 IVES 9 IVES Conference Series 9 The valorization of wine lees as a source of mannoproteins for food and wine applications

The valorization of wine lees as a source of mannoproteins for food and wine applications

Abstract

AIM. Wine yeast lees constitute a winemaking by-product that, unlike grape skins and seeds, are not sufficiently exploited to add value to the winemaking sector, as their treatment and disposal generally represents a cost for wineries [1]. Recently, some valorization strategies proposed the integrated extraction of ethanol, polyphenols, and tartaric acid, while only a few studies investigated ways to exploit the remaining wine lees’ yeast biomass. In particular, no studies attempted the extraction of mannoproteins (MPs), yeast cell wall polysaccharides with known foaming, emulsifying and wine-stabilizing activities [2], from the wine lees’ yeast biomass. To fill this gap, this research aims at developing an efficient and food-grade method for the extraction of yeast MPs from commercial wine lees, and to test the obtained extracts as wine stabilizers, foaming agents, and food emulsifiers.

METHODS. Several protocols were studied to extract MPs from wine lees. Ultimately, commercial wine yeast lees were extracted at pH 3.4 using an autoclave-based treatment (121°C, 20 min). The obtained MPs extracts were characterized by SEC-HPLC, SDS-PAGE or CI-ELLSA [3]. The functionalities of the MPs’ extracts were tested in wine by assessing their foam-promoting ability and their stabilizing potential against protein and tartrate instabilities. Additionally, MPs extracts were tested as emulsifying and foaming agents in model food matrices. The results were compared to those obtained using commercial MPs-based products and/or MPs extracts from pure cultures of the same yeast strains.

RESULTS. Among the extraction protocols tested, the autoclave emerged as the best performing in terms of extract’s effectiveness and, therefore, it was selected for the subsequent extractions. Firstly, MPs obtained from white winemaking lees positively impacted both wine’s foaming properties (+260% height; +360% stability) and tartrate stability (-11%) compared to untreated wine samples. Conversely, the extracts were ineffective in stabilizing wine against protein haze formation [4]. Subsequently, MPs extracts obtained autoclaving red and white wine lees and tested in model food matrices showed encouraging emulsifying activity (≃55% emulsion stability) and foaming properties (stability >3h). In this case, the extract from red wine lees performed better than its analog derived from the same yeast strain grown in the laboratory, thus suggesting a possible impact of wine polyphenols in enhancing the surfactant action of MPs [5].

CONCLUSIONS

The extraction of MPs from wine lees with a simple and food-grade autoclave-based method can represent an effective valorization strategy that, if integrated with the already available techniques to recover ethanol, tartaric acid, and polyphenols, would result in a better exploitation of this by-product with a consequent improvement of the environmental and economic sustainability of the wine industry.

DOI:

Publication date: September 7, 2021

Issue: Macrowine 2021

Type: Article

Authors

Alberto De Iseppi

Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, Italy, Andrea CURIONI1,2; Matteo MARANGON1; Giovanna LOMOLINO1; Simone VINCENZI1,2; Benoit DIVOL3

¹ Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, Italy
² Centre for Research in Viticulture and Enology (CIRVE), Conegliano, Italy
³ South African Grape and Wine Research Institute, Stellenbosch University, South Africa

Contact the author

Keywords

wine yeast lees, by-product valorisation, mannoproteins, stability, foam, emulsion

Citation

Adaptation to climate change by determining grapevine cultivar differences using temperature-based phenology models

Grapevine phenology is advancing with increased temperatures associated with climate change. This may result in higher fruit sugar concentrations at harvest and/or earlier compressed harvests and changes in the synchrony of sugar with other fruit metabolites. One adaptation strategy that growers may use to maintain typicity of wine style is to change cultivars. This approach may enable fruit

Corvina and Corvinone grape berries grown in different areas and their aptitude to postharvest dehydration

The Valpolicella area (Veneto Region, Italy) is famous for its high quality wines: Amarone and Recioto, both obtained from partial post-harvest dehydrated red grapes.

Testing the pathogen e-learning and field training course on grapevine virus knowledge and management

One of the reasons of the spread of grapevine virus diseases in
vineyards around the world is the lack of knowledge by the main actors of the wine sector. To face this problem, five partners worked together to develop the PAThOGEN project, a training program aimed to improve grapevine virus knowledge and management. The partnership gathers one French technical center (IFV), one Spanish university (USC), one Italian applied research center (CREA), one Spanish foundation
specialized in training and technology transfer (FEUGA) and one Italian SME specialized in the development of informatics tools and in knowledge transfer (HORTA).The objectives of PAThOGEN are: (i) to develop and
maintain a high-quality work-based Vocational and Education Training program, (ii) to improve the skills of professionals of the wine sector.

PyExpress – A pipeline for fast and reliable UAV image processing in vineyards

Increasing drought poses a challenge to viticulture, with complex impacts on grape yield and quality. The use of Unmanned Aerial Vehicles (UAV) in Precision Viticulture offers a valuable tool to detect drought stress, capturing its spatio-temporal variability and thus, supports management strategies.

Bioprotection and oenological tannins association to protect Rosé wine color

The bioprotection of musts or grapes is a strategy for limiting sulfiting during winemaking and more specifically at pre-fermentative step. The most preconized yeasts in bioprotection mainly belong to Metschnikowia pulcherrima and Torulaspora delbrueckii species. While previous studies have demonstrated that bioprotectant non-Saccharomyces strains were able to protect musts and wines against microbial spoilage as well as sulfites, they cannot protect must against oxidation which appears to be the main limit of this practice.