Macrowine 2021
IVES 9 IVES Conference Series 9 The relationship between enzyme treatment and polysaccharide extraction in wine making, and subsequent sensory effects in Cabernet Sauvignon wines

The relationship between enzyme treatment and polysaccharide extraction in wine making, and subsequent sensory effects in Cabernet Sauvignon wines

Abstract

AIM: To determine the effect of both ripeness and enzyme maceration on the astringency and bitterness perception of Cabernet Sauvignon winesRecent work has contributed to a more detailed understanding of the grape cell wall deconstruction process from ripening through crushing and fermentation, providing a better understanding of what role polysaccharides play in post-harvest fermentation of grapes(1,2). Current research on glycomics in red wine making suggest polysaccharides are important sensory impact molecules (3–6).

METHODS: Our experimental system harvests Cabernet Sauvignon grapes at three different ripeness levels and makes wine both with and without enzyme treatment. Using glycan-array technology (Comprehensive Microarray Polymer Profiling – CoMPP) as an analytical tool, we explore comparative levels of polysaccharides derived from cell walls that pass through the fermentation process to wines. These results are confirmed using GC-MS analysis of hydrolyzed polysaccharides, in addition to analysis of extracted tannins and polyphenols. Wines are submitted for sensory analysis to test astringency and bitterness perception after alcohol level equalization, providing a novel look at emzyme macerations sensory effect, focusing on polysaccharide levels in wine.

RESULTS/DISCUSSION: Data shows ripeness has a more limited effect than expected on polysaccharide profiles in finished wine, but enzyme addition causes a marked decrease in soluble polysaccharides. An increase in polymeric pigments and tannins is noted with enzyme use. Sensory testing of these wines established a relationship between perceived astringency and polysaccharide, but also shows the traditionally accepted relationship between phenol content of red wines and perceived astringency is more complicated.

CONCLUSIONS:

Enzyme maceration has an effect on perceived astringency in finished wines, but does not affect bitterness. Ripeness has a limited effect on polysaccharide extraction, but no significant differences in wine astringency. In this study, bitterness was not affected by ripeness nor enzyme maceration.

DOI:

Publication date: September 24, 2021

Issue: Macrowine 2021

Type: Article

Authors

Brock Kuhlman, Bodil JØRGENSEN,   José L. ALEIXANDRE TUDO , John P. MOORE,

South African Grape and Wine Research Institute, Stellenbosch University, Stellenbosch, South Africa, Plant Glycobiology, Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark , Universitat Politecnica de Valencia, Instituto de Ingenieria de Alimentos para el Desarrollo (IIAD), Departamento de Tecnología de Alimentos and Stellenbosch University, South African Grape and Wine Research Institute (SAGWRI), Department of Viticulture and Oenology  Wessel DU TOIT, Department of Viticulture and Oenology, Stellenbosch University, Stellenbosch, South Africa ,  Grape and Wine Research Institute, Stellenbosch University, Stellenbosch, South Africa

Contact the author

Keywords

enzyme maceration, astringency, polysaccharide extraction, polyphenolic extraction, bitterness

Citation

Related articles…

Grape must quality and mesoclimatic variability in Fruška Gora wine-growing region, Serbia

The Fruška Gora mountain is a traditional wine-growing region in Serbia situated in the Pannonian Basin. Due to such a position, the vicinity of the Danube River and the presence of concave configuration, it is suitable for grape production. This paper provides analyses of spatial variations in meteorological parameters and grape juice quality within Fruška Gora wine region over three consecutive vintages (2018-2020). The examined period can be defined as warm with cool nights during September (AVG 18,9°C; GDD 1918°C; CI 12°CF) and with the presence of mesoclimatic variability. The East part of the study area was somewhat drier and hotter compared to other parts of the region. The analyses of grape must samples (190 in total) of five cultivars (Cabernet-Sauvignon, Merlot, Chardonnay, Sauvignon blanc and Grašac (Welschriesling)) commonly grown across the region (19 sites), were performed using Fourier Transform Infrared Technology (FTIR). Among all cultivars, Sauvignon blanc was harvested first in the East area (DOY=246±5, GDD at harvest=1552±74, 22.2±0.7 °Brix), while the latest harvest was recorded for Cabernet-Sauvignon in the West (DOY=283±5, GDD at harvest=1936±187, 23.4±1.0 °Brix ). Both the red and white cultivars had higher acidity and YAN in the grape must if the vines were grown in the North and East compared to South and West areas. According to PCA analysis, Grašac showed the lowest variation in grape must chemical composition. Thus, the results confirm that Grašac is the most stable cultivar in Fruška Gora. All monitored cultivars reached technological fruit ripeness by the end of the growing season. However, it was difficult to reach full ripeness of red cultivars, mostly beacuse of uncoupling of technolocical and phenolic ripeness. Thus, Cabernet-Sauvignon had higher variations in GDD sums at harvest compared to other cultivars, which probably increased variations in grape must quality.

Elucidating vineyard site contributions to key sensory molecules: Identification of correlations between elemental composition and volatile aroma profile of site-specific Pinot noir wines

The reproducibility of elemental profile in wines produced across multiple vintages has been previously reported using grapes from a single scion clone of Vitis vinifera L. cv. Pinot noir. The grapevines were grown on fourteen different vineyard sites, from Oregon to southern California in the U.S.A., which span distances from approximately hundreds of meters to 1450 km, while elevations range from near sea level to nearly 500 m. In addition, sensorial (i.e. aroma, taste, and mouthfeel) and chemical (i.e. polyphenolic and volatile) differences across the different vineyard sites have also been observed among these wines at two aging time points. While strong evidence exists to support that grapes grown in different regions can produce wines with unique chemical and sensorial profiles, even when a single clone is used, the understanding of growing site characteristics that result in this reproducible differentiation continues to emerge. One hypothesis is that the elemental profile that a vineyard site imparts to the grape berries and the resulting wine is an important contributor to this differentiation in chemistry and sensory of wines. For example, various classes of enzymes that catalyze the formation of key aroma compounds or their precursors require specific metals. In this work, we begin to report correlations between elemental and volatile aroma profiles of site-specific Pinot noir wines, made under standardized winemaking conditions, that have been previously shown to be distinguished separately by these chemical analyses.

A predictive model of spatial Eca variability in the vineyard to support the monitoring of plant status

[lwp_divi_breadcrumbs home_text="IVES" use_before_icon="on" before_icon="||divi||400" module_id="publication-ariane" _builder_version="4.19.4" _module_preset="default" module_text_align="center" module_font_size="16px" text_orientation="center"...

Bioclimatic shifts and land use options for Viticulture in Portugal

Land use, plays a relevant role in the climatic system. It endows means for agriculture practices thus contributing to the food supply. Since climate and land are closely intertwined through multiple interface processes, climate change may lead to significant impacts in land use. In this study, 1-km observational gridded datasets are used to assess changes in the Köppen–Geiger and Worldwide Bioclimatic (WBCS)

Climate, Viticulture, and Wine … my how things have changed!

The planet is warmer than at any time in our recorded past and increasing greenhouse emissions and persistence in the climate system means that continued warming is highly likely. Climate change has already altered the basic framework of growing grapes for wine production worldwide and will likely continue to do so for years to come. The wine sector can continue to play an important role in leading the agricultural sector in addressing climate change. From developing on…