New isotopic criteria for the short-term dating of brandies and spirits

As a result of the atmospheric atomic experiments carried out in the 1960s a method for short-term dating of wines and spirits could be based on the determination of the ¹⁴C radioactivity of ethanol. However, due to the turnover of atmospheric ¹⁴CO₂ this method is no longer applicable to the most recent samples. The aptitude of stable isotopes of carbon and hydrogen to provide new probes for dating brandies such as cognacs and armagnacs is evaluated. The overall carbon isotope ratio of ethanol is measured by isotope ratio mass spectrometry and the site-specific hydrogen parameters of the methyl, (D/H)_I, and methylene, (D/H)_II, sites are determined by the SNIF-NMR method. The isotopic results can be interpreted in terms of fractionation phenomena associated with thermo-kinetic evaporation undergone in the casks during the ageing period. A theoretical estimation of the vintage founded on this isotopic evolution requires the knowledge of the isotope ratios of the starting product. In principle, these values can be estimated on the basis of the meteorological parameters associated with the growing period of the corresponding vine. However, although the combined contributions of climatic effects and of evaporation phenomena conveniently explain the general isotopic behaviour, the influence of oenological practices such as ullage (replacement of the amount of a liquid lost in a cask by evaporation) must also be considered. Further progress towards an unequivocal dating procedure using stable isotope ratios is expected from the access to isotope databanks of the wine precursors. © 1998 SCI.     

A quick method for obtaining partition factor of congeners in spirits

A quick method for obtaining empirical relative volatilities of congeners in relation to ethanol in wine-spirits systems is proposed. Wines with and without lees of fermentation were distilled in a static device similar to an equilibrium cell. Relative volatilities were deduced from vapour and liquid compositions when the system reached a stationary state. They strongly depended on the alcoholic strength but the quantity of lees was not influential. Data were employed to establish the partition factor of 10 characteristic congeners in the spirits obtained from sherries. Relative volatilities and partition factors were close to those obtained in equilibrium stills.     

Exposure of Taiwan residents to polychlorinated biphenyl congeners from farmed, ocean-caught, and imported fish

This study is to assess PCB levels in five frequently consumed fish species in Taiwan, tilapia, milkfish, white pomfret, hairtail, and cod. Seventeen congeners were measured in fillet samples purchased from major markets in northern, central, and southern Taiwan. All 136 samples had traces of PCBs. The median concentrations were 0.18, 0.46, 0.62, 0.69, and 7.34 ng/g wet wt and 1.01, 0.28, 1.14, 5.06, and 19.3 pg-WHO-TEQ/g lipid in tilapia, milkfish, white pomfret, hairtail, and cod samples, respectively. Cod (the imported fish) had the highest wet weight PCB concentrations. The fish caught off-shore (white pomfret and hairtail) had higher levels than the farmed fish (tilapia and milkfish). The congener profiles varied among species. PCB 105/153 and 126 accounted for more than 28% and 53% of the 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (WHO-TEQs) in hairtail and cod, respectively; while PCB 156 was the major TEQ contributor in the other species. The estimated median PCB intake of the general public from consumption of the five species ranged from 0.000023 to 0.048 pg-WHO-TEQ/kg/day. It was also found that samples farmed or caught along the southern coast had higher PCB levels than those from other parts of Taiwan, indicating possible elevated PCB contamination around that area.     

Chemical characteristics of Śliwowica Łącka and other plum brandies

BACKGROUND: ?liwowica ??cka is a strong, distilled, home‐made plum brandy produced in a submontane region of Poland. The aim of the present study was to determine the chemical composition of this alcoholic beverage (samples from the years 2001–2004) and compare it with that of other plum brandies. Gas chromatography and spectrophotometry methods were used to detect major volatile components. RESULTS: Home‐made Polish plum brandies generally contained more ethanol (64.7–72.5% v/v), methanol (5.59–8.74 g L^?1100°) and butanol (32–335 mg L^?1100°) and less isobutanol (406–491 mg L^?1100°), pentanol (4.3–14.9 mg L^?1100°) and 2‐phenylethanol (61–68 mg L^?1100°) than other samples. The amyl alcohols/1‐propanol and isobutanol/1‐propanol ratios might be used as indices to distinguish spontaneously fermented plum brandies from those produced by monoculture. Statistically significant differences (P < 0.01) were found in the plum brandy sensory characteristics examined. Total sensory scores of Polish plum brandies ranged between 12.0 and 14.3, while Slovakian Slivovica received the highest score (16.7). CONCLUSION: The results showed that plum brandies produced in the ??cko area are characterised by a similar and original chemical composition that results mainly from spontaneous fermentation as well as traditional production technology. Copyright © 2007 Society of Chemical Industry     

Application of principal component analysis to simple determinations of brandies as a means of verifying quality

Phenolic composition of distillates aged in wood has been widely studied, thus giving rise to different standards that establish their genuineness and quality. The present paper sets out the results for classification of Spanish brandies and cognacs according to quality by applying analysis of variance and principal component analysis to the results of simple chemical (pH, phenol content) and physical (colour) determinations and/or the relationships between them. Chemical changes that occur during the aging process are related to these parameters.

