Influence of freezing skin grapes to extract phenolic compounds during red wine maceration

¹ Departement of Fruit Production and Enology, Faculty of Agronomy and Forestry Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile
² Master International Vintage- École Supérieure d'Agriculture d'Angers, Angers, France

Abstract

Wine quality depends on phenolic and aromatic compounds that are mainly located in skins and seeds of grapes and can be better extracted if suitable extraction technologies are applied. An increase in extractability has impact in the mouth feel, color and age ability of the wines. Using liquid or solid CO₂ is a way to promote the breakdown of the cells membranes and enhance extraction of these compounds and protecting grapes and wine from oxidation. The main goal was to test the impact of solid CO₂ addition to destemmed grapes with a new CO₂ dispenser equipment in order to freeze the berry skins and improve the phenolic extraction in an economic and sustainable way in cv. Cabernet Sauvignon and Pinot Noir. The experiment designed for both cultivars was a treatment with CO₂ addition and a control without CO₂ addition each one with three replicates. Destemmed grapes submitted to carbonic snow reached temperature of the skins between − 1 and − 4 °C during four minutes under equipment treatment. The consumption of carbon dioxide was estimated around 0.3(kg ⋅kg⁻¹)CO₂ per berries. Wines of Cabernet Sauvignon and Pinot noir from fresh grapes and frozen grapes were made and were being compared in phenolic composition and sensory attributes.