WINETECH Technical Yearbook 2021

OENOLOGY RESEARCH | JANUARY/FEBRUARY 2021

RESEARCHERS FROM THE SOUTH AFRICAN Grape and Wine Research Institute and Department of Viticulture and Oenology at Stellenbosch University performed a Winetech-funded study to investigate the minimum concentrations of 3MH and 3MHA needed to notably alter the wine’s sensorial properties. INTRODUCTION The presence of sufficient concentrations of volatile thiols will result in the wine having prominent tropical fruit characteristics with sensory attributes described as passion fruit, guava, grapefruit, tomato leaf and blackcurrant. These compounds are particularly potent in wines due to their very low sensory perception thresholds (table 1). However, perception thresholds reported for individual aroma compounds provide a general indication regarding the minimum concentration needed for any aroma to be sensorially perceived. The problem with perception thresholds is that they are often determined in a model wine solution and not in real wines. Determining the perception threshold in & WESSEL DU TOIT 2 : 1 Basic Wine, Stellenbosch; 2 South African Grape and Wine Research Institute, Department of Viticulture and Oenology, Stellenbosch University, Stellenbosch KEYWORDS: Thiols, sensory perception threshold. Do smaller thiol increases have a significant sensorial effect? CARIEN COETZEE 1 , MATIJA LESKOVI Ć 2 , JEANNE BRAND 2

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