麦芽、酒花多酚对啤酒风味、非生物稳定性的影响

利用12°P 下面发酵啤酒的中试实验,分析经过处理的酒花与麦芽多酚对啤酒质量、风味、非生物稳定性的影响。结果证实在麦汁煮沸过程中麦芽多酚,特别是酒花多酚能够提高新鲜啤酒及储藏啤酒的还原力,降低其羰基化合物含量(TBA 值为代表)。如降低麦芽中多酚含量或采用二氧化碳酒花浸膏生产的啤酒,其 TBA 值会增加。而经过 PVPP 稳定化处理后啤酒倾向于稍低的还原力。麦芽与酒花中的多酚影响新鲜啤酒的“粗糙感”程度,而经过 PVPP 稳定性处理后的啤酒没有观察到明显的影响,强制老化啤酒的老化程度取决于糖化中多酚含量。麦芽多酚与酒花中多酚均对啤酒的风味稳定性有积极影响,PVPP 稳定化处理对啤酒的风味稳定性有积极影响。多酚,特别是酒花多酚能够降低9个月储藏啤酒的风味老化程度,主要表现在前4个月。结果同时也证实了麦芽与酒花中的多酚对啤酒非生物稳定性的负面影响,经过 PVPP 稳定化处理后,在采用不同多酚含量原料所酿造的啤酒之间,以及保质期预测值之间的差异会降低到最低。     

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。     

多酚物质对啤酒非生物稳定性及风味稳定性的影响

本文简要综述了多酚物质对啤酒非生物稳定性和风味稳定性的影响。多酚物质既是啤酒潜在的浑浊物质，同时也是风味物质。多酚是影响啤酒风味的重要因素，多酚—蛋白质生成的络合物作为非生物浑浊的前驱也属于啤酒风味老化的过程范围。因此，有必要控制啤酒酿造过程中的多酚物质含量和组成。     

啤酒多酚物质对啤酒风味稳定性的影响

多酚是啤酒中重要的风味物质，对啤酒质量（非生物稳定性、风味稳定性以及口味）有着重要的影响。作者分析了啤酒中多酚物质的来源以及对啤酒风味稳定性的影响，并利用高效液相色谱测定了啤酒多酚中的单酚物质，研究发现其中的（＋）-儿茶素、（-）-表儿茶素、阿魏酸和槲皮素等单酚具有较高的抗氧化能力。     

多酚物质对啤酒风味稳定性的影响

研究多酚物质对啤酒风味稳定性的影响.结果表明,啤酒的风味稳定性与啤酒的抗氧化性显著相关,啤酒的抗氧化性与多酚含量显著相关;不同的单酚抗氧化能力差异较大;抗氧化性随单酚含量的增加而增加;酒体中的单酚抗氧化性随酒体保存的时间延长而减小;不同来源的多酚抗氧化性不同;不同辅料生产的啤酒抗氧化能力不同.多酚含量和组成影响啤酒的风味稳定性,多酚适量存在可提高啤酒风味稳定性.     

影响啤酒苦味因素的探讨

啤酒苦味主要来源于酒花。在啤酒生产过程中由于酒花质量差，添加方法不当，麦汁及啤酒风味物质组成不合理，酵母自溶等原因，都可能使啤酒苦味发生变化。如何保持啤酒酒体协调，风味稳定，尽可能减少啤酒不正常苦味，则是本文所要探讨的问题。l多酚物质对啤酒苦味的影响酿造啤酒所用的大麦、酒花中都含有多酚物质多元酚及其衍生物。造成啤酒苦味的多酚物质主要存在于大麦皮壳及糊份层中。多酚物质在大麦中约为0．1～0．3％，酒花中含量为4～14％，其中60％为花色音。多酚物质对啤酒风味起着重要作用。多酚物质在多酚氧化酶和过氧化氢酶的作…     

