Correlations Between Phenolic Composition and Perceived Astringency of Wines

Abstract

The astringent sensation of wines is attributable to the composition and concentration of phenolic compounds. However, in many cases, experimental results have shown a gap in relation to sensory astringency. The aim of the present study was to evaluate the relationships between the experimental evidence of astringent attributes and perceived astringency. To this end, the concentrations of phenolic compounds, namely, the total phenolic content (TPC), the polymeric tannin content (PTC), the proanthocyanidin content (PAC) and the total anthocyanin content (TAC), in wines made from a variety of grape breeding lines were estimated and their relationships to perceived astringency were evaluated. The TPC and the PTC showed strong positive correlations with perceived astringency. In contrast, the PAC showed a moderate correlation with perceived astringency, which was lower than that shown by the PTC despite their similar phenolic compositions. Unlike the other attributes, the TAC showed a weak correlation with perceived astringency. We concluded that the TPC and the PTC showed good correlations with perceived astringency and could be used as an index for predicting the astringency of wines.

Effects of Berry Thinning on the Physicochemical, Aromatic, and Sensory Properties of Shine Muscat Grapes

“…The total phenolic concentration (TPC) of the extracts was measured using the modified Folin-Ciocalteu's reagent assay [10]. An aliquot (1 mL) of extract solution was evaporated and dissolved in dimethyl sulfoxide.…”

“…The proanthocyanidin concentration (PAC) in the extracts was measured using a vanillin-acetic acid assay [10]. A 30 µL extract solution was pipetted into each well of a 96-well microplate, and 150 µL of a vanillin working solution (0.5% vanillin in 4% HCl in acetic acid) was added.…”

“…The polymeric tannin concentration (PTC) in the extracts was measured using a BSA precipitation assay [10]. A 0.2 mL of the extract solution was mixed with 1 mL of BSA solution (1 mg/mL BSA in a washing buffer) in a microtube and incubated at 25 • C for 10 min.…”

Relationships between Instrumental and Sensory Quality Indices of Shine Muscat Grapes with Different Harvesting Times

“…The PTC of grape berries was significantly lower in the berries harvested at 16 WAFB than in the others. The polymeric tannin content is an important parameter for judging the eating and drinking quality of grapes and wines since polymeric tannin, rather than other phenolic constituents, such as anthocyanins and proanthocyanidins is responsible for the astringent sensation [ 11 ]. In contrast, the skin rupture strength and flesh firmness values of Shine Muscat grapes were significantly higher in berries harvested at 16 WAFB than in the others.…”

“…The polymeric tannin content (PTC) in the extracts was determined using a BSA precipitation assay [ 11 ] with slight modifications. Grape skins were manually separated from the pulp using a flat spatula and immediately soaked in deionized water.…”