New refractive index method for measurement of alcoholic strength of small volume samples.
A study of the correlation between the refractive index (RI) method adopted by the European Community (EC) and a reference pycnometric method for the measurement of alcoholic strength was undertaken. A new RI method with greater accuracy was also developed. Alcoholic strength measured by both RI methods presented a relatively constant negative bias compared with results by the pycnometric method. Differences found between the RI methods and the pycnometric method were 0.6-0.9% (v/v) when RI was measured by the EC method and 0.4-0.5% (v/v) when the new RI method developed in our laboratory was used. Statistical analysis of the results showed that differences between the 2 RI methods and the reference pycnometric method were statistically significant at the 95% confidence level. Correction factors are proposed for the accurate use of measurements of alcoholic strength obtained for small volume samples.
Gerogiannaki-Christopoulou
Maria
M
Agricultural University of Athens, Department of Food Science and Technology, Iera Odos 75, Votanikos, Athens 118 55, Greece. agerogiannaki@yahoo.ca
Kyriakidis
Nikolaos V
NV
Athanasopoulos
Panagiotis E
PE
D000434:Alcoholic Beverages / Q000032:analysis*; D002138:Calibration; D000431:Ethanol / Q000032:analysis*; D007202:Indicators and Reagents; D012031:Refractometry; D015203:Reproducibility of Results; D012996:Solutions
D007202:Indicators and Reagents; D012996:Solutions; D000431:Ethanol