Exergy analysis: A tool to study the sustainability of food supply chains

This paper explores the potential of using exergy analysis to study and compare the environmental impact of food supply chains. The method identifies the links where exergy destruction takes place and shows where improvements are possible to minimize this destruction. The supply chains of three products were investigated: pork mincemeat, novel protein food (NPF) made from dry peas and pea soup. Exergy content and requirements of the various streams, products and processes were calculated for the three chains. As exergy is expressed in one unit, the Joule, the inputs and outputs of each chain are easily comparable. The contributions of the links to the total exergy loss are different in each chain. In the NPF chain, greatest input is required in the processing link whereas for the pork chain, primary processing and transportation require the highest inputs. The NPF chain is only slightly more efficient (1.2 times) than the pork meat chain. Such analyses are also useful in the design and redesign of supply chains.