Simple Measurement of the Vinegar Extracts

Abstract

To estimate the total extract and the salt-free extract in vinegars from refractometric readings for sucrose and other analytical values, Multiple Regression Analysis was applied to analytical data on 33 commercial vinegars. The predictor variables were data of the extracts and criterion variables were other 7 kinds of analytical data. The following regressive equations were obtained on the total extract and the salt-free extract, respectively:
Y₁_1.01X₁-0.386X₂+0.892X₃-0.639 (2)
(Y₂=1.00X₁-0.380X₂-0.6645)
where, Yi is the predicted value of the total extract (%), Y₂ is the predicted value of the salt-free extract (%), X₁ is refractometvic reading for sucrose (.S), X₂ is total acid (%) and X₃ is salt content (%). Each equation accounted for more than 99. 5% of the total variation, and results of the analysis of variance were highly significant. The equations were fitted, to data of 35 commercial vinegars sampled from an other lots different from the initial samples; correlations between the predicted and the observed values of the total and the salt-free extract were highly significant with correlation coefficients of more than O. 99. Most predicted data were fallen into the range of 99% confidence limit. Accordingly, the prediction equations were found to be applicable for simple measurement of the vinegar extracts.