Red clover isoflavonoids as anthocyanin color enhancing agents in muscadine wine and juice

Isoflavonoid extracts from red clover (Trifolium pratense) leaves were found to enhance overall color and stability of anthocyanin 3,5-diglucosides present in muscadine grape (Vitis rotundifolia) juice and wine through intermolecular copigmentation reactions. Predominant isoflavonoids present in red clover included formononetin, biochanin A, and prunetin and were the major polyphenolics identified to influence anthocyanin color and stability. Since red clover isoflavonoids have poor water solubility characteristics, this allowed for removal of extraneous non-isoflavonoid compounds using hot water and subsequent extraction with ethanol. Isoflavonoid solubility was evaluated as a function of ethanol concentration with recoveries up to 57% found in 20% solutions. Changes in maximum absorbance, total soluble phenolics, isoflavonoids, and anthocyanins were evaluated in muscadine juice and wine following the addition of isoflavonoid extracts with maximum color enhancement found at an anthocyanin to cofactor ratio of 1:8, after which their solubility was prohibitive. Additionally, dried leaves and ethanolic extracts of red clover were added prior to and following fermentation of muscadine wine (11% ethanol) stimulating the natural copigmentation that takes place during red wine fermentation and aging processes. Once fermentation was complete, finished wines were evaluated over a 9-week storage period at 20 and 37 °C. Despite low levels of isoflavonoids present, color improvement and anthocyanin stability was observed in the wines during storage. Little information is available on copigmentation reactions occurring in actual food systems, yet red clover isoflavonoids proved to be novel and effective color enhancing compounds when used in low concentrations in young muscadine wines.     

基于UPLC-Q-TOF-MS分析酵母对葡萄酒中糖苷态香气物质释放的影响

采用超高效液相色谱-四极杆-飞行时间-质谱法,研究2种酵母Red Fruit和Zymaflore ST分别在‘北冰红’和‘威代尔’冰酒的发酵过程中,对不同糖苷态香气物质含量的影响,以及瓶储1年后葡萄酒中糖苷态香气物质含量的变化。结果表明,‘威代尔’冰酒中有更丰富的糖苷态香气物质种类和含量。酵母Red Fruit和Zymaflore ST发酵的‘北冰红’冰酒中,戊糖基-葡萄糖苷类香气物质均略有下降,但酵母Zymaflore ST发酵对己糖基-葡萄糖苷类香气物质影响不显著。酵母Zymaflore ST发酵‘威代尔’冰酒中,戊糖基-葡萄糖苷、己糖基-葡萄糖苷和葡萄糖苷类的香气物质均显著降低,而酵母Red Fruit对糖苷类型的香气物质均无显著影响(己糖基-葡萄糖苷类除外)。瓶储1年后,‘北冰红’冰酒中各种糖苷态香气物质含量均大幅降低。研究认为,酵母Red Fruit和Zymaflore ST对发酵过程中‘北冰红’糖苷态香气释放影响很小,糖苷态香气释放可能主要在陈酿阶段,而酵母Zymaflore ST发酵较有利于‘威代尔’糖苷态香气的释放。该结果为冰酒的酿造和陈酿工艺设计提供了参考。     

葡萄酒中香气物质研究进展

香气是葡萄酒感官评价的重要指标,也是影响葡萄酒质量风格和消费者导向的重要因素。各种风格特色的葡萄酒中具有的香气成分复杂多样,葡萄品种、发酵工艺、陈酿条件等因素均会影响其最终香气。保持品种典型性、提高发酵香气并改善陈酿风味一直是葡萄酒风味研究追求的目标,因此,全面分析葡萄酒中香气物质的形成途径和呈香机制至关重要。从发酵调控角度重点论述了品种和发酵香气成分的生成规律及酿造工艺对葡萄酒香气物质生成的调控机制,深入介绍相关风味酶和香气前体物质同香气物质的关系;探讨陈酿香气的生成路径并总结不同橡木制品和陈酿技术对葡萄酒陈酿香气特征的影响机理;简要阐述了香气物质的检测技术和香气物质间感知协同作用的研究方法,分析关键香气物质相互作用及基质效应对葡萄酒风味感知的影响。最后对未来研究方向和趋势提出展望,以期为建立以风味导向为基础的葡萄酒工艺调控手段提供理论依据和技术支持。     

