Objective. In general, there are many CO₂-abatement measures including renewable energy utilization. However, we might have to consider the reduction of the indirect CO₂ emission, e.g., behavior and/or preference etc., on life cycle assessment (LCA) basis. For elderly people, there are surely difficulties in reducing CO₂ emission. That is, they would not be able to take the specific countermeasures such as promotion of PV system and/or eco-car, because of their limited incomes. For them, somewhat reasonable motivation without any obligation might have to be provided. In this paper, we investigated the relationship between the specific CO₂ emission and salt content of the cooking for the elderly who worry about their health condition, and they would try to pay more attention to the high-blood pressure problem. Due to this fact, a good motivation for their behavior of CO₂ emission abatement would be accrued.
Results and Discussion. Here, we selected the 171 menus for elderly people from the cooking database of “Bob & Angie”. The selected menus are satisfied with the condition of their calorie intake per day of 1800 kcal/day. At the same time, the numerical data of salt content of each menu was provided in the cooking database. For all of the menus, we estimated the life cycle CO₂ emission in the functional unit of g-CO₂/kcal. From the results, we estimated the correlation between the CO₂ emission and salt content based on the four categories: the category of main and side dishes and/or soup, that of food preparations of boiling, steaming and grilling etc., that of food materials of meat, fish and vegetable, that of different cuisines of Japanese, Western and Chinese dishes. As a result, the coefficient of correlation between the CO₂ emission and salt content for the category of main and side dishes and/or soup was the highest of 0.996. The average CO₂ emissions for the category were 1.115 g-CO₂/kcal in the main dish, 1.801 g-CO₂/kcal in the side dish and 2.907 g-CO₂/kcal in the soup. In the other categories, the coefficients of correlation were between 0.905 and 0.986.
Conclusions. In this paper, we were able to find out the evidence that there would be the specific correlation between CO₂ emission and salt content in cooking for elderly people. Due to their efforts to reduce the risks of illness, that is, their desires to remain physically healthy, it implies that the CO₂ emissions for their dietary behavior are mitigated.