The food production system has been acknowledged as a problem that needs to be addressed in order to achieve a sustainable society. Hertwich and Peters (2009), estimate that 10-30% of an individual’s environmental impact is related to the industrial production and consumption of food. The problem is aggravated by the wastage of one third of the global food production. The consequences of the wastage of food are the loss of resources, such as energy, water, land and labour and unnecessary emissions of pollutants.

In order to address this problem several actions have been proposed. The Sustainable Development Goal 12.3, which Sweden has committed to fulfil, aims to reduce by half the amount of food waste along the production and supply chain by 2030.

Retail is an important player in the food supply chain. Its influence spreads both upstream to suppliers and downstream to consumers. Therefore, this research aims to contribute to reduction of the environmental impacts related to food waste in retail, by identifying products with high environmental impacts. The main goals of this study are 1) the quantification of food waste produced by the supermarket and 2) to examine the environmental impacts of selected products in order to assess the impacts generated by the waste production at the supermarket.

The findings of the research revealed 1) the importance of not only measuring the food waste in terms of mass, but also in terms of environmental indicators and costs. The results indicate bread as an important contributor for the environmental footprint of the supermarket and a potential product for interventions 2) Sorting the organic content of the products from its packaging before sending it to the current waste treatment leads to a reduction in the carbon footprint.

The research identified the following recommendations: 1) increasing supermarket personnel and consumers’ awareness regarding the environmental impact of food waste, 2) finding alternative routes for waste treatment and 3) improving logistic operations.

The global food system is a major driver of many environmental impacts, particularly those related to climate change, biodiversity loss, and depletion of freshwater resources. These problems are aggravated by a substantial waste of food throughout the supply chain, where retailers are responsible for large quantities of waste. Although other parts of the supply chain account for relatively higher waste generation, retailers are particularly important because of their influence both downstream and upstream in the supply chain. 

This thesis aims to design and evaluate strategies for food waste prevention and valorisation, particularly for bread products, by analysing food waste quantities, identifying the causes and risk factors, and proposing and evaluating measures for preventing and valorising food waste.

This aim was achieved through a variety of approaches. First, food waste was quantified for one year in a typical mid-sized urban supermarket in Sweden. This information was used to identify hotspots at the product-level in relation to mass, environmental impacts, and cost. Bread was identified as a hotspot and also as a product with a high potential for waste prevention and valorisation measures. A second quantification was performed with the goal of estimating the quantity of surplus bread throughout the Swedish supply chain and to identify the risk factors for waste generation, particularly at the supplier–retailer interface. Finally, this thesis investigated current and future circular economy strategies for the prevention, valorisation, and management of bread surplus by evaluating the environmental performance of multiple strategies and comparing them with current waste management practices. 

The results from the first quantification indicated that bread was a category with significant contribution in all environmental impact categories analysed, with the greatest contribution in terms of the total mass of waste and the economic costs incurred by the supermarket. The second quantification estimated 80 500 tonnes of bread waste/year in Sweden, equivalent to 8 kg per person/year, which was mainly concentrated at household and retail levels, specifically at the supplier–retailer interface. The results provided evidence that the take-back agreement between suppliers and retailers is a risk factor for high waste generation. Therefore, current business models may need to be changed to achieve a more sustainable bread supply chain with lower waste generation. However, the currently established return system between bakeries and retailers enables a segregated flow of bread waste that is not contaminated with other food waste products. This provides an opportunity for alternative valorisation and waste management options that are not viable for mixed waste streams.

The results from the environmental assessment for the prevention, valorisation and waste management pathways supported a waste hierarchy, where prevention has the highest environmental savings, followed by donation, the use of surplus bread as animal feed, and for beer and ethanol production. Anaerobic digestion and incineration offer the lowest environmental savings, particularly in low impact energy systems. The results suggest that Sweden can make use of the established return system to implement environmentally preferred options for the management of surplus bread.

Bread waste represents a significant part of food waste in Sweden. At the same time, the return system established between bakeries and retailers enables a flow of bread waste that is not contaminated with other food waste products. This provides an opportunity for alternative valorisation and waste management options, in addition to the most common municipal waste treatment, namely anaerobic digestion and incineration. An attributional life cycle assessment of the management of 1 kg of surplus bread was conducted to assess the relative environmental impacts of alternative and existing waste management options. Eighteen impact categories were assessed using the ReCiPe methodology. The different management options that were investigated for the surplus bread are donation, use as animal feed, beer production, ethanol production, anaerobic digestion, and incineration. These results are also compared to reducing the production of bread by the amount of surplus bread (reduction at the source). The results support a waste hierarchy where reduction at the source has the highest environmental savings, followed by use of surplus bread as animal feed, donation, for beer production and for ethanol production. Anaerobic digestion and incineration offer the lowest environmental savings, particularly in a low-impact energy system. The results suggests that Sweden can make use of the established return system to implement environmentally preferred options for the management of surplus bread.

