基于电子鼻和气相色谱-质谱联用技术分析不同品种苹果酒香气物质

以陕西白水的嘎啦、红星、瑞雪、瑞阳4种苹果为原料酿造苹果酒,采用电子鼻（E-nose）和顶空固相微萃取-气相色谱-质谱联用（HS-SPME-GC-MS）技术分析4种苹果酒香气物质。结果表明,电子鼻检测到4种苹果酒的香气特性差异较大,利用主成分分析（PCA）法和线性判别分析（LDA）法可完全将其区分开;HS-SPME-GC-MS共检测出76种挥发性香气物质,包括醇类11种、酯类43种、醛类7种、酮类3种、酸类7种、萜烯和其他5种;嘎啦、红星、瑞雪、瑞阳苹果酒分别有66种、43种、45种、47种香气物质,总含量分别为7.17 mg/L、7.08 mg/L、6.64 mg/L、7.56 mg/L,且4种酒共有特征香气物质包括：丁酸乙酯、2-甲基丁酸乙酯、乙酸异戊酯、己酸乙酯、辛酸乙酯、癸酸乙酯。电子鼻结合HS-SPME-GC-MS分析可以成功区分不同品种苹果酿造苹果酒的挥发性成分。     

混菌发酵对‘123’苹果酒香气成分的影响

选用葡萄汁有孢汉逊酵母（Hanseniaspora uvarum）与卡利比克迈耶氏酵母（Meyerozyma caribbica）两种非酿酒酵母,按照不同菌株与接种顺序,分别与酿酒酵母（Saccharomyces cerevisiae）混合发酵（1∶1）制备‘123’苹果酒;以单菌发酵为对照,分析发酵过程中酵母生长变化、理化指标、香气成分和感官品质。结果表明,非酿酒酵母数量在顺序接种发酵过程中稳定在106～107数量级;与单菌对照组相比,混菌发酵组乙醇含量降低了0.49%vol～1.6%vol,挥发酸增加了0.02～0.11 g/L。先接种有孢汉逊酵母48 h后再接种酿酒酵母混菌发酵酒样（HS2）发酵结束时酒样挥发性香气物质总量达到最高（9 302.20μg/L）,其中品种香气较单菌发酵增加了63.4%。2,4-二叔丁基苯酚、正辛醇、乙酸异戊酯、己酸乙酯、辛酸乙酯等为HS2酒样的特征香气物质（OAV>1）,在感官上为‘123’苹果酒增加了果香与花香。因此,先接种有孢汉逊酵母再接种酿酒酵母（1∶1）混菌发酵方案适合应用于‘123’苹果酒酿造。     

“减硫法”酿造对苹果酒中挥发性香气成分的影响

采用顶空固相微萃取-气相色谱-质谱联用法（HS-SPME-GC-MS）对“减硫法”和常规法酿造的小国光苹果酒中的挥发性香气 物质进行测定和分析。 结果表明,两种苹果酒中共检测到挥发性香气物质66种,包括15种醇类、30种酯类、7种脂肪酸类、3种酮类、6种 芳香族类、3种萜烯类和2种其他类。与常规法酿造相比,“减硫法”酿造有助于提升苹果酒中酯类物质,特别是具有丰富果香和花香的 乙基酯类物质的含量,增加了36.11 mg/L;同时还能有效降低苹果酒中的高级醇,特别是具有酒精味和溶剂味的异戊醇的含量,降低 了14.68 mg/L;但也会降低苹果酒中脂肪族类、芳香族类和萜烯类物质的含量（分别为9.98 mg/L,10.77 mg/L,1.54 mg/L）,造成苹果酒 中乳酪香、烘烤香和部分花香的减弱。 适当减少二氧化硫的使用量可在一定程度上改善苹果酒的香气品质。     

