Enoforum 2021
IVES 9 IVES Conference Series 9 Enoforum Web 9 Enoforum Web Conference 2021 9 In-line sensing of grape juice press fractioning with UV-Vis spectroscopy

In-line sensing of grape juice press fractioning with UV-Vis spectroscopy

Abstract

UV-Visible spectroscopy in conjunction with chemometrics, was successfully applied to objectively differentiate sparkling wine press juice fractions of Pinot noir. Two measurements methods were applied: reflectance using a fibre optic probe in-line and transmission using a benchtop spectrophotometer. Different wavelength ranges for UV-Visible spectroscopy were evaluated and their ability to measure total phenolic concentrations in press juice fractions was compared. The differentiation of free run, early and late press fractions shows promise as a tool for the rapid discrimination of fractions when grapes for sparkling wine are pressed. Calibrations for total phenolics were prepared from press fraction spectral data using partial least square regression (PLSR) with a large number of wavelengths (230-700 nm) and multiple linear regression (MLR) using a small number of key wavelengths. Calibration performance for both reflectance and transmission spectra was similar, but the best performing calibration used reflectance spectra. Reflectance spectroscopy can thus be used in-line to predict total phenolics in grape juice with an acceptable accuracy and to discriminate press fractions. Insights from this research will lead to the design and building of a fitting that can be attached to any press outlet, with the potential to automate press fractioning.

DOI:

Publication date: April 23, 2021

Issue: Enoforum 2021

Type: Article

Authors

DAMBERGS Robert1*, LONGO Rocco2, KERSLAKE Fiona2

1 Charles Sturt University
2 Tasmanian Institute of Agriculture

Contact the author

Tags

Enoforum 2021 | IVES Conference Series

Citation

Related articles…

Towards a European data basis based of advanced multi-isotopic signatures and artificial intelligence: the wine in blue project

Major and trace elements are essential for the development of grapes used for the wine. They are primarily originating from the soil. Some elements are also seldomly added during the wine making process. Therefore, the largest spectrum of major, trace and ultra-trace elements in the final wine product is a good signature of its geographical origin. In the frame of the European tracewindu, we have developed a very original multi-isotopic dilution method using triple quadrupole icp/ms.
Read More

Evolution of grape aromatic composition in cv. Ugni blanc

Cognac is a protected appellation of origin where world-famous brandies are produced. These brandies are obtained by the traditional double distillation of wines from Ugni blanc cultivar

Read More

Great highlands wine growing terroir: conditions and expressions

During 1982 started our wine growing project at the Puntalarga Hill, between 2500 and 2600 meters a.s.l.: 5.78 ºN, 72.98 ºW. Pinot noir, white Riesling and Riesling x Silvaner crossings are the most planted grapevines. Since 1984 research and development activities are carried out on pertinent subjects.

Read More

Understanding the impact of rising temperatures due to climate change on aromatic compositions in Malbec wines from Mendoza, Argentina

Mendoza is one of Argentina’s most important and outstanding wine regions producing the renowned Malbec wines due to its optimal soil and weather conditions. However, the effects of 21st-century climate change would negatively impact Malbec wines quality. This study investigated the effect of temperature increase and the impact of plant hormone abscisic acid (ABA) used to mitigate the negative effect of temperature increase on Malbec wines aromatic composition through GC-MS. Four treatments were applied on vines at field condition: Control, Control + 3 ºC, ABA and ABA + 3 ºC.

Read More

Aromatic profile evolution of corvina, corvinone and rondinella grapes during withering

AIM AND METHODS: Grape withering is one of the key steps in the production of the most renowned red wines of the Valpolicella area, namely Amarone and Recioto. This practice, which was already used since Roman times, entails important modifications in grape composition and in the chemical and sensorial characteristics of the corresponding wines, especially in terms of aromatic profile. The aim of this research is evaluating the aromatic evolution during grape withering of the three main varieties used in Valpolicella wines: Corvina, Corvinone and Rondinella.Samples of the three varieties were analyzed at harvest and at different stages of withering, namely10%, 20% and 30% of weight loss. Free and glycosidically bound compounds were extracted and analyzed using Gas Chromatography- Mass Spectrometry (GC-MS). RESULTS: For all the samples the data were normalized to eliminate the effect of concentration due to grape dehydration. Terpene content and evolution varied considerably in relationship to grape variety. Corvinone was richer in cyclic terpenes (including phellandrene, limonene, and cymene) and they decreased during withering.

Read More