SENSORY PROFILE CHANGES INDUCED BY THE ANTIOXIDANT TREATMENTS OF WHITE WINES - THE CASE OF GLUTATHIONE, ASCORBIC ACID AND TANNIN TREATMENTS ON FETEASCA REGALA WINES PRODUCED IN NORMAL CELLAR CONDITIONS

Abstract

The present work aims to determine in which way the sensory profiles of the Feteasca regala white wines are affected by treatments with various antioxidants under normal wine cellar conditions and whether the changes induced are perceivable by tasters. The tested antioxidants were the reduced glutathione (GSH) and ascorbic acid (AA), both added during the fermentation of Feteasca regala musts, and also catechinic tannin and carbon dioxide added in the young wines during bottling. The GSH in doses of 0, 20 and 40 mg/l was added in the must just before fermentation, with or without an addition of 50 mg/l AA. The following 50 l variants were thus obtained: G0, G20, G20A50, G40 and G40A50. The young wines were then racked and bottled, adding in each variant during the bottling process either 0 or 20 mg/l catechinic tannin (T0 and T20) and using or not carbon dioxide for protection against oxygen. The main sensory parameters of wines were analyzed by using a protocol developed in our laboratory and also ranked by using the OIV-UIO score sheet for wine contests. Sensory profiles for each variant were obtained and discussed. The parameters which affected the sensory profiles of the wines were statistically analyzed for groups of samples containing the same type of treatment, to determine the treatments with significant influences on the sensory parameters. It was observed that in normal cellar conditions, where protection against oxygen is difficult to maintain in all winemaking stages, the GSH did not improve the aroma intensity and the floral scent perceived in the wines treated, the control wines scoring better for these parameters. The dose of 40 mg/l GSH improved both parameters as compared to the dose of 20 mg/l, but they were still under the values of the control samples. Also, the GSH used without AA increased the perception of bitterness, while in the presence of AA the bitterness induced by GSH was diminished. The tannin did not change the bitterness or the intensity of aroma, but influenced the floral scent, which was better perceived in the samples treated with it. Carbon dioxide treatments during bottling did not have a significant influence on any of the tested parameters.