Impact of non-Saccharomyces in malolactic fermentation of white and red winemaking

Chitosan is a polysaccharide produced from the deacetylation of chitin extracted from crustaceous and fungi. In winemaking chitosan is mainly used in the clarification of grape juice and wine, stabilization of white wines, removal of metals and to prevent wine spoilage by undesired microorganisms. The addition of chitosan to model wine systems was able to retard browning, reduce levels of metallic ions (Fe and Cu) and to protect varietal thiols due to its antiradical activity1. The present experiment was planned in order to evaluate the use of chitosan as a secondary antioxidant at three different stages of Sauvignon blanc fermentation and winemaking. Sauvignon blanc juices from three different locations were obtained at a commercial winery in Marlborough, New Zealand. One lots of grapes was collected from a receival bin and pressed into juice with a water-bag press, and a further juice sample was collected from a commercial pressing operation. Chitosan (1 g/L, low molecular weight, 75 – 85% deacetylated) was added to the juice after pressing, after cold settling, after fermentation, or at all these stages. Controls without any chitosan additions were also prepared.

In the current climatic context, with milder winters leading to earlier budburst in most wine regions, vines are exposed to the risk of spring frosts for a longer period. Depending on the year, frost can lead to yield losses of between 20 and 100 %, jeopardizing the economic survival of wine estates. In addition, by destroying young shoots, spring frosts can impact the following season’s production, by reducing the number of canes available for pruning, for example. Late pruning is one method to combat spring frosts.

Proseccco is a famous italian Protected Designation of Origin (PDO) produced in two regions: Veneto e Friuli Venezia Giulia, however, the production is mainly concentrated in the province of Treviso. These territories are characterized by plains with some hilly areas and temperate climate. Its Production regulation provides a minimum utilization of 85% of Glera grapes, a local white grape variety, and up to a maximum of 15% of other local and international varieties. Prosecco second fermentation takes place, according to the Charmat method, in autoclaves.

In this video recording of the IVES science meeting 2021, Sophie Tempère (Institut des Sciences de la Vigne et du Vin – ISVV, Université de Bordeaux) speaks about the recovery of olfactory capacity following a COVID-19 infection. This presentation is based on an original article accessible for free on IVES Technical Reviews.

Study the influence of sample preparation methods on the volatile organic compounds (VOCs) profiling for fermentative beverages by GCxGC-TOFMS analysis. METHODS: Five common sample preparation methods were tested on pooled red wine, white wine, cider, and beer. Studied methods were DHS, Liquid-liquid extraction, mSBSE, SPE and SPME. VOCs were analyzed by GCxGC-TOFMS followed by data analysis with ChromaTOF. RESULTS: The volatile organic compounds (VOCs) profiling results were very dependent on the sample preparation methods.