Macrowine 2021
IVES 9 IVES Conference Series 9 Effect of plant fining agents in the must flotation process. Functional characterization

Effect of plant fining agents in the must flotation process. Functional characterization

Abstract

Flotation is one of the most used processes for clarifying white grape must after the pressing process. To date, gelatine is the more used fining agent, its action being improved when combined with bentonite and silica sol. However, in recent years, there is a growing commercial interest in replacing this animal origin protein with plant proteins, due, on the one hand, to the problems associated with allergies and, on the other hand, also thinking in the vegan wine consumers. However the efficiency of plant proteins as floculating agents are lower than gelatine and varies among them, the reason behind the different behaviour being unknown (Marchal et al., 2003; Gambuti et al., 2016; Petinelli et al., 2020). The objective of this work was to compare the flocculating efficiency of a commercial gelatine, a pure pea protein and the same pea protein chemically modified and to relate this efficiency to their amino acid composition and protein functions.The determination of the efficiency was carried out by measuring the percentage of clean must after 1 h from flotation beginning and the measuring of the absorbance at 440 nm to control the browning, while the content of amino acids and peptides was carried out by HPLC-MS. The UNIPROT database was used to obtain the protein functions associated with the peptidesThe results showed that the modified pea protein showed very similar effciency as flotation agent to that of the commercial gelatine and higher than the pure pea protein. The important structural modification made to the pea protein made it more reactive, probably due to a higher exposure of its structure and the apolar and positively charged amino acids, and to the appearance of peptides with protein functions of binding to carbohydrates and proteins, which are also present in animal protein. With these results it can be concluded that pure vegetal proteins may not have sufficientt functional properties to behave as good flocculating agents, although certain chemical modification in their structure may further simulate the behaviour shown by animal protein.

DOI:

Publication date: September 7, 2021

Issue: Macrowine 2021

Type: Article

Authors

Ana Belén Bautista-Ortín, Sonia, Albendea-Roa,  Jurado

University of Murcia,Bermúdez-Galvez, (University of Murcia) Gómez-Plaza, Encarna (University of Murcia), Mar (Agrovin S.A.), Ricardo (Agrovin, S.A.)

Contact the author

Keywords

finning, amioacids, proteins, flotation, white wine

Citation

Related articles…

Viticultural sites and their valorisation in Istria (Croatia)

Pratiquement tout le territoire d’Istrie possède les bonnes conditions naturelles pour la viticulture, laquelle dans ce lieu a une tradition millénaire. La viticulture était et reste toujours la plus importante branche de production agraire et d’économie. Les sites viticoles en Istrie sont caractérisés par des diverses conditions naturelles.

Under-vine management effects on grapevine production, soil properties and plant communities in South Australia

Under-vine (UV) management has traditionally consisted of synthetic herbicide use to limit competition between weeds and grapevines. With growing global interest towards non-synthetic chemical use, this study aimed to capture the effects of alternative UV management at two commercial Shiraz vineyards in South Australia, where the sole management variables were UV management since 2016. In adjacent treatment blocks, cultivation (CU) was compared to spontaneous vegetation (SV) in McLaren Vale (MV), and herbicide was compared to SV in Eden Valley (EV). Soil water infiltration rates were slower and grapevine stem water potential was lower in CU compared to SV in MV, with the latter having a plant community dominated by soursob (Oxalis pes-caprae) during winter; while in EV, there was little separation between the treatments. Yields were affected at both sites, with SV being higher in MV and HE being higher in EV. In MV, the only effect on grape must was a lower 13C:12C isotope ratio in CU, indicating greater grapevine water stress. In the grape must at EV, SV had higher total soluble solids, total phenolics, anthocyanins, and yeast available nitrogen; and lower pH and titratable acidity. Pruning weights were not affected by the treatments in MV, while they were higher in HE at EV. Assessments revealed that the differing soil types at the two sites were likely the main determinants of the opposing production outcomes associated with UV management. In the silty loam soil of MV, the higher yields in SV were likely due to more plant-available water, as a potential result of the continuous soil bio-pores formed by winter UV vegetation. Conversely, in the loamy sand soils of EV with a lower cation exchange capacity, the lower yields and pruning weights in SV suggest the UV vegetation competed significantly with the grapevines for available water and nutrients.

Non-targeted analysis of C13-norisoprenoid aroma precursors in Riesling

Significant wine aroma can be formed from non-volatile precursors that are linked to sugars, including but not limited to grape-derived monoterpene and C13-norisoprenoid glycosides.

The role of tomato juice serum in malolactic fermentation in wine

Introduction: Malolactic fermentation (MLF) is a common process in winemaking to reduce wine acidity, maintain microbial stability and modify wine aroma. However, successful MLF is often hampered by their sluggish or stuck activity of malolactic bacteria (MLB) which may be caused by nutrient deficiency, especially when MLB are inoculated after alcoholic fermentation (Alexandre et al., 2004; Lerm et al., 2010). Identification and characterization of essential nutrients and growth factors for MLB allows for production of highly efficient nutrient supplements for MLF.

Sustainability as system innovation: sustainability as system innovation: a returnable system for glass wine bottles

Introduction increasing sustainability is essential and a societal challenge, requiring fundamental changes in behaviour and attitudes. This applies to both producers and consumers. For the wine industry in particular, such a change is a major challenge. An eip-agri research project is evaluating the introduction of a returnable glass system in the german wine industry as a key solution for increasing sustainability. Given the need for change associated with a returnable system, the project is theoretically grounded in systems innovation, as this approach provides solutions for complex, transformative change.