正丁醇处理对‘粉红女士’苹果贮藏期间挥发性物质的影响

苹果的香气成分是构成苹果品质的重要因素,香气主要由挥发性物质描述,因此研究苹果挥发性物质具有重要意义。本试验为探究正丁醇处理对‘粉红女士’苹果挥发性物质的影响,以‘粉红女士’苹果为试材,分别用10和25 μL·L?1正丁醇溶液处理,采用有机溶剂萃取法提取挥发性物质,并利用气相色谱质谱联用仪（GC-MS）对其香气成分进行分析。结果表明:在各处理的整个贮藏期‘粉红女士’苹果果实中共检测出25种挥发性物质,包括酯类、醇类、醛类、酸类和萜烯类,以酯类和醛类物质为主;随着贮藏时间的延长,果实的挥发性物质种类减少,乙酸戊酯、丁酸丁酯、2-甲基-丙酸己酯、法尼醇和2-甲基丁酸未被检测到;25 μL·L?1处理组果实的乙酸戊酯、丁酸丁酯、2-甲基-丙酸己酯、法尼醇和2-甲基丁酸含量在贮藏第7 d和第14 d时明显高于对照组和10 μL·L?1处理组,此浓度正丁醇的添加能够促进贮藏前期果实挥发性酯类物质的产生。通过气味活性值分析发现有气味活性的化合物有19种,其中呈果香味的乙酸己酯是‘粉红女士’苹果主要的呈香物质。本研究表明,正丁醇的添加影响了‘粉红女士’苹果果实中酯类物质的产生,且25 μL·L?1处理组效果最显著,同时该研究可为‘粉红女士’苹果挥发性物质的研究提供理论基础。     

葡萄汁有孢汉逊酵母与酿酒酵母混合发酵对嘎啦苹果酒品质的影响

以嘎啦苹果为实验材料,探究了葡萄汁有孢汉逊酵母（Hanseniaspora uvarum）（云-268）与酿酒酵母（Saccharomyces cerevisiae）混合发酵对苹果酒基本理化指标、酚类物质、香气物质及感官特性的影响。结果表明,相比于酿酒酵母单一发酵,混合发酵苹果酒中乙醇和总酸含量显著降低（P<0.05）,降幅分别为8.72%和9.02%,总酚含量显著增加（P<0.05）,增幅为23.01%;其香气物质种类（36种）明显多于单一发酵苹果酒（31种）,其中香气活度值OAV>1的物质有12种;进一步分析发现,混合发酵苹果酒中具果香味的乙酸酯类和花香味的萜烯类等物质含量显著提高（P<0.05）,具酸腐味的脂肪酸类物质含量显著降低（P<0.05）,对具青草味的C6醇类物质含量影响不大;感官品评结果表明混合发酵苹果酒酒液澄清、禾杆黄色、入口酸度中等偏低,甜度适中,口感平衡,具有丰富的果香味。因此,葡萄汁有孢汉逊酵母与酿酒酵母混合发酵（1:1）能够明显提高苹果酒的品质,增加其发酵香,为低醇果香味的苹果酒酿造奠定了一定的研究基础。     

苹果新品种‘瑞雪’、‘瑞香红’及其亲本香气物质差异分析

为明确苹果新品种果实香气成分特点,进一步推广新品种。本研究以新选育出的‘瑞雪’、‘瑞香红’苹果及其亲本‘粉红女士’和‘富士’为实验材料,采用顶空固相微萃取法结合气相色谱质谱联用技术检测4种苹果果实香气物质成分,并研究并分析香气物质种类、含量以及特征香气值的差异性。结果表明:4个苹果品种共检测分析出58种香气成分和16种特征香气物质,其中‘瑞雪’含有3种特有香气成分和10种特征香气物质,‘瑞香红’含有7种特有香气成分和13种特征香气物质。4个苹果品种中,新品种‘瑞香红’具有最多的香气成分种类和最高的香气物质含量。‘瑞雪’、‘瑞香红’两个新品种的特征香气物质的种类数均高于其亲本,‘瑞雪’中的（Z）-2-庚烯醛、己醛和壬醛等醛类特征香气物质在4个品种中含量较高,‘瑞香红’中的乙酸己酯、丙酸己酯、丁酸己酯和2-甲基丁酸己酯等酯类特征香气物质含量最高,这些特征香气物质的差异可能是两个新品种具有独特香气的重要原因。     

