Titratable acidity of the corn–milk yogurt was measured
according to AOAC methods No. 947.05 (AOAC, 2000).
The determination of syneresis was carried out 24 h after
the completed fermentation (Wu, Hulbert, & Mount,
2001). The analysis was achieved using Whatman filter paper
(number 1) on a Buchner funnel, on which was spread 20 g of
yogurt as thin layer to cover the surface of the filter paper.
The funnel was inserted into an Erlenmeyer flask connected
to a vacuum pump and the yogurt was filtered under vacuum
for 10 min. The weight of filtrate divided by the initial
weight 100 gave the percentage syneresis.