viability and vitality were studied during the production of a xanthohumol enriched beer (10 mg/L xanthohumol) on a 50 L pilot plant scale. The results showed that yeast viability was not significantly affected, but yeast vitality in the xanthohumol enriched brewing trials was slightly better. The content of higher alcohols, esters and organic acids was similar to the control in all the xanthohumol enriched brewing trials, however the content of sulphur dioxide, acetaldehyde and saturated fatty acids was lower in the xanthohumol enriched brewing trials. To the authors' knowledge, this is the first time brewing trials have been carried out showing that xanthohumol has a positive effect on a yeast's physiological condition.     

Does Beer Contain Compounds That Might Interfere with Cholesterol Metabolism?

Elevated blood cholesterol is a problem for many people. Although a significant proportion of this cholesterol arises from metabolism within the body, approximately 50% comes from our diet. Certain plant sterols (phytosterols) are known to inhibit the absorption of this dietary cholesterol by the human body, and there are now several commercially available food products that contain these phytosterols. Barley malt, yeast and hops also contain phytosterols or similar materials that might potentially act as inhibitors of cholesterol uptake but this effect has not been studied. In this work we examine one aspect of the potential for competition between cholesterol and selected beer components when binding to a protein. The method used was ligand docking. This uses computer modeling to examine the binding energies expected when the ligand (e.g. cholesterol or analogue) binds to a protein. The two proteins examined were both natural cholesterol binding proteins. The cholesterol analogues, sitosterol (from barley) and ergosterol (from yeast), had similar binding energies to cholesterol and thus had potential for competition. Other molecules (iso‐xanthohumol, 8‐prenylnaringenin (8PN) and iso‐humulone) had lower binding energies suggesting that they would not compete effectively. Standard beers normally contain very low levels of either sitosterol or ergosterol, although some wheat beers that contain high levels of yeast may contain elevated levels of ergosterol. We have also developed a beer that contains elevated levels of sitosterol by incorporating whole grain material. The level of β‐sitosterol in these beers was still very low and even a whole grain beer would not contain sufficient of the cholesterol analogues to completely inhibit cholesterol uptake or transport.     

The impact of different hop compounds on the growth of selected beer spoilage bacteria in beer

Beer spoiling lactic acid bacteria are a major reason for quality complaints in breweries around the world. Spoilage by a variety of these bacteria can result in haze, sediment, slime, off-flavours and acidity. As these bacteria occur frequently in the brewing environment, using certain hop products that inhibit the growth of these spoilers could be a solution to prevent problems. To investigate the impact of seven different hop compounds (α-acids, iso-α-acids, tetrahydro-iso-α-acids, rho-iso-α-acids, xanthohumol, iso-xanthohumol and humulinones) on the growth of six major beer spoilage bacteria (Lactobacillus brevis. L. backi, L. coryniformis, L. lindneri, L. buchneri, Pediococcus damnosous), two concentrations (10 and 25 mg/L) of each hop substance were added to unhopped beer. The potential growth of the spoilage bacteria was investigated over 56 consecutive days. A comparison of the results shows a strong inhibition of growth of all spoilage bacteria at 25 mg/L of tetrahydro-iso-α-acids closely followed by α-acids as the second most inhibitory substance. The results showed a high resistance of L. brevis to all hop compounds as well as an inhibition of L. coryniformis and L. buchneri at low concentrations of most hop components. In comparison with the control sample, L. lindneri showed increased growth in the presence of some hop compounds (rho-iso-α-acids, xanthohumol, iso-xanthohumol, humulinones). © 2020 The Authors. Journal of the Institute of Brewing published by John Wiley & Sons Ltd on behalf of The Institute of Brewing & Distilling