Protection of volatile esters and terpenes during storage of a white wine and a model wine medium by a mixture of N-acetyl-cysteine and caffeic acid

A mixture of N-acetyl-cysteine + caffeic acid, at 10 + 30 mg/L respectively, was tested as inhibitor of the decrease of volatile esters and terpenes during storage of Debina white wine. Moreover, the inhibition of the decrease of isoamyl acetate, ethyl hexanoate and linalool in a model wine medium by the mixture, at 1.25 + 3.75 to 10 + 30 mg/L, was tested. Several volatiles, such as isoamyl acetate, ethyl hexanoate, ethyl octanoate, ethyl decanoate and linalool, decreased during wine storage. The mixture of N-acetyl-cysteine + caffeic acid restricted the decrease of these volatiles to a large extent. In the model medium, the mixture inhibited the decrease of the three volatiles in a dose dependent manner. It was active at any concentration tested. The present results indicate that mixture of N-acetyl-cysteine + caffeic acid, containing each compound at low concentration, may be taken into account as an effective inhibitor of the disappearance of volatile aroma in wines.     

Inhibition of the decrease of volatile esters and terpenes during storage of a white wine and a model wine medium by glutathione and N-acetylcysteine

Glutathione and N‐acetylcysteine, each at 20 mg L^?1, were tested as inhibitors of the decrease of volatile esters and terpenes during storage of Debina white wine. Moreover, the inhibition of the decrease of isoamyl acetate, ethyl hexanoate and linalool in a model wine medium by glutathione and N‐acetylcysteine, each at 0–20 mg L^?1, was also tested. Several volatiles, such as isoamyl acetate, ethyl hexanoate, ethyl octanoate, ethyl decanoate and linalool, decreased during wine storage. Glutathione or N‐acetylcysteine significantly restricted the decrease of these volatiles. In the model medium, each thiol inhibited the decrease of the three volatiles in a dose‐dependent manner. N‐acetylcysteine inhibited the decrease of all three volatiles at 2.5 mg L^?1 while glutathione at 2.5 or 5.0 mg L^?1. The present results indicate that glutathione and N‐acetylcysteine may be taken into account as potent inhibitors of the disappearance of aromatic esters and terpenes in wines.     

搅拌棒萃取-气相色谱-质谱联用法分析‘媚丽’桃红葡萄酒中的香气成分

采用搅拌棒萃取法-气相色谱-质谱联用技术,对‘媚丽’桃红葡萄酒中的香气成分进行定量检测。结果表 明：‘媚丽’桃红葡萄酒中共检测到55 种香气成分,包括26 种酯类物质、4 种酸类物质、9 种醇类物质、6 种萜烯 类物质、3 种C13-降异戊二烯等。通过计算香气活性值发现,其中12 种香气成分对‘媚丽’桃红葡萄酒的香气有重 要贡献。这些物质是：乙酸乙酯、丁酸乙酯、己酸乙酯、辛酸乙酯、乙酸异戊酯、异丁酸乙酯、异戊酸乙酯、异戊 醇、2-苯乙醇、里哪醇、β-大马士酮和β-紫罗兰酮。感官分析结果表明：‘媚丽’桃红葡萄酒具有玫瑰香、苹果、 草莓、菠萝等香气。     

Effect of added sulphur dioxide levels on the fermentation characteristics of strawberry wine

The aim of this study to evaluate the effects of sulphur dioxide (SO₂) on strawberry wine fermentation and on the quality of the final wine product. Major aroma compounds, reducing sugars, ethanol, titratable acid and microflora were analyzed during the fermentation of strawberry wine supplemented with 0–100 mg/L SO₂. As the amount of added SO₂ increased, the consumption of reducing sugars and soluble solids and ethanol production decreased during early fermentation, but increased during late fermentation. During the fermentation process, the concentrations of 2‐phenethanol, isobutanol and isopentanol significantly increased and those of n‐propanol, isoamyl acetate and ethyl lactate decreased with increasing amount of added SO₂. The production of n‐butanol, ethyl acetate and ethyl butyrate was slightly dependent on the amount of added SO₂. Yeast cells were the dominant microbe in the fermenting strawberry pulp, and indigenous bacteria and fungi populations decreased rapidly or disappeared because of their sensitivity to SO₂. It was concluded that 60–80 mg/L SO₂ should be added during strawberry wine fermentations to improve wine quality. Copyright © 2016 The Institute of Brewing & Distilling     

