酿酒酵母-酒类酒球菌接种方式对樱桃酒品质的影响

对比分析了酿酒酵母(F10)-酒类酒球菌(VP41)顺序接种和同时接种2种模式对樱桃酒的发酵过程、酒体成分、生物胺含量以及感官质量的影响。结果显示,同时接种模式能够缩短发酵时间,更高效地萃取樱桃果浆中的多酚和花色苷,降低色胺、苯乙胺、亚精胺和组胺的生成量,赋予樱桃酒更浓郁的果香。因此,酿酒酵母-酒类酒球菌同时接种模式具有在樱桃酒生产中推广应用的潜力。     

Antimicrobial activity of nisin against Oenococcus oeni and other wine bacteria

Nisin is a bacteriocin used against food spoilage bacteria. Sulphur dioxide is a potent antioxidant as well as an antimicrobial agent widely used in the wine industry. In this study we describe the effect of these important antibacterial agents on the growth of a collection of 64 lactic acid bacteria (23 Oenococcus, 29 Lactobacillus, 3 Leuconostoc and 9 Pediococcus), 23 acetic acid bacteria and 20 yeast isolates, most of them recovered from wine. Minimal inhibitory concentrations (MIC) and minimal bactericide concentrations of nisin, potassium metabisulphite and ethanol were determined. Nisin MIC(50) values for the tested isolates were as follows: 0.024, 12.5, 200 and > or micro for oenococci, lactobacilli-pediococci-leuconostoc, acetic acid bacteria and yeasts, respectively. Synergistic effects on bacterial growth inhibition were observed, and potassium metabisulphite MIC(50) values decreased from one to three orders of dilution when it was combined with subinhibitory concentrations of nisin in the growth media. This effect was observed in all lactic acid bacteria species of our study. Significant differences in nisin sensitivity were observed between Gram-positive and Gram-negative bacteria, and between Oenococcus oeni and other species of lactic acid bacteria. It is concluded that appropriate combinations of nisin and metabisulphite could control the growth of spoilage bacteria in wine and therefore allow a decrease in the levels of sulphur dioxide currently used by the wine industry.     

Oak wine barrel as an active vessel: A critical review of past and current knowledge

ABSTRACT

We review the role of the oak barrel as an active vessel for wine maturation. We present a historical background to highlight that previously established aspects of processes occurring with wine inside the oak barrel are still without confirmation. We argue that recently published new findings on the topic are determining factors in defining the manner in which the oak barrel works with wine. Several studies have been published reviewing how the wine barrel functions as an active vessel that releases chemical compounds into the wine, improving its physical, chemical, and sensory properties. Nevertheless, there are hardly any studies that describe how a wine barrel functions as an active vessel. The present review details the main factors affecting the gas exchange capacity of the barrel, such as the pressure drop generated within the barrel, the formation of a headspace, the effect of wood anatomy, the different oxygen entry routes, the role of wood moisture content and soluble ellagitannins, and the effect of barrel toasting on cooperage. Finally, a hypothesis is proposed regarding the function of the barrel as an active vessel, which determines the manner in which it interacts with the wine that it contains during aging.     

Both arginine and fructose stimulate pH-independent resistance in the wine bacteria Oenococcus oeni

The wine bacteria Oenococcus oeni has to cope with harsh environmental conditions including an acidic pH, a high alcoholic content, and growth inhibitory compounds such as fatty acids, phenolic acids and tannins. So how can O. oeni bacteria naturally present on the surface of grape berries acquire a natural resistance that will alleviate the effect of wine stresses? One mechanism displayed by O. oeni and many other bacteria against the damaging effects of acid environments is arginine consumption through the arginine deiminase pathway. Various studies have shown that the bacterial protection conferred by arginine depends on the rise in pH associated with ammonia production. However, many experimental results disagree with this point of view. The aim of this study was to clarify the protective effect of arginine on O. oeni stress adaptation. Is it only by increasing the pH through ammonia production that this effect is triggered, or does stimulation of appropriate cellular responses play an additional role? This study shows that: (a) arginine in combination with fructose triggers the expression of a subset of genes which are also stress-responsive; (b) cultivation of O. oeni in a fructose- and arginine-supplemented medium prior to wine exposure protects bacteria against subsequent wine shock, and (c) this acquired stress resistance is independent of pH.     

