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。     

Singlet Oxygen Detection Using Red Wine Extracts as Photosensitizers

Moderate consumption of red wine provides beneficial effects to health. This is attributed to polyphenol compounds present in wine such as resveratrol, quercetin, gallic acid, rutin, and vanillic acid. The amount of these antioxidants is variable; nevertheless, the main beneficial effects of red wine are attributed to resveratrol. However, it has been found that resveratrol and quercetin are able to photosensitize singlet oxygen generation and conversely, gallic acid acts as quencher. Therefore, and since resveratrol and quercetin are some of the most important antioxidants reported in red wines, the aim of this research was to evaluate the photosensitizing ability of 12 red wine extracts through photo‐oxidation of ergosterol. The presence of ¹O₂ was detected by ergosterol conversion into peroxide of ergosterol through ¹H NMR analysis. Our results showed that 10 wine extracts were able to act as photosensitizers in the generation of singlet oxygen. The presence of ¹O₂ can damage other compounds of red wine and cause possible organoleptic alterations. Finally, although the reaction conditions employed in this research do not resemble the inherent conditions in wine making processing or storing, or even during its consumption, this knowledge could be useful to prevent possible pro‐oxidant effects and avoid detrimental effects in red wines.     

The Impact of Milling and Thermal Processing on Phenolic Compounds in Cereal Grains

Consumption of wholegrain foods has been recommended for healthy diets. The beneficial health properties of wholegrain products have been associated with the presence of higher amounts of dietary fiber and antioxidants and lower calories as compared to their respective refined ones. Phenolic compounds are mainly attributed to antioxidant properties of wholegrain foods. This review article provides a single comprehensive source that describes effects of milling and thermal processing on phenolic compounds and antioxidant properties in cereals. In general, milling and pearling processes affect the distribution of phenolic, compounds and thus antioxidant properties vary among the milling fractions. Thermal processes such as baking and extrusion could cause negative or positive effects on phenolic compounds and antioxidant properties of the end product subject to grain type and processing conditions. Thus factors that enhance health benefits of wholegrain cereal products have been discussed.     

Resveratrol,human health and winemaking perspectives

Resveratrol, (3, 5, 4′-trihydroxystilbene) is a non-flavonoid polyphenol stilbene synthesized by plants when damaged by infectious diseases or ionizing radiation. Although present in more than seventy plant species, grapes and wine are the major dietary contributors of resveratrol, responsible for 98% of the daily intake. In 1992, Renaud and De Lorgeril first linked wine polyphenols, including resveratrol, to the potential health benefits ascribed to regular and moderate wine consumption (the so called “French Paradox”). Since then, resveratrol has received increasing scientific interest, leading to research on its biological actions, and to a large number of published papers, which have been collected and discussed in this review. The relatively low amounts of resveratrol measured in wine following moderate consumption, however, may be insufficient to mitigate biological damage, such as that due to oxidative stress. On this basis, the authors also highlight the importance of viticulture and the winemaking process to enhance resveratrol concentrations in wine in order to bolster potential health benefits.     

Performance of purified grape pomace as a fining agent to reduce the levels of some contaminants from wine

The quality of red wine depends on the absence of compounds which may affect its safety and/or stability such as ochratoxin A, biogenic amines and some metals and trace compounds. The presence of ochratoxin A in musts and wines is due to fungal contamination of the grapes and has been classified as a possible human carcinogen. Biogenic amines are formed by the microbiological decarboxylation of the corresponding amino acid precursors during the fermentation or ageing and storage, and, at high concentrations, they may induce adverse reactions in sensitive people. Trace elements may have both a nutritional and a toxic effect on health, but also can cause turbidity and stability problems. Their presence is affected mainly by natural factors such as soil mineral content and direct contact with tank surfaces and metallic tubing during winemaking. One of the best options to remove these compounds when present in excess in wine is fining. However, some fining agents commonly used may themselves present problems related with their allergenic properties or with their propensity to increase the protein content, which can cause turbidity problems. In an attempt to avoid such these problems, purified grape pomace was tested as a fining alternative since it has been seen to have a high capacity to reduce the astringency, turbidity and also the ochratoxin A content. The main aim of this work, therefore, was to study if this material can limit the presence of ochratoxin A, biogenic amines and metals and some trace elements in a Monastrell red wine, thus increasing the value and safety of this product.     

