DESENVOLVIMENTO E CARACTERIZAÇÃO FÍSICO ... - UFSM

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Vinifications were carried out, in duplicate, in 5 liters flasks and the fermentation was
monitored by the daily measurement of Brix value and temperature. The fermentation was
considered complete when the Brix level was stable. For the clarification step was used bentonite
(300 mg/l) prepared according to Daudt and Durante (1986), facilitating the sedimentation of nonfermentable
solids. After the clarification step the wines were stored in glass bottles (237 ml) under
the temperature of 6 °C until analysis.
2.2 General composition of jelly palm pulp and wine
Alcohol, pH, total acidity (as tartaric acid), volatile acid (such as acetic acid) were
performed in wines (Amerine and Ough, 1988). The Brix value, total acidity, pH and reducing
sugar were determined in the jelly palm pulp (AOAC, 2005).
2.3 Analisys of the major volatile compounds
The major volatile compounds were extracted by a static headspace procedure according to
Bernardi et al., (2013). For the extraction, 10 ml of jelly palm wine were transferred to a 20 ml
glass vial added to 3 g of NaCl and 30 µl of 3-octanol (822.2 mg/l internal standard). Headspace
sampling temperature of 50 °C and equilibrium time of 30 min were applied under continuous
stirring (500 rpm).
The analysis of the volatile compounds was conducted using a Varian 3400 Star gas
chromatograph (Palo Alto, CA, USA) equipped with a split/splitless injector and a flame ionization
detector (GC-FID). A ZB-WAX capillary column (30 m × 0.25 mm × 0.25 μm film thickness)
(Phenomenex, CA, USA) was used. The temperature of the injector and detector was set to 230
and 250 °C respectively. The oven temperature was held at 35 °C for 2 min and raised to 80 °C at
2 °C/min, then programmed to run to 150 °C at 4 °C/min and raised to 200 °C at 30 °C/min
remaining for 5 min. Carrier gas was hydrogen at an initial flow rate of 2 ml/min (constant pressure
of 15 psi). Quantification was conducted with an external calibration curve constructed using the
internal standard to correct analyte losses, as described by Bernardi et al., (2013).
2.4 Analysis of the minor volatile compounds