Effects of time of grape pomace fermentation and distillation cuts on the chemical composition of grape marcs

 The effects of fermentation time and distillation cuts on the composition of distillates in terms of ethanal, 1,1-diethoxyethane, methanol, 1-butanol, 2-butanol, 1-propanol, 2-methyl-1-propanol, 2-methyl-1-butanol, 3-methyl-1-butanol, ethyl acetate, ethyl 2-hydroxypropanoate, 3-methylbutyl acetate, hexyl acetate, 2-phenylethyl acetate, hexanol, trans-2-hexenol, trans-3-hexenol, cis-3-hexenol, 2-phenylethanol, ethyl butyrate, ethyl hexanoate, ethyl octanoate, ethyl decanoate, ethyl dodecanoate, 2-methylpropanoic acid, 3-methylbutanoic acid, hexanoic acid, octanoic acid, decanoic acid, and dodecanoic acid were assessed through data generated according to a factorial design using analysis of variance and principal component analysis. Four times of storage of pomace obtained following winemaking of two grape varieties of white Verde wine (Alvarinho and Loureiro) and three distillation cuts were considered; volatile compounds in the 24 samples generated were analyzed directly, and indirectly after extraction and concentration, by capillary gas chromatography. The results generated have suggested clear differences (P<0.05) between distillate cuts obtained throughout fermentation times for each grape variety. The major differences between the different distillate fractions analyzed were accounted for by the contents of diethyl butanoate, ethyl 2-hydroxypropanoate, and the sum of 3-methylbutanoic and 2-methylpropanoic acids for Loureiro, whereas the main differences were accounted for by the contents of diethyl butanoate and the sum of the carboxylic acids for Alvarinho.     

Effects of time of grape pomace fermentation and distillation cuts on the chemical composition of grape marcs

 The effects of fermentation time and distillation cuts on the composition of distillates in terms of ethanal, 1,1-diethoxyethane, methanol, 1-butanol, 2-butanol, 1-propanol, 2-methyl-1-propanol, 2-methyl-1-butanol, 3-methyl-1-butanol, ethyl acetate, ethyl 2-hydroxypropanoate, 3-methylbutyl acetate, hexyl acetate, 2-phenylethyl acetate, hexanol, trans-2-hexenol, trans-3-hexenol, cis-3-hexenol, 2-phenylethanol, ethyl butyrate, ethyl hexanoate, ethyl octanoate, ethyl decanoate, ethyl dodecanoate, 2-methylpropanoic acid, 3-methylbutanoic acid, hexanoic acid, octanoic acid, decanoic acid, and dodecanoic acid were assessed through data generated according to a factorial design using analysis of variance and principal component analysis. Four times of storage of pomace obtained following winemaking of two grape varieties of white Verde wine (Alvarinho and Loureiro) and three distillation cuts were considered; volatile compounds in the 24 samples generated were analyzed directly, and indirectly after extraction and concentration, by capillary gas chromatography. The results generated have suggested clear differences (P<0.05) between distillate cuts obtained throughout fermentation times for each grape variety. The major differences between the different distillate fractions analyzed were accounted for by the contents of diethyl butanoate, ethyl 2-hydroxypropanoate, and the sum of 3-methylbutanoic and 2-methylpropanoic acids for Loureiro, whereas the main differences were accounted for by the contents of diethyl butanoate and the sum of the carboxylic acids for Alvarinho. Received: 23 January 1998 / Revised version: 5 June 1998     

Dynamics of volatile and non-volatile compounds in cocoa (Theobroma cacao L.) during fermentation and drying processes using principal components analysis

Different volatile and non-volatile compounds produced during the fermentation-drying process are considered as indicatives of cocoa beans quality. We found thirty-nine different compounds identified by SPME-HS/GC-MS and related to the desirable notes and off-flavor that have been reported. Volatile and non-volatile compounds were associated with acidity and changes of pH, such as acetic and lactic acid. Using the principal component analysis (PCA), relations between compounds and fermentation and drying day were associated with dynamics of these compounds. The identification of principal compound produced during the fermentation and drying processes can be helpful in searching for off-flavor indicator and as a fermentation index, such as isobutyric, isovaleric and propionic acids. Oxidation of 3-methyl-1-butanol-to-3-methyl-1-butanol acetate can be of use in evaluating the degree of fermentation. At drying, the compounds with the highest levels were acetic and isobutyric acid, ethyl and 3-methyl-1-butanol acetate, pentanal and 2,3-pentanedione, and 1,3-butanediol and 2,3-butanediol. Therefore, acetic acid and isobutyric acid, due to their high levels and their low threshold value could play an important role in the aromatic quality of cacao drying.     

