Anthocyanin composition of the red wine Babić affected by maceration treatment

Identification of anthocyanins in the wine made of the Croatian autochthonous grape variety of Babić (Vitis vinifera L.) was carried out and their profile was determined by means of high-performance liquid chromatography with diode array and mass spectrometric detection. Dependence of anthocyanins content and profile on maceration treatment conditions was investigated. Statistically significant differences of anthocyanins concentration in wines Babić produced by various maceration treatments were confirmed by the use of multivariate analysis of variances. The investigation results indicated that the maceration temperature exerts higher influence on anthocyanins concentration than the duration of maceration. In addition, on the basis of anthocyanin composition and using different multivariate statistical analyses, differentiation of wines Babić according to maceration treatments was procured.     

The antimicrobial effect of wine on Listeria innocua in a model stomach system

A model stomach, containing a food matrix and a synthetic gastric fluid, was used to study the bactericidal effect of ingested wine on Listeria innocua. Volumes of wine equivalent to the ingestion of one glass and half a bottle, led, over a period of less than 2 h, to a reduction of 3 and 4 logarithmic cycles of the initial population respectively. The influence of ethanol and organic acids, wine constituents with known antimicrobial properties, was investigated. Ethanol exhibited a higher bactericidal effect than the mixture of the main wine organic acids. When testing the organic acids separately, malic and lactic acids were found to have the strongest effect. The combination of ethanol with the organic acids acted synergistically but to a lesser extent than wine itself. The results suggest that the ingestion of wine during a meal may diminish the quantity of Listeria persisting further in the alimentary tract.     

Identification of aroma components of Spanish ‘Verdejo’ wine

Aroma components of ine resulting from fermentation of grape must from the Verdejo cultivar ere isolated by continuous liquid-liquid extraction and further fractionation on a silica gel column. One hundred and thirty-to substances, including alcohols, esters, carbonyl compounds, terpenes, acids and sulphur compounds, ere identified by using GC-MS; some had not been previously detected in ines. Data are given hich could lead to the characterisation of the Verdejo cultivar and the effect of the elaboration of young ines. The sensory contribution of some volatile compounds to the flavour of Verdejo ine is also studied.     

A novel humid electronic nose combined with an electronic tongue for assessing deterioration of wine

We report herein the use of a combined system for the analysis of the spoilage of wine when in contact with air. The system consists of a potentiometric electronic tongue and a humid electronic nose. The potentiometric electronic tongue was built with thick-film serigraphic techniques using commercially available resistances and conductors for hybrid electronic circuits; i.e. Ag, Au, Cu, Ru, AgCl, and C. The humid electronic nose was designed in order to detect vapours that emanate from the wine and are apprehended by a moist environment. The humid nose was constructed using a piece of thin cloth sewn, damped with distilled water, forming five hollows of the right size to introduce the electrodes. In this particular case four electrodes were used for the humid electronic nose: a glass electrode, aluminium (Al), graphite and platinum (Pt) wires and an Ag-AgCl reference electrode. The humid electronic nose together with the potentiometric electronic tongue were used for the evaluation of the evolution in the course of time of wine samples. Additionally to the analysis performed by the tongue and nose, the spoilage of the wines was followed via a simple determination of the titratable (total) acidity.     

大学生就业失信行为影响研究

大学生就业失信行为是近年来高校就业工作中出现的新问题。具体表现为求职材料、面试过程和协议履约的失信。运用酒与污水定律分析了此类失信行为对本人、本级同学、低年级同学和学校四个层面的影响,提出通过加强大学生就业诚信教育,建立健全就业诚信监督机制等措施,以降低就业失信行为影响。     

Applications of an oak extract on Petit Verdot grapevines. Influence on grape and wine volatile compounds

Petit Verdot vineyards were treated at veraison with a commercial aqueous French oak extract in order to determine if the extract’s volatile components can be transferred to grapes and then to wines. Three different formulations (25% (one application), 25% (four applications) and 100%) were tested, together with an eugenol and guaiacol standard solution to better follow their behaviour. The volatile compounds of treated grapes and their wines after alcoholic and malolactic fermentation and after 8 months were analysed by stir bar sorptive extraction and gas chromatography mass spectrometry (SBSE-GC–MS). The results showed that the grapes stored the volatile compounds mainly as non-volatile precursors, and some of these were released after winemaking. In the case of wines, it was possible to distinguish the control versus the ones from vineyard treatments. The different oak extract applications were evident only after alcoholic fermentation sampling, making it very interesting for young wines.     

