Effect of Irradiation on Bacteriological and
Vitamin Levels
Results
Guinea pig diet was irradiated. Vitamin and microbiological assays were performed on the
product before and after irradiation. As the results indicate, irradiation achieved
excellent reduction of the microbial load while having minimal effects on the vitamin
content of the product. Although the data appears to indicate that irradiation increases
the levels of some vitamins, these elevated values are the result of analytical variation.
PicoLab® Diet Products are formulated to provide optimal vitamin levels after
irradiation.
| Analytical Data | |
| % of Vitamin Remaining after Irradiation | |
| Vitamin A | 94 |
| Vitamin D | 98 |
| Vitamin E | 110 |
| Thiamin | 97 |
| Riboflavin | 103 |
| Pyridoxine | 93 |
| Niacin | 99 |
| Pantothenic Acid | 98 |
| Choline | 100 |
| Folic Acid | 96 |
| Vitamin C | 86 |
| Biotin | 100 |
| Vitamin B12 | 92 |
| Microbiological Assay | Units | Control | |
| Irradiated | |||
| Total aerobic plate | CFU/g1 | 51667 | <1 |
| Total yeast | CFU/g | 1 | <1 |
| Total mold | CFU/g | 417 | <1 |
| Total mesophilic anaerobic spores | MPN/g2 | 1100 | <3 |
| Mesophilic aerobic spores | CFU/g | 41500 | <1 |
| Thermophilic anaerobic spores | MPN/g | 1100 | <3 |
| Total Thermophilic aerobic spores | CFU/g | 6167 | <1 |
| Total flat sour spores | CFU/g | 2802 | <1 |
1 CFU/g = Colony Forming Units per gram
2 MPN/g = Most Probable Number per gram
The lower limit of detection for Total Aerobic Plate, Total Yeast, Total Mold, Mesophilic
Aerobic Spores, Total Thermophilic Aerobic Spores and Total Flat Sour Spores is less than
one colony forming unit per gram (CFU/g). The lower limit of detection for Total
Mesophilic Anaerobic Spores and Thermophilic Anaerobic Spores is less than three most
probable number per gram (MPN/g).
11/12/02