 IVES 9 IVES Conference Series 9 Influence of short-time skin maceration combined with enzyme treatment on the volatile composition of musts from fresh and withered fiano winegrapes

Influence of short-time skin maceration combined with enzyme treatment on the volatile composition of musts from fresh and withered fiano winegrapes

Abstract

AIM: The increasing market competitiveness is promoting the production of special dry wines with distinctive characteristics, obtained either from minor winegrape varieties and/or the inclusion of partially dehydrated grapes. With the aim of taking advantage of the grape quality traits in terms of aroma potential, short-time skin contact prior pressing in combination with the use of exogenous enzymes can facilitate the release of volatile organic compounds (VOCs) into the grape must. In addition, the possible presence of glycosidase activity enhances the hydrolysis of odourless glycosidically-bound precursors, which have a particular importance for non-aromatic grape varieties. [1,2] In this study, the effect of eight enzyme treatments with different single activity during short-term pre-fermentative maceration was investigated on the volatile composition of musts, obtained from both fresh and withered winegrapes cv. ‘Fiano’.

METHODS: The study was carried out on fresh or partially dehydrated (20% of weight loss) ‘Fiano’ white winegrapes from Campania region (southern Italy). For each sample, twenty-seven berry sets of 500 g each were randomly selected and crushed in presence of 10 mg/kg of potassium metabisulphite. Then, three berry sets were individually treated with pectin lyase (PL), polygalacturonase (PG), pectin methylesterase (PME), xylanase (XYL), arabinase (ARA), protease (PRO), β-glucanase (GLN), or β-glucosidase (GLU) enzymes at a dose of 10 mg/kg, homogenized and subjected to pre-fermentative maceration for 13 h at 12 °C. The other three berry sets were treated similarly but without enzyme addition (control). Subsequently, the musts obtained were separated from the skins and used for the determination of free and glycosidically-bound VOCs using solid-phase extraction followed by GC-MS analysis [3].

RESULTS: Regarding the free volatile fraction of musts, few compounds were influenced by the different enzyme treatments tested. This effect appeared to be more evident for glycosylated volatile compounds, for which the concentration of total compounds, aromatic alcohols, C6 alcohols, and certain terpenes (nerol and geraniol) significantly prevailed in musts from fresh grapes treated with PG. Moreover, samples from withered Fiano grapes treated with PG and ARA were characterized by higher contents of terpenes (cis-8-hydroxylinalool, nerol, geraniol, and α-terpineol), C6 alcohols (trans-2-hexenol and 1-hexenol), and benzenoids (eugenol).

CONCLUSIONS:

The addition of enzymes during short-term pre-fermentative maceration resulted to have effect mainly on the glycosylated volatile fraction of the musts obtained from fresh and withered grapes. In particular, exogenous enzyme activities such as PG exhibit major influence on the volatile profile of musts derived from fresh and withered ‘Fiano’ grapes, which could contribute to enhance the sensory perceived aroma of the resulting wines.

DOI:

Publication date: September 10, 2021

Issue: Macrowine 2021

Type: Article

Authors

Stefano Boz

University of Torino, Italy,Susana RÍO SEGADE, University of Torino, Italy Stefano BOZ, University of Torino, Italy Mattia MALABAILA, University of Torino, Italy Domen ŠKRAB, University of Torino, Italy Maria Alessandra PAISSONI, University of Torino, Italy Simone GIACOSA, University of Torino, Italy Luca ROLLE, University of Torino, Italy

Contact the author

Keywords

volatile compounds; enzymes; pre-fermentative maceration; fiano winegrapes

Citation

REDWINE project: use of Chlorella vulgaris to prevent biotic and abiotic stress in Palmela’s region, Portugal, vineyards

The new EU Green Deal aims to achieve GHG emissions reduction by at least 55% by 2030 and a climate neutral EU economy by 2050.
REDWine concept will be realized through the establishment of an integrated Living Lab demonstrating the viability of the system at TRL 7. The Living Lab will be able to utilize 2 ton of fermentation off-gas/year (90% of total CO2 produced in the fermenter) and 80 m3 of liquid effluent (100% of the liquid effluent generated during fermenter washing) to produce 1 ton (dry weight) of Chlorella biomass/year. This biomass will be processed under a downstream extraction process to obtain added-value extracts and applied in food, cosmetic and agricultural end-products and to generate a new EcoWine. REDWine will focus on the recovery of off-gas from a 20.000L fermenter of red wine production existing in Adega Cooperativa de Palmela (ACP, located in Palmela, Portugal).

VineAI: artificial intelligence for fungal disease

Early and accurate grapevine disease detection and surveillance are crucial for optimizing vineyard management practices.

Physicochemical behaviour of wine spirit and wine distillate aged in Sherry Casks® and Brandy casks

Brandy is a spirit drink made from “wine spirit” (<86% Alcohol by Volume – ABV; high levels of congeners and they are mainly less volatile than ethanol), it may be blended with a “wine distillate” (<94.8%ABV; low levels of congeners and these are mainly more volatile than ethanol), as long as that distillate does not exceed a maximum of 50% of the alcoholic content of the finished product[1]. Brandy must be aged for at least 6 months in oak casks with <1000L of capacity. During ageing, changes occur in colour, flavour, and aroma that improve the quality of the original distillate.

IN DEPTH CHARACTERIZATION OF OENOLOGICAL CHARACTERISTICS OF TWO LACHANCEA THERMOTOLERANS STARTER STRAINS

Non-Saccharomyces starter cultures became increasingly popular over the years because of their potential to produce more distinctive and unique wines. The major benefit of the use of Lachancea thermotolerans as a fermentation starter is its ability to produce relevant amounts of lactic acid and reduce alcoholic strength, making it valuable for mitigating negative impacts of climate change on grapes and wine quality. Besides, like any other non-Saccharomyces yeast, L. thermotolerans can significantly affect a whole range of other physico-chemical wine parameters.

Effects of post-fermentative cold maceration on chemical and sensory characteristics of Syrah, Cabernet Franc and Montepulciano wines

Astringency sensation decreases slowly during the aging of red wine. Complex reactions of condensation and precipitation of wine polyphenols are involved in this phenomenon. Wine composition and conditions of aging, such as temperature and oxygen availability, strongly influence evolution of the phenol matrix. Recently, a Post-Fermentative cold Maceration (PFM) technique was tested with the aim of accelerating reactions leading to the reduction of astringency and exploiting chemical compounds not extracted from the solid parts of grapes during the previous traditional maceration phase. To this purpose, an innovative maceration system was engineered and used to perform PFM trials on marc derived from vinification of different varieties of red grapes.