Spoilage yeasts in the wine industry

Yeasts play a central role in the spoilage of foods and beverages, mainly those with high acidity and reduced water activity (a(w)). A few species are capable of spoiling foods produced according to good manufacturing practices (GMPs). These can survive and grow under stress conditions where other microorganisms are not competitive. However, many of the aspects determining yeast spoilage have yet to be clarified. This critical review uses the wine industry as a case study where serious microbiological problems are caused by yeasts. First, the limitations of the available tools to assess the presence of spoilage yeasts in foods are discussed. Next, yeasts and factors promoting their colonisation in grapes and wines are discussed from the ecological perspective, demonstrating that a deeper knowledge of vineyard and winery ecosystems is essential to establish the origin of wine spoilage yeasts, their routes of contamination, critical points of yeast infection, and of course, their control. Further, zymological indicators are discussed as important tools to assess the microbiological quality of wines, although they are rarely used by the wine industry.The concepts of the susceptibility of wine to spoilage yeasts and wine stability are addressed based on scientific knowledge and industrial practices for monitoring yeast contamination. A discussion on acceptable levels of yeasts and microbiological criteria in the wine industry is supported by data obtained from wineries, wholesalers, and the scientific literature.Finally, future directions for applied research are proposed, involving collaboration between scientists and industry to improve the quality of wine and methods for monitoring the presence of yeast.     

苹果酸-乳酸发酵对葡萄酒中活性成分的影响

苹果酸-乳酸发酵是优质红葡萄酒酿造中必不可少的工艺之一,经过苹果酸-乳酸发酵,不但能有效降低葡萄酒的酸度,而且活性成分的含量或种类也会增加,从而提高葡萄酒对人体健康的正面影响。本文综述了经苹果酸-乳酸发酵的葡萄酒中氨基酸、益生菌、有机酸、多酚类物质、高级醇和酯类的变化,并简要介绍其抗癌、抗氧化、抗心血管疾病及抗菌消炎的功效,另外,还发现了一些活性成分如维生素、矿物质等在苹果酸-乳酸发酵前后的变化情况罕有报道,可作为进一步的研究方向。本文以期为研究利用中国野生葡萄种质资源、酿造优质中国野生葡萄酒提供参考。     

Should Red Wine Be Considered a Functional Food?

Abstract: Functional foods may be regarded as foods that have nutritional value, but in particular, they also have beneficial effects on one or more body functions. Thus, functional foods may improve health and/or reduce the risk of developing certain diseases when taken in amounts that can be consumed in a normal diet. Based on nearly 2 decades of research since the term “French paradox” was first coined in 1992, wine would appear to fit this definition. Yet there seems to be reluctance to consider wine as a functional food. In this review, we present an overview of the accumulated evidence for the health benefits of wine—and its key phenolic components such as resveratrol, quercetin, catechin—and show that these alone are not enough to firmly establish wine as a functional food. What is required is to create clearly defined products based on wine that are targeted to consumers’ needs and expectations when it comes to purchasing functional foods. Moreover, the crucial question of alcohol and health also needs to be addressed by the functional food industry. Suggestions are presented for working through this issue, but in many regards, wine is like any other food—it should be consumed sensibly and in amounts that are beneficial to health. Overindulgence of any kind does not promote good health.     

Chemical compounds and mechanisms involved in the formation and stabilization of foam in sparkling wines

The visual properties of sparkling wine including foam and bubbles are an indicator of sparkling wine quality. Foam properties, particularly foam height (FH) and foam stability (TS), are significantly influenced by the chemical composition of the wine. This review investigates our current knowledge of specific chemical compounds and, the mechanisms by which they influence the foam properties of sparkling wines. Grape and yeast proteins, amino acids, polysaccharides, phenolic compounds, organic acids, fatty acids, ethanol and sugar are examined with respect to their contribution to foam characteristics in sparkling wines made with the Traditional, Transfer, and Charmat and carbonation methods. Contradictory results have been identified that appear to be due to the analytical methods used to measure and quantify compounds and foam. Biopolymer complexes are discussed and absent knowledge with regards to thaumatin-like proteins (TLPs), polysaccharides, amino acids, oak-derived phenolic compounds and organic acids are identified. Future research is also likely to concentrate on visual analysis of sparkling wines by in-depth imaging analysis and specific sensory analysis techniques.     