Saccharomyces cerevisiae and Hanseniaspora uvarum mixed starter cultures: Influence of microbial/physical interactions on wine characteristics

The growing trend in the wine industry is the revaluation of the role of non-Saccharomyces yeasts, promoting the use of these yeasts in association with Saccharomyces cerevisiae. Non-Saccharomyces yeasts contribute to improve wine complexity and organoleptic composition. However, the use of mixed starters needs to better understand the effect of the interaction between these species during alcoholic fermentation. The aim of this study is to evaluate the influence of mixed starter cultures, composed by combination of different S. cerevisiae and Hanseniaspora uvarum strains, on wine characteristics and to investigate the role of cell-to-cell contact on the metabolites produced during alcoholic fermentation. In the first step, three H. uvarum and two S. cerevisiae strains, previously selected, were tested during mixed fermentations in natural red grape must in order to evaluate yeast population dynamics during inoculated fermentation and influence of mixed starter cultures on wine quality. One selected mixed starter was tested in a double-compartment fermentor in order to compare mixed inoculations of S. cerevisiae/H. uvarum with and without physical separation. Our results revealed that physical contact between S. cerevisiae and H. uvarum affected the viability of H. uvarum strain, influencing also the metabolic behaviour of the strains. Although different researches are available on the role of cell-to-cell contact-mediated interactions on cell viability of the strains included in the mixed starter, to our knowledge, very few studies have evaluated the influence of cell-to-cell contact on the chemical characteristics of wine.     

Oenococcus oeni,a species born and moulded in wine: a critical review of the stress impacts of wine and the physiological responses

Oenococcus oeni is a lactic acid bacterium highly adapted to the stressful environment of wine, and is widely used as an industrial starter culture to conduct malolactic fermentation (MLF), the conversion of L‐malate to L‐lactate. Some cold‐climate wine regions still produce wines which prove too stressful for the application of a starter culture, resulting in sluggish or stuck MLFs which compromise the quality and stability of the wine. The literature on the three primary stress factors, low pH, ethanol and SO₂, is reviewed as well as their toxic mechanisms; possible interactions between the stress factors are also discussed. In particular, the toxic mechanisms of SO₂, an extremely inhibitory compound, are poorly understood. in vitro studies as well as in vivo studies in other prokaryotes point to numerous mechanisms which could have widespread impacts on the cell envelope, proteins and DNA in O. oeni. We also review the responses of O. oeni to these stress factors and offer a simplified model of events which cultures inoculated into particularly stressful wines may experience. Although significant advances have been made in our understanding of the stress responses in recent years, many fundamental aspects still require study.     

不同发酵条件对模拟葡萄酒中酒酒球菌柠檬酸代谢的影响

以酒酒球菌31-DH进行模拟酒苹果酸-乳酸发酵,使用离子排斥色谱法测定相关代谢物质的含量,研究苹果酸-乳酸发酵期间及发酵后p H、乙醇和葡萄糖对柠檬酸代谢的影响。结果表明:该方法耗时短、前处理简单、分离度良好、回收率为87%¹08%、精密度为0.77%⁴.33%,满足分析要求。当发酵液处于低p H,高酒精度,低葡萄糖浓度时,柠檬酸代谢缓慢,乳酸、乙酸及2,3-丁二醇的产量较低,双乙酰含量峰值较高。当发酵液中不含有乙醇时,苹果酸、柠檬酸、葡萄糖代谢迅速,伴随菌体的大量生长,乳酸、乙酸、2,3-丁二醇含量较高,但无双乙酰的产生。当发酵液中不含有葡萄糖时,柠檬酸代谢速率加快,乳酸产量较低,2,3-丁二醇及双乙酰产量较高。p H、乙醇、葡萄糖均显著影响酒酒球菌31-DH对柠檬酸的代谢。      

Antimicrobial activity of pediocin PA-1 against Oenococcus oeni and other wine bacteria

Pediocin PA-1 is an antimicrobial peptide produced by lactic acid bacteria (LAB) that has been sufficiently well characterised to be used in food industry as a biopreservative. Sulphur dioxide is the traditional antimicrobial agent used during the winemaking process to control bacterial growth and wine spoilage. In this study, we describe the effect of pediocin PA-1 alone and in combination with sulphur dioxide and ethanol on the growth of a collection of 53 oenological LAB, 18 acetic acid bacteria and 16 yeast strains; in addition, production of pediocin PA-1 by Pediococcus acidilactici J347-29 in presence of ethanol and grape must is also reported. Inhibitory concentrations (IC) and minimal bactericide concentrations of pediocin PA-1 were determined against LAB, and revealed a bacteriostatic effect. Oenococcus oeni resulted more sensitive to pediocin PA-1 (IC₅₀ = 19 ng/ml) than the other LAB species (IC₅₀ = 312 ng/ml). Cooperative inhibitory effects of pediocin PA-1 and either sulphur dioxide or ethanol were observed on LAB growth. Moreover, the pediocin PA-1 producing P. acidilactici strain J347-29 was able to grow and produce the bacteriocin in presence of ethanol (up to 4% ethanol in the fermentation broth) and grape must (up to 80%), which indicated that pediocin PA-1 can be considered as a potential biopreservative in winemaking.     