微生物与发酵工艺对苹果酒品质影响的研究概述

苹果酒是世界第二大发酵果酒品类。中国作为世界第一大苹果生产国,苹果酒市场潜力巨大,但苹果原料、发酵菌种和生产工艺的标准体系还有待完善。文章综述了苹果品种、成熟度、发酵菌种和发酵工艺对苹果酒品质的影响。挥发性香气物质和非挥发性的糖、有机酸和多酚类物质是苹果酒的主要成分。酯类是苹果酒的主要香气成分,多酚对苹果酒的口感起重要作用。苹果原料、酵母菌种、发酵温度等对苹果酒的品质有显著影响。通过酿酒苹果品种的筛选、非酿酒酵母属酵母的开发和多菌种的混合发酵来提升苹果酒的风味多样性,将是苹果酒的研究热点。     

不同酵母对威士忌品质的影响

以大麦芽为原料,选用3种不同酵母（ACBC-1、ACBC-2及ACBC-3）发酵制备威士忌。比较不同酵母的发酵性能、理化指标及出酒率,采用气相色谱（GC）法测定威士忌挥发性香气物质,通过气味活度值（OAV）确定关键香气化合物并进行主成分分析（PCA）,并对制备的酒样进行感官评价。结果表明,酵母ACBC-1发酵性能最好,其发酵液的理化指标良好（总酸3.73 g/L,残糖3.00 g/100 g,酒精度6.42%vol,pH 4.1）,出酒率最高（70.78 mL/kg）。3个酒样共检出24种风味物质,其中醇类化合物为主,占77%～98%;OAV＞1的酯类化合物种类最多（5种）,其中乙酸苯乙酯、乙酸异戊酯及乙酸苯乙酯是关键香气物质,对酒样的香气贡献最大。3种酵母制备威士忌酒样感官评分顺序ACBC-1（90分）＞ACBC-2（76分）＞ACBC-3（71分）。结果表明,酵母ACBC-1适合酿造威士忌。     

1-MCP结合纳他霉素对富士苹果贮后货架品质和芳香物质的影响

以富士苹果为实验试材,研究1-甲基环丙烯（1-methylcyclopropene,1-MCP）（1 μL/L）结合不同质量浓度纳他霉素（0、400、800、1 200 mg/L）对贮后常温货架期间果实品质的影响及其货架期芳香物质的变化。结果表明,与对照组相比,1-MCP结合纳他霉素处理富士苹果后能更好地减缓果实质量损失率的增加和硬度的下降,保持果实VC、可滴定酸和可溶性固形物含量,其中800 mg/L纳他霉素处理保鲜效果优于其他处理;主要特征香气成分有己醛、反式-2-己烯醛、乙酸-2-甲基丁酯、乙酸己酯和正己醇等,不同处理富士苹果芳香物质种类存在一定差异性,其组成及相对含量在货架期内发生相应变化,4 种处理醇类物质相对含量均减少,对照组与1 200 mg/L纳他霉素组酯类、醛类物质以及总芳香物质相对含量增加,400 mg/L纳他霉素组酯类物质相对含量增加,800 mg/L纳他霉素组酯类物质相对含量减少,总芳香物质相对含量略有减少,其变化规律与理化指标分析结果相吻合。     

柠檬形克勒克酵母和酿酒酵母混合发酵对脐橙全果酒风味物质的影响

探究非酿酒酵母和酿酒酵母在混合培养时的接种顺序对酵母生长及风味物质的影响。采用柠檬形克勒克酵母和酿酒酵母混合同时、混合顺序,以及其单独发酵的方式进行脐橙全果酒的酿造,通过顶空固相微萃取-气质联用技术及主成分分析法对酒中的风味物质进行分析和比较。4种脐橙全果酒中共检测出38种香气成分,包括醇类9种、酯类11种、萜烯类9种、酮和酚5种,其中萜烯类所占比例最大(30%以上)。混合顺序发酵酒中风味物质种类和含量均最高(37种,21. 957 mg/L),混合同时发酵酒次之(35种,20. 704 mg/L),且混合发酵酒中酯类和萜烯类显著高于单独发酵。采用混合顺序发酵的方式,使风味物质得到了改善,所得脐橙全果酒香气更浓郁,为酿造品质更佳的脐橙全果酒提供理论依据。     

