The environmental impact of viticulture: analysis of the influence type of biofertilisers on wine quality and microbiology activity of soil

During red wine vinification, maceration allows the must, and consequently the wine, to be enriched with several compounds that contribute to the creation of the typical organoleptic characteristics of red wines. Among these, extraction of polyphenols (PPs) during maceration is a major process of enological interest. The purpose of this study was the evaluate the suitability of a rapid analytical approach based in linear sweep voltammetry to monitor PPs extraction during vinification.

AIM AND METHODS: Grape withering is one of the key steps in the production of the most renowned red wines of the Valpolicella area, namely Amarone and Recioto. This practice, which was already used since Roman times, entails important modifications in grape composition and in the chemical and sensorial characteristics of the corresponding wines, especially in terms of aromatic profile. The aim of this research is evaluating the aromatic evolution during grape withering of the three main varieties used in Valpolicella wines: Corvina, Corvinone and Rondinella.Samples of the three varieties were analyzed at harvest and at different stages of withering, namely10%, 20% and 30% of weight loss. Free and glycosidically bound compounds were extracted and analyzed using Gas Chromatography- Mass Spectrometry (GC-MS). RESULTS: For all the samples the data were normalized to eliminate the effect of concentration due to grape dehydration. Terpene content and evolution varied considerably in relationship to grape variety. Corvinone was richer in cyclic terpenes (including phellandrene, limonene, and cymene) and they decreased during withering.

A white wine model solution (12% v/v ethanol, 4 g/L tartaric acid, pH 3.2) was used to assess wine colloidal instability as well as the influence of several wine components on bentonite performance in protein removal.

In this video recording of the IVES science meeting 2021, Alice Maria Correia Vilela (University of Trás-os-Montes and Alto Douro, Vila Real, Portugal) speaks about bio-modulating wine acidity: the role of non-Saccharomyces yeasts. This presentation is based on an original article accessible for free on IVES Technical Reviews.

It is a well-established fact that premature oxidation is noxious for wine aromatic quality and longevity. Although some oxidation-related aroma molecules have been previously identified, there are not works carrying out systematic research about the changes in the profiles of odour-active volatiles during wine oxidation.