How many bags of compost do you generate in a week because your food went bad? One or two? But how about supermarkets? Every time you buy food, you may look for the items that look freshest. The one with the furthest expiry date. Most firm. Most ripe. Most pretty. You are not the only one that seeks these characteristics in the food products you buy, so what happens to the food that gets left behind? Once food items become spoiled to the point that supermarkets have deemed they will not be bought, they become waste.
Between six supermarkets studied in Sweden over a three-year period, 1570 tonnes of food waste (excluding bread) was generated (Scholz et al. 2015). Comparatively, the average person in Sweden generates 72kg (0.072 tonnes) of food waste each year. Scholz et al. (2015) analyzed the mass composition and ratio of annual supermarket waste and found discrepancies between the number of food items wasted per category, and their relative greenhouse gas emissions. Results showed that while fruits and vegetables comprised a whopping 85% of food waste by mass, they only contributed to 46% of the wasted carbon footprint (Scholz et al. 2015). As for meat products, they only contributed to 3.5% of the wasted mass but 29% of the total wasted carbon footprint (Scholz et al. 2015).
In addition to the environmental impact, Brancoli et al. (2017) also state that meat waste contributes more to a supermarket’s economic loss than produce. One technique to reduce meat waste is outlined by Eriksson et al. (2016) whereby reducing storage temperature results in lower quantities of waste. Eriksson et al. (2017) described that changing the storage temperature for deli products from 8˚C to 5˚C results in 15% less food waste. They also point out that minced meats, which are often stored chilled, could be kept frozen to reduce their wastage as well. For produce, the authors categorized the main contributors to still be fresh, edible, and have a high quality (Scholz et al. 2015). This wastage is likely due to supermarkets often providing 7% more food than expected as customer demands can be difficult to project, and as newer and “better” products replace old, although still edible, ones (Brancoli et al. 2017).
Supermarkets do have tools to reduce their food waste. Keeping foods frozen and at different temperatures, and possibly purchasing less, are small steps that could make big a difference.
References
Brancoli, P., Rousta, K., Bolton, K. Life Cycle Assessment of supermarket food waste. Resources, Conservation and Recycling. 188, 39-46 (2017).
Eriksson, M., Strid I., Hansson, P. Food waste reduction in supermarkets – Net costs and benefits of reduced storage. Resources, Conservation and Recycling. 107, 73-81 (2017).
Scholz, K., Eriksson, M., Strid, I. Carbon Footprint of Supermarket Food Waste. Resources Conservation & Recycling. 94, 56-65 (2015).
Guelph Food Waste Research Project 