Tracking the variation of small-batch micro-oxygenated wines using phenolic, anthocyanin and colorimetric determinations

摘要

This research tracked the variation in micro-oxygenated (MOX) Merlot wines exposed to 0, 5, 10, 20 and 60 mL 02/L/month for 40 days, using compositional [total phenolics, flavanols, tartaric esters, flavonols, condensed tannins, anthocyanins (total, ionized), degree of ionization of anthocyanins, chemical age (i, ii)] and colorimetric [color density, color intensity, color hue, % yellow, % red, % blue, L*, a*, b*, chroma, hue angle and saturation] determinations. Two-factor analyses of variance, principal component analysis (PCA) and relative standard deviations (rSTDs) were used to evaluate MOX and tank variation. PCA also summarized the interrelationships among the determinations. Lower tank-to-tank variation was observed for higher MOX rates. Thelowest rSTDs were observed for total phenolic and hue angle suggesting these variables were most sensitive for tracking MOX and tank effects, respectively. Duo-trio sensory tests discerned aroma, flavor-by-mouth and visual differences at the higher MOXtreatments. The high number of significant inter-correlations among the many compositional/colorimetric determinations suggested that a subset of analyses could be used for the routine tracking of MOX treatments. With the high variability associated withdelivery of low MOX rates in small tanks, it is recommended that winemakers monitor all tanks on an individual basis to ensure adequate quality control.