Macrowine 2021
IVES 9 IVES Conference Series 9 Impact of malolactic fermentation on volatile composition and sensory properties of white and rosé wine from the greek variety moschofilero

Impact of malolactic fermentation on volatile composition and sensory properties of white and rosé wine from the greek variety moschofilero

Abstract

Moschofilero is a native grape variety, classified as a ‘gris’ type variety, that is cultivated in PDO Mantineia, Peloponissos, Greece. It is used for the production of both white and rosé wines. Due to high altitude of the vineyards, the harvest is done by mid October, and many vintages are characterised by high acidities and low pH values. Besides that, Moschofilero wines record usually low alcohol levels and thus these wines lack body and generally are considered to be ‘medium’ to ‘low’ body wines. The aim of our work was on one hand to evaluate the impact of three different O. oeni strains, to qualitative characteristics of Moschofilero white and rose wine and to check if MLF boosts the mouthfeel of the wines. Laboratory scale alcoholic fermentation (AF) monitoring was performed every day by density measurements, while malic acid degradation was measured with the RQflex reflectometer. Two different S. cerevisiae strains were used to perform AF and three commercial strains of O. oeni for MLF. Classical wine analyses (acidity, sulfite, residual sugars) and organic acid composition (tartaric, malic, citric, lactic, succinic and acetic acid) were performed in all wines after MLF. Fermentative volatile compounds (esters and superior alcohols) were determined by SPME followed by GC–MS and diacetyl concentration was analysed by GC-ECD. All produced wines were evaluated sensorially. All O. oeni strains could perform MLF and degrade the malic acid (2.5 g/L) but had a different effect on wine composition. The major variation was observed for the acetic acid (0.25 g/L, 0.35 g/L and 0.45 g/L respectively for the three strains) as also for the diacetyl production (max 1.5±0.5 mg/L). The volatile compounds levels were found to be slightly different in the produced wines and strain effect was observed for both, bacterial and yeast species. The effect of malolactic fermentation to Moschofilero white and rosé wines depends on the bacterial strains as well as the yeast strain used for alcoholic fermentation. MLF can lead to decreased grassy character, boost the fruity notes and improve the wine mouthfeel, depending on the strain used.

DOI:

Publication date: September 3, 2021

Issue: Macrowine 2021

Type: Article

Authors

Kotseridis Yorgos, Maria Dimopoulou, Marilena Panagopoulou, Vicky Tροιανοu, Niki Proχenia

Laboratory of Enology and Alcoholic Drinks (Lead), Agricultural University of Athens, Department of Wine, Vine and Beverage Sciences, School of Food Science, University of West Attica, Greece.
Laboratory of Enology & Alcoholic Drinks (Lead), Agricultural University of Athens, Athens, Greece.
Innovino, Research & Development, Pallini, Greece.
Laboratory of Enology & Alcoholic Drinks (Lead), Agricultural University of Athens, Athens, Greece.

Contact the author

Keywords

malolactic fermentation, moschofilero, lactic acid bacteria, o. oeni, mouthfeel

Citation

Related articles…

Effects of graft quality on growth and grapevine-water relations

Climate change is challenging viticulture worldwide compromising its sustainability due to warmer temperatures and the increased frequency of extreme events. Grafting Vitis vinifera L.

Pruned vine biomass exclusion from a clay loam vineyard soil – examining the impact on physical/chemical properties

The wine industry worldwide faces increasing challenges to achieve sustainable levels of carbon emission mitigation. This project seeks to establish the feasibility of harvesting winter pruned vineyard biomass (PVB) for potential use in carbon footprint reduction, through its use as a renewable biofuel for energy production. In order to make this recommendation, technical issues such as the potential environmental impact, chemical composition and fuel suitability, and logistical challenges of harvesting biomass needs to be understood to compare with the results from similar studies. Of particular interest is the role PVB plays as a carbon source in vineyard soils and what effect annual removal might have on soil carbon sequestration. A preliminary trial was established in the Waite Campus vineyard (University of Adelaide) to test current management strategies. Vines are grown in a Eutrophic, Red Dermosol clay loam soil with well managed midrow swards. A comparison was undertaken of mid-row treatments in two 0.25 Ha blocks (Shiraz and Semillon), including annual cultivation for seed bed preparation, the deliberate exclusion of PVB (25 years) and incorporation of PVB (13 years) at an average of 3.4 and 5.5 Mg/Ha-1 for Shiraz and Semillon respectively. In both 0-10cm and 10-30cm soil core sample depths, combined soil carbon % measures in the desired range of 1.80 to 3.50, were not significantly different between treatments or cultivars and yielded an estimated 42 Mg/ha-1 of sequestered soil carbon. Other key physical and chemical measures were likewise not significantly different between treatments. Preliminary results suggest that in a temperate zone vineyard, managed such as the one used in this study, there is no long term negative impact on soil carbon sequestration through removing PVB. This implies that growers could confidently harvest PVB for use in several end fates including as a bio fuel.