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%。     

李子果酒主发酵过程中理化指标及挥发性成分变化分析

该研究对李子果酒主发酵过程中的理化指标进行测定,并采用顶空固相萃取-气相色谱-质谱（HS-SPME-GC-MS）联用技术对其挥发性成分进行分析。结果表明,在李子果酒主发酵过程中,随着发酵时间的延长,pH值、酒精度呈先升高后趋于稳定的趋势;总酸、总糖含量呈先下降后趋于稳定的趋势;挥发酸含量呈上升趋势。主发酵结束后,李子果酒的酒精度为11.10%vol、总酸含量为9.13 g/L、pH值为3.76、挥发酸含量为0.25 g/L、总糖含量为22.90 g/L。主要变化的挥发性物质为6种醇类（乙醇、1-己醇、异戊醇、异丁醇、顺式-3-己烯-1醇、苯基乙醇）和6种酯类（乙酸乙酯、乙酸异戊酯、辛酸乙酯、乙酸己酯、己酸乙酯、癸酸乙酯）。通过对李子果酒主发酵过程动态变化分析,为提高李子果酒品质提供理论依据。     

Establishment of Monstera deliciosa fruit volatile metabolomic profile at different ripening stages using solid-phase microextraction combined with gas chromatography–mass spectrometry

The volatile metabolomic profile of Monstera deliciosa fruits (M. deliciosa, ceriman) at three ripening stages, ripe, half-ripe and unripe, was established using headspace solid-phase microextraction (HS-SPME) combined with gas chromatography–quadrupole mass spectrometry detection (GC–qMS). To obtain the optimal HS-SPME conditions, the main experimental parameters that influence the extraction efficiency and experimental response were analyzed. The highest extraction efficiency was achieved with 1 g of ceriman sample, using a polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber for 60 min at 40 °C with 15% NaCl (w/w). After optimization, all ceriman samples were analyzed with the best extraction conditions that allowed to identify 80 volatile metabolites (VOMs), belonging to different chemical groups namely ethyl esters (88.61–77.94%), terpenoids (18.08–9.83%), carbonyl compounds (3.41–1.05%), higher alcohols (1.41–0.51%) and lactones (0.14–0.03%). Thirty-eight of the identified volatile metabolites (47.50%) have not been reported in M. deliciosa, so far, providing a more complete characterization of its volatile composition. The predominant VOMs identified in M. deliciosa fruits were ethyl butanoate, linalool, ethyl hexanoate, ethyl 2-methyl butanoate, butanoic acid, ethyl benzoate and propyl butanoate. Remarkable differences were found in both the quantitative and qualitative composition of M. deliciosa fruits at different ripening stages.Principal component analysis (PCA) provided a suitable tool to differentiate the volatile profile of target fruits among three ripening stages.     

The effect of heat and light on the composition of some volatile compounds in wine

HS-SPME–GC–MS analysis of Aglianico del Vulture red wine from Southern Italy showed the presence of ethyl acetate, 3-methyl-1-butanol, 3-methylbutyl acetate, ethyl hexanoate, diethyl butanedioate, ethyl octanoate, and ethyl decanoate. Thermal treatment for 24 h in the 20–60 °C range showed that for most of the compounds analysed the simple transition from 20 to 30 °C induces a significant modification on the composition of volatile compounds. A sharp decrease was observed for ethyl acetate, diethyl butanedioate, and 3-methylbutyl acetate; a moderate decrease was observed for ethyl hexanoate, while an increase was observed for 3-methyl-1-butanol, ethyl octanoate, and ethyl decanoate. The temperature of 40 °C induces the maximum evolution of this type of compound. Higher temperatures induce a reduction of volatile compounds in wine. Irradiation of Barolo (red wine, Northern Italy), Amarone (red wine, Northern Italy), and Brunello di Montalcino (red wine, Central Italy), at 20 °C was performed with a 13 W neon lamp. 3-Methyl-1-butanol was affected by the irradiation. In the case of Barolo and Amarone, we observed a moderate increase, while, for Brunello di Montalcino, a decrease was observed. In the same way, esters were degraded during irradiation. In the red wine one or more components (phenols?) are able to protect esters from photodegradation. In diethyl butanedioate and ethyl hexanoate, octanoate, and decanoate we observed an initial increase of the concentration of the esters in some cases.     

