The apple juice was added to the soymilk at the concentrations
of 15 or 25%. Soymilk without apple juice was used as a control.
Preliminary experiments were performed to determine the optimal
apple juice concentrations. The soymilk with or without added
apple juice with a total weight of 140 g was placed to sterile screwcaped
glass jars (210 cc in volume). The soymilk with or without
added apple juice was inoculated with 10 g of subcultured
L. acidophilus cultures in soy milk, in order to achieve the initial
populations of 7 log cfu/ml (Santos, Libeck, & Schwan, 2014) and
fermented for 24 h at 37 C. The pH values of samples were
determined during the fermentation process. Fermentations were
conducted until reaching pH 4.6 for control samples (Bozanic,
Brletic, & Lovkovic, 2008). After the fermentation process, the fermented
products were cooled to 4 C, and stored at 4 C for 21 days.