早酥梨果酒酿造工艺优化及其香气成分分析

利用响应面法研究了早酥梨果酒加工的最优条件,并用SPME-GC-MS技术分析了果酒主要香气成分。结果表明:早酥梨在初始可溶性固形物含量24°Brix、pH 4.3、28℃发酵温度、0.68g/L的接种量的最优条件下发酵9d,并经过陈酿后得到12.4%的酒精体积分数且品质良好的果酒,高级醇3-甲基-1-丁醇和苯基乙醇为其主要香气成分。     

Characterization of major volatile compounds in whey spirits produced by different distillation stages of fermented lactose-supplemented whey

This research aimed to advance the understanding of acceptable sensory qualities of potable whey-based spirit from nonsupplemented, mid-supplemented, and high-supplemented whey samples by analyzing major volatile compounds during different stages of distillation (head, heart, and tail). The results demonstrated that commercial Saccharomyces cerevisiae strain in lactase-hydrolyzed whey showed rapid and complete sugar hydrolysis and efficient ethanol production in 24, 30, and 36 h on average, producing up to 29.5, 42.1, and 56.4 g/L of ethanol, respectively. The variations in titratable acidity, specific gravity, pH value, residual protein, sugar content, and alcohol yield were investigated during the fermentation. The total amount of volatile compound concentrations significantly decreased from the head (2,087–2,549 mg/L) to the tail whey spirits (890–1,407 mg/L). In the whey spirit, 2-methyl-1-butanol, 3-methyl-1-butanol, 2-methyl-1-propanol, 1-propanol, acetaldehyde, and ethyl acetate were the most prevalent dominant compounds, accounting for the largest proportion of total volatile compounds. The volatile compounds detected were far below the acceptable legal limit. The results suggest that high sensory qualities of potable whey-based spirits can be produced by fermentation of lactose-supplemented whey with S. cerevisiae cells.     

Characterisation of volatile compounds in an alcoholic beverage produced by whey fermentation

An alcoholic beverage (35.4% v/v ethanol) was produced by distillation of the fermented broth obtained by continuous whey fermentation with a lactose-fermenting yeast Kluyveromyces marxianus. Forty volatile compounds were identified in this drink by gas chromatography. Higher alcohols were the most abundant group of volatile compounds present, with isoamyl, isobutyl, 1-propanol, and isopentyl alcohols being found in highest quantities (887, 542, 266, and 176 mg/l, respectively). Ethyl acetate had the highest concentration (138 mg/l) among the esters. Besides higher alcohols and esters, other components, including aldehydes, acids and terpenes were also identified in the whey spirit. Considering that the quality of an alcoholic beverage can be evaluated by the relation between isoamyl alcohol/2-methyl-1-propanol and 2-methyl-1-propanol/1-propanol, which have to be higher than unity, it was concluded that a novel spirit of acceptable organoleptic characteristics can be produced by cheese whey continuous fermentation with K. marxianus.     

Congener profiles in the detection of illicit spirits

A range of spirituous beverages available in Australia has been analysed for the major volatile congeners using gas chromatography. A data bank has been generated and its use and limitations in the detection of illicit spirits is discussed. The spirits include Australian and imported brandies, tequilas, grappas, fruit brandies, wine fortifying spirits, rums, whiskies including bourbon, malt and blended scotch, gins, vodkas and sundry other beverages. Methanol. acetaldehyde, 1-propanol, 2-methyl-1-propanol, 2-butanol, 1-butanol, 2-methyl-1-butanol. 3-methyl-1-butanol, ethyl lactate and ethyl acetate were determined.     