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Beurteilung des Brandies- Qualität über die hauptsächlichen Bestandteile

Zusammenfassung Die phenolische Zusammensetzung der in Holzfässern gelagerten Destillate wurde studiert, um daraus verschiedene Standards zu erarbeiten, so daß daraus die Unverfälschtheit und Qualität abgeleitet werden kann.

     

Characterisation and differentiation of grape brandies by multiple discriminant analysis

Gas chromatography has shown that clear, quantitative differences exist between the various flavour constituents of German and French grape brandies as well as French cognacs. The amounts of some selected flavour compounds from 24 grape brandies have been submitted to multiple discriminant analysis. Discriminant analysis was carried out in three parts corresponding to the column chromatographic pre-separation of volatile compounds into three fractions (I: non-polar compounds; II: oxo compounds; III: hydrophilic substances). Using the components of fraction I a statistically highly significant differentiation between French cognacs and the remaining groups of grape brandies was obtained. With the components of fractions II and III some misclassifications occurred. Only after employing all the constituents of fractions I-III was a statistically highly significant separation between French and German grape brandies as well as the group of cognacs achieved. Among the esters predominantly the ethyl esters of octanoic, butanoic, 2-furanoic and 2-hydroxy-isocaproic acid contributed towards the separation and classification of individual groups. The best differentiation was given by the contents of 1-octanol and damascenone.     

Classification of brandies and wine distillates using front face fluorescence spectroscopy

This study demonstrates the use of front face fluorescence spectroscopy and multivariate data analysis for differentiating brandies from wine distillates. Owing to the low price of the wine distillates, they are sometimes used for the counterfeiting brandies. For this reason, there is a need for a rapid method for drink authentication to reassure consumers and protect regional designations. Total luminescence and synchronous scanning fluorescence spectra were recorded followed by a classification of samples using principal component analysis (PCA) and hierarchical cluster analysis (HCA). Both PCA and HCA carried out on the emission spectra (360–650 nm) recorded at excitation wavelength 350 nm and synchronous fluorescence spectra (200–700 nm) collected at wavelength interval 90 nm provide very good differentiation between the two spirit classes. Less good classification was obtained using excitation spectra (225–425 nm) obtained at emission wavelength 440 nm. These results indicate that the front face fluorescence spectroscopy offers a promising approach for the authentication of brandies.     

Potential risk indicators of retained placenta and other diseases in multiparous cows

Retained placenta (RP), defined as fetal membranes not being expelled within 24 h after calving, is a costly disease in multiparous dairy cows that has been linked to immune suppression, infections, elevated lipid mobilization, and depleted status of antioxidants including α-tocopherol, and that increases the risk of other diseases (OD) in early lactation. Early detection of cows at increased risk of developing RP, OD, or both in early lactation could improve treatment success and result in improved milk production and reproductive performance. To identify risk indicators of RP, OD, or both, we used a nested case-control design and compared multiparous dairy cows that developed RP (n = 32) with cows that remained healthy (H; n = 32) or cows that developed OD (n = 32) in early lactation. We compared peripartal body condition score (BCS) as well as serum concentrations of α-tocopherol, metabolites [β-hydroxybutyrate (BHBA), cholesterol, glucose, nonesterified fatty acids (NEFA), and urea N], haptoglobin, and macrominerals (i.e., calcium, magnesium, and phosphorus) on d −21, −14, −7, −3, −1, 0, 1, 3, 7, 14, 21, 28, 35, 42, and 49 postpartum. In addition, average serum concentrations were calculated for each cow for the last 3 wk prepartum, for 3 and 2 wk prepartum combined, for the last week prepartum, and for the morning after calving and compared between groups. The RP cows had lower BCS than the H or OD cows until 2 wk postpartum. During the prepartal periods, RP and OD cows had lower α-tocopherol concentrations (corrected or not for cholesterol concentration) and higher NEFA and BHBA concentrations than H cows. Thus, lower prepartal BCS could be an early predictor for RP risk, and lower α-tocopherol concentrations and higher NEFA and BHBA concentrations could be early predictors for disease.     

