Fundamental Toxicological Sciences

Paper Details

Fundamental Toxicological Sciences
Vol. 7 No. 4 May 19, 2020 p.167-170
Bacteriological evaluation of feasibility of food poisoning from long-term stored “pack-cooked” meals
  • Toshihiro Kobayashi (Faculty of Human Sciences, Kobe Shoin Women’s University /
Toshihiro Kobayashi , Harumi Sakuda
Faculty of Human Sciences, Kobe Shoin Women’s University
Keywords: Pack cooking, Heat-resistant plastic bag cooking, Food poisoning, Soup runs, Standard plate count

Recently, a “pack cooking” method, which uses heat-resistant plastic bags, has attracted attention for being simple and safe for emergencies such as natural disasters. One serving is filled in a pack. It uses less kitchenware and clean water, so “pack cooking” will particularly be a powerful tool for soup runs. However, its risk for food poisoning has not been given attention. It is important to consider the safety of “pack-cooked” meals, because medical shortage is as much a problem as food shortage during natural disasters. We conducted a bacteriological evaluation of curry and rice as typical “pack-cooked” meals, assuming that they were stored at room temperature for a long time. “Pack-cooked” meal samples were stored at 25°C and 4°C for 24 hr, and their homogenates were used as sample for bacteriological analysis. Obvious standard plate count bacteria were found in “pack-cooked” curry, which was stored at 25°C for 24 hr, whereas those stored at 4°C for 24 hr did not. Furthermore, there was a sample that was stored at 25°C for 24 hr in which coliform bacteria were detected. Since 25°C is equivalent to room temperature, our results demonstrate that the “pack-cooked” curry stored at room temperature for 24 hr could cause food poisoning. While “pack cooking” is a useful method, it is important to understand that prolonged storage at room temperature of “pack-cooked” meals should be avoided.