蜂蜜酒发酵前后挥发性风味成分的迁移变化

目的 探究蜂蜜酒发酵前后挥发性风味成分的迁移变化。方法 本研究采用电子鼻（electronic nose,E-nose）和气相色谱-离子迁移谱联用（gas chromatography-ion mobility spectrometry,GC-IMS）技术对蜂蜜酒发酵前后挥发性风味成分的迁移变化进行比较分析。建立指纹图谱、气相离子迁移谱图,对挥发性物质进行定性分析,同时结合主成分分析（principal component analysis,PCA）比较样品间差异。结果 电子鼻检测发现发酵后甲基类物质和醇类、醛类、酮类物质明显增加;GC-IMS检测出53种挥发性物质,定性出26种挥发物质组分,发酵后2-甲基丁醛、己醛、2-甲基-1-丙醇、乙酸、乙醛、乙酸乙酯、正丙醇、丁酸乙酯、乙酸异戊酯、丁醇、3-甲基-1-丁醇、辛酸乙酯、丙烯醛和乙酸异丁酯等风味物质成分明显增加。结论 经过发酵后的蜂蜜酒在保留蜂蜜原有风味的同时又显著增加了大量新的风味成分,形成蜂蜜酒独特的风味特征。     

白酒酿造中主要基质利用的过程分析

淀粉是白酒发酵的主要基质,但淀粉在转化为酒精的过程中,受到哪些因素的影响,淀粉对发酵过程又有什么影响。通过实验窖池进行了白酒发酵,通过发酵结果可知,淀粉浓度高,糖化速度快,易污染杂菌,造成发酵失败;淀粉浓度高,还会造成酵母菌生长过于旺盛,迅速衰老,对白酒产量不利;入窖温度会对淀粉的消耗造成影响,入窖温度高,淀粉消耗大,造成较高的成本;曲药的储存时间对其中淀粉有较大的影响,直接影响曲药的质量,间接影响白酒的产量和质量。     

Discrimination of Chinese vinegars based on headspace solid-phase microextraction-gas chromatography mass spectrometry of volatile compounds and multivariate analysis

Headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography mass spectrometry (GC-MS) was applied for the determination of the characteristic volatile profiles of Chinese vinegars. Multivariate statistical techniques, such as principal component analysis (PCA) and cluster analysis (CA), were used to characterize the different Chinese vinegars by types, fermentation method, and production area. A total of 56 volatile compounds were identified, including 15 esters, 10 aldehydes, 5 acids, 12 alcohols, 5 ketones, 4 volatile phenols, 2 pyrazines, and 3 miscellaneous compounds. The major compounds in Chinese vinegars were furfural, acetic acid, ethyl acetate, 3-hydroxy-2-butanone, 3-methyl-1-butanol, isopentyl acetate, benzaldehyde, phenylethyl alcohol. The PCA results showed that characterizing the Chinese vinegars by HS-SPME-GC-MS was highly related to their type, fermentation method, and production area, and all these influencing factors were not independent. The CA results indicated that the fermentation method had a greater effect than vinegar type and production area. The results showed that HS-SPME-GC-MS together with chemometrics could provide practical reference for characterization of Chinese vinegars. Practical Application: HS-SPME coupled with GC-MS was applied for the determination of the characteristic volatile profiles of Chinese vinegars. The major compounds in Chinese vinegars were furfural, acetic acid, ethyl acetate, 3-hydroxy-2-butanone, 3-methyl-1-butanol, isopentyl acetate, benzaldehyde, phenylethyl alcohol. HS-SPME-GC-MS together with chemometrics was an efficient tool for evaluating vinegar authenticity.     

冰糖红梨酒发酵工艺优化及香气成分分析

为获得冰糖红梨酒最佳发酵工艺,提升红梨附加值,促进其产业化,本文以魏县红梨为主要原料,开发冰糖红梨果酒.在单因素实验的基础上,通过正交试验优化冰糖红梨酒的发酵工艺,并对优化后的冰糖红梨酒风味成分进行分析.结果显示最优发酵条件为:发酵温度19℃,初始糖度18°Brix,酵母接种量0.06％,初始pH4.8,焦亚硫酸钾添加...     

Influence of different banana cultivars on volatile compounds during ripening in cold storage

The aroma responsible for the flavor of fruits is highly susceptible to low temperatures in storage. The present study investigated the volatile composition of the Nanicão and Prata banana cultivars by testing pulp and whole fruit under cold storage conditions. The volatile fractions were characterized using headspace solid phase micro-extraction (HS-SPME) and gas chromatography–mass spectrometry (GC–MS). The cold storage induced changes in the volatile profile relative to the profile of the control group. The result of principal component analysis revealed that cold storage more strongly affects the Nanicão than the Prata cultivar. Esters such as 2-pentanol acetate, 3-methyl-1-butanol acetate, 2-methylpropyl butanoate, 3-methylbutyl butanoate, 2-methylpropyl 3-methylbutanoate and butyl butanoate were drastically reduced in the cold group of the Nanicão cultivar. Our results suggest that the metabolism responsible for the production of volatile compounds is related to the ability to tolerate low temperatures.     

