The role of flexible packaging in the life cycle of coffee and butter

摘要

Background, aim and scope The evaluation of packaging's environmental performance usually concentrates on a comparison of different packaging materials or designs. Another important aspect in life cycle assessment (LCA) studies on packaging is the recycling or treatment of packaging wastes. LCA studies of packed food include the packaging with specific focus on the contribution of the packaging to the total results. The consumption behaviour is often assessed only roughly. Packaging is facilitating the distribution of goods to the society. Broader approaches, which focus on the life cycle of packed goods, including the entire supply system and the consumption of goods, are necessary to get an environmental footprint of the system with respect to sustainable production and consumption. Materials and methods A full LCA study has been conducted for two food products: coffee and butter packed in flexible packaging systems. The aim was to investigate the environmental performance of packaging with respect to its function within the life cycle of goods. The study looks at the environmental relevance of stages and interdependencies within the life cycle of goods whilst taking consumers' behaviour and portion sizes into consideration. The impact assessment is based on the following impact categories: non-renewable cumulative energy demand (CED), climate change, ozone layer depletion (ODP), acidification, and eutrophication.rnResults The study shows that the most relevant environmental aspects for a cup of coffee are brewing (i.e. the heating of water) and coffee production. Transport and retail packaging are of minor importance. Brewing and coffee production have an impact share between 40% (ODP, white instant coffee) and 99% (eutrophication, black coffee). Milk added for white coffee is relevant for this type of preparation. The instant coffee in the one-portion stick-pack needs more packaging material per cup of coffee and is prepared by a kettle with lower energy demand, such as a coffee machine, thus leading to higher shares of the retail packaging in all indicators. A one-portion stick-pack can prevent wastage and resources related to coffee production can be saved. The most relevant aspect regarding the life cycle of butter is butter production, dominated by the provision of milk. Over 80% of the burdens in butter production stem from the provision of milk for all indicators discussed. Regarding climate change, methane and dinitrogen monoxide, emissions of milk cows and fodder production are most relevant. Fertilisation during livestock husbandry is responsible for most burdens regarding acidification and eutrophication. The distribution and selling stage influences the indicators CED and ODP distinctly. The reasons are, on the one hand, the relatively energy-intensive storage in supermarkets and, on the other hand, the use of refrigerants for chilled storage and transportation. The storage of butter in a refrigerator for 30 days is responsible for about 10% of the CED. Discussion Several aspects have been modelled in a sensitivity analysis. The influence of coffee packaging disposal is very small due to the general low influence of packaging. In contrast, the brewing behaviour is highly relevant for the environmental impact of a cup of coffee. That applies similarly to the type of heating device-i.e. using a kettle or an automatic coffee machine. Wastage leads to a significant increase of all indicators. Under the wastage scenario, the coffee from one-portion stick-packs has a considerable better environmental performance concerning all indicators because, in case of instant coffee wastage of hot water and in case of ground coffee wastage of prepared coffee, has been predicted. Regardless of urban or countryside distances, grocery shopping has a low impact. The storage time of butter is relevant for the results in the indicator non-renewable CED. This is mainly the case when butter is stored as stock in the freezer. The end of