The pH values reduced from 4.91 to 4.38 in fermented heat-treated litchi juice, and from 5.31 to 4.48 in fermented high hydrostatic pressure - treated litchi juice as stored for 4 weeks at 4 °C (Fig. 2), reflecting some acid products produces during storage. Guo et al. (2009) reported that after 24 h of fermentation, the L. casei reduced the pH of fermented milk to 5.59, and after storage for 28 days at 4 °C, the pH reached 4.60.