影响啤酒风味物质简述

影响啤酒风味的物质可分为：醇、酯、羰基化合物、酸、含硫化合物、胺（挥发性）和酚基化合物等，而来源于产生于这种物质主要是：麦芽、谷物辅料、酒花、酵母的发酵等，这里主要阐述由于发酵作用而产生的影响啤酒风味的形成机理，当然双乙酸也是影响啤酒风味的重要原因之一。     

酒花香味的水溶性前驱物影响碑酒风味

据报导,美国米勒公司的研究人员对酒花香味的水溶性前驱物以及它在啤酒风味中的作用进行了研究在酒花二氧化碳液态萃取时,酒花的固形物中含有30%的水溶性化合物。无机物、含氮物质(蛋白质)、多酚、碳水化合物等都会集聚在这部分水溶性化合物中。通过精细的分析,研究人员证实,这些化合物中的某些成分可在啤酒风味中发生作用,直接影响到啤酒的风味特征。因此,他们将尽可能地深入研究酒花与啤酒风味之间的关系。     

影响啤酒苦味因素的探讨

苦味是啤酒区别于其它酒类的重要特性之一．主要来源于酒花．在啤酒生产过程中由于酒花质量差，添加方法不当，麦汁及啤酒风味物质组成不合理，酵母自溶等原因，都可能使啤酒苦味发生变化．如何保持啤酒酒体协调，风味稳定，尽可能减少啤酒不正常苦味，是本文所要探讨的问题．1．多酚物质对啤酒苦味的影响酿造啤酒用大麦、酒花中都含有多酚物质，多元酚及其衍生物．造成啤酒苦味的多酚物质主要存在于大麦皮壳及糊粉层中。多酚物质在大麦中含量约为0．1～0．3％，酒花中含量为4～14％，其中60％为花色音。多酚物质对啤酒风味起若重要作用。多…     

啤酒风味物质研究进展

近年来,啤酒产业不断发展,人们对啤酒的风味要求不断提高。啤酒的风味是衡量其品质的关键指标,种类繁多的挥发性和非挥发性成分是啤酒具有特有风味的主要原因。啤酒因原料、酵母、发酵工艺、贮藏等条件的不同,成品风味有很大差异。本文综述了啤酒风味物质的组成,从啤酒的香气成分、苦味成分和不良风味3个方面阐述风味物质的来源。啤酒花中萜烯类化合物、酵母发酵产生的酯和高级醇是啤酒重要的香气来源。麦汁、干加酒花、添加功能性原料、无醇的新型啤酒等新技术的应用也对啤酒的香气有一定协同作用。啤酒花中的α-酸、β-酸及多酚物质赋予啤酒特有的苦味。酒花添加量、添加时间,啤酒过滤和灭菌对啤酒苦味具有一定的影响。啤酒的酿造过程中产生的双乙酰、含硫化合物和贮藏期间产生的老化味会使啤酒产生不良风味。超高压技术对降低啤酒不良风味有一定作用。通过本综述,有望推动改进啤酒生产配方、提升啤酒风味、改进工艺和贮藏条件等方面研究的深入进行。     

Beef broth flavour: study of flavour development

Of the range of preparation conditions studied here, the beef broths with the most favourable sensory characteristics (P ≤ 0.05) were those manufactured with minced meat in a 7.5 g l⁻¹ NaCl solution in proportions of 1:2 (w/v), heated at 85 °C for 60 min (the beef broth flavour was clean, clear, without any off‐flavour). Our data indicate the importance of accurately determining the heat treatment, since intermediate treatments yielded beef broths of good quality, whereas less intense treatments produced broths with raw meat and bloody and metallic flavours, and intensely heated broths had a warmed‐over or sour and astringent flavour. At higher temperatures the cooking time required to obtain a good‐quality broth decreased. From the analysis of variance of the sensorial data, temperature plays a more important role than cooking time in the development of the sensory properties of beef broths. © 2000 Society of Chemical Industry     