Bioactive compounds in wine: Resveratrol,hydroxytyrosol and melatonin: A review

Regular moderate wine consumption is often associated with reduced morbidity and mortality from a variety of chronic diseases in which inflammation is the root cause. This review is focused on three of the numerous bioactive compounds present in wine: resveratrol, hydroxytyrosol and melatonin. Resveratrol and hydroxytyrosol are polyphenols. Melatonin, recently described in wine, is an indoleamine. Their structures, concentrations in wine, bioavailability, pharmacokinetic and health promoting properties are reviewed. Resveratrol seems to be one of the most promising compounds due to its bioactivity, with wine being the main source of resveratrol in diet. Hydroxytyrosol, which its main source in diet is olive oil has been also found in both red and white wine in considerable amounts. Melatonin has been found in wine in low amounts. However, both high bioactivity and bioavailability have been attributed to it. They show antioxidant, cardioprotective, anticancer, antidiabetic, neuroprotective and antiaging activities. However, human studies are still in the initial stages and therefore further studies are needed.     

Towards development of a Wine Neophobia Scale (WNS): Measuring consumer wine neophobia using an adaptation of The Food Neophobia Scale (FNS)

A Wine Neophobia Scale (WNS) was created from The Food Neophobia Scale (FNS) modified by substituting the word ‘food’ with ‘wine’ and discarding one item. Respondents (n = 207) completed the WNS in order to identify scale items. Analysis indicated that the item “I am very particular about the wine I drink” should be removed. Exploratory Factor Analysis (EFA) followed by Confirmatory Factor Analysis (CFA) provided a unidimensional model that was internally reliable. The final WNS contained eight items, rated on a 9-point scale, and giving a maximum score of 72. The WNS was test/retested, checked for reliability and validated using a cohort of 471 Australian wine consumers and was then applied to 1000 Australian respondents who had consumed wine in the past two weeks. WNS scores were split into quartile segments and respondents who scored 39 or more were identified as wine neophobics.The degree of wine neophobia increased with age, but decreased with higher education and greater income. The demographic categories where wine neophobics predominated were: in the older than 55 years of age group; having no tertiary education; and an average household income of less than AUD$75 K. Wine neophilics were mostly younger than 54 years of age, with a tertiary education and an average household income above AUD$75 K. These results confirmed the potential of the WNS to be used as a tool for pre-screening and segmentation of wine consumers.     

Preliminary evaluation of biogenic amines content in Chilean young varietal wines by HPLC

Biogenic amines are organic nitrogenous compounds produced in wines mainly during malolactic fermentation. Its presence is a health risk for sensitive individuals and it could negatively affect the wine quality. The objective of this work was to determine the biogenic amines content in Chilean young varietal wines. For that, a liquid chromatographic method with pre-column derivatization was optimized and validated to achieve a reliable quantification of the most important biogenic amines in wines, i.e. histamine, tyramine, spermine, spermidine, putrescine, cadaverine and phenylethylamine. Using a face-centered central composite design derivatization and chromatographic conditions were optimized. Derivatization with dansyl chloride showed an optimum yield for all biogenic amines at 60 °C during 60 min. These derivatives were optimally separated with a C₁₈ YMC-Pack ODS-A column set a 40 °C using a mobile phase composed of acetonitrile and water under gradient conditions. An effective separation and quantification of the biogenic amines was achieved in 40 min using ultraviolet detection at 254 nm. Validation was established according to ICH guidelines, calibrations in matrix fitted a linear regression model with R² > 0.997. Repeatability (n = 6) and intermediate precision (n = 3) in matrix showed RSD values <2.34% and <3.16%, respectively. This method was applied to determine for the first time the biogenic amines content in Chilean wines. Twenty-seven samples of young varietal wines, i.e. Cabernet Sauvignon (n = 9), Merlot (n = 8) and Carménère (n = 10) were analyzed finding a biogenic amines content from 18.12 to 39.84 mg L^-1, where putrescine showed the highest concentration in all grape varieties. No significant difference was found between grapes varieties regarding total biogenic amines content (P = 0.7842, df = 26). Along with putrescine, histamine and tyramine were the most abundant biogenic amines but similar levels were also observed with spermidine.