Identification of ethylene oxide in herbs,spices and other dried vegetables imported into Italy

Gas chromatography-mass spectrometry was used to analyse ethylene oxide (EO) in 63 samples of dried vegetable materials for food use derived from import commodities and subjected to quality control for three food-transformation industries. EO residues were quantified through the determination of ethylene chlorohydrin (ECH). About 29% of the samples analysed contained more than 0.3 mg kg^?1 of EO. Thus, this specific analytical control limited to 20% of import aromatic matters needs to be increased. This paper demonstrates the importance of this specific control considering the banned use of microbial decontamination EO treatment in the European Union.     

Marine sponges as biomonitor of polychlorobiphenyl contamination: concentration and fate of 24 congeners

The aim of this study was first to assess the relevance of a marine sponge, Spongia officinalis, as a biomonitor of PCB. Twenty-four chlorobiphenyl congeners have been measured along a pollution gradient both in sponges and seawater. S. officinalis displays a capacity to accumulate all types of congeners. The highest concentration factors were found for hexa- and heptachlorobiphenyls. Concentrations recorded in sponges agreed quite well with the PCB concentrations of study sites. The prevalence of CB138 and CB153 definitely demonstrated the urban origin of the PCB detected, despite the ban on their production and the existence of a wastewater treatment plant since 1987. The CB138/CB153 ratio is approximately 1.2 in commercial mixtures as well as in seawater. In sponges, this ratio varies strongly in space and time, from 1 in sponges at the most polluted site to 0.3 at the reference site. This change in the ratio of these two very persistent congeners, which is not observed in seawater, indicates a metabolism of CB138 in sponges. As it was recently demonstrated for nonpersistent organic contaminants, sponges might well be able to degrade PCB, but further work is needed to identify the processes involved.     

Principal component analysis of proteolytic profiles as markers of authenticity of PDO cheeses

The casein fraction of 13 Portuguese PDO cheeses were analysed using Urea-PAGE and reverse phase-high performance liquid chromatography (RP-HPLC) and then subjected to chemometric evaluation. The chemometric techniques of cluster analysis (CA) and principal component analysis (PCA) were used for the classification studies. Peptide mapping using Urea-PAGE followed by CA revealed two major clusters according to the similarity of the proteolytic profile of the cheeses. PCA results were in accordance with the grouping performed using CA.CA of RP-HPLC results of the matured cheeses revealed the presence of one major cluster comprising samples manufactured with only ovine milk or milk admixtures. When the results of CA technique were compared with the two PCA approaches performed, it was found that the grouping of the samples was similar.Both approaches, revealed the potential of proteolytic profiles (which is an essential aspect of cheese maturation) as markers of authenticity of PDO cheeses in terms of ripening time and milk admixtures not mentioned on the label.     

Influence of indigenous yeasts on the fermentation and volatile profile of plum brandies

The aim of this study was to determine the influence of different yeasts isolated from fresh blue plum fruits (Aureobasidium sp.) and spontaneously fermenting plum musts (Kloeckera apiculata and Saccharomyces cerevisiae), as well as commercial wine and distillery strains, on the fermentation and chemical composition of plum brandies. Gas chromatography methods were used to detect major volatile components. The most rapid fermentation occurred in musts inoculated with S. cerevisiae. However, the highest concentration of ethanol was detected in samples after spontaneous fermentation (8.40% v/v). Plum brandies obtained after distillation contained from 66.3 (K. apiculata) up to 74.3% v/v ethanol (spontaneous fermentation). The samples after spontaneous fermentation were distinguished by a high content of acetoin, ethyl acetate and total esters, accompanied by a low level of methanol and fusel alcohols. Non-Saccharomyces yeasts were responsible for higher concentrations of esters and methanol, while S. cerevisiae strains resulted in increased levels of higher alcohols. It was also found that isolated indigenous strains of S. cerevisiae synthesized relatively low amounts of higher alcohols compared to commercial cultures. Samples obtained using the distillery strain of S. cerevisiae received the highest score (18.2) during sensory analysis and were characterized by a well-harmonised taste and aroma.     

