Spatial characterisation of terrain units in the Bottelaryberg-Simonsberg-Helderberg wine growing area (South Africa)

GEOSPHERA s. r. l. e TERR.A.IN. CNS, forti della grande esperienza dei loro collaboratori nell’ambito delle scienze naturali, della geologia, della geofisica e dell’informatica, garantiscono risposte innovative alle problematiche della moderna agricoltura rivolgendosi direttamente ai viticoltori, ai commercianti vinicoli ed ai liberi professionisti.

Light-struck taste is a defect prevalent in white wines bottled in clear glass light-exposed for a considerable amount of time leading to a loss of color and appearance of sulfur-like odors. The reaction involves riboflavin (RF), a highly photosensitive compound that undergoes to intermolecular photoreduction by the uptake of two electron equivalents from an external donor, the methionine. The reaction includes different steps forming methional which is extremely unstable and decomposes to methane thiol and acrolein. The reaction of two molecules of methane thiol yields dimethyl disulfide. Methane thiol is highly volatile, has a low perception threshold (2 to 10 µg/L in wine) and confers aroma-like rotten eggs or cabbage.

Climate change is introducing a high variability on grape ripening, causing uncertainty, excessive spending on pesticides and eventually frustrating results in terms of the quality of the vintage, with the increasingly frequent appearance of aromatic problems associated with overripeness, raisining and greenness, which sometimes only appear in bottled wines.

Over the last decade, much attention has been paid on the oxidative susceptibility of white wines, given its key role in determining their ageing potential.

Context and purpose of the study. The wine industries face significant challenges from two highly detrimental viruses: leafroll and red blotch.