Determination of glycerol
The Laborlab Liquiform Triglyceride commercial kit (using
enzymatic colorimetric method) was employed for the determination
of glycerol in the wine (MacGowan et al., 1983). Thirty-microliter
aliquots of wine samples were transferred to test tubes, and 3 ml of
the enzyme reagent was added to each tube. The tubes were
homogenized and incubated for 15 min in a water bath at 37°C. The
tubes were cooled, and the values of absorbance were measured
at 505 nm on a spectrophotometer (FEMTO).