沙棘原汁澄清处理对沙棘酒香气成分的影响

为研究沙棘原汁澄清处理对沙棘酒发酵速度和香气成分形成的影响,利用果胶酶对沙棘原汁进行澄清处理。分别对沙棘澄清汁和未处理的沙棘原汁调整到糖度23%、pH3.7,然后接入0.18%的活性干酵母于28.5℃下发酵,陈酿后采用气-质联用仪（GC-MS）对各发酵酒进行香气成分检测。结果表明:以澄清汁为原料发酵的沙棘酒中检测出58种香气化合物;原汁发酵的沙棘酒中检测出52种香气成分,其中有28种非两者共有,产生了非常明显的香气差异。主要香气成分为3-甲基-1-丁醇和辛酸乙酯,用澄清汁发酵的沙棘酒其相对含量分别为31.24%和10.40%,较原汁发酵的沙棘酒分别提高了16.45%和5.32%。因此表明对沙棘汁澄清处理更有利于沙棘酒香气的形成。      

红树莓果与发酵酒香气成分变化

采用顶空-固相微萃取法(HS-SPME)和气相色谱-质谱联用仪(GC-MS)萃取检测鉴定红树莓果实和果酒酵母1399酿造的红树莓果酒香气物质成分和含量,对比红树莓果实、红树莓果酒主发酵、后发酵的香气成分变化.结果表明,红树莓果实、果酒主发酵和后发酵中共检测出醇类26种,酯类35种,酸类7种,烷烃烯烃类26种,胺类25种,醛酮苯酚类物质12种,其他类11种.果实中主要的呈香物质为R-4-甲基-1-(1-甲基乙基)-3-环己烯-1-醇、己醛和2-己烯醛,相对含量分别为8.00％、14.73％、9.08％;果酒主发酵和后发酵中香味变化明显的为乙醇、癸酸乙酯、苯甲酸乙酯、辛酸乙酯,其含量对比变化分别为8.78％、17.24％; 22.05％、22.61％; 11.37％、17.98％;18.67％、6.58％.在此基础上,初步得出了红树莓汁经发酵和陈酿作用,香气成分的总体变化规律.     

EFFECT OF ENZYMATIC MACERATION ON SYNTHESIS OF HIGHER ALCOHOLS DURING MANGO WINE FERMENTATION

Mango is a popular and highly produced fruit in India. Wine from two mango cultivars Banginapalli and Totapuri was prepared and the mode of higher alcohols synthesis during wine fermentation was evaluated. Mangoes were peeled off and juice was extracted immediately after crushing (control) and also after 10 h of pectinase treatment. The recovered juice was allowed to ferment at 15 and 20C. During fermentation, higher alcohols and sugars were measured. Contents of all the higher alcohols analyzed increased during fermentation. More volatiles were observed in wine produced from Totapuri cultivar (358  ±  12.7 mg/L) than wine from Banginapalli cultivar (340  ±  10.5 mg/L). Pectinase treatment increased the synthesis of iso-amylalcohol, 2-phenyl ethanol, n-propanol, n-butanol and methanol during fermentation. Sensory evaluation scores of wine correlated to the sum of higher alcohols. The results of the present study suggest that the pectinase treatment increases the mango juice yield and results in better wine sensory quality.

PRACTICAL APPLICATIONS

Nowadays, the number of wine consumers is increasing rapidly all over the world. In order to meet the demand, researchers are developing alternative wine producing technologies. In the present study, we made an attempt to produce wine from mango, the king fruit of world. The main objectives of this study are to increase the quality and quantity of mango juice for wine production and evaluate the aroma compounds kinetic parameters during wine fermentation. This study also provides an adequate process for both juice and wine production from mango and other tropical fruits. The findings regarding pectinase treatment, formation of major volatile compounds and sensory evaluation can be valuable references to the wine industry.     