The effect of flavour modulators on chewing gum flavour duration

This study investigated the impact of flavour modulators on dynamic flavour perception, salivation and chewing behaviour of chewing gum. Thirty-nine participants chewed gum for 15 min while assessing flavour intensity, chewing patterns and saliva flow rate. Four flavour modulators (Cooling, Tingling, Salivating and Warming) were added to a citrus-flavoured gum and compared with a control gum, citrus flavour only. Flavour modulators increased flavour duration as measured by flavour intensity half-time; the time needed to reduce the flavour intensity by half. The ‘Salivation’ modulator had the smallest effect and ‘Warming’ had the largest effect on flavour duration. Salivary flow rate was significantly increased by the flavour modulators and was highly correlated with the flavour duration. Chewing behaviour was not affected by the modulators. We conclude that the interaction between the citrus flavour, saliva and flavour modulators (Intensates® flavours) increased the perceived flavour duration during chewing by up to 86% compared with Control.     

Stereoisomeric flavour compounds

The enantiomeric distribution of 3-mercaptohexanol (1) and 3-methylthiohexanol (2) in yellow and purple passion fruits was determined by capillary gas chromatography (GC) using two different chiral stationary phases and a flame photometric detector. The results were confirmed by enantioselective capillary GC combined with mass spectrometric detection.1 shows an enrichment of the (S)-enantiomer, but the enantiomeric purity varies in a wide range. Irrespective from the enantiomeric distribution of1, 2 was detected with high enantiomeric purity in favour of the (S)-enantiomer. Using the method presented the addition of synthetic, racemic2 is easily detected.     

Stereo-isomeric flavour compounds

2-Alkyl-substituted 4-methyl(4,5-dimethyl)-1,3-dioxolanes are synthesized by the cyclization of propan-1,2-diol and butan-2,3-diol with “Strecker aldehydes” as the carbonyl compounds. The stereo-isomeric 1,3-dioxolanes are separated by micro-preparative multidimensional gas chromatography and their structures assigned using¹H-NMR spectroscopy (300 MHz). These references with definite stereochemistry are required for reliable interpretation of their chromatographic behaviour with Ni(II)-bis-[3-heptafluorobutanoyl-(1R,2S)-pinanoate] and Ni(II)-bis-[heptafluorobutanoyl]-(1R)-camphorate] respectively, as the chiral stationary phases.     

Stereoisomeric flavour substances

Summary Racemic mixtures of 5-hydroxyalkanoic acid-isopropylesters were converted into the diastereomers (5R), (5S)-[(R)-2-phenylpropionyloxy]-alkanoic acid-isopropylesters (11 · 11'-16 · 16) and (5R),(5S)-[(S)-Tetrahydro-5-oxo-furancarbonyloxy]-alkanoic acid-isopropylesters (22 · 22-26 · 26), respectively. These were then separated by liquid chromatography. The absolute configurations of11-16 and11–16 were derived from¹H-NMR studies and the optical activity of the lactones,1-6 and1–6 could be estimated after hydrolysis and recyclization. The optically pure stereoisomers of2-6, 2–6 have been obtained from22-26 and22–26 on a preparative scale. The sensoric characteristics of the optically pure -lactones are given.

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Stereoisomere AromastoffeXXIII. S-Lacton Aromakomponenten-Struktur und Eigenschaften der Enantiomeren

Zusammenfassung Racemische 5-Hydroxyalkansäu-re-isopropylester werden in diastereomere (5R),(5S) [(R)-2-Phenylpropionyloxy]-alkansäure-isopropyl-ester (11 · 11-16 · 16) bzw. in diastereomere (5R),(5S)[(S)-Tetrahydro-5-oxo-2-furancarbonyloxy]-alkansäsure-isopropylester (22 · 22-26 · 26) überführt und flüssigchromatographisch getrennt. Die absoluten Konfigurationen werden aus den¹H-NMR Daten abgeleitet und nach Hydrolyse und Recyclisierung der Drehsinn der optisch aktiven -Lactone1-16 und1–6 bestimmt. Aus den optisch reinen Stereoisomeren22-26 und22–26 werden die optisch reinen -Lactone2-6 und2-6 im präparativen Maßstab erhalten. Die sensorischen Eigenschaften der optisch reinen -Lactone werden mitgeteilt.