Retail is an important actor regarding waste throughout the entire food supply chain. Although it produces lower amounts of waste compared to other steps in the food value chain, such as households and agriculture, it has a significant influence on the supply chain, including both suppliers in the upstream processes and consumers in the downstream. The research presented in this contribution analyses the impacts of food waste at a supermarket in Sweden. In addition to shedding light on which waste fractions have the largest environmental impacts and what part of the waste life cycle is responsible for the majority of the impacts, the results provide information to support development of strategies and actions to reduce of the supermarket's environmental footprint. Therefore, the food waste was categorised and quantified over the period of one year, the environmental impacts of waste that were generated regularly and in large amounts were assessed, and alternative waste management practices were suggested. The research revealed the importance of not only measuring the food waste in terms of mass, but also in terms of environmental impacts and economic costs. The results show that meat and bread waste contributes the most to the environmental footprint of the supermarket. Since bread is a large fraction of the food waste for many Swedish supermarkets, this is a key item for actions aimed at reducing the environmental footprint of supermarkets. Separation of waste packaging from its food content at the source and the use of bread as animal feed were investigated as alternative waste treatment routes and the results show that both have the potential to lead to a reduction in the carbon footprint of the supermarket.

Integrating the cultivation of edible filamentous fungi in the thin stillage from ethanol production is presently being considered. This integration can increase the ethanol yield while simultaneously producing a new value-added protein-rich biomass that can be used for animal feed. This study uses life cycle assessment to determine the change in greenhouse gas (GHG) emissions when integrating the cultivation of filamentous fungi in ethanol production. The result shows that the integration performs better than the current scenario when the fungal biomass is used as cattle feed for system expansion and when energy allocation is used. It performs worse if the biomass is used as fish feed. Hence, integrating the cultivation of filamentous fungi in 1st generation ethanol plants combined with proper use of the fungi can lead to a reduction of GHG emissions which, considering the number of existing ethanol plants, can have a significant global impact.

The use of food waste as feedstock in the manufacture of high-value products is a promising avenue to contribute to circular economy. Considering that the majority of environmental impacts of products are determined in the early phases of product development, it is crucial to integrate life cycle assessment during these phases. This study integrates environmental considerations in the development of solid-state fermentation based on the cultivation of N. intermedia for the production of a fungal food product using surplus bread as a substrate. The product can be sold as a ready-to-eat meal to reduce waste while generating additional income. Four inoculation scenarios were proposed, based on the use of bread, molasses, and glucose as substrate, and one scenario based on backslopping. The environmental performance was assessed, and the quality of the fungal product was evaluated in terms of morphology and protein content. The protein content of the fungal food product was similar in all scenarios, varying from 25% to 29%. The scenario based on backslopping showed the lowest environmental impacts while maintaining high protein content. The results show that the inoculum production and the solid-state fermentation are the two environmental hotspots and should be in focus when optimizing the process. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

This paper quantifies bread waste throughout the Swedish supply chain and investigates the loss rate of prepackagedbread products at the supplier-retailer interface. The goal is to understand the extent of bread waste inSweden and to identify risk factors for high quantities of waste at the supplier-retailer interface, in order toprovide information supporting waste prevention measures. The study uses primary data, in combination withnational statistics and data from sustainability reports and the literature. Primary data were collected from 380stores of a Swedish retail company and a bakery. Bread waste was calculated to be 80 410 tons/year in Sweden,the equivalent of 8.1 kg per person/year, and was found to be concentrated at households and in retail, specificallyat the supplier-retailer interface. The results provide evidence that take-back agreements between suppliersand retailers, where the retailer only pays for sold products and the supplier bears the cost of the unsoldproducts and their collection and treatment, are risk factors for high waste generation. Current business modelsmay need to be changed to achieve a more sustainable bread supply chain with less waste.