红枣发酵酒香气成分分析及感官品质评价

以甘肃地区3 个红枣品种（临泽小枣、小口枣和民勤圆枣）为原料酿造红枣酒,测定其基本理化指标和挥发性香气成分,并进行感官评价分析,以期对红枣酒的酿造及枣酒品质分析提供依据。结果表明：3 种枣酒的理化指标均符合国标要求,但临泽小枣酒样的总酸含量和色度值最高且差异显著;香气成分结合香气轮分析表明,小口枣酒样中的酯类、醇类和萜烯类香气物质含量显著较高,民勤圆枣酒样中酸类和醛酮类香气化合物含量显著较高,大马士酮、苯乙醛、己酸乙酯、乙酸异戊酯、丁酸乙酯和异戊醇可能是构成红枣酒花香、果香和溶剂味的主要成分;感官评价结果显示,小口枣酒样香气最为浓郁优雅,临泽小枣酒样具有较好的色泽和典型性,2 种枣酒的感官品质均较佳,可用于甘肃特色枣酒的生产。     

2 种产量赤霞珠葡萄酒香气和花色苷的比较

应用气相色谱-质谱联用和高效液相色谱-电喷雾离子源-质谱联用技术对卢龙县2 种产量（7 500和10 500 kg/hm2）赤霞珠葡萄酒中香气和花色苷类物质进行定性与定量分析。共检测出32 种香气物质（包括高级醇、酯类、脂肪酸、萜烯和降异戊二烯类、挥发性酚类等）和16 种花色苷类物质（包括5 种基本花色苷及其乙酰
化和香豆酰化衍生物）。结果表明,7 500 kg/hm2产量条件下赤霞珠葡萄酒中拥有较高含量的高级醇、酯类、脂肪酸、挥发性酚类及香气总量,其中异戊醇、2-苯基乙醇、乙酸乙酯、乙酸异戊酯、己酸乙酯和辛酸含量显著高于10 500 kg/hm2产量,而10 500 kg/hm2产量葡萄酒中萜烯类和降异戊二烯类物质含量略高。10 500 kg/hm2产量处理的葡萄酒中的花色苷总量高于7 500 kg/hm2产量处理的葡萄酒中花色苷总量,但花色苷单体中除花翠素葡萄糖苷和二甲花翠素葡萄糖苷外,其余花色苷含量差异均不显著。因此,幼果膨大期疏穗降低产量对葡萄酒香气组成和含量的影响大于对花色苷的影响。     

Concentration of volatile compounds in Chardonnay wine fermented in stainless steel tanks and oak barrels

The influence of the type of container used in alcoholic fermentation on the formation of volatile compounds in wine from Chardonnay variety was studied. To do so, must from Chardonnay variety was fermented in both stainless steel tanks and in new Nevers oak barrels. The results obtained showed that wine fermented in barrels had a greater concentration of higher alcohols and esters than wine fermented in tanks. Concentration of isoamyl acetate, ethyl hexanoate, ethyl octanoate and ethyl decanoate was four times higher in wine fermented in oak barrels than in wine fermented in stainless steel tanks. With regard to the concentration of acids, a greater concentration of medium-chain fatty acids (C6:0–C10:0) was noticeable in wine fermented in oak barrels. Given that these acids are toxic for the yeasts, they may be responsible for the slower fermentation rate of wine fermented in oak barrels.     

Impact of cover crops in vineyard on the aroma compounds of Vitis vinifera L. cv Cabernet Sauvignon wine

This study compared the influence of different cover crops with clean tillage on wine aroma compounds of 5-year-old Cabernet Sauvignon vines. White clover, alfalfa, and tall fescue were used in the vineyard and compared with clean tillage. Aroma compounds of wine were analysed by solid-phase microextraction gas chromatography–mass spectrometry (SPME-GC/MS). Forty-seven volatile compounds were identified and quantified. Wines made from grapes grown with various cover crops had higher levels of aroma compounds. Ethyl acetate, isoamyl acetate, ethyl octanoate, ethyl hexanoate, phenylethyl acetate, isoamyl alcohol, linalool, citronellol, β-damascenone, α-ionone, and 5-amyl-dihydro-2(3H)-furan were the impact odorants of sample wines. Wines from cover crop also had higher contents of these impact odorants than the control. For different cover crops, alfalfa sward yielded the highest levels, followed by the tall fescue treatment. According to the data analysis of aroma compounds and sensory assess, permanent cover crop may have the potential to improve wine quality.     