Yeast interactions and wine flavour

Wine is the product of complex interactions between fungi, yeasts and bacteria that commence in the vineyard and continue throughout the fermentation process until packaging. Although grape cultivar and cultivation provide the foundations of wine flavour, microorganisms, especially yeasts, impact on the subtlety and individuality of the flavour response. Consequently, it is important to identify and understand the ecological interactions that occur between the different microbial groups, species and strains. These interactions encompass yeast-yeast, yeast-filamentous fungi and yeast-bacteria responses. The surface of healthy grapes has a predominance of Aureobasidium pullulans, Metschnikowia, Hanseniaspora (Kloeckera), Cryptococcus and Rhodotorula species depending on stage of maturity. This microflora moderates the growth of spoilage and mycotoxigenic fungi on grapes, the species and strains of yeasts that contribute to alcoholic fermentation, and the bacteria that contribute to malolactic fermentation. Damaged grapes have increased populations of lactic and acetic acid bacteria that impact on yeasts during alcoholic fermentation. Alcoholic fermentation is characterised by the successional growth of various yeast species and strains, where yeast-yeast interactions determine the ecology. Through yeast-bacterial interactions, this ecology can determine progression of the malolactic fermentation, and potential growth of spoilage bacteria in the final product. The mechanisms by which one species/strain impacts on another in grape-wine ecosystems include: production of lytic enzymes, ethanol, sulphur dioxide and killer toxin/bacteriocin like peptides; nutrient depletion including removal of oxygen, and production of carbon dioxide; and release of cell autolytic components. Cell-cell communication through quorum sensing molecules needs investigation.     

Old world and new world wine concepts of terroir and wine: perspectives of three renowned non-French wine makers

The concept of ‘terroir’ has roots steeped in French history of wine and evocative stories of the land. Today terroir is important as a quality marker in brand management for upmarket wines. French wines have benefited from their historical connotation with terroir but other wine growing countries have also adopted the term to mean characteristics in wine attributable to place of origin. However there is no universally accepted definition of terroir except to say it refers to a particular place. This paper addresses this ambiguity by seeking the practice-based views of three experienced non-French winemakers. This reveals a social dimension to terroir that in various degrees supports and extends both the technical/scientific progress and brand value for premium wines in both Old and New World regions. This article contributes to the growing body of research that seeks to understand the practicality of terroir as a marketing and brand value indicator.     

酒酒球菌和酿酒酵母共接种发酵动力学模型建立

为研究酿酒酵母(Saccharomyces cerevisiae)和酒酒球菌(Oenococcus oeni)共发酵过程中菌体生长、底物消耗和产物生成的动力学变化,选取本土O.oeni ZX-1、MG-1分别与S.cerevisiae VW、AW同时接种,每隔24 h测定发酵体系内S.cerevisiae活菌数、还原糖含量、乙醇体积分数、O.oeni活菌数和L-苹果酸含量,采用经典Logistic、Boltzmann、SGompertz和DoseResp模型对测定值进行非线性拟合。结果表明,Boltzmann模型可以较好地反映S.cerevisiae生长和乙醇体积分数变化;Logistic模型对还原糖含量变化拟合效果最佳;4个处理组的O.oeni生长和L-苹果酸含量变化动力学模型中,Boltzmann模型和DoseResp模型拟合系数R²一致,均能较好预测共发酵过程中O.oeni生长和L-苹果酸含量的变化趋势。综合分析,供试本土O.oeni分别与S.cerevisiae VW、AW共接种均可顺利完成发酵,建立的动力学模型可为本土菌株的工业化酿酒工艺优化控制提供数据...     

