Increasing amino acids content of white wines with enzymes treatments

Abstract

Wine’s chemical structure is affected by many biochemical transformations during the winemaking process, which are catalysed by specific enzymes. These compounds participate in the formation of amino acids, which also have fundamental functions in the sensory quality of wine. Therefore, this research focuses on monitoring the effect of enzymes on amino acid concentration during the fermentation of Feteasca regala and Sauvignon blanc wines. A total of 22 amino acids were quantified using an ultra-high liquid chromatography system coupled with mass spectrometry detection. Data indicated a major impact of the analysed variables (enzyme type and grape variety) on wine’s characteristics. Considerable amounts of some essential amino acids, such as histidine, isoleucine, phenylalanine, and tryptophan, were found in samples treated with pectinases preparations. The administration of pectinases was more effective in the Feteasca regala wines in the applied work conditions, although the -glycosides generated the highest values for most amino acids in the Sauvignon blanc. Pectinases can provide more acceptable sensory characteristics of wine compared to -glycosides in the applied work conditions (when they are applied in the pre-fermentation stage), while these samples generally showed the lowest intensity for some negative descriptors, such as phenolic, mineral or a bitter taste.