Influence of the yeast strain on Monastrell wine colour

Two commercial yeast strains were assayed during the winemaking process of Monastrell grapes to determine their influence on colour and phenolic composition of the resulting wines during alcoholic fermentation and maturation. The results showed that in 2002, the wines did not present great differences but in 2003 higher colour intensity and phenolic compounds content were detected when one of the commercial strains was used. A discriminant statistical analysis clearly showed that different yeasts led to different wines as regard their chromatic characteristics.Industrial relevanceThe importance of yeast in winemaking is extensively known since they are responsible for the transformation of sugars into ethanol and for the formation of the most significant aroma compounds in wines. However, they may also participate in wine colour and this role is usually not taken into account in the wine industry. The choice of a yeast strain is an important factor since these microorganisms have the capacity to retain or adsorb phenolic compounds and, on the other hand, yeast may contribute to stabilizing wine colour, as a result of participating in the formation of vitisins during fermentation or liberating mannoproteins that have the capacity to bind to anthocyanins and tannins, protecting them from precipitation. Two commercial yeast strains were assayed during the winemaking process of Monastrell grapes to determine their influence on colour and phenolic composition of the resulting wines during alcoholic fermentation and maturation. The results showed that higher colour intensity and phenolic compounds content were detected when one of the commercial strains was used, both during fermentation and wine aging, and may be used as a tool during winemaking for obtaining stable and highly coloured wines.     

葡萄酒香气来源和形成研究进展

香气是衡量葡萄酒质量的一个重要部分。以葡萄酒香气的3大来源-品种香、发酵香、陈酿香为主线,对葡萄酒中活跃香气成份的形成进行概述。包括葡萄果实中的香气物质和葡萄利用酵母在酒精发酵时期产生的香气物质。同时,对苹果酸-乳酸发酵、葡萄酒的老化、成熟与葡萄酒香气的关联也进行了讨论,以期促进葡萄酒香气的进一步研究。     

果酒中香气化合物的生物转化与调控机制研究进展

果酒发酵过程中微生物及其代谢酶引发的一系列生化反应对其风味形成具有重要作用,但目前仍存在生物调控手段不完善,香气形成机理不清晰等问题,制约着我国果酒产品的开发和品质提升。本文对不同果酒中香气化合物种类及其生成途径进行阐述,分析香气前体物质代谢和微生物发酵对果酒香气的贡献;从生物调控角度重点论述不同果酒发酵过程香气成分的变化规律及微生物和酶对果酒香气化合物的影响机制,分析发酵菌种、发酵方式、微生物产酶能力及其酶活力大小等因素对果酒香气形成的作用,深入介绍微生物、酶同果酒香气的关系;最后,对未来果酒的研究热点进行展望,为建立以风味导向为基础的果酒定向调控手段提供理论依据和技术支持。     

不同酵母对赤霞珠桃红葡萄酒香气的影响

利用CY3079、Zymaflore X16、TXL和STR四种不同类型的商业酵母发酵赤霞珠新鲜桃红葡萄酒,采用顶空固相微萃取（HS-SPME）结合气相色谱质谱（GC-MS）联用技术,分别对酒精发酵结束和瓶储陈酿一年的葡萄酒样品进行香气物质的定性与定量分析。结果表明,4种酵母发酵的赤霞珠桃红葡萄酒中香气物质的种类相似,但其含量差异显著。酒精发酵结束阶段,CY3079和Zymaflore X16酵母发酵的桃红葡萄酒中脂肪酸乙酯的含量高于其他酵母发酵的酒样,使它们具有更加浓郁的果香、甜香和花香;而Zymaflore X16和STR酵母产生乙酸异戊酯和乙酸苯乙酯的能力较强。经过一年的瓶储陈酿,所有处理的桃红葡萄酒中脂肪酸乙酯和高级醇乙酸酯的含量显著下降,导致其果香的强度降低,同时减少了不同酵母发酵酒样之间的差异。     