The role of diet in prevention and management of type 2 diabetes: implications for public health

The aim of this review is to examine the current scientific knowledge on the relationship between diet and Type 2 diabetes and consider further implications for public health. The review focuses on the main nutritional elements which have been identified as significant in the prevention and management of Type 2 diabetes. Research findings on the role of carbohydrate, fiber, alcohol, and individual fatty acids are discussed, while the role of specific micro-nutrients and the influence of obesity are comprehensively presented. The association between dietary habits and Type 2 diabetes etiology and management is also reviewed, in order to examine the positive effects of adherence to a healthy dietary pattern, including the plausible role of the Mediterranean diet.     

Ascorbic acid and white wine production: a review of beneficial versus detrimental impacts

We review the use of ascorbic acid in winemaking and the benefits as well as the detrimental outcomes associated with its use. Initial discussion focuses on the antioxidant activity of ascorbic acid. The impact of the wine matrix and wine production practices, especially storage in bottle and oxygen ingress, on its antioxidant efficiency is discussed. The complementary roles of the antioxidant pair, ascorbic acid and sulfur dioxide, are presented. Thereafter, the ability of ascorbic acid to contribute to spoilage processes is covered. This includes both pro‐oxidant and non‐oxidative mechanisms induced by ascorbic acid that may lead to a reduced shelf life of white wine. Based on this review of scientific literature, the conditions most conducive to the beneficial impacts of ascorbic acid in wine are highlighted. Areas where lack of chemical knowledge still exists are identified for future research.     

Milk fatty acids and potential health benefits: An updated vision

BackgroundMilk fat intake is often associated with a high risk of suffering from cardiovascular disease (CVD) due to its high saturated fat content. However, not all saturated fatty acids (SFA) are equal and they present structural differences that promote distinct effects on the biological processes. In addition, there is a growing scientific consensus pointing to dairy fat as a natural source of bioactive components.Scope and approachThe present review provides the most recent knowledge on the bioactive properties of fatty acids detected in dairy products and their potential effects on consumer health. The metabolic processes that involve these fatty acids and serious chronic diseases such as CVD, obesity, diabetes or cancer are explained and discussed throughout the text based on in vitro, animal and human studies. Moreover, information gaps are highlighted to inspire further research in the field.Key findings and conclusionsRecent investigations support that milk SFA should no longer be considered as a single group in terms of metabolism or negative effects in case of excess. Even they suggest that individual SFA possess specific properties associated with important physiological functions. Whole dairy products would also promote human health due to the presence of certain bioactive fatty acids. Among them, it is worth mentioning the maintenance of gut microbiota and weight control from short and medium-chain SFA, the essential role of branched-chain SFA in gut health at birth and the prevention of chronic inflammatory diseases by vaccenic and rumenic acids.     

Phenolic compounds: evidence for inhibitory effects against obesity and their underlying molecular signaling mechanisms

Phenolic compounds are widely present in the plant kingdom. Many epidemiological studies have indicated that consumption of some plant-derived foodstuffs with high phenolic content is associated with the prevention of some diseases and that these compounds may have similar properties to antioxidants, antimutagenic agents, antithrombotic agents, anti-inflammatory agents, anti-HIV-1, and anticancer agents. However, obesity is an important topic in the world of public health and preventive medicine. Relationships between body mass index, waist circumference, or waist-to-hip ratio and the risk of development of some diseases (such as heart disease, dyslipidemia, hypertension, non-alcoholic fatty liver disease, diabetes, kidney failure, cancer, stroke, osteoarthritis, and sleep apnea) have been observed. Evidence that phenolic compounds have beneficial effects in fighting obesity is increasingly being reported in the scientific literature. These in vitro and in vivo effects of phenolic compounds on the induction of pre-adipocytic and adipocytic apoptosis and inhibition of adipocytic lipid accumulation are considered in detail here. This review presents evidence of their inhibitory effects on obesity and their underlying molecular signaling mechanisms.     

