Discrimination of juice press fractions for sparkling base wines by a UV-Vis spectral phenolic fingerprint and chemometrics

The feasibility of an ultraviolet-visible (UV-Vis) spectral phenolic fingerprint (SPF),combined with principal component analysis (PCA), is evaluated as a rapid, simple, and reliable technique for the discrimination of grape juice press fractions destined for the production of sparkling white wines. Juice press fractions of Vitis vinifera L. Chardonnay and Pinot noir grapes comprising free-run (i.e., juice released during the loading of press), cuvée (i.e., first press fraction), and taille (i.e., subsequent press fraction), were analyzed by SPF combined with multivariate data analysis. Two trials were carried out, a laboratory and a commercial scale trial. In both trials, cuvée and taille of Chardonnay and Pinot noir grapes were clearly separated in their corresponding PCA plots based on their SPF. The proposed method enables a rapid and objective discrimination of juice press fractions, which can be obtained using relatively inexpensive UV-Vis spectrophotometric equipment. Insights arising from this research suggest a future possibility of objective, real-time discrimination of juice quality that could liberate the winemaker from tasting juice at the press

Preliminary study of Australian Pinot noir wines by colour and volatile analyses, and the Pivot© Profile method using wine professionals

The aim of this preliminary study was to identify potential colour components, volatile and sensory attributes that could discriminate Pinot noir wines from five Australian winegrowing regions (Adelaide Hills, Yarra Valley, Mornington Peninsula, Northern and Southern Tasmania). The sensory analysis consisted of the Pivot© Profile method that was performed by wine professionals. A headspace solid-phase microextraction-gas chromatography-mass spectrometry method was used to quantify multiple volatile compounds, while the Modified Somers method was used for colour characterisation. Analysis of data suggested ethyl decanoate, ethyl 2-methylpropanoate, ethyl 2-methylbutanoate, in addition to decanoic acid as important contributors to the discrimination between regions. Similarly, wine hue, chemical age indices, total anthocyanin, and (%) non-bleachable pigment also discriminated wines between regions. The sensory analysis showed that wines from Mornington Peninsula were associated with the ‘red fruits’ aroma, ‘acidic’, and ‘astringency’ palate descriptors, while those from Adelaide Hills were associated with the ‘brown’ colour attribute. This study indicates regionality is a strong driver of aroma typicity of wine

Estimation of total soluble solids in grape berries using a hand-held NIR spectrometer under field conditions

BACKGROUND Recent studies have reported the potential of near infrared (NIR) spectral analysers for monitoring the ripeness of grape berries as an alternative to wet chemistry methods. This study covers various aspects regarding the calibration and implementation of predictive models of total soluble solids (TSS) in grape berries using laboratory and in-field collected NIR spectra. RESULTS The performance of the calibration models obtained under laboratory conditions indicated that at least 700 berry samples are required to assure enough prediction accuracy. A statistically significant error reduction (ΔRMSECV = 0.1°Brix) with P Peer reviewe

Differential radiosensitivity of mouse embryonic neurons and glia in cell culture

The responses of neurons and glial cells to ultraviolet and γ-radiation were studied in cell cultures of embryonic mouse brains. A decrease in the ratio of glia to neurons occurred after both forms of irradiation. [3H]thymidine labelling followed by autoradiography revealed that all glia were capable of replication, whereas 70% of neurons were non-replicating under the conditions of the study. Ultraviolet radiation caused a decrease in the proportion of replicating neurons but did not affect the proportion of replicating glia, whereas γ-radiation caused a decrease in DNA replication in both cell types. Levels of ultraviolet radiation-induced unscheduled DNA synthesis were lower in neurons than in glia. It is concluded that sensitivity to both ionizing and ultraviolet radiation of neurons and glial cells in embryonic brain cultures is determined primarily by the capacity for and state of DNA replication. Neurons which have already reached the stage of terminal differentiation are more resistant than replicating neurons of glial cells

Fungal contaminants in the vineyard and wine quality

Fungal diseases such as powdery mildew and bunch rots reduce yield and quality of grapes and affect chemical and sensory properties of wine. The effects of powdery mildew, botrytis bunch rot and ripe rot on grape and wine quality are reviewed. Approaches to detection and quantification of fungal contamination are examined, including enzyme, immunological and DNA assays and near infrared reflectance spectroscopy. Such approaches offer efficient and objective means of quantifying fungal contamination at the winery to facilitate quality control and decisions about use of grapes. Alternatives to conventional fungicides for disease management and their effects on quality are also examined. © 2010 Woodhead Publishing Limited All rights reserved.E. S. Scott, R. G. Dambergs and B. E. Stumme

Selection of differentiated neurons in embryonic mouse brain cultures using arabinofuranosylcytosine

Treatment of primary mouse embryonic brain cultures with arabinofuranosylcytosine (AraC) results in selective survival of differentiated neurons. These neurons are nonreplicating and are electrically active. Selection of neurons with AraC is superior to that with fluorodeoxyuridine and provides neuron-enriched cultures suitable for a variety of studies of neuron function in vitro

A review of the state of the art, limitations, and perspectives of infrared spectroscopy for the analysis of wine grapes, must, and grapevine tissue

As a fast and easy-to-operate technique, infrared (IR) spectroscopy has gained wide industrial acceptance for routine wine analysis. Considering the continuing improvements in hardware and software design and the analytical requirements of realtime or multiparametric analysis by themodern grape and wine industry, it is anticipated that in the near future IR spectroscopy will progressively become a routine method for process monitoring and process control in different stages of grape and wine production. This review highlights recent developments and applications of IR spectroscopy (nearand mid-infrared) to measure compositional parameters inwine grapes, grape juice, and grapevine tissues (e.g., leaves, stems, grapevine wood). In addition, some critical aspects and limitations in instrument availability, type of application, and overall understanding of the technology, which can be barriers for adoption of IR technologies by the grape and wine industry, will be discussed.R. Dambergs, M. Gishen and D. Cozzolin

A review of the state of the art, limitations, and perspectives of infrared spectroscopy for the analysis of wine grapes, must, and grapevine tissue

© 2015 Taylor & Francis Group, LLC.As a fast and easy-to-operate technique, infrared (IR) spectroscopy has gained wide industrial acceptance for routine wine analysis. Considering the continuing improvements in hardware and software design and the analytical requirements of real-time or multiparametric analysis by the modern grape and wine industry, it is anticipated that in the near future IR spectroscopy will progressively become a routine method for process monitoring and process control in different stages of grape and wine production. This review highlights recent developments and applications of IR spectroscopy (near- and mid-infrared) to measure compositional parameters in wine grapes, grape juice, and grapevine tissues (e.g., leaves, stems, grapevine wood). In addition, some critical aspects and limitations in instrument availability, type of application, and overall understanding of the technology, which can be barriers for adoption of IR technologies by the grape and wine industry, will be discussed

Two-dimensional correlation analysis of the effect of temperature on the fingerprint of wines analysed by mass spectrometry electronic nose

Abstract not availableDaniel Cozzolino, Wies Cynkar, Robert Dambergs, Paul Smit