橄榄浸泡酒中香气成分的GC-MS分析

利用液液萃取法和顶空固相微萃取法两种方法对橄榄浸泡酒中的香气成分进行萃取,然后用气相色谱-质谱法进行检测分析,共鉴定出46种香气成分,包括醇类、酯类、酮类、醛类和酸类。橄榄浸泡酒的主要香气成分是异戊醇、异丙醇、2-丁醇、苯乙醇、2-羟基-丙酸乙酯、己酸乙酯、乙酸异戊酯、辛酸乙酯、丁酸乙酯等。     

贺兰山东麓马瑟兰干红葡萄酒香气成分的分析

利用顶空固相微萃取(HS-SPME)结合气相色谱质谱联用技术(GC-MS),初探宁夏贺兰山东麓的马瑟兰葡萄酿制的干红葡萄酒的香气物质组成及含量,并与同一种植地的赤霞珠干红葡萄酒的香气成分进行对比。结果表明,马瑟兰干红葡萄酒中共检出香气成分42种,其中辛酸乙酯、正己酸乙酯、4-甲氧基-4-甲基-2-戊醇、2,4-二甲基-3-戊醇、芳樟醇、香叶醇、乙酸异戊酯、2-丙基-1-庚醇、癸酸乙酯、2-甲基-2-硝基-1-丙醇相对含量较高。赤霞珠干红葡萄酒中共检出香气成分30种,其中辛酸乙酯、正己酸乙酯、2-丙基-1-庚醇、乙酸异戊酯、3-乙基-3-甲基庚烷、己酸己丁酯、十六烷、2,2-二甲基丁烷相对含量较高。     

A Dynamic Analysis of Higher Alcohol and Ester Release During Winemaking Fermentations

Isobutanol, isoamyl acetate and ethyl hexanoate production during winemaking fermentations was precisely described. Volatile compound concentrations and their rates of change and losses in the exhausted gas were determined throughout the fermentation. Negligible amounts of isobutanol were lost, whatever the fermentation temperature. In contrast, 56 % of the ethyl hexanoate and 34 % of the isoamyl acetate were stripped by CO₂ when the temperature profile simulated red winemaking conditions. Even at a moderate temperature of 20 °C, typical of white wine fermentations, 40 % of the ethyl hexanoate and 21 % of the isoamyl acetate were lost. The effect of temperature on the production of the volatile compounds was assessed by running fermentations at different temperatures, with the same medium and strain. By taking into account the volatile compound losses in the exhausted gas, changes in volatile compound production were found to be smaller than those usually calculated from the concentrations in the wine. These findings highlight the potential importance of knowledge concerning aroma gas–liquid balances for both an understanding of yeast metabolism and the identification of innovative control strategies minimizing aroma losses.     

Production of nutraceutics from chestnut burs by hydrolytic treatment

Chestnut (Castanea sativa) burs (CB) were processed by solvent extraction (with ethanol, toluene–ethanol or n-hexane) and/or isothermal autohydrolysis, and the potential as nutraceutics of the solubilized fractions of dietary fiber and antioxidants was evaluated. Among the studied alternatives, the most suited consisted on ethanol extraction, which yielded 21.0 g gallic acid equivalents (GAE)/100 g ethanolic CB extract, with EC_50,DPPH = 0.38 g/L. Ethanol-extracted CB were treated with water at 120 °C, and the soluble fraction was mixed with ethanol to precipitate 8.8 g soluble fiber/100 g CB, with a Water Retention Capacity of 2.4 g/g and an oil absorption capacity of 23.7 g/g. The mother liquors from the above precipitation stage were concentrated and extracted with ethyl acetate to yield an organic phase containing soluble phenolics with high antioxidant activity (EC_50,DPPH = 0.103 g/L) at a yield of 7 g/100 g CB. When the aqueous phase before the ethyl acetate extraction was treated with sulfuric acid, an additional antioxidant fraction (EC_50,DPPH = 0.395 g/L) was obtained. The properties and characteristics of these extracts produced make them good candidates to be used as active ingredients.     

Volatiles of orange juice and orange wines using spontaneous and inoculated fermentations

The effect of spontaneous fermentation and inoculated fermentation on the volatile compounds of orange wine was studied. The differences on volatile compounds of orange juice and orange wine were also observed. The volatile compounds were analyzed by sensory and instrumental analysis. Solid phase microextraction was used for extraction of volatile compounds. Sensory analysis indicated that no significant differences existed on the wine odor between the two methods. A total of 17 and 19 volatile compounds were identified and quantified in spontaneous and inoculated fermentations, respectively. Esters followed by alcohols and terpenes were the most abundant volatile compounds in the two orange wines. Thirteen of these compounds were present both in the two methods. Totally 31 volatile compounds were found in orange juice, and terpenes were quantitatively the dominant group. Esters were found to be the important volatile compounds formed during fermentation, such as isoamyl acetate, ethyl hexanoate, ethyl benzoate, diethyl succinate, ethyl decanoate and ethyl laurate, etc.