Current understanding of food waste quantities in the Brazilian retail sector is limited. In order to develop efficient measures for food waste prevention and valorisation, reliable data on waste generation and composition are necessary. In this study, a compositional analysis of street market waste was conducted in São Paulo, Brazil. In total, 4.1 tonnes of waste were sorted into 27 waste fractions, categorised using a three-level approach. The average waste generation in the studied street markets was 23.7 kg per stall, of which 12.8 kg was classified as unavoidable food waste, 3.6 kg as packaging waste, and 7.4 kg as avoidable waste. The results show large amounts of unavoidable food waste, comprised of coconut, sugarcane bagasse, and peels. A large share of the avoidable food waste is comprised of single leaves, tomatoes, oranges, and bananas. Large variations were observed among the street markets analysed, both in terms of the food waste generation rate, and composition. The results from scaling up the data at the city level indicated a total wastage of 59,300 tonnes per year, of which 18,400 tonnes are classified as avoidable food waste.

Reducing food waste is necessary for achieving healthy diets and sustainable food systems due to its negative impacts on resource conservation, food security, and environmental, social and economic costs. This paper aim is to quantify the amount and types of food that is wasted by the consumers in different restaurant configurations. The second aim is to understand the reasons which lead them to waste food and the greenhouse gas emissions associated with the waste. To fulfil the aims, a mixed methodology was used, including primary data collection in restaurants for the quantification of food waste, interviewing consumers and staff, along with calculating the environmental impact from the waste using life cycle assessment. The results show that different incentives and levels of interaction in consumer’s choice of food types exert influence on plate food waste. When incentive and interaction are low, the amount of food waste is larger. It is the case of a la carte restaurants. The best performance in the restaurant categories was when both incentive and level of interaction were higher. Buffet where the consumers pay by weight, therefore, is the configuration that generates less food waste on the consumer's plate. The main wasted products are rice and beans, followed by beef, and then other carbohydrates. The life cycle assessment indicated a carbon footprint varying from 128 to 324 g CO2 eq./plate from the wasted food. The result of the interviews showed that the food waste on the plate is not visible to consumers, since in the majority of cases, they believe that their food waste on the plate in the day of the observation was an exception. There is a large potential to reduce food waste by giving consumers the possibility to influence the serving to get the right portion size. Also, to further emphasize this behaviour by creating incentives for consumers only to serve as much food as they actually eat.

First-generation ethanol plants offer successful, commercial-scale bioprocesses that can, at least partially, replace fossil fuels. They can act as platforms to integrate lignocelluloses, wastes and residuals when establishing 2nd generation ethanol. The present review gathers recent insights on the integration of intrinsic and extrinsic substrates into lot generation ethanol plants, through microbial conversion or cogeneration systems. It shows that, among different lot generation ethanol plants, sugar-based ethanol by-products, dominate integration studies characterized by strong techno-economic and life-cycle assessment components. In comparison, there are fewer studies that focus on grain-derived lignocellulosic residuals and other wastes. There is consensus that integrating second generation feedstocks into first generation plants can have positive techno-economic and environmental impacts. In addition to realizing production of ethanol from 2nd generation feedstocks, these possibilities can impact waste management by establishing relevant biorefineries and circular economy. They can also supply a wide range of renewable products. Considering the potential of this waste management strategy, further research on these and many other substrates is needed. This will shed light on the effect of the integration, the relevant types of microorganisms and pretreatments, and of other physical parameters on the effectiveness of running lot generation plants with integrated second generation feedstocks.

To achieve a closed nutrient cycle and more sustainable food production, enhanced nutrient recycling in the agri-food system is a necessity. Pyrolysis is an emerging technology to recycle the nutrient content of sewage sludge. The produced biochar can be used to reduce the need for mineral fertilizers; in addition, pyrolysis can also handle potential pollutants such as microplastics and pathogens present in sewage sludge. In this research, a life cycle assessment (LCA) was carried out to determine the environmental impact of sewage sludge pyrolysis as an alternative to current practices of two different cases of sewage sludge treatment in two municipalities in Sweden. The results indicated that avoiding mineral fertilizer production by using biochar has a significant influence on the environmental benefits. Furthermore, it showed that an integrated system of anaerobic digestion followed by pyrolysis could perform as the most environmental-friendly option for sewage sludge treatment with a lower risk of transferring pollution to the soil.

The management of staggering volume of food waste generated (∼1.3 billion tons) is a serious challenge. The readily available untapped food waste can be promising feedstock for setting up biorefineries and one good example is bread waste (BW). The current review emphasis on capability of BW as feedstock for sustainable production of platform and commercially important chemicals. It describes the availability of BW (>100 million tons) to serve as a feedstock for sustainable biorefineries followed by examples of platform chemicals which have been produced using BW including ethanol, lactic acid, succinic acid and 2,3-butanediol through biological route. The BW-based production of these metabolites is compared against 1G and 2G (lignocellulosic biomass) feedstocks. The review also discusses logistic and supply chain challenges associated with use of BW as feedstock. Towards the end, it is concluded with a discussion on life cycle analysis of BW-based production and comparison with other feedstocks.

