Journal: Journal of Cleaner Production, vol. 142, p. 395–402–8, 2017
International Standard Numbers:
Open Access: none
This study was carried out as part of the packaging optimization program in Norway, and the purpose was to study waste generation, energy use and greenhouse gas (GHG)-emissions from the whole product value chain of meals prepared from fresh ingredients at home, based in semi-prepared ingredients or as ready to eat meals. Consumer attitudes to ready to eat meals was also included in the study. The study was done with basis in Life Cycle Assessment methodologies and Material Flow Analyses, based in real cooking situations and experimental design. Portion sizes and left-overs from cooking and eating data are based in the experimental design. Food waste data from the retail sector is based in the Norwegian statistics from the ForMat project, whereas packaging data was measured from the used products. The consumer study was done through a standard web panel with 1000 respondents, with respondents representative for the Norwegian population. Reallocation of impacts from wasting of food to the place waste is generated has been applied combined with conventional Life Cycle Assessment (LCA) methods.
We found that ready to eat meals had higher energy consumption and GHG-emissions than meals prepared from fresh ingredients, which again had slightly higher energy consumption and GHG-emissions than semi-prepared ingredients. Production of ingredients (especially meat) was the most important element for all products. Main contributions to the differences between the dinner types were the use stage, packaging production and transport based in conventional LCA allocation. The effect of food wasting was best shown with the reallocation method, where the impact of total food waste was on the same level as impacts from the use stage. Preventing food waste from retail and use stages would contribute to 13% reduction in GHG-emissions. Ready made food generated more food waste in the retail sector, whereas food waste by consumers was lower than for the two other types of meals. Lower degree of filling contributed to more transport work and higher emissions and energy consumption from transport. More packaging, especially plastic packaging did also contribute to higher GHG-emissions from incineration compared to the other solutions. Consumers regarded packaging solutions from ready to eat meals to be too big and with materials that are difficult to recycle. Changing from only using traditional dinner meal based on fresh ingredients to only ready to eat dinner by a Norwegian household equals GHG-emissions from a standard car driving 900 km or 8% of the average total driving distance per year in Norway.