Apple Aminoacid Profile and Yeast Strains in the Formation of Fusel Alcohols and Esters in Cider Production

The amino acid profile in dessert apple must and its effect on the synthesis of fusel alcohols and esters in cider were established by instrumental analysis. The amino acid profile was performed in nine apple musts. Two apple musts with high (>150 mg/L) and low (<75 mg/L) nitrogen content, and four enological yeast strains, were used in cider fermentation. The aspartic acid, asparagine and glutamic acid amino acids were the majority in all the apple juices, representing 57.10% to 81.95%. These three amino acids provided a high consumption (>90%) during fermentation in all the ciders. Principal component analysis (PCA) explained 81.42% of data variability and the separation of three groups for the analyzed samples was verified. The ciders manufactured with low nitrogen content showed sluggish fermentation and around 50% less content of volatile compounds (independent of the yeast strain used), which were mainly 3‐methyl‐1‐butanol (isoamyl alcohol) and esters. However, in the presence of amino acids (asparagine, aspartic acid, glutamic acid and alanine) there was a greater differentiation between the yeasts in the production of fusel alcohols and ethyl esters. High contents of these aminoacids in dessert apple musts are essential for the production of fusel alcohols and most of esters by aromatic yeasts during cider fermentation.     

气相色谱-质谱法分析乳酸菌发酵苹果汁香气成分

以乳酸菌单一菌种和多菌组合分别发酵苹果汁,采用紫外-可见分光光度计测定发酵过程中苹果汁光密度(optical density,OD)的变化,采用顶空固相微萃取和气相色谱-质谱联用技术检测9组发酵苹果汁的香气成分,结合不同香气物质的阈值与香气值分析特征香气成分,并对各组苹果汁进行感官评价。结果表明:在发酵过程中苹果汁的OD值呈对数上升趋势。各组苹果汁中共鉴定出48种香气成分,主要包含醇类、酯类、醛类、酮类和酚类,其中酯类是各发酵组中种类最多且含量最大的香气类别,其次是醇类。9组苹果汁的主要香气成分和香气值较大并有突出贡献的特征香气成分均为丁酸乙酯、2-甲基丁酸乙酯、2-甲基丁基乙酸酯和乙酸己酯等。多菌发酵和单菌发酵苹果汁的香气成分含量及香气值差异显著(P0.05),说明多菌发酵中醇类、酯类和其他类香气物质的总含量明显高于单菌发酵,且赋予苹果汁更强烈的果香、青香和花香。多菌发酵组的总体感官评分高于单菌发酵组,当副干酪乳杆菌20241、动物双歧杆菌6165、嗜热链球菌6063、嗜酸乳杆菌6005活菌数比为1∶1∶1∶1时,感官评分最优。研究结果为今后乳酸菌在发酵果蔬汁方面的研究和应用提供理论依据。     

Analysis of key aroma components in cider from Shaanxi (China) Fuji apple

Aroma components play an important role in the quality of cider. To understand the contribution of every component to cider aroma quality, major aroma components present in ten ciders processed with different technological methods with different yeasts and apple orchards were determined by Headspace-solid phase microextraction–gas chromatography–mass spectrometry and internal standard method. Experimental results by principal component analysis indicated that ethyl acetate, acetic acid isobutylester, isopentylacohol acetate, ethyl caprylate, ethyl 4-hydroxybutanoate, isopentylalcohol, 3,4,5-trimethyl-4-heptanol, nonyl alcohol, 3-methylthio-1-propanol serve as the key aroma components in cider from Shaanxi (China) fuji apple. A model was established and verified for evaluating aroma quality based on factor analysis by comparing with the sensory evaluation method.     

