 IVES 9 IVES Conference Series 9 Quality of Merlot wines produced from terraced vineyards and vineyards on alluvial plains in Vipava valley, Slovenia (pdo)

Quality of Merlot wines produced from terraced vineyards and vineyards on alluvial plains in Vipava valley, Slovenia (pdo)

Abstract

AIM: Different factors affect the style and quality of wine and one of the most important are environmental factors of vineyard location. The aim of this study was to compare the quality of Merlot wines produced from grapes growing on skeletal and dry soils of terraced vineyards and deep loamy soils of alluvial plains of Vipava Valley, a warm climate winegrowing district in Slovenia.

METHODS: Five vineyards on terraces and five on alluvium plains were chosen. Viticulture parameters such as number of buds, number of clusters and leaf area on each vine were unified in 2019 and 2020 as described in Sivilotti et al. (2020). Stem water potential (SWP) was measured during the season (Deloire and Heyns, 2011). 5 kg of grapes were sampled in triplicates at the time of grape maturity. Basic physicochemical parameters of grapes were determined before microvinification. Microvinifications were analysed after alcoholic and malolactic fermentation. Concentration of total phenols (TP), total anthocyanins (TA), high (HMWP) and low molecular weight (LMWP) proanthocyanidins (PAS) were determined spectrophotometrically as described in Rigo et al. (2000). Moreover, structural characteristics of PAs in wines, i.e. mean degree of polymerisation (mDP), percentage of galloylaton (%G) and percentage of prodelphinidins (%P) were determined by UHPLC-DAD-MS/MS as described in Lisjak et al. (2019) and in Sivilotti et al. (2020). Esters were analysed by GC-MS (Bavčar and Baša Česnik, 2011) and higher alcohols by GC-FID (Bavčar et al., 2011).

RESULTS: SWP was more negative on terraces. According to basic physico chemical parameters and darker seed colour, grapes from terraces showed advanced ripening in comparison to grapes grown in alluvial plains. Wines from terraces had higher concentrations of TA, TP, HMWP, ash and total dry extract in comparison to wines from alluvial plains and PAs reported higher %G. Furthermore, aromatic profiles of wines were also different. In general, higher concentrations of higher alcohols and lower concentrations of esters were detected in wines from terraces.

CONCLUSIONS:

The Merlot wines from grapes sampled in terraced vineyards differed in chemical composition from those from alluvial plains. In general, wines from terraces had higher polyphenol content, some quality parameters such as ash and total dry extract, structural differences of grape tannins and different profile of some aroma compounds

DOI:

Publication date: September 10, 2021

Issue: Macrowine 2021

Type: Article

Authors

Alenka Mihelčič

Agricultural Institute of Slovenia, Hacquetova ulica 17, 1000 Ljubljana, Slovenia ,Andreja VANZO, Agricultural Institute of Slovenia, Hacquetova ulica 17, 1000 Ljubljana, Slovenia Borut VRŠČAJ, Agricultural Institute of Slovenia, Hacquetova ulica 17, 1000 Ljubljana, Slovenia Paolo SIVILOTTI, University of Udine, via delle Scienze 206, 33100 Udine, Italy Klemen LISJAK, Agricultural Institute of Slovenia, Hacquetova ulica 17, 1000 Ljubljana, Slovenia

Contact the author

Keywords

terraces, alluvial plains, soil, stem water potential, wine quality, polyphenols, volatile compounds

Citation

Impact of dosage sugar-type and ageing on finished sparkling wine composition and development of Maillard reaction-associated compounds

The Maillard reaction (MR) is a non-enzymatic reaction between reducing sugars and amino acids, resulting in the production of volatile and flavour-active compounds.

Challenges for the Implementation of commercial inoculum of arbuscular fungi in a commercial Callet vineyard (Vitis vinifera L.)

Over the past 70 years, scientific literature has consistently illustrated the advantageous effects of arbuscular mycorrhiza fungi (AMF) on plant growth and stress tolerance. Recent reviews not only reaffirm these findings but also underscore the pivotal role of AMF in ensuring the sustainability of viticulture. In fact, various companies actively promote commercial inoculants based on AMF as biofertilizers or biostimulants for sustainable viticulture. However, despite the touted benefits of these products, the consistent effectiveness of AMF inoculants in real-world field conditions remains uncertain.

Raman spectroscopy as a rapid method to assess grape polyphenolic maturation and wine malolactic fermentation on site

Wineries can increase their economic and environmental sustainability by optimizing the winemaking procedures, from harvest to wine maturation and conservation. Based on analytical data of the chemical composition and wine sensory evaluation, the enologist makes his own decision regarding the enological interventions at the harvest date selection, winemaking and post-winemaking.

Preliminary characterisation of mannoproteins from different wine yeast strains and impact on wine properties

Mannoproteins (MPs) are released from the yeast cell wall during alcoholic fermentation and aging on the lees, and influence aspects of wine quality such as haze formation and colour stability. Yet, as this is a slow process with microbiological and sensory risks, the exogenous addition of extracted MPs poses an efficient alternative. While Saccharomyces cerevisiae has long been studied as a prominent source for MPs extraction, their structure and composition greatly differ between yeast species. This may influence their behaviour in the wine matrix and subsequent impact on wine properties. However, although wine yeast species other than S. cerevisiae possibly present an untapped source of MPs, they are still ill-characterised in terms of chemical composition and influence on wine.

Anthocyanins, flavonols and hydroxycinnamates of eight vitis vinifera cultivars from the balearic islands

In 2008 the anthocyanin, flavonol and hydroxycinnamate (HCT) contents of the skins of five coloured berry cultivars (‘Escursac’, ‘Esperó de Gall’, ‘Galmeter’, ‘Valent negre’ and ‘Vinater negre’), of two white cultivars (‘Argamussa’ and ‘Prensal blanc’) and of one weakly rose cultivar (‘Giró ros’), native from Balearic Islands, were characterized.