Mathematical models of the dynamics of fermentation of wine yeasts under the influence of vitamins

Parallèlement à la connaissance des aptitudes viticoles, le terroir témoigne d’une identité locale, d’une spécificité des conditions de productions et d’une originalité des lieux.

AIM The main lead exposure route is the intake of contaminated food, water, and alcoholic beverages, in particular wine. At the gastric level, Pb is transformed into a soluble compound which, when conveyed into the bloodstream, is the long-term cause of saturnism, intoxication with neurotoxic, nephrotoxic and hematopoietic effects, and with the neurological developmental delay of children. Pb is classified by the International Agency for Research on Cancer as a 2A class, possible carcinogenic to humans. In an opinion on possible health risks, CONTAM considered that cereals, vegetables, drinking water, and wine give a greater contribute to dietary exposure to Pb in Europe. Large quantities of wine, beer, and other alcoholic products drinking can increase daily Pb intake above the maximum permitted levels.

In a long-term experiment carried out in Chinon vineyard (37, France) during 23 years, the effects of several organic amendments were studied on soil, vine, grapes and wine. Four main treatments were compared on a calcareous sandy soil: control without organic amendment, dry crushed pruning wood at 2.1.t-1.ha-1.year-1 (D1), cow manure at 10 t-1. ha-1.year-1 (D1) and cow manure applied at 20 t-1.ha-1.year-1 (D2). D1 levels were calculated to fill the annual humus losses by mineralization.

Les indices bioclimatiques constituent un bon outil pour piloter le développement vitivinicole dans une région précise

Making high quality but affordable Pinot noir (PN) wine is challenging in most terroirs and New Zealand’s (NZ) situation is no exception. To increase the probability of making highly typical PN wines producers choose to grow grapes in cool climates on lower fertility soils while adopting labour intensive practices. Stringent yield targets and higher input costs necessarily mean that PN wine cost is high, and profitability lower, in line-priced varietal wine ranges. To understand the reasons why higher yielding vines are perceived to produce wines of lower quality we have undertaken an extensive study of PN in NZ. Since 2018, we established a network of twelve trial sites in three NZ regions to find individual vines that produced acceptable commercial yields (above 2.5kg per vine) and wines of composition comparable to “Icon” labels. Approximately 20% of 660 grape lots (N = 135) were selected from within a narrow juice Total Soluble Solids (TSS) range and made into single vine wines under controlled conditions. Principal Component Analysis of the vine, berry, juice and wine parameters from three vintages found grape berry mass to be most effective clustering variable. As berry mass category decreased there was a systematic increase in the probability of higher berry red colour and total phenolics with a parallel increase in wine phenolics, changed aroma fraction and decreased juice amino acids. The influence of berry size on wine composition would appear stronger than the individual effects of vintage, region, vineyard or vine yield. Our observations support the hypothesis that it is possible to produce PN wines that fall within an “Icon” benchmark composition range at yields above 2.5kg per vine provided that the Leaf Area:Fruit Weight ratio is above 12cm2 per g, mean berry mass is below 1.2g and juice TSS is above 22°Brix.