The acid-base buffering properties of Alxa bactrian camel milk

The buffering properties of Alxa bactrian camel whole milk was investigated by titrating with base or acid. A "loop" was observed in the pH range 6.6-4.3 when sample was firstly titrated with acid and then back titrated with base. A "loop" was not observed when sample was firstly titrated with base and then back titrated with acid. When the milk sample was titrated from initial pH to 2.0 with HCl, camel milk exhibited a pronounced maximum buffering at approximately pH 4.4 and the value of dB/dpH was about 0.073. When acidified camel milk sample was back titrated from pH 2.0 to 11.0 with NaOH, there was low buffering index at approximately pH 4.9 (0.024), and maximum buffering index occurred at approximately pH 6.1 (0.051). The sample was firstly titrated from initial pH to 11.0 with NaOH, camel milk exhibited a weaker buffering peak at approximately pH 7.1 and the value of dB/dpH was about 0.018, when the alkalized milk sample was back titrated from pH 11.0 to 2.0 with HCl, the maximum buffering index occurred at approximately pH 5.1 and the value of dB/dpH was about 0.047. (C) 2014 Published by Elsevier B.V.