Table 4 shows the contents in the nitrogen compounds studied:
ammonium ion, amino acids and urea. Total aminic nitrogen concentration
(sum of aminoacids, ammonium and urea) was similar
in the traditional Pedro Ximenez wine, in the obtained with free
cells (F) and with immobilized yeasts in the second batch (B2)
decreasing in subsequent reuses. Free amino acids in wine can
mainly from grapes although some of them can be released by
yeasts at the end of fermentation or produced by proteolysis during
yeast autolysis.