 IVES 9 IVES Conference Series 9 Phenolic extraction and mechanical properties of skins and seeds during maceration of four main italian red wine grape varieties

Phenolic extraction and mechanical properties of skins and seeds during maceration of four main italian red wine grape varieties

Abstract

AIM: Red grape varieties are characterized by different phenolic contents (prominently tannins and anthocyanins) found in skins and seeds. The extractability of these compounds varies during maceration, as well as the mechanical properties of skins and seeds. Four main Italian red winegrape varieties were tested to understand these differences during a simulated maceration process.

METHODS: Vitis vinifera L. cv. Aglianico, Nebbiolo, Primitivo, and Sangiovese grape skins, seeds, and joint skin+seeds were subjected to 10-day simulated maceration in a buffer solution (pH 3.40), with increasing contents of ethanol to simulate the fermentation trend. The phenolic extractable content (tannins and anthocyanins by spectrophotometry and HPLC) was evaluated during the simulated maceration. Mechanical-acoustic properties of skins and seeds were performed before and after maceration.

RESULTS: The combined total phenolics release during the maceration of separately-extracted seeds and skins were higher compared to the joint extraction (seeds+skins); in this latter case, the seeds contribution become significant (p < 0.05) after 3 (Nebbiolo), 4 (Aglianico) or 10 days (Primitivo and Sangiovese). In three cases out of four the anthocyanin content was found slightly reduced when the seeds were jointly present: these appeared red-coloured at the end of the maceration, and a further extraction and quantitation of the colouring matter retained by seeds was conducted. Diverging effects on the skin or seeds mechanical-acoustic measurements were found with the maceration process, depending by the variety.

CONCLUSIONS

Varietal differences were highlighted in phenolic compounds simulated extraction from solid parts, particularly for seeds contribution and for their ability to hold colour pigments.

ACKNOWLEDGMENTS

MIUR project PRIN n. 20157RN44Y. P. Arapitsas, A. Gambuti, M. Marangon, L. Moio, L. Nouvelet, G. Parpinello, D. Perenzoni, L. Picariello, D. Slaghenaufi, G.B. Tornielli, A. Versari, S. Vincenzi

DOI:

Publication date: September 7, 2021

Issue: Macrowine 2021

Type: Article

Authors

Simone Giacosa

University of Torino, Italy – Maria Alessandra PAISSONI, University of Torino, Italy – Susana RÍO SEGADE, University of Torino, Italy – Andrea CURIONI, University of Padova, Italy – Fulvio MATTIVI, University of Trento, Italy – Paola PIOMBINO, University of Napoli, Italy – Arianna RICCI, University of Bologna, Italy – Maurizio UGLIANO, University of Verona, Italy – Vincenzo GERBI, University of Torino, Italy – Luca ROLLE, University of Torino, Italy

Contact the author

Keywords

italian red winegrapes, phenolic extraction, anthocyanins, tannins, grape seeds

Citation

Screening sensory-directed methodology for the selection of non-saccharomyces wine yeasts based on perceived aroma quality

The present work contributes by developing a rapid sensory-directed methodology for the screening and selection of high quality wines with different sensory profiles Therefore, Verdejo and Tempranillo musts were fermented with 50 different yeasts each under controlled laboratory conditions. Resulting samples were firstly categorized according to five levels of quality by a panel of wine professionals (Sáenz-Navajas, Ballester et al. 2013). Higher quality samples were described by flash profiling by a semi-trained panel
(Valentin, Chollet et al. 2012) and most distinctive samples were screened by gas chromatography-olfactometry (GC-O) (López, Aznar et al. 2002).

Use of UHPH to improve the implantation of non-Saccharomyces yeasts

Ultra High-Pressure Homogenization (UHPH) is a high-pressure pumping at 300 MPa (>200 MPa) with a subsequent depressurization against a highly resistant valve made of tungsten carbide covered by ceramic materials or carbon nanoparticles. The intense impact and shear efforts produce the nano-fragmentation of colloidal biopolymers including the elimination of microorganism (pasteurization or sterilization depending on in-valve temperature) and the inactivation of enzymes.

Designing and managing a sustainable vineyard in a climate change scenario

Extension of the growing season, compression of the annual growth cycle and higher frequency and severity of weather extreme events are consistent features of global warming. While mitigation of factors causing global warming is necessary in the medium-long term, wine growers need “ready to go” adaptation practices to counteract negative effects bound to climate change. This must be done in a sustainably way, meaning that remunerative yield, desired grape quality, low production cost and environment friendly solutions must be effectively merged. In this work, we will review contribution given over the last two decades prioritizing issues related to scion and rootstock choice, changes in vineyard floor management, new perception related to the use of irrigation in vineyards, adaptation practices aimed at decompress maturity, solutions to counteract or minimize damages due to late frost and sunburn and, lastly, some hints on how precision viticulture can help with all of this.

New ways of grape pomaces valorization: production of functional beverages or nutraceuticals

The wine industry generates each year 20 million tons of by-products. Among them grape pomaces represent a big part that can be considered as a source of potentially bioactive molecules such as polyphenols. Kombucha fermentation is an ancestral process which allow to increase the biological properties of tea by the action of a microbial consortium formed by yeasts and bacteria called scoby.

Pinot noir: an endemic or a flexible variety?

Pinot noir has its historical roots in Burgundy and is generally considered as an endemic vine variety which means that its adaptation is very specific to this environment