VINIoT – Precision viticulture service

The project VINIoT pursues the creation of a new technological vineyard monitoring service, which will allow companies in the wine sector in the SUDOE space to monitor plantations in real time and remotely at various levels of precision. The system is based on spectral images and an IoT architecture that allows assessing parameters of interest viticulture and the collection of data at a precise scale (level of grape, plant, plot or vineyard) will be designed. In France, three subjects were specifically developed: evaluation of maturity, of water stress, and detection of flavescence dorée. For the evaluation of maturity, it has been decided first to work at the berry scale in the laboratory, then at the bunch scale and finally in the vineyard. The acquisition of the spectral hyperstal image as well as the reference analyzes to measure the maturity, were carried out in the laboratory after harvesting the berries in a maturity monitoring context. This work focuses on a case study to predict sugar content of three different grape varieties: Syrah, Fer Servadou and Mauzac. A robust method called Roboost-PLSR, developed in the framework of this work (Courand et al., 2022), to improve prediction model performance was applied on spectra after the acquirement of hyperspectral images. Regarding the evaluation of water stress, to work with a significant variability in terms of water status, it has been worked first with potted plants under 2 different water regimes. The facilities have allowed the supervision of irrigation and micro-climatic conditions. The regression models on agronomic variables (stomatal conductance, water potential, …) are studied. To detect flavescence dorée, the experimental plan has consisted of work at leaf scale in the laboratory first, and then in the field. To detect the disease from hyper-spectral imaging, a combination of multivariate curve resolution-alternating least squares (MCR-ALS) and factorial discriminant analysis (FDA) was proposed. This strategy proved the potential towards the discrimination of healthy and infected leaves by flavescence dorée based on the use of hyperspectral images (Mas Garcia et al., 2021).

Climate ethnography and wine environmental futures

Globalisation and climate change have radically transformed world wine production upsetting the established order of wine ecologies. Ecological risks and the future of traditional agricultural systems are widely debated in anthropology, but very little is understood of the particular challenges posed by climate change to viticulture which is seen by many as the canary in the coalmine of global agriculture. Moreover, wine as a globalised embedded commodity provides a particularly telling example for the study of climate change having already attracted early scientific attention. Studies of climate change in viticulture have focused primarily on the production of systematic models of adaptation and vulnerability, while the human and cultural factors, which are key to adaptation and sustainable futures, are largely missing. Climate experts have been unanimous in recognising the urgent need for a better understanding of the complex dynamics that shape how climate change is experienced and responded to by human systems. Yet this call has not yet been addressed. Climate ethnography, coined by the anthropologist Susan Crate (2011), aims to bridge this growing disjuncture between climate science and everyday life through the exploration of the social meaning of climate change. It seeks to investigate the confrontation of its social salience in different locations and under different environmental guises (Goodman 2018: 340). By understanding how wine producers make sense of the world (and the environment) and act in it, it proposes to focus on the co-production of interdisciplinary knowledge by identifying and foreshadowing problems (Goodman 2018: 342; Goodman & Marshall 2018). It seeks to offer an original, transformative and contrasted perspective to climate change scenarios by investigating human agency -individual or collective- in all its social, political and cultural diversity. An anthropological approach founded on detailed ethnographies of wine production is ideally placed to address economic, social and cultural disruptions caused by the emergence of these new environmental challenges. Indeed, the community of experts in environmental change have recently called for research that will encompass the human dimension and for more broad-based, integrated through interdisciplinarity, useful knowledge (Castree & al 2014). My paper seeks to engage with climate ethnography and discuss what it brings to the study of wine environmental futures while exploring the limitations of the anthropological environmental approach.

A better understanding of the climate effect on anthocyanin accumulation in grapes using a machine learning approach

The current climate changes are directly threatening the balance of the vineyard at harvest time. The maturation period of the grapes is shifted to the middle of the summer, at a time when radiation and air temperature are at their maximum. In this context, the implementation of corrective practices becomes problematic. Unfortunately, our knowledge of the climate effect on the quality of different grape varieties remains very incomplete to guide these choices. During the Innovine project, original experiments were carried out on Syrah to study the combined effects of normal or high air temperature and varying degrees of exposure of the berries to the sun. Berries subjected to these different conditions were sampled and analyzed throughout the maturation period. Several quality characteristics were determined, including anthocyanin content. The objective of the experiments was to investigate which climatic determinants were most important for anthocyanin accumulation in the berries. Temperature and irradiance data, observed over time with a very thin discretization step, are called functional data in statistics. We developed the procedure SpiceFP (Sparse and Structured Procedure to Identify Combined Effects of Functional Predictors) to explain the variations of a scalar response variable (a grape berry quality variable for example) by two or three functional predictors (as temperature and irradiance) in a context of joint influence of these predictors. Particular attention was paid to the interpretability of the results. Analysis of the data using SpiceFP identified a negative impact of morning combinations of low irradiance (lower than about 100 μmol m−2 s−1 or 45 μmol m−2 s−1 depending on the advanced-delayed state of the berries) and high temperature (higher than 25oC). A slight difference associated with overnight temperature occurred between these effects identified in the morning.