| dc.description.abstract | ELF magnetic field at low intensity has been proveneffective on cells' proliferation, and expected to be a breaktrough activation technologyof bacteria S. thermophilus, L. lactis bacteria, and L. acidhopilus, in the process of making cream cheese. Considering the main issue in the process of making cream cheese was the optimization of the growth of bacteria often did not match the expectations. Therefore, this study aimed to determine the effective dose of ELF magnetic field exposure on the optimization of the growth of bacteriaS.thermophilus, bacteria L. lactis and L. acidhopilus.
This research used the ELF magnetic field with the intensity of 100 and 300 uTuT presented at the proliferation of three types of bacteria by long exposure to 5, 15, 25, 35, 45 minutes. Measurement of the amount of bacteria and medium PH was performed 1 hour, 2 hours, and 16 hours after being exposed to ELF magnetic fields.The results of this study indicated that the optimal growth in all three types of bacteria was experienced by groups which were exposed by ELF magnetic fields with an intensity of 100 uT for 5 minutes. The measurement result on the second hour after the exposure showed the growth speed of bacteria S. thermophilus reached 100 cal, bacteria L. Latis reached 33 times, and the bacteria L. Acidhopilus reached 41 times.The pH measurement result explained that ELF magnetic field at 100 uT for 5 minutes significantly decreasing the medium pH grew three types of bacteria, The lowest S. thermophilus at 4.10, the medium pH grows L. Latis reached the lowest value at 4.34, and the bacterium L. Acidhopilus reached the lowest value at 4.23.Therefore it could be concluded that ELF magnetic field exposure with the intensity of 100 uT for 5 minutes is an effective dose for optimizing of the growth of bacteria S. thermophilus, L. Latis, and L. Acidhopilus. | en_US |