蓝靛果酒带渣发酵工艺的优化及其香气分析

以冷冻蓝靛果为原料,对蓝靛果发酵的工艺进行优化,筛选适合的澄清剂,并对成品中的香气成分进行分析。研究酵母添加量、初始糖度、初始pH、发酵温度对蓝靛果酒发酵过程中的总酸、残糖量及酒精度的影响,在单因素的基础上进行四因素三水平的响应面优化。结果表明,蓝靛果酒最佳的发酵工艺参数为初始糖度20 °Bx,初始pH3.5,发酵温度18℃,酵母添加量3.5%(w/w),在此工艺下蓝靛果酒感官评分91分;通过果胶酶、壳聚糖、明胶、CMC四种澄清剂对蓝靛果酒澄清作用的分析,最适澄清剂为2%(v/v)CMC,明胶相对最弱;通过GC-MS进行分析成品果酒的香气成分,得到蓝靛果酒香气的主要成分为丁二酸二乙酯、月桂酸乙酯、苯乙醇、甲酸异戊酯、棕榈酸乙酯、2-甲基-1-丁醇。产品具有浓郁的果香和酒香,口感清冽爽口,具有典型的果酒特色。     

Effect of ‘wheat Qu’ on the fermentation processes and volatile flavour‐active compounds of Chinese rice wine (Huangjiu)

Wheat Qu is a unique saccharifying agent used for Chinese rice wine brewing. In recent years, the impact of wheat Qu on Chinese rice wine flavour has attracted great interest. In this study, Chinese rice wine fermentations were conducted with different saccharifying agents (wheat Qu and mixed commercial enzymes) to study the effect of wheat Qu on the fermentation process and aroma characteristics of Chinese rice wine. Our results showed that wheat Qu not only acted as a saccharifying agent, but also increased yeast activity and the formation of aroma compounds. A higher yeast growth and fermentation rate, in addition to a lower yeast death rate, were observed when wheat Qu was used as a saccharifying agent. Global analysis of the aromatic profiles revealed that the use of wheat Qu greatly promoted the formation of the aroma compounds during a Chinese rice wine fermentation. The concentrations of the volatile phenolic compounds and higher alcohols were higher in the Chinese rice wine samples fermented with wheat Qu. It was concluded that the role of wheat Qu cannot simply be replaced by commercial enzymes and that the Chinese rice wine aromatic profiles can be modulated depending on the amount of wheat Qu used in the fermentation. Copyright © 2013 The Institute of Brewing & Distilling     

催陈方式对山竹果酒理化特性和香气成分的影响

采用加热、微波和超声波等催陈方法对山竹果酒进行处理,考察不同催陈方式对山竹果酒各理化指标（总酯、总酸、色度）的影响,并通过顶空固相微萃取-GC-MS方法对挥发性香气成分进行了分析,探讨了催陈方式对香气成分的影响。结果表明：加热和微波处理有利于果酒总酯含量的提高,最大值达到2.97 g/L,加热处理的果酒色度比原果酒色度升高了53.3%,微波处理有利于果酒酸度的降低,原果酒的总酸含量由2.21 g/L降低至1.72 g/L。香气成分表明：三种催陈方式对果酒品质和香气都有所改善,山竹果酒经加热处理后,醇类物质降低了11.89%,脂类物质含量升高了11.28%,并生成了2-甲基丁酸乙酯等新物质。经微波处理后的醇类物质含量略有降低, 脂类物质含量略有升高,而超声处理后醇类物质含量由原来的84.61%降低了7.42%,脂类物质含量由原来的15.3%升高了7.1%,并生成乙酸己酯、松油醇、乙酸苯乙酯等新物质, 对香气成分有较大的改善。     