标准化工艺条件下大河乌猪火腿发酵过程中的挥发性风味物质变化

该研究采用固相微萃取-气相色谱-质谱（solid-phase microextraction-gas chromatography-mass spectrometry,SPME-GC-MS）技术结合偏最小二乘－判别分析（PLS-DA）和相对气味活度值（relative odor activity value,ROAV）对发酵90 d、150 d、210 d、270 d、450 d和630 d的大河乌猪火腿的挥发性风味物质进行分析。结果表明：发酵过程中共鉴定到137种挥发性风味成分,包括醛、醇、酸、烃、酮、酯、芳香族类及其他类化合物,其中,醛类（51.63%~68.17%）和醇类（12.73%~23.64%）的种类和含量最为丰富;随着发酵时间的延长,挥发性风味物质种类增加了23种,但四个不同发酵期（210 d、270 d、450 d、630 d）的大河乌猪火腿中挥发性风味物质组成相似,说明发酵至210 d时主体风味化合物已经形成;发酵过程中关键风味物质有1-庚醇、3-甲基-1-丁醇、3-甲基丁醛、2,3-辛二酮、苯乙醛、己醛、辛醛、壬醛等16种。标准化工艺条件下发酵时间对火腿挥发性风味物质的形成有一定的影响,且大河乌猪火腿的加工期可定为10~12个月,研究为大河乌猪火腿标准化加工技术提供理论依据。     

香坊肠杆菌发酵果酒的香气物质分析

以香坊肠杆菌为菌种,以新鲜苹果和梨子为原料制作发酵果酒,对发酵过程进行跟踪检测,利用顶空固相微萃取—气相色谱—质谱联用技术分析检测其香气成分,并对比了香坊肠杆菌发酵和安琪酵母菌发酵第28天果酒产生的香气物质的异同。结果表明:香坊肠杆菌发酵前期产生的香气成分主要有苯乙醇、3-甲基-1-丁醇、2-甲基丁醇及其相应的乙酸酯,后期出现庚醛、2,4,5-三甲基-1,3-二氧戊环、癸酸乙酯、辛酸乙酯、异丁酸等。安琪酵母菌发酵产生的香气成分主要有癸酸乙酯、苯乙醇、辛酸乙酯、2,4,5-三甲基-1,3-二氧戊环、3-甲基-1-丁醇、乙缩醛、十二酸乙酯等。与安琪酵母菌发酵相比,香坊肠杆菌发酵既有果酒的基本香气构成,又有其独特的香气特点。     

不同干酵母发酵豆粕的挥发性成分分析

采用顶空固相微萃取和气相色谱-质谱联用技术,对豆粕和4种干酵母发酵豆粕后的挥发性成分进行了主成分分析。豆粕中共鉴定出36种挥发性成分,主要成分为1-辛烯-3-醇、1-己醇、酯类化合物和醛类化合物,其中1-辛烯-3-醇含量最高,占34.03%。豆粕经过安琪酵母、马利酵母、舒可曼酵母和超凡酵母发酵后,发酵产物中分别鉴定出54、51、57、52种挥发性物质,1-辛烯-3-醇、3-甲基-1-丁醇、1-己醇、苯乙醇和酯类为发酵产物的主要挥发性成分;1-辛烯-3-醇的含量与发酵前相比下降明显,其中超凡酵母发酵后含量降至10.28%。通过主成分分析得知,超凡酵母和舒可曼酵母发酵后的豆粕的挥发性成分在整体上较为接近,而与安琪酵母、马利酵母明显不同。     

Monitoring of chemical parameters of oxygen-treated musts during alcoholic fermentation and subsequent bottle storage of the resulting wines