Potential formation of ethyl carbamate in simulated wine inoculated with Oenococcus oeni and Lactobacillus plantarum

The production of ethyl carbamate (EC) and its precursor citrulline by two strains of Oenococcus oeni and one of Lactobacillus plantarum during malolactic fermentation (MLF) was studied in different conditions of pH, temperature, and ethanol and l -malic acid concentrations. The potential EC, defined as the concentration of EC after wine is heated at 80 °C for 48 h, was also investigated. The O. oeni strains were able to degrade arginine in the conditions studied and to excrete some citrulline. In these strains, the conditions that led to a slight increase in EC were a high ethanol concentration, low pH and a high l -malic acid concentration. However, the potential EC increased with higher pH. In the case of L. plantarum , arginine was not degraded and citrulline was not produced, although the potential EC was comparable with that of the O. oeni strains studied.     

Biomarkers of meat tenderness: Present knowledge and perspectives in regards to our current understanding of the mechanisms involved

Biomarkers of the meat quality are of prime importance for meat industry, which has to satisfy consumers' expectations and, for them, meat tenderness is and will remain the primary and most important quality attribute. The tenderization of meat starts immediately after animal death with the onset of apoptosis followed by a cooperative action of endogenous proteolytic systems. Before consideration of the biomarkers identified so far, we present here some new features on the apoptotic process. Among them, the most important is the recent discovery of a complex family of serpins capable to inhibit, in a pseudo-irreversible manner, caspases, the major enzymes responsible of cell dismantling during apoptosis. The biomarkers so far identified have been then sorted and grouped according to their common biological functions. All of them refer to a series of biological pathways including glycolytic and oxidative energy production, cell detoxification, protease inhibition and production of Heat Shock Proteins. Some unusual biomarkers are also presented: annexins, galectins and peroxiredoxins. On this basis, a detailed analysis of these metabolic pathways allowed us to identify some domains of interest for future investigations. It was thus emphasized that mitochondria, an important organelle in the production of energy from carbohydrates, lipids and proteins are a central element in the initiation and development of apoptosis. It was therefore stressed forward that, in fact, very little is known about the postmortem fate of these organelles and their multiple associated activities. Other topics discussed here would provide avenues for the future in the context of identifying reliable predictors of the ultimate meat tenderness.     

葡萄酒中的酚类化合物及其对酒酒球菌生长的影响研究进展

本文综述了葡萄酒中酚类化合物的组成、特性及功能,并就有关酚类化合物对酒酒球菌生长的影响及酒酒球菌对酚类化合物的代谢进行了综述,以期为酒酒球菌苹果酸-乳酸发酵提供理论依据和指导。     

Beta-glucosidase activity in a Saccharomyces cerevisiae wine strain

Beta-glucosidase activity contributes to aroma formation during the winemaking process. This study investigated whether beta-glucosidase activity was expressed by wild Saccharomyces cerevisiae strains and by a laboratory strain. beta-Glucosidase activity was assayed on several culture media and under various growth conditions. The highest activities were obtained in Yeast Extract Peptone medium, but activity was also detected using grape juice as the growth medium, although a 25% drop activity was observed when anaerobic conditions were employed. A number of parameters affecting beta-glucosidase activity were evaluated. Optimal conditions for activity were pH 4 and a temperature of 40-50 degrees C. The results showed beta-glucosidase activity to be present during the process of winemaking, although different from the optimal conditions.     

White wine phenolics: current methods of analysis

White wine phenolic analyses are less common in the literature than analyses of red wine phenolics. Analytical techniques for white wine phenolic analyses using spectrophotometric, chromatographic, spectroscopic, and electrochemical methods are reported. The interest of research in this area combined with the advances in technology aimed at the winemaking industry are promoting the establishment of novel approaches for identifying, quantifying, and classifying phenolic compounds in white wine. This review article provides an overview of the current research into white wine phenolics through a critical discussion of the analytical methods employed. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

The effects of freezing and freeze-drying of Oenococcus oeni upon induction of malolactic fermentation in red wine

Summary The use of Oenococcus oeni starter cultures for the induction of malolactic fermentation (MLF) in wine permits control over the timing of the process and the quality of the wine. Successful inoculation of bacterial starter cultures into wine depends on the selection of suitable strains and on the preparation and conservation of those cultures. Medium for Leuconostoc oenos (MLO) is the best medium for easy and rapid growth of O. oeni cultures under laboratory controlled conditions for isolation and identification. However, this study showed that O. oeni cells inoculated in MLO failed to induce MLF in wine while cells grown in Medium of Preculture (MP) or wine, stored at −20 °C or freeze-dried retained the ability to induce MLF when inoculated in wine. Our results suggest that the use of freeze-dried cultures of O. oeni previously grown in MP is the best choice for industrial application.