Title : Evaluation of the usefulness of heat-retention pack cooking for people requiring special consideration (patients with chronic kidney disease) in disaster situations
Abstract:
Purpose: During disasters, household cooking is frequently conducted under conditions of power outages and gas supply disruptions, necessitating low-energy, practical, and safe cooking methods. Special consideration is required for vulnerable populations who need individualized nutritional management, particularly individuals with impaired renal function, whose prevalence is expected to increase in aging societies. These individuals require restriction of potassium intake, making appropriate preparation of potassium-rich vegetables essential. In addition, psychological and physiological stress during disasters can increase oxidative stress, underscoring the importance of maintaining dietary antioxidant intake from vegetables. This study aimed to evaluate whether a pack cooking method that enables individualized preparation (PC method) and a heat-retention pack cooking method combining pack cooking with insulated, energy-saving cooking (HPC method) can achieve potassium reduction comparable to conventional boil-and-discard cooking, while preserving antioxidant properties under disaster-simulated household cooking conditions.
Methods: Komatsuna (Japanese mustard spinach), cabbage, Chinese cabbage, potato, and carrot were used as test vegetables. In the PC method, vegetables were placed in high-density polyethylene bags, air was removed, the bags were sealed, and the samples were heated in boiling water. In the HPC method, samples were briefly heated in boiling water and then cooked using retained heat by wrapping the pot with a flame-retardant emergency blanket, simulating household cooking during power outages and gas supply interruptions. As a comparison, Soaking the sample in water? alone as a pre-treatment was also examined. After cooking, potassium content was measured to evaluate potassium reduction. In addition, DPPH radical scavenging activity and total polyphenol content were assessed to evaluate antioxidant capacity. Temperature changes inside and outside the samples during cooking were recorded to confirm heating adequacy. Furthermore, color difference, soluble solids content (Brix), and sensory evaluation were conducted to assess food quality and palatability.
Results: All vegetables prepared using the PC and HPC methods showed a significant reduction in potassium content comparable to that achieved by boil-and-discard cooking (p<0.01). Antioxidant capacity, as indicated by DPPH radical scavenging activity and total polyphenol content, showed similar trends between the PC and HPC methods, suggesting that antioxidant properties were largely retained. In contrast, Soaking the sample in water? alone resulted in minimal potassium reduction. Temperature measurements confirmed that the core temperature of all samples reached 85°C within 5 minutes, ensuring microbiological safety.
Conclusions: The PC and HPC methods are feasible, simple, and energy-efficient household cooking techniques suitable for disaster situations involving power outages and gas supply disruptions. These methods are particularly useful for providing nutritionally appropriate meals for individuals with impaired renal function while supporting antioxidant intake under disaster-related stress, indicating their potential applicability for disaster nutrition support in home settings.
