Analysis of temporal dominance of sensation data using correspondence analysis on Merlot wine with differing maceration and cap management regimes

Abstract

Temporal dominance of sensation (TDS) is a dynamic sensory method that aims to capture the changing sensory profile of a product. TDS returns a frequency table indicating which attribute is selected as most dominant at a given time point. This paper outlines the relationships between TDS, descriptive analysis (DA) and chemical measures taken from a single product set. Merlot wine produced using nine different wine production practices comprised the product set. Principal component analysis (PCA) applied to the DA and chemical data table showed similar treatment discrimination. The DA captured 84.0% of the variability within two components, while the chemical measures captured 91.3%. Correspondence analysis (CA) was applied to the TDS frequency table along with calculating TDS curves. CA accounted for 43.1% of treatment variability within the first two components. The resulting CA factor map provided results consistent with the TDS curves, and allowed global TDS differences to be visually displayed in a single graphic. In addition, bootstrapping followed by calculating 95% confidence ellipses showed treatment discrimination within the CA factor map. Descriptive analysis captured the increasing astringency with longer maceration, while TDS captured the bitter persistence once the astringent sensation decreased.