Phenolic Compounds Content in Merlot Wines Obtained through Different Thermomaceration Techniques

Abstract

This paper’s objectives were to determine the anthocyanic extraction level and their distribution by correlating the total phenolic content with different thermic maceration techniques applied to ‘Merlot’ grapes. In this study, three maceration processes were employed: thermoflash maceration (thermobaric), thermomaceration, and also classical maceration-fermentation, in order to compare the extraction degree of anthocyans from red grape skins into wine. In order to determine the sample’s anthocyan profile, a standard HPLC method of analysis (OIV-MA-AS315-11) was used. The wines obtained through thermoflash maceration contain significantly higher quantities of phenolic compounds (3572 mg GAE L⁻¹) and total anthocyans (340 mg L⁻¹), in contrast with the classical maceration-fermentation winemaking technology. Also, the participation percentage in the anthocyanic profile of malvidin-3-monoglicoside, an intense blue-purple coloured pigment is 60.1% and is with 10% superior to classical method of maceration. The obtained wines were characterised through high degree of stability for the anthocyans due to high values for the ratio between the acetylated and coumarylated anthocyans (9.36).