发酵过程中添加磷酸氢二铵对苹果酒香气物质的影响

以富士苹果为原料,分别在发酵前、酵母生长对数期和稳定期前期添加280 mg/L的磷酸氢二铵（DAP）,研究DAP的添加对酵母发酵性能和苹果酒香气物质的影响。结果表明,发酵过程中添加DAP可加快酵母发酵速率,在酵母发酵前和酵母生长对数期添加DAP显著降低了琥珀酸含量（P＜0.05）;在稳定期前期添加DAP显著降低了苹果酸含量（P＜0.05）,总香气含量最高（11.09 mg/L）,更有利于苹果酒中挥发性香气化合物的合成,但对酵母数影响不大。     

Evolution of aroma compounds in sparkling ciders

This paper reports the influence of yeast strain and aging time on the volatile composition of sparkling cider made according to the traditional method. Two sparkling ciders were obtained from the same base cider using a selected cider yeast strain (Saccharomyces bayanus) and a commercial wine yeast strain (Saccharomyces cerevisiae). Analysis of volatile compounds (alcohols, esters and carbonylic compounds) were performed every 3 months, from 3 to 15 months. The analysis of variance revealed that the majority of differences between sparkling ciders are due to the aging time. Acetaldehyde and acetoin decrease with time, while higher alcohols, ethyl acetate, ethyl lactate and ethyl octanoate significantly increase during aging in contact with lees. The concentrations of methanol, 2-phenyletanhol, ethyl lactate and ethyl octanoate were higher in the cider made with the selected yeast strain (S. bayanus).     

YEAST STRAIN AND KINETIC ASPECTS OF THE FORMATION OF FLAVOUR COMPONENTS IN CIDER

An apple juice was fermented at 8°C using twelve strains of Saccharomyces uvarum. Glucose, fructose, malic and L-lactic acids, isobutanol, 2,3 butanediol, isoamyl alcohol, ethyl acetate and titratable acidity were determined and monitored in the course of fermentation. It was observed that yeast strains differed from one another mainly in fermentation rates. When components were determined in ciders of the same remaining fructose concentration, rather than after the same fermentation time, the only significant effect of the yeast strain was on the amounts of glucose and ethanol in sweeter cider (fructose 34 g/litre), or on the amounts of glucose, acetic acid, isobutanol and amyl alcohols in dryer ciders (fructose 17 g/litre). A sensory analysis showed that standard deviations of concentrations of remaining or formed components in ciders fermented by different yeast strains, was sufficient to be detected by the taste panel. Added glucose in this range of concentration (1.5 g/litre) in cider reduced the perception of sourness while the addition of acetic acid (0.3 g/litre) reduced the perception of the scented flavour. Added Isobutnol (6 mg/litre) reduced the perception of sweetness. No significant effect of added isoamyl alcohol (30 mg/litre) could be detected. Chemical determinations were correlated by means of regression equations derived from earlier work with some organoleptic characteristics. No anticipated effect of the yeast strain could be detected on any studied flavour characteristic. It is concluded that in ciders of the same attenuation, the effect if it does exist, of the S.uvarum strain isolated from ciders, must be low.     

氯化铵对苹果白兰地挥发性香气成分的影响

采用顶空固相微萃取-气相色谱-质谱联用技术分析添加氯化铵及无添加对照发酵苹果白兰地酒中的香气成分.经分析鉴定：在苹果白兰地的挥发性物质中,酯类和醇类相对含量较高,构成了苹果白兰地的主要香气成分;苹果白兰地发酵中添加氯化铵有助于提高主要酯类物质的相对含量,其中相对含量较高的香气物质为：乙酸乙酯、3-甲基-乙酸-1-丁酯、乙酸己酯、己酸乙酯、辛酸乙酯、癸酸乙酯、3-甲基-1-丁醇和乙醇等.     

河源南高丛蓝莓酒精发酵前后挥发性成分变化

目的明确广东河源地区南高丛蓝莓特征风味成分以及蓝莓发酵后香挥发性成分变化规律。方法采用顶空固相微萃取-气质联用法分析了河源南高丛蓝莓的风味成分,以及发酵成蓝莓酒后的风味成分变化。结果河源南高丛蓝莓主要风味成分为柠檬烯以及其他烯烃、醛类等物质,发酵成蓝莓酒后主要特征风味成分为乙酸乙酯、辛酸乙酯等酯类和醇类物质。结论河源南高丛蓝莓在挥发性成分上与以往报道的温带地区蓝莓有一定的区别,蓝莓发酵成蓝莓酒后烯烃、醛类物质显著减少或消失,而酯类和醇类显著增加,同时生成了长链烷烃和脂肪酸酯类物质。