4. Conclusions
The inactivation efficiency of two-stage MBCO2 on E. coli in CBM
was lower than that in PS. The reason was considered to be due tothe presence of various components in CBM and the difference of
initial pH. In addition, only a 3-log reduction in aerobic bacteria in
UBM was occurred by two-stage MBCO2 with the heating coil at 45
and 50 C. It was recognized that protease-resistance of casein and
most of the free amino acid contents in UBM were also changed and
decreased by the two-stage MBCO2, respectively.