Possibility of utilizing frozen foods as rolling stock

• Published in: Journal for the Integrated Study of Dietary Habits Vol. 35; no. 1; pp. 29 - 34
• Main Authors: Ito, Satoshi, Sekine, Masashi, Charoenthaipanich, Ratchapun, Ueno, Masayuki
• Format: Journal Article
• Language: Japanese
• Published: THE JAPAN ASSOCIATION FOR THE INTEGRATED STUDY OF DIETARY HABITS 2024; 日本食生活学会
• ISSN: 1346-9770; 1881-2368
• DOI: 10.2740/jisdh.35.1_29

The government recommends that each household should maintain a seven-day food supply in preparation for disasters. However, to facilitate this, several challenges must be addressed, such as securing storage space, cost, and renewal of stockpiles. Rolling stock is recommended as a viable solution. This study investigates the safety of frozen foods to determine their suitability for inclusion in rolling stock food.　The temperature of the frozen food (gyoza) was monitored over time, following the power supply was stopped. We also examined hygiene indicator bacteria, including general bacteria, coliform group, and Staphylococcus aureus, to assess safety. Then, we examined if it was possible to heat the food to a temperature range that effectively sterilizes bacteria causing food poisoning, by cooking it in a plastic bag.　Our findings show that when the freezer was fully loaded with frozen gyoza, the temperature reached 0 °C after 77 h after the power supply was stopped. When the freezer was opened and almost half of the frozen gyoza was removed, the temperature reached 0 °C within 56 h. The count of viable hygiene indicator bacteria conformed to the standards for frozen foods, ensuring that the food was ready for consumption 72 h after the power supply was stopped. Moreover, when heated in a plastic bag, the food reached a temperature of 75 °C, which can sterilize bacteria causing food poisoning, after 35 min.　In conclusion, our study demonstrated that frozen food can be safely consumed for up to 72 h, following the power supply was stopped, and it can be used as a rolling stock food in the disaster events.