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Dedicated to Professor Dr. C. H. Brieskorn, Würzburg, FRG, on the occasion of his 75th birthday     

Physical chemistry of flavour

The sensation of flavour occurs when certain flavour-active molecules are released from food and are transported to stimulate sensors in the mouth and nose. The human brain integrates all the signals from the sensors and produces an overall flavour perception. The way in which flavour molecules are released from food during eating, and the manner in which they are retained during processing and storage, are all governed by various aspects of physical chemistry. This review describes some of the basic principles of partition, a key parameter in the physical chemistry of flavour. An overview of the theory and measurement of partition is given, along with some applications to model and real food systems.     

The flavour components of plum

Summary Gas chromatographic and gas chromatographic-mass spectrometric examination of the aroma components of canned plums obtained by both atmospheric distillation and headspace techniques showed them to be both quantitatively and qualitatively different from those of fresh plums. 25 components were identified, the major ones being 3-hydroxy-butan-2-one, benzaldehyde, nonanal and 2-furaldehyde. Benzaldehyde and nonanal together with benzyl acetate are believed to make a significant contribution to the aroma of canned plums.

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Die Geschmackskomponenten der Pflaume:Eine Untersuchung über die flüchtigen Inhaltsstoffe der Pflaumen in Dosen

Zusammenfassung Gaschromatographische und gaschromatographische-massenspektrometrische Analysen zeigten, daß die Aromastoffe der dosenkonservier ten Pflaumen, sowohl durch atmosphärische Destillation als auch nach der Kopfraum-Technik erhalten, quantitativ sowie qualitativ verschieden von denen der frischen Pflaumen sind. Es wurden 25 Komponenten identifiziert, darunter als Hauptbestandteile 3-Hydroxy-butan-2-on, Benzaldehyd, Nonanal und 2-Furfurol. Benzaldehyd und Nonanal zusammen mit Benzylacetat stellen einen bedeutsamen Beitrag zum Aroma dosenkonservierter Pflaumen dar.

     

Yeast interactions and wine flavour

Wine is the product of complex interactions between fungi, yeasts and bacteria that commence in the vineyard and continue throughout the fermentation process until packaging. Although grape cultivar and cultivation provide the foundations of wine flavour, microorganisms, especially yeasts, impact on the subtlety and individuality of the flavour response. Consequently, it is important to identify and understand the ecological interactions that occur between the different microbial groups, species and strains. These interactions encompass yeast-yeast, yeast-filamentous fungi and yeast-bacteria responses. The surface of healthy grapes has a predominance of Aureobasidium pullulans, Metschnikowia, Hanseniaspora (Kloeckera), Cryptococcus and Rhodotorula species depending on stage of maturity. This microflora moderates the growth of spoilage and mycotoxigenic fungi on grapes, the species and strains of yeasts that contribute to alcoholic fermentation, and the bacteria that contribute to malolactic fermentation. Damaged grapes have increased populations of lactic and acetic acid bacteria that impact on yeasts during alcoholic fermentation. Alcoholic fermentation is characterised by the successional growth of various yeast species and strains, where yeast-yeast interactions determine the ecology. Through yeast-bacterial interactions, this ecology can determine progression of the malolactic fermentation, and potential growth of spoilage bacteria in the final product. The mechanisms by which one species/strain impacts on another in grape-wine ecosystems include: production of lytic enzymes, ethanol, sulphur dioxide and killer toxin/bacteriocin like peptides; nutrient depletion including removal of oxygen, and production of carbon dioxide; and release of cell autolytic components. Cell-cell communication through quorum sensing molecules needs investigation.     

浅谈酱油风味

从酱油风味的概念入手，叙述酱油风味形成的条件及机理，并提出改善酱油风味的建议。