Stable carbon isotopic analysis and the botanical origin of ethanol in Brazilian brandies

Carbon isotopic composition (δ¹³C) of Brazilian brandies was used to determine the contribution of sugar from C3 or C4 plants to their ethanol content. C3 plants have an average δ¹³C value of −27‰, against an average value of −12‰ for C4 plants. This difference is large enough to permit determination of the origin of the ethanol fermented from plants. There are two types of brandy in Brazil: one called “conhaque-de-gengibre”, where ethanol from any plant can be used, and another called “brandy”, where only ethanol from grapes can be used. The less expensive brandies, classified as “conhaque de gengibre”, have their ethanol content derived exclusively from sugar-cane (average δ¹³C equal to −12.9‰), while in the Brazilian brandies it was a mixture of sugar-cane and grapes (average δ¹³C equal to −18.0‰). In Brazilian “brandies” there was an inverse relationship between its price and the carbon isotopic composition, indicating that higher prices is associated to larger proportions of ethanol from grapes.     

Variation in the concentrations of higher alcohols,methanol and ethyl acetate in brandies

86 samples of brandy representing the produce of 15 countries, were analysed for methanol, propan-1-ol, the butanols, the pentanols and ethyl acetate, and wide variations were found between individual samples within each group. The determination of these congeners is not sufficient to identify a sample as a brandy.     

低场核磁共振在肉与肉制品水分测定与分析中的应用研究进展

目的：开展预包装即食牛肉保质期快速、准确和无损的预测方法研究,对于保障产品货架期安全具有重要意义。方法：以预包装即食牛肉为分析对象,采集样品低场核磁H质子的T₂弛豫时间,建立即食牛肉水分含量定量分析模型,结合样品感官接受性等建立预包装即食牛肉保质期预测模型。结果：预包装即食牛肉低场核磁谱图横向弛豫时间可较好地反映出随着贮存时间的延长航天即食牛肉的品质变化。建立了即食牛肉含水量预测模型,模型的预测误差小于4%;建模集相关系数（r）为0.9405,校正标准差（RMSECV）为34.5,相对分析误差（RPD）为3.1,对10个分别贮存一定时间但未参与建模的样本分别进行距离货架期终点的预测,预测结果与实测值的的相关性达0.99,预测结果的误差范围为0.7%～9.9%,RMSEP为13.6,预测模型的精确度满足货架期预测的精度要求。结论：低场核磁共振技术在预包装即食牛肉产品保质期预测方面具有应用潜力。

     

Effect of maturation conditions on sensory and antioxidant properties of old Serbian plum brandies

?ljivovica and Prepe?enica are traditional Serbian distillated beverages made from varieties of plum, of the genus Prunus. The ageing in wooden casks not only improves the sensory characteristics, but also changes the content of total polyphenols and contributes to the other important health properties, such as the increase of their antioxidant capacity. In this study, home-made brandy (?ljivovica and Prepe?enica) samples were used, which matured in casks during the time period from 10 to 47?years. The aim of this investigation was to examine the influence of the ageing parameters (time period and type of wooden casks) and raw material (plum cultivars) on the total polyphenol content, amount of certain phenol compounds, sensory properties, colour and antioxidant properties in matured brandies. The individual phenol components were determinated using HPLC system equipped with diode array detector, while the total phenol content and antioxidant activity was estimated using spectrophotometric methods (Folin?CCiocalteu, DPPH, FRAP and TEAC). Total polyphenol content (TPC) of aged Prepe?enica samples was ranged from 230.26 to 890.26?mg/L gallic acid equivalents (GAE mg/L), whereas the TPC of ?ljivovica sample was 110.38?mg/L. Antioxidant capacity of analysed Prepe?enica samples and ?ljivovica sample was in strong correlation with TPC. Total sensory score of all samples was very high and varied between 18.2 and 19.8. The obtained results have shown that the benefit of longer maturation on sensory characteristics is well recognized, but the improvement has some limitation.     

Image texture features as indicators of beef tenderness

Image processing techniques were developed to predict cooked-beef tenderness from fresh-beef image characteristics. Cattle from different finishing treatments were processed in a commercial plant. Two short loin steaks were sampled from each carcass; one used for sensory evaluation and the other for imaging. The samples varied significantly in both US quality grades and sensory tenderness scores. Color, marbling and texture features were extracted from the beef images. Statistical and neural network analyses were performed to relate the image features to sensory tenderness scores. Image texture features were found to be useful indicators of beef tenderness. Partial least squares and neural network models were able to predict beef tenderness from color, marbling and image texture features to R(2)-values up to 0.70.     

Investigation into the use of carbon isotope ratios (13C/12C) of Scotch whisky congeners to establish brand authenticity using gas chromatography-combustion-isotope ratio mass spectrometry

Volatile congeners of whisky have been analysed by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). Acetaldehyde, ethyl acetate, n-propanol, isobutanol and amyl alcohol from a popular blended whisky have been separated using established GC conditions and their δ¹³C%. values determined. Eight samples of the whisky blend taken over the last 2 years of production have been analysed to allow the authentic range to be determined. A radar diagram has been used to graphically represent the δ¹³C%. data. This was used as a simple means of comparing the carbon isotope profiles of whiskies. Two other whisky samples were analysed and shown to differ from the whisky blend on the basis of the δ¹³C values.     

