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。     

苹果酒香气成分代谢研究进展

苹果酒是指由苹果或苹果汁生产的一种低酒精度的发酵果酒,具有较高的营养成分和保健价值,备受人们的关注和喜爱。香气成分是评价苹果酒质量的关键因素。本文对苹果酒中主要香气成分的种类和来源、香气成分的分析方法、主要香气物质的合成途径等方面进行了综述,并对苹果酒香气成分代谢研究进行了展望。     

苹果酒的香气(综述)

苹果的香气由几十种甚至上百种物质构成，这些香气物质主要来源于原料苹果中固有的挥发性香气物质和苹果酒发酵过程中酵母的代谢产物。苹果原料中主要是一类香气物质；发酵过程中产生的主要是二类香气物质。影响香气物质生成量的因素有：原料、酵母菌种、发酵工艺、苹果酸一乳酸发酵。（孙悟）     

苹果酒香气成分研究进展

苹果酒的香气成分是构成苹果酒质量的重要因素,决定着苹果酒的风味和典型性.文中综述了苹果酒中主要的香气成分及其来源,并介绍了国内外苹果酒中香气成分的提取和分析方法.     

模糊综合评判结合响应面法优化苹果酒发酵工艺

采用模糊综合评判结合响应面法优化苹果酒发酵工艺参数,并用顶空固相微萃取气质联用（HS-SPME/GC-MS）技术分析其香气成分。以红富士苹果为原料,结合单因素试验结果,选取了酵母接种量、初始糖度、初始pH值三个主要工艺参数,采用中心组合试验设计,以苹果酒品质的模糊评判结果为目标,构建主因素突出型综合评判模型,进行响应面法分析。得到苹果酒最佳发酵工艺条件为：初始糖度19 g/100 mL,初始pH值3.5,接种量10%,发酵温度22 ℃。此条件下的苹果酒颜色金黄,酒体澄清有光泽,口感丰满协调、风格良好。苹果酒中共检测到33种香气成分,结合气味活性值（OAV）法鉴定出10种关键香气组分,这些香气物质构成了苹果酒的独特的风味。     

不同原料苹果酒的酿造特性研究

以‘金世纪’单一苹果品种及‘金世纪’、‘嘎啦’、‘澳洲青苹’混合（1∶1∶1）苹果品种为原料酿造苹果酒,并对其进行理化指标、多酚物质、香气成分测定及感官品评。结果表明,两种苹果酒理化指标差异不显著（P＞0.05）;混合发酵苹果酒中的酚类物质总量（61.88 mg/L）显著高于单独发酵苹果酒（56.90 mg/L）（P＜0.05）,其中以原儿茶酸、儿茶素、原花青素、表儿茶素和绿原酸为主。香气主要以醇类和酯类物质为主,两种苹果酒中醇类物质含量分别为216.83 mg/L和78.85 mg/L;酯类以乙酸乙酯、乙酸丙酯、乳酸乙酯和乙酸己酯为主,前三者在混合发酵苹果酒中含量均显著高于单独发酵苹果酒（P＜0.05）,使其香气更加浓郁和复杂。混合发酵苹果酒在澄清度、回味、香气、风味平衡方面更好,但在色泽方面稍差。因此,混合苹果品种发酵更适合于苹果酒的酿造。     

五种苹果品种对苹果发酵酒香气组成及感官质量的影响

以红香蕉、青香蕉、大国光、小国光、红富士5个苹果品种为原料酿造苹果酒,分别从苹果汁、苹果酒的理化指标、苹果酒的香气组成及感官质量等方面考察苹果品种对苹果酿酒特性的影响。结果表明,在供试的5个品种苹果中,红富士苹果表现出较好的酿酒特性,另外几种苹果酒也表现出明显的品种特性,具有潜在的应用价值。青香蕉、红香蕉的出汁率较低;红香蕉、青香蕉特征香气为丁酸乙酯和2-甲基丁酸乙酯等;小国光、大国光特征香气为乙酸异戊酯、乙酸苯乙酯、β-大马酮和β-紫罗兰酮等;红富士特征香气为己酸乙酯、辛酸乙酯和异戊酸乙酯等;大国光、小国光和红富士果香味较显著;红香蕉、青香蕉的酸味较强;红香蕉苦味较强;红富士表现出较好的香气愉悦度和口感愉悦度。该研究为酿酒品种的选用提供参考。     

苹果酒、醋中香气物质分析

采用GC-MS法对'95-54'、'95-117'苹果酒、醋中的香气物质的种类与含量进行检测分析.95-54苹果酒中检测出48种香气物质,占总峰面积的90.36％.95-54苹果醋中检测出42种香气物质,占总峰面积的98.66％.95-117苹果酒中检测出43种香气类物质,占总峰面积的86.59％.95-117苹果醋中检测出49种香气物质,占总峰面积的99.37％.这些香气物质主要是醇类、醛类、酮类、酸类、酯类、缩醛类和萜烯类.分析得出不同品种的苹果酒和苹果醋都存在一定的共性和差异,苹果酒和醋之间的香气差异也均符合酒醋基本特征.     

