Comparison of Titratable acidities in selected wines locally made in Uganda

Abstract

Wine is one of the oldest products where microbiological processes contribute significantly to the final quality of the product. In wine, there are a great number of organic acids, even more than 40, which differ in origin. Therefore the acid amount in wine can vary in wide ranges depending on the grape variety, ripeness degree, climatic conditions during ripening, type of soil, vineyard position, conditions according to which alcohol fermentation was done, wine storage and standing. Titratable acidity of wines is in the range of 4.0-8.0g/dm3 (0.4 to 0.8%) expressed in tartaric acid because a part of tartaric acid is deposited in the form of salts during alcohol fermentation, for wines that are less than 0.4%, there arises a suspicion about their origin. The aim of this study was to determine and compare the titratable acidities of locally made wines in Uganda and samples of selected wines used were sourced from markets. Three samples locally made were bought and one internationally recognized was bought. Classical titration was done using sodium hydroxide against the wine samples and results revealed that the titratable acidities of the locally made wines were 0.500, 0.575 0.520 for Obre wine, Bella wine and Mercelino wine respectively and were in the normal ranges as published. However, the P values obtained were 0.119, 0.031 and 0.318 for Obre wine, Bella wine and Mercelino wine respectively hence the null hypothesis was accepted for Obre wine and Mercelino wine but was rejected for Bella wine.