Inter-and intramolecular isotope correlations in organic compounds as a criterion for authenticity identification and origin assignment

Summary The mean ¹³C values of organic substances are not always sufficient for their assignment to a natural or synthetic origin. This is because natural variations in the ¹³C values produce overlapping ranges. However, on the basis of relationships through biosynthetic pathways, isotopic correlations between different substances from the same origin and between given parts of positions within molecules can be postulated. It is demonstrated that external or internal standardization provides more reliable results on the basis of-value determinations. As shown, even the addition of small amounts (10%) of C₄ sugars to C₃ plant products (honey, orange juice) can be identified by correlating the ¹³C value of the sugar to that of other products (protein, cellulose, acids) from the same source. Glycosides are compounds bearing their own internal standard of a primary product, namely the sugar moiety. Other compounds are examples of isotopic correlations between different parts of one molecule originating from different biosynthetic pathways and even from different stages of the same pathway; completely different patterns occur in synthetic analogues. For reduction in the expenditure of labour used to obtain these results, methodological improvements are needed. One of these, the coupling of gas chromatography (GC) to isotope ratio mass spectrometry (IRMS), provides the basis for fast and sensitive multicompound on-line isotope analysis for¹³C. Progress towards the extension of this principle to the corresponding analysis of other bioelements is reported, enlarging the potential to a multicompound multielement on-line GCIRMS for authenticity proofs in food and flavour analysis.

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Inter- und intramolekulare Zusammenhänge von Isotopenverhältnissen bei organischen Verbindungen als Kriterium für ihre Naturbelassenheit und zur Erkennung ihrer Herkunft

Zusammenfassung Die globalen ¹³C-Werte organischer Moleküle allein lassen oftmals keinen Schluß darüber zu, ob diese synthetischen oder natürlichen Ursprungs sind, da sich die Bereiche der ¹³C-Werte wegen der existierenden natürlichen Variationsbreiten überlappen. Auf der Basis bekannter Biosynthesewege kann man jedoch davon ausgehen, daß sich zum einen zwischen unterschiedlichen Substanzen gleicher Herkunft in den ¹³C-Gesamtwerten Zusammenhänge ergeben werden, ferner, daß zwischen bestimmten Teilen eines einzelnen Moleküls oder sogar seinen einzelnen Kohlenstoffatomen feste Beziehungen der Isotopenverhältnisse vorliegen. Diese Tatsachen ermöglichen eine interne Standardisierung, so daß auf Grund der gemessenen ¹³C-Wert-Verhältnisse die Herkunft einzelner Verbindungen nunmehr sicher erkannt werden kann. So wird gezeigt, daß bereits die Zugabe geringer Mengen (ca. 10%) von C₄-Zuckern zu Produkten aus C₃-Pflanzen (Honig, Orangensaft) nachgewiesen werden kann, wenn man den ¹³C-Wert des betreffenden Zuckers mit dem anderer Produkte (Protein, Cellulose, Säuren) der selben Herkunft vergleicht. Die natürlichen Glykoside erweisen sich als sehr gute Beispiele dafür, daß einzelne Verbindungen ihren internen Standard in Form eines Primärproduktes der Biosynthese, nämlich des Kohlenhydrates, in sich selbst tragen. Bei anderen Verbindungen erkennt man entsprechende Zusammenhänge der Isotopenverteilung in einzelnen Molekülteilen, wenn diese aus unterschiedlichen Biosynthesewegen kommen, oder sogar bei Molekülteilen, die aus unterschiedlichen Stadien des gleichen Weges herstammen. Bei synthetischen Verbindungen ist dagegen das Muster der Isotopenverteilung davon völlig verschieden. Zur Minderung des hohen Arbeitsaufwandes für die Probenaufbereitung ist eine Weiterentwicklung von Meßmethoden erforderlich. Eine davon ist die direkte Kopplung der GC mit der Isotopenverhältnis-Massenspektroskopie, eine empfindliche und schnelle Methode für die¹³C-Analyse von Gemischen. Diese Methode läßt sich auch auf andere Elemente (H, N, O) ausdehnen und damit weiterentwikkeln zu einer Multikomponenten-Multielement-Analytik für den Nachweis von Verfälschungen bei Lebensmitteln und Aromastoffen.