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…

A synthesis approach on the impact of elevated CO2 on berry physiology and yield of Vitis vinifera

Besides the increase in global mean temperature the second main challenge of a changing climate is the increase in atmospheric carbon dioxide (CO2) in relation to physiology and yield performance of grapevines. The benefits of increasing CO2 levels under greenhouse environment or open field studies have been well investigated for various annual crops. Research under free carbon dioxide enrichment on field-grown perennial plants such as grapevines is limited to a few studies. Further, chamber and greenhouse experiments have been conducted mostly on potted vines under eCO2 conditions.
Read More

Incidences of the climate, the soil and the harvest date on Colombard aromatic potential in Gascony

This experiment tries to characterize the role of soil, climate and harvest date on the composition of grape-derivated thiols, 3-mercapto-hexanol (3MH) and 3-mercapto-hexile acetate (A3MH), in the white wines from Colombard varieties in Gascony (South-West of France). A network of 6 plots has been observed since 1999 on different pedologic units. The plots have common agronomical characteristics, plantation spacing (2,900 to 3,500 vines per ha), plantation aging (1985-1990), strength conferred by rootstock (SO4, RSB), soil management (grass covered 1 by 2) and training system (vertical shoot positionning pruned in single Guyot). Meteorological stations are located near the plots.

Read More

Enological potential of autochtonous grape cultivars from Castilla y León (Spain) to elaborate sparkling wines: polyphenolic and biogenic amines and amino acid composition of base wines

In white wines, Verdejo wine stands out because of its high content in total amino acids. The total content in biogenic amines was low in all wines analyzed and putrescine was the predominant biogenic amine.

Read More

Evaluation of Polarized Projective Mapping as a possible tool for attributing South African Chenin blanc dry wine styles

Multiple Factor Analysis (MFA) According to the Chenin blanc Association of South Africa, there are three recognized dry wine styles, Fresh and Fruity (FF), Rich and Ripe Unwooded (RRU), and Rich and Ripe Wooded (RRW), classically attributed with the help of sensory evaluation. One of the “rapid methods” has drawn our attention for the purpose of simplifying and making style attribution for large sample sets, evaluated during different sessions, more robust. Polarized Projective Mapping (PPM) is a hybrid of Projective Mapping (PM) and Polarised Sensory Positioning (PSP). It is a reference-based method in which poles
(references) are used for the evaluation of similarities and dissimilarities between samples.

Read More

Grape stems as preservative in Tempranillo wine

SO2 is the most widely used preservative in the wine industry. However, there are several drawbacks related with the use of SO2 in wine such as its toxicity and the unpleasant odor in case of excess.

Read More