户太8号桃红葡萄酒贮藏期香气物质损失及添加剂护香效果分析

研究户太8号桃红葡萄酒贮藏期的香气物质变化规律,并比较几种添加剂处理的护香效果,旨在优化设计葡萄酒的陈酿工艺。研究以户太8号桃红葡萄酒为试材,当葡萄酒发酵结束后分别添加适量葡聚糖、没食子酸、甘露糖蛋白和谷胱甘肽处理,而后定期采集酒样,对酒样香气通过仪器和感官进行分析。香气成分采用SPME-GC-MS定性定量分析,香气特征通过感官培训的品评小组量化品评。结果表明:户太8号桃红葡萄酒中共定量出33种香气物质,有9种成分的气味活性值(OAV)大于1,11种成分的OAV在0.1~1.0。贮藏期间,酒样中乙酸酯和中链脂肪酸乙酯含量在贮藏初期急剧下降而后趋于平稳,高级醇含量逐渐升高至平缓,脂肪酸、萜烯类和苯乙基类化合物的含量逐渐升高并在贮藏后期降低。贮藏1年后,葡聚糖处理的酒样中果香酯、苯乙基类以及己(烯)醇类化合物等香气物质含量明显高于其他处理组,而其他处理组之间差异不显著。感官分析也表明,葡聚糖处理组比其他处理组具有更好的温带水果、甜香、花香和小浆果香的香气特征。研究发现,在发酵结束后添加300mg/L葡聚糖对贮藏期户太8号桃红葡萄酒表现出较好的护香作用。     

优良本土酿酒酵母的酿酒特性及产香能力初析

酿酒酵母产生的多种挥发性物质影响葡萄酒的香气风格,筛选本土酿酒酵母对改善葡萄酒同质化有积极作用.以13株不同来源的酿酒酵母和1株商业对照为试验菌株,对供试酵母的酒精耐受性、嗜杀性、产硫化氢能力及生长曲线进行了测定.随后在模拟汁中探究酵母的发酵特性,用固相微萃取-气相色谱/质谱(solid-phase microextr...     

酒类酒球菌β-葡萄糖苷酶研究进展

酒类酒球菌（Oenococcus oeni）是葡萄酒苹果酸乳酸发酵（MLF）中的主要微生物,糖苷物质是葡萄酒中的重要香气前体物,β-葡萄糖苷酶是降解糖苷物质的关键酶。酒类酒球菌β-葡萄糖苷酶对增加葡萄酒香气,提升葡萄酒整体品质具有重要作用。该文介绍了β-葡萄糖苷酶的定义、分类、作用机制和测定方法,阐述了酒类酒球菌β-葡萄糖苷酶活,探讨了pH值、发酵温度、乙醇浓度、糖含量和二氧化硫含量对酶活的影响,在分子生物学水平上研究了酒类酒球菌β-葡萄糖苷酶基因,并对酒类酒球菌葡萄糖苷酶未来的研究热点和研究方向进行了展望。这对深入认识葡萄酒生物增香机理和提高葡萄酒整体品质具有重要意义。     

菠萝皮渣糯米果酒发酵过程中主要成分变化研究

以菠萝皮渣和糯米为原料,进行糯米果酒发酵,并采用相关国标检测方法、液相色谱（LC）及气相色谱质谱联用（GC-MS）法,分析菠萝皮渣糯米果酒在发酵过程中可溶性固形物、酒精度、有机酸、挥发酸和香气成分等成分变化。结果表明：发酵过程中糖度迅速降低、酒精度升高后维持稳定,pH值在3.50～3.80之间,呈先降后升趋势,酸度先降低直至陈酿后期轻微升高。有机酸含量在发酵过程中总体呈下降趋势,草酸、酒石酸含量逐渐降低,柠檬酸、苹果酸、丙酮酸、乳酸含量先降后升,琥珀酸和乙酸呈上升趋势。果酒中挥发酸含量不断下降,第60天甲酸、乙酸含量分别为0.30 mg/L和0.26 mg/L。菠萝皮渣糯米果酒中共检测出88种香气成分,其中41种酯类、22种醇类、10种酸类和15种其他类,发酵过程中乳酸乙酯、乙酸异戊酯、2-甲基丁酸乙酯、正己酸乙酯、辛酸乙酯、乙酸苯乙酯、癸酸乙酯、月桂酸乙酯和十六酸乙酯含量较高,相对含量在0.27%～20.57%。     

紫色甘薯酒香气成分分析和发酵规律

采用顶空固相微萃取法对紫色甘薯酒的香气成分进行提取,经气相色谱-质谱联用法结合计算机检索对其香气成分进行分析和鉴定,并且跟踪监测紫色甘薯酒整个发酵过程中酒度、花色苷、色差、pH值、可溶性固形物等化学成分的变化。结果表明：从紫色甘薯酒中共鉴定出香气物质57种,占整个峰面积的97.13%;紫色甘薯酒的主体香气物质主要有异丁醇、异戊醇、辛酸乙酯、苯乙醇等;在紫色甘薯酒发酵的过程中,酒度和挥发酸呈逐渐上升的趋势;花色苷、可溶性固形物和色差呈逐渐下降的趋势;pH值在整个发酵的过程中则变化不大。     

