Determining the Effects of High Intensity Ultrasound on the Reduction of Microbes in Milk and Orange Juice Using Response Surface Methodology
Table 5
Comparison of the predicted and actual log microbial reductions in milk and juice attemperatures and times listed (all samples were run at 216 m amplitude).
Time (min)
Temp. (°C)
Predicted log reduction (range)
Actual log reduction
Indigenous thermophilic bacteria in milk
5.8
84.8
15 (12.2, 17.95)
6.541
0.17 (10.2 sec)
72
5.85 (3.20, 8.51)
5.24
0.33 (20 sec)
72
5.85 (3.24, 8.47)
5.39
Spores in milk
5.8
84.8
2.29 (1.52, 3.07)
2.01
0.17 (10.2 sec)
72
1.66 (1.09, 2.23)
1.56
0.33 (20 sec)
72
1.68 (1.17, 2.11)
1.66
S. cerevisiae in orange juice
5.8
84.8
9.42 (9.12, 9.72)
6.571
0.17 (10.2 sec)
72
6.72 (6.49, 6.94)
6.561
0.33 (20 sec)
72
6.72 (6.49, 6.94)
6.571
The reduction represents the maximum amount of microbes in the sample.