Estimates suggest that a substantial volume of food intended for human consumption is lost or wasted globally, underlining the importance of reducing food waste to address environmental concerns. This study examines the generation and associated carbon footprint of 25 different food waste fractions from ten Brazilian street markets. The aim is to identify hotspots within food product categories, analyse the causes of food waste and investigate potential risk factors that hinder the reduction of food waste. This research seeks to provide support when deciding on prevention and valorisation measures, and waste management strategies to enhance the sustainability of the agrifood system. The study reveals that 4.98 kg and 20.15 kg of food per stall are wasted every week in street markets at Ribeirão Preto and São Paulo, respectively, resulting in an average carbon footprint of 6.74 kg and 35.20 kg CO2 eq. per stall. The three food product categories that have the largest carbon footprint are (1) unavoidable food waste, (2) leaves, flowers and stems, and (3) meat. The annual food waste generation in Ribeirão Preto and São Paulo street markets is estimated to be 0.50 and 2.22 kg per capita per year, respectively. This suggests that diverting organic food waste, particularly unavoidable waste, from landfills to other waste management methods holds significant potential for reducing the carbon footprint. Leaves, flowers and stems as well as meat should be prioritized for prevention measures.

Rhodosporidium toruloides, an oleaginous yeast, is a potential feedstock for biodiesel production due to its ability to utilize lignocellulosic biomass-derived hydrolysate with a considerably high lipid titer of 50–70 % w/w. Hence, for the first-time environmental assessment of large-scale R. toruloides-based biodiesel production from wood hydrolysate and crude glycerol was conducted. The global warming potential was observed to be 0.67 kg CO2 eq./MJ along with terrestrial ecotoxicity of 1.37 kg 1,4-DCB eq./MJ and fossil depletion of 0.13 kg oil eq./MJ. The highest impacts for global warming (∼45 %) and fossil depletion (∼37 %) are attributed to the use of chloroform for lipid extraction while fuel consumption for transportation contributed more than 50 % to terrestrial ecotoxicity. Further, sensitivity analysis revealed that maximizing biodiesel yield by increasing lipid yield and solid loading could contribute to reduced environmental impacts. In nutshell, this investigation reveals that environmental impact varies with the type of chemical utilized.

Efficient and purposeful transport of food, from primary production to waste management, is essential to drive the necessary transition towards sustainable production and consumption of food within planetary boundaries. This is particularly the case for bread, one of the most frequently wasted food items in Europe. In Sweden, bread is often sold under a take-back agreement where bakeries are responsible for transportation up to the supermarket shelf and for the collection of unsold products. This provides an opportunity for reverse logistics, but creates a risk of inefficient transport that could reduce the environmental benefits of prevention and valorization of surplus bread. This study assessed the climate change impact of bread transport in Sweden and evaluated the impact of alternative food transport pathways. Life cycle assessment revealed the climate change impact of conventional bread transport, from bakery gate to waste management, to be on average 49.0 g CO2e per kg bread with 68 % deriving from long-distance transport, 26 % from short-distance delivery, and 6 % from waste transport. Evaluation of alternative bread transport pathways showed the highest climate savings with a collaborative transport approach that also reduced the need for small vehicles and decreased transport distances. The overall contribution of waste transport to the total climate impact of food transport was low for all scenario routes analyzed, suggesting that food waste management facilitating high-value recovery and valorization could be prioritized without increasing the climate impact due to longer transport. It has been claimed that conventional take-back agreements are responsible for most of the climate change impact related to bread transport, but we identified long distances between bakeries and retailers as the main contributor to transport climate impacts. © 2023 The Authors

Purpose

Considering the general agreement in the literature that environmental labelling should be based on consequential modelling, while all actually implemented environmental labelling schemes are based on attributional modelling, we investigate the arguments for this situation as provided in the literature, and whether a dual label, representing on the same label the attributional and consequential results for the same product, can be a relevant solution or at least contribute to a more informed discussion.

Methods

We developed a dual label for three hypothetical, comparable products and presented this for a small test audience, asking three questions, namely “Which product would you choose?”, “Was the attributional information useful?” and “Would you accept to have only the attributional information?”

Results and discussion

From this small pilot exercise, it appears that informed consumers may have a strong preference for consequential information and that the main problem in communicating consequential results is that they are perceived as less trustworthy and more uncertain due to the fact that the consequences are located in the future. It thus appears important to build into a consequential label some increased level of guarantee of future good behaviour.

Conclusions

We propose to apply the above questions to a more statistically representative audience to confirm or refute the findings of this little test exercise.