Current knowledge of the health benefits and disadvantages of wine consumption

This review examines studies reporting effects of various components in red and white wine that may offer potential health benefits or disadvantages. While this article does not advocate consumption of wine for this purpose, it intends to allow the reader to approach a decision of their own based on its content. Naturally occurring substances (e.g., resveratrol, quercetin, and catechin) are discussed and the multiplicity of their action is detailed. These include their pharmacological roles as antioxidants, anti-inflammatory and anti-clotting agents [1]. Such mechanistic roles extend to improved clinical outcomes [2] inclusive of reductions in coronary heart disease, cerebrovascular disease, dyslipidemia, and thromboses via inhibited platelet aggregation. Derived from grape skin, many of these ingredients are an excellent source of polyphenols (anthocyanins leucoanthocyanins). Current theory advocates that polyphenols in red wine protect the cardiovascular system and function as antioxidants. They prevent substances from being converted to harmful oxidized chemical states, including low-density lipoprotein (LDL) [3], also known as bad cholesterol. Largely involved in the build-up of arterial plaque, LDL can promulgate coronary heart disease. Reduction of LDL, and elevation of high-density lipoprotein (HDL) [4], are factors thought to contribute to a reduced risk of coronary heart disease. Other agents known as anthocyanins aid in restricting the formation of nitrosamines and other nitroso compounds found in foods. Therefore, such agents protect cells from the ill effects of nitrosamines and add to the nitroso-lowering effect of ascorbic acid. Other studies involving red wine examine correlations between consumption and reduction in the formation of breast cancer and ischemic heart disease at moderate and high consumption 5, 6. Others assess overall improvement in mortality rates in women; reduction of type II diabetes [7]; effectiveness as an anti-bacterial agent; and the claimed superiority of wine over alternative beverages containing an equivalent amount of alcohol 8, 9. Also, numerous studies expanding on the above points and concerns about additives, contaminants, pesticides, and carcinogens contained in wine are discussed below.     

葡萄酒中多酚及多酚氧化酶研究现状与展望

葡萄酒富含多种营养与保健成分,具有预防心脑血管疾病、抗氧化、抗菌、抗癌、助眠等保健功效,葡萄酒中多酚类物质因具有极强的抗氧化、抗菌与预防心脑血管疾病等生理药理活性而倍受人们推崇,但多酚氧化酶会氧化破坏葡萄酒中的多酚,不仅会使葡萄酒变色变质变味,还会使其营养和保健价值明显降低。对葡萄酒中的多酚以及多酚氧化酶进行深入研究不仅有利于优质葡萄酒的研发与生产,还将为相关食品药品与果酒科学的研究提供借鉴。该文主要对目前国内外对葡萄酒中多酚及多酚氧化酶的种类、制备方法、酶活测定方法、酶活的影响因素等内容的研究现状进行了概述,并对有待加强的研发内容及其前景进行了展望。     

The 'buttery' attribute of wine--diacetyl--desirability, spoilage and beyond

The diketone, diacetyl, is a major flavour metabolite produced by lactic acid bacteria (LAB). Of the LAB associated with wine, Oenococcus oeni is encouraged during the malolactic (ML) fermentation, a biodeacidification of wine during which the metabolism of diacetyl occurs. Diacetyl, which imparts a buttery aroma and flavour to many fermented foods and beverages, is a key flavour compound of most fermented dairy products. In wine, diacetyl has important stylistic implications. The biosynthesis of diacetyl is dependent upon citric acid metabolism and diacetyl is an intermediate metabolite which can be further reduced to acetoin and the alcohol, 2,3-butanediol. This review will focus on the sensory perception, metabolism, genetics and analysis of diacetyl during wine production. The extensive knowledge of diacetyl metabolism in dairy LAB is used to enhance the understanding of diacetyl metabolism of wine LAB. Factors which can effect the formation and concentration of diacetyl in wine are discussed. These include malolactic bacterial strain, wine chemical and physical parameters (pH, temperature, citric acid, sulfur dioxide, aeration) and the presence of yeast lees. Finally, the affects of other wine components, such as phenolics, are discussed.     

The bioavailability and absorption of anthocyanins: towards a better understanding

Evidence that anthocyanin compounds have beneficial effects for health are increasingly being reported in the scientific literature and these compounds are now widely recognised as potential therapeutic compounds. Berry fruit are rich sources of anthocyanins and berry fruit products or derived beverages can provide 10s to 100s of milligrams of anthocyanins in a single serve. Anthocyanins exhibit complex chemical behaviours in vitro and this will result in complex behaviour in vivo. This review attempts to summarize some aspects of anthocyanin biochemistry and discusses these in the context of what is currently known about bioavailability and absorption. Compared with other flavonoid groups, such as flavonols, relatively little is known about details and mechanisms of anthocyanin absorption and transport and much remains to be discovered.