The effect of hyper-oxygenation of Airén white wines on color characteristics, phenolic composition, and volatile profile has been evaluated in different processing steps, not previously reported in conjunction: musts, musts during the alcoholic fermentation, resulting young wines and after 1 year of bottle storage. Hyper-oxygenation treatment achieved a positive effect on color stabilization by means of significantly lower contents of most important phenolic compound families (hydroxycinnamic acid derivatives, benzoic acids, flavonols, and flavan-3-ols) in oxygen-treated musts in fermentation, young wines, and one-year-stored white wines. Therefore, browning was avoided in wines elaborated from hyper-oxygenated musts and their values of a* (green–red component of color) were maintained, in contrast to what occurred in control wines. With regard to volatile profile, the concentration of the majority of individual volatile compounds was significantly higher in wines derived from hyper-oxygenated musts, even after 1 year of bottle storage, especially those derived from alcoholic fermentation (alcohols: 2-methyl-1-butanol and 3-methyl-1-butanol, polar esters: ethyl lactate and ethyl glutarate, C₆ alcohols: 3-methyl-1-pentanol, and acetates: 2-phenylethyl acetate). This study enhances knowledge regarding the effects of hyper-oxygenation process during and after alcoholic fermentation and 1 year of bottle aging, especially as there is scarce literature available on the subject.     

葡萄果醋饮料的工艺研究

以玉米、麸皮为主要原料,经酒精发酵后加入葡萄皮渣进行醋酸发酵而制得葡萄果醋,再经调配,制成风味独特的葡萄果醋饮料。通过单因素实验、正交试验,优化了工艺条件和配方。结果表明,以玉米、麸皮汁为发酵基料,基料的糖含量为16°Brix,pH 3.5,酵母接种量为10%,发酵温度30℃,经酒精发酵6 d,酒精体积分数达到6%～7%时进入醋酸发酵,糖含量4°Bx,醋酸菌接种量10%,发酵温度30℃,醋酸发酵6 d。风味配方为:葡萄果醋10%,柠檬酸0.1%,蔗糖9%。     

人参果果醋饮料的研制

目的：以人参果为原料研制人参果果醋饮料。方法：通过酒精发酵、醋酸发酵和饮料调配等工艺处理,制取人参果果醋饮料。结果：通过正交试验确定醋酸发酵的工艺条件为pH4.0、发酵温度30℃、发酵时间6d、醋酸菌接种量7%;人参果果醋饮料的配方为果醋原液添加量10%、果醋液含糖量12%、食盐添加量0.4%。结论：本实验所得工艺可制得营养丰富、酸甜适口的人参果果醋饮料。     

Quantitative Determination for the Major Volatile Organic Compounds of <Emphasis Type="Italic">Tuber melanosporum</Emphasis> Fermentation System by Distillation–Solid-Phase Extraction–Gas Chromatography

A method using distillation–solid-phase extraction coupled with gas chromatography and flame ionization detector was developed for assaying the major volatile organic compounds (VOCs) (i.e., 3-methyl-1-butanol, 2-methyl-1-butanol, and 2-phenylethanol) in the Tuber melanosporum fermentation system. Satisfied linearity, precision, accuracy, and recovery obtained in the method validation test indicate that the method was simple, accurate, and reproducible. Furthermore, the developed analytical method was used for the dynamic monitoring of the T. melanosporum fermentation process, and the highest amount of major VOCs was occurred on days 9 and 10. This method can be employed to monitor the VOCs in the fermentation process and thus to evaluate the VOC quality of the truffle fermentation system.     

不同菌种发酵对蚕豆酱风味成分的影响

本试验采用顶空固相萃取结合气质联用的技术检测由米曲霉、黑曲霉、根霉、毛霉4种不同单一菌种发酵的蚕豆酱在后发酵15d和40d两个时期酱醅中的香气成分。数据表明各菌种发酵的蚕豆酱在后发酵15d至40d酱醅中的挥发性成分变化较大,主要特征风味物质种类不断丰富。在后发酵前期阶段蚕豆酱中醇类和酸类物质占主要地位,随着发酵时间的延长,蚕豆酱中的醛类、酯类和杂环类物质含量会上升,而酮类及酸类物质减小。由米曲霉、黑曲霉、根霉及毛霉纯种发酵制作的4种酱中主要的特征风味物质有2,3-丁二醇、3-甲基丁醇、2-甲基丁醇、芳樟醇、苯乙醇、苯甲醛、苯乙醛、琥珀酸-3,4-二甲基苯基庚基酯、三甲基吡嗪等,且由米曲霉发酵的蚕豆酱风味物质较丰富,该菌种是制作蚕豆酱的良好发酵剂。