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.
Agricultural University of Athens, Department of Food Science and Technology, Iera Odos 75, Votanikos, Athens 118 55, Greece. agerogiannaki@yahoo.ca
Maria
M
Gerogiannaki-Christopoulou
Nikolaos V
NV
Kyriakidis
Panagiotis E
PE
Athanasopoulos
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