DESENVOLVIMENTO E CARACTERIZAÇÃO FÍSICO ... - UFSM

57
The extraction of minor volatile compounds of jelly palm wine was conducted using a solid
phase microextraction technique according to Bernardi et al., (2013). The volatile compounds were
extracted using a DVB/CAR/PDMS fiber; 10 mL of jelly palm wine was transferred to a 20 ml
glass vial added to 3g of NaCl and 10 µl of 3-octanol (82.2 mg/l internal standard solution). Time
of extraction was 45 minutes preceded for 5 min of equilibrium at 35 °C under constant stirring
(500 rpm).
The analysis of the volatile compounds was conducted using a Varian 3400 Star gas
chromatograph equipped with a Split/Splitless injector and a flame ionization detector (GC-FID).
A ZB-WAX plus capillary column (60 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 from 35 °C to 80 °C at
4 °C/min, then programmed to run from 80 °C to 200 °C at 30 °C/min remaining at 200 °C/min for
5 min. Carrier gas was hydrogen at an initial flow rate of 2 ml/min (constant pressure of 30 psi).
The relative concentrations of the investigated compounds were calculated by relating the area of
the internal standard to the area of the compound of interest. Response factor between internal
standard and analytes was assumed as one.
Volatile compounds were identified in a Shimadzu QP2010 gas chromatograph coupled to a
mass spectrometer GC/MS. GC conditions were the same as those used for the GC-FID
chromatographic analysis. Helium was the carrier gas at a flow rate of 2 ml/min. MS was operated
in electron ionization mode (EI) at 70 eV, scanning from 35 to 350 m/z. The volatile compounds
were identified by comparing their mass spectra to those of commercial spectra databases (Wiley,
NIST05) and by comparing experimental retention index (RI) with the literature. Some compounds
were positively identified by injecting the authentic standards into the GC-FID and GC/MS
systems.
2.5 Sensory Analysis
The final beverages were evaluated by 40 panelists, males and females, (staff and students
of the Federal University of Santa Maria - UFSM). The panelists were selected for participation on
the basis of their preference for wines, interest, and availability. Refrigerated (10 °C) samples of
20 ml were served in clear glasses with a volume of 50 ml; these were marked with three digit