杏汁发酵与杏皮渣发酵对杏酒香气质量的影响

为优化杏酒的发酵工艺,提高杏果的综合利用价值,减少资源浪费和环境污染,以杏汁和杏皮渣为原料,分别加入两种酵母进行发酵,比较发酵工艺对杏酒基本理化指标、香气物质和感官特性的影响。采用4 种发酵工艺,工艺1为杏汁＋酵母BV818,工艺2为杏汁＋酵母CECA,工艺3为杏皮渣＋酵母BV818,工艺4为杏皮渣＋酵母CECA。用气相色谱-质谱测定杏酒中的香气物质,并对杏酒进行感官评价。在杏酒中共检测出41 种香气物质,包括酯类29 种、醇类5 种、醛类2 种和萜烯类5 种,其中酯类物质种类最多,且含量最高,占香气总量的72.7%。在工艺1～4的酒样中,香气总量分别为14 765.27、15 034.37、12 580.27 μg/L和7 347.61 μg/L,用杏汁发酵的杏酒中香气总量显著高于用杏皮渣发酵的杏酒。在4 种工艺酒样中均能检出且气味活性值大于1的香气物质为杏酒的特征香气物质,共有6 个,分别为辛酸乙酯、己酸乙酯、乙酸异戊酯、芳樟醇、癸酸乙酯和丁酸乙酯。主成分分析结果显示,工艺2的酒样与乙酸异戊酯、丁酸乙酯、己酸乙酯、辛酸乙酯和芳樟醇5 种特征香气物质处于同一象限,说明该酒样具有杏酒的典型香气特征。感官评价结果显示,杏酒具有杏、桃、柑橘、苹果、梨等果香和槐花、金银花等花香,采用工艺2酿造的杏酒,感官评分最高。结论：用杏汁发酵的杏酒,香气物质含量较高,以果香和花香为主,酒体轻盈,口感清爽,而用杏皮渣发酵的杏酒,总酚含量较高,香气复杂,酵母味明显,酒体饱满。本研究为杏酒发酵工艺的优化提供技术支持,也为进一步研究杏酒香气物质的合成提供理论依据。     

芦笋猕猴桃复合果酒发酵过程中挥发性香气物质的变化

以芦笋副产物为原料,经榨汁与猕猴桃汁混合,发酵制备芦笋猕猴桃复合果酒,并采用固相微萃取-气相色谱-质谱联用对芦笋猕猴桃复合果酒在发酵前期、中期、后期、后发酵、陈酿期中挥发性香气物质成分进行分析。整个发酵阶段共检测出78种挥发性香气物质,各发酵阶段中含量较高的挥发性香气物质均为酯类和醇类。其中,乙酯含量在总酯所占比例相对较大,分别为54.72%、79.20%、72.92%、76.60%和70.14%。随着发酵的进行,挥发性香气物质种类呈逐渐下降并趋于平稳的趋势,质量浓度呈先上升后下降并趋于平稳的状态。乙酸异戊酯、己酸乙酯、苯乙酸甲酯、辛酸乙酯、苯乙酸乙酯、癸酸乙酯、异戊醇、异丁醇、苯乙醇和2,4-二叔丁基苯酚为整个发酵阶段中共有的挥发性香气物质。采用气味活性值分析法得到13种特征香气物质,己酸乙酯和辛酸乙酯为整个发酵阶段中共有的特征香气物质,其中辛酸乙酯是在各发酵阶段中OAV值最大的化合物。发酵前期的主要特征香气物质为辛酸乙酯、苯乙醛;发酵中期和发酵后期的的主要特征香气物质为辛酸乙酯、己酸乙酯;后发酵和陈酿期的主要特征香气物质为辛酸乙酯、2-甲基丁基乙酸酯。该研究分析了芦笋猕猴桃复合果酒的特征风味,为其产业化开发提供理论参考。