苹果蒸镏酒的后修饰

苹果浓缩汁生产时回收的天然苹果香料其主要呈香成分为环-α-己醇和酸酯类化合物，将其应用于苹果蒸镏酒的后修饰，以调整苹果酒的香气，添加量为10mL／L。使用柠檬酸调酸，添加量为3g／L。经修饰后的苹果酒酒质纯正爽口，果香宜人。     

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。     

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.     

啤酒糟苹果醋不同发酵阶段挥发性香气成分及抗氧化性变化分析

采用顶空固相微萃取（HS-SPME）结合气质联用（GC-MS）法测定啤酒糟苹果汁、苹果酒、苹果醋的挥发性成分,探究啤酒糟苹果醋不同发酵阶段挥发性香气成分及抗氧化性变化。结果表明,苹果醋不同发酵阶段样品共检测出50种挥发性化合物,其中酯类16种、醇类8种、醛类8种、酸类7种、酚类4种、其他类4种、酮类2种、醚类1种。啤酒糟苹果汁、苹果酒、苹果醋中分别共检测出12种、15种、24种挥发性物质。抗氧化活性试验结果表明,DPPH自由基的清除率顺序为啤酒糟苹果酒＞啤酒糟苹果汁＞啤酒糟苹果醋,Fe3+还原能力顺序为啤酒糟苹果汁＞啤酒糟苹果酒＞啤酒糟苹果醋。     

干型苹果酒发酵工艺条件的优化

本文是以红富士苹果为原料,经打浆、护色、酶处理、调整成分、发酵、澄清等工艺生产干型苹果酒。通过单因素试验确定了防褐变和澄清的最佳条件为:打浆后加入0.1%柠檬酸和0.04%VC护色;添加0.25%壳聚糖于苹果酒中澄清24 h。通过正交试验得到苹果酒最佳发酵工艺条件为:初始糖度为20%,接种量为8%,发酵时间为10 d。最终得到的干型苹果酒呈浅黄绿色,澄清透明,酒体丰满,酸甜适中,具有悦人的苹果果香和清新的酒香。     

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。     

Cross‐modal influence of colour from product and packaging alters perceived flavour of cider

With recent and rapidly growing consumer demand for alcoholic apple cider, markets have responded to provide for this demand. However, unlike the beer and wine industries, little consumer research exists to explore consumers' perception of cider. A large body of sensory research suggests that altering the colour of a food can significantly influence both perceived flavour of, and hedonic response to the food, despite there being no change to the food's taste or aroma qualities themselves. Our study was designed to understand how colour influences the perception of cider. A stock apple cider was subtly coloured red or green, and presented to consumers to evaluate hedonic response and for perception of flavour attributes. Following this, a cider identical to the control cider was presented with one of two labels, each featuring red or green prominently. Both the colour of the cider itself and the colour of the label significantly influenced perceived flavour and hedonic response to the ciders. Specifically, cider coloured green was perceived as being served at a colder temperature than the control, and the red sample showed an increase in perceived body. Red labelling of the cider made it seem both sweeter and fruitier. This study adds to the body of literature on multisensory perception of flavours, and may have significance for the cider industry's strategies for formulation and marketing. Copyright © 2018 The Institute of Brewing & Distilling     

Changes in headspace volatile attributes of apple cider resulting from thermal processing and storage

One attribute that frequently reflects a product's organoleptic impact is its aroma. In research presented here, a Fox-3000 Electronic Nose was used to determine and compare the aromatic profiles of samples of apple cider subjected to various thermal treatments. Initial results have indicated that exposure to temperatures of up to 90 °C for approximately 28 s acts to stabilize the aromatic properties of apple cider over a 7-day period. In contrast, there are significant changes in the aromatic profiles of fresh apple cider having no such thermal treatment over the same time period. A comparison of samples thermally treated at 60, 70, and 80 °C to non-processed cider showed minimal statistical difference on the basis of similarity indices obtained after 24-h of storage of the samples at 4 °C. Treatment at 90 °C showed significant differences from the unprocessed samples in the same test sequence. After storage for 7-days, samples that were thermally treated exhibited minimal differences from each other, however, were quite different from the non-processed sample on the basis of similarity index analysis. GC analysis was done to confirm potential differences between the samples measured using the electronic nose. Sensory testing is required to determine whether these differences affect the overall quality perception by consumers.     

苹果酒发酵过程中绿原酸胁迫对酿酒酵母生理特性的影响

在苹果酒发酵过程中,酿酒酵母会对各种胁迫和环境变化做出代谢应答.绿原酸是苹果和苹果酒中含量相对较高的一种苹果多酚类物质.本文以绿原酸为代表性苹果多酚,考察不同质量浓度的绿原酸胁迫对酿酒酵母生理特性的影响.结果表明:酿酒酵母CICC 31084在绿原酸胁迫下,主要通过改变胞内超氧化物歧化酶(SOD)活性、过氧化氢酶(CA...