Open access publications in the SLU publication database

Abstract

Food waste occurs along the entire food supply chain and gives rise to great financial losses and waste of natural resources. The retail stage of the supply chain contributes significant masses of waste. Causes of this waste need to be identified before potential waste reduction measures can be designed, tested and evaluated. Therefore this thesis quantified retail food waste and evaluated selected prevention and valorisation measures, in order to determine how the carbon footprint of food can be reduced by decreasing food waste in supermarkets.

Food waste was quantified in six supermarkets in the Uppsala-Stockholm region of Sweden. Data were recorded over five years between 2010 and 2014 by the retail company in a daily waste recording procedure. In addition, suppliers contributed data on deliveries and rejections. The main suppliers contributed data on wholesale pack size and shelf-life, which allowed the relationship between these and their effect on waste to be analysed. Life cycle assessment was used to investigate the carbon footprint associated with production and distribution of food and managing the waste.

The wasted mass was dominated by fresh fruit and vegetables and rejection on delivery was the main reason for this food being wasted. Expressed in terms of carbon footprint rather than mass, the relative importance of meat waste increased and that of fruit and vegetables decreased.

A reduction in storage temperature to prolong shelf-life proved to have the potential to reduce waste in all supermarket departments studied. However, when the temperature reduction was achieved by extended use of the current electricity mix, a net lowering of carbon footprint was only found for the meat department. For food products with a high carbon footprint, e.g. beef, there was much greater potential to lower the carbon footprint by preventing waste through source reduction than by upgrading the waste management option. If food waste cannot be prevented, donation to charity and anaerobic digestion of the waste were found to have the greatest potential to reduce the carbon footprint, depending on the substituted bread value and biogas potential, respectively. This follows the EU waste hierarchy, although there are variations from the trend of more favourable options at higher levels of the hierarchy.