-84-
Abstract
The effect of different temperatures, quantities of
Saccharomyces cerevisiae
and pHs in palm
sugar sap fermentating conditions, on methanol and acetaldehyde content in distilled liquor was studied.
Samplings of distilled liquor were obtained between the beginnings of distillation until 98
O
C. The
methanol and acetaldehyde content were analyzed by using gas chromatography with flame ionization
detector(FID). Chromatographic separation was carried out using capillary column (Carbowax DB-624)
and used 3-pentanone as internal standard. The temperature programmed of column increased from
50
O
C(hold 2 min) until 200
O
C (hold 2 min) with rate 40
O
C/min, The carrier gas was Helium gas,
flowed 2.0 mL/min. Temperature of FID was 250
O
C and ratio of air:H2 was 450 : 45 mL/min.
An analysis of each calibration curve for quantities of methanol, acetaldehyde and ethanol
was achieved linearity as equations: y=185.12x-0.7021 (R
2
=0.9764), y=2216.3x-0.7998 (R
2
=0.9987)
และy=0.0495x+0.6951 (R
2
=0.9839), respectively. Detection limit of methanol, acetaldehyde and
ethanol were 8.830×10
-2
mg/L, 3.970×10
-2
mg/L และ 21.440×10
-5
%(v/v), respectively and limit of
quantification were 31.830×10
-2
mg/L, 13.226×10-2 mg/L และ 71.468×10
-5
%(v/v), respectively.
The results of the study showed that starting fermentation at pH 4.0, controlling temperature
at 32
O
C and using S.
cerevisiae
10%(v/v) were optimum fermentating condition for minimum
methanol and acetaldehyde contents
Keywords:
Fermentating Conditions; Palm Sugar Sap; Methanol; Acetaldehyde; Distilled Liquor
