A humongous amount of food goes to waste yearly. The use of renewable energy sources is encouraged to reduce global warming. Food waste as a source of energy and water as a food-water-energy nexus has shown to be a viable source of renewable energy. This paper proposes a food waste recycling system that uses a mechanical presser to the extraction of moisture from the food waste with its desiccate being fed to an anaerobic digester to produce biogas. Literature on the topic is reviewed and the benefits and limitations of the system are also discussed.

Most existing food-related research efforts focus on recipe retrieval, user preference-based food recommendation, kitchen assistance, or nutritional and caloric estimation of dishes, ignoring personalized and conscious food recommendations resources of the planet. Therefore, in this work, we present a personalized food recommendation scheme, mapping the ingredients to the most resource-friendly dishes on the planet and in particular, selecting recipes that contain ingredients that consume as little water as possible for their production. The system proposed here is able to understand the user&rsquo:s behavior and to suggest tailor-made recipes with lower water quantity used in production. By continuously using the system, the user can gradually reduce their water footprint and benefit from a healthier diet. The proposed recommendation system was compared with the results of two papers available in the literature that represent the state of the art, obtaining similar results. Therefore, the results of the presented recommendation system can be considered reliable.

Throughout the world, much food produced is wasted. The resource impact of producing wasted food is substantial; however, little is known about the energy and water consumed in managing food waste after it has been disposed. Herein, we characterize food waste within the Food-Energy-Water (FEW) nexus and parse the differential FEW effects of producing uneaten food and managing food loss and waste. We find that various food waste management options, such as waste prevention, landfilling, composting, anaerobic digestion, and incineration, present variable pathways for FEW impacts and opportunities. Furthermore, comprehensive sustainable management of food waste will involve varied mechanisms and actors at multiple levels of governance and at the level of individual consumers. To address the complex food waste problem, we therefore propose a “food-waste-systems” approach to optimize resources within the FEW nexus. Such a framework may be applied to devise strategies that, for instance, minimize the amount of edible food that is wasted, foster efficient use of energy and water in the food production process, and simultaneously reduce pollution externalities and create opportunities from recycled energy and nutrients. Characterization of FEW nexus impacts of wasted food, including descriptions of dynamic feedback behaviors, presents a significant research gap and a priority for future work. Large-scale decision making requires more complete understanding of food waste and its management within the FEW nexus, particularly regarding post-disposal impacts related to water.

Agricultural production is the main consumer of water. Future population growth, income growth, and dietary shifts are expected to increase demand for water. The paper presents a brief review of the water footprint of crop production and the sustainability of the blue water footprint. The estimated global consumptive (green plus blue) water footprint ranges from 5938 to 8508 km³/year. The water footprint is projected to increase by as much as 22% due to climate change and land use change by 2090. Approximately 57% of the global blue water footprint is shown to violate the environmental flow requirements. This calls for action to improve the sustainability of water and protect ecosystems that depend on it. Some of the measures include increasing water productivity, setting benchmarks, setting caps on the water footprint per river basin, shifting the diets to food items with low water requirements, and reducing food waste.

The purpose of this paper is to analyze the effect of environmental innovation on the balance of the food, energy, and water (FEW) nexus in the food service industry. The study was carried out through the completion of questionnaires by managers of food service companies in Brazil. Structural equation modeling (SmartPLS) was used for the analysis, which was based on 206 responses. The results show that food waste can be reduced by innovation in the planning of menus and purchases and in the process of food preparation. Furthermore, the reduction of natural resource consumption, especially of water and energy, can be achieved by leveraging changes in internal processes. In this sense, the typical trade-offs associated with the FEW nexus can be solved through environmental innovation. In addition, collaborative approaches between farms, suppliers and governments are essential for the implementation of the innovation processes. The paper presents suggestions for scholars, policy makers and managers in the food service industry to address the FEW nexus challenges.

Water scarcity is a pervasive threat to society that is expected to intensify alongside a growing and more affluent population and a changing climate. In this paper, we review the existing literature to assess the potential of lessening water scarcity by reducing food loss and waste. Existing studies reveal the scope of food loss and waste and its accompanying impact on water resources, thereby providing a foundation for policy action. We highlight existing or proposed food loss and waste reduction measures and review available evidence concerning their impact on water resources. Our review reveals that there is a deficit of research that can guide specific policy interventions aimed at mitigating water scarcity by reducing food loss and waste. Instead, the last decade of research has primarily focused on quantifying the current water footprint of food loss and waste for different locations, points within the supply chain, and food groups. Yet, the degree of uncertainty inherent in these estimates, their lack of precision, and several simplifying assumptions make it difficult to translate this research into robust policy measures to reduce the environmental burden of food loss and waste. We conclude by advancing a research agenda that will (i) quantify and reduce uncertainty through enhanced data collection and methods; (ii) holistically assess policy measures, including system level impacts and feedback; (iii) develop methods and technologies for transparent supply chain tracing. Together, advances in these areas will guide and ground food loss and waste policy toward reducing water scarcity.

The increase in world population and the resulting demand for food, water, and energy are exerting increasing pressure on soil, water resources, and ecosystems. Identification of approaches to reduce the related cross-sectoral environmental impacts for the water–energy–food nexus is, therefore, crucial. The purpose of the review was to discuss the circular economy approaches devoted to understand the interdependencies among these three sectors. In particular, the review focuses on the importance of the application of life cycle thinking and life cycle assessment for understanding the interconnections in the nexus along the whole supply chains. Moreover, researches related to water and energy use in the agrifood sector are presented, addressing food waste management alternatives in a circular economy perspective.

Large quantities of food are wasted globally. Sugars such as monosaccharides and oligosaccharides are valuable carbohydrate compounds that can be hydrolyzed from food waste, particularly from carbohydrate-rich bakery waste. These sugars can be extracted from the waste as a value-added compound for manufacturing other food products. Sub-critical water treatment is a new and emerging extraction technique that is considered as a green extraction technology. Water at high temperature and pressure can be used to hydrolyze and extract the sugars. This paper reviews (1) the general process for producing sugars from food wastes, (2) recovery of sugar (particularly oligosaccharides) from food waste via sub-critical water treatment, and (3) the potential of bakery waste as the resources of sugar recovery.

In this study, 13 types of organic materials were oxidized using H₂O₂in a continuous flow reactor under the condition of supercritical water. The effect of the operational parameters on the conversion of total organic carbon (TOC) and total nitrogen (TN) was investigated, and the resulting quality of treated water was analyzed. It was found that these materials were easily oxidized with a TOC conversion achieving 99 % at temperature of 460 °C and TN conversion reaching 94 % at temperature of 500 °C. Rice decomposition was rapid, with TOC and TN decomposition rates of 99 % obtained within residence of 100 s at temperature of 460 °C. At temperature of 460 °C, pressure of 24 MPa, residence time of 100 s, and excess oxygen of 100 %, the quality of treated water attained levels commensurate with China’s Standards for Drinking Water Quality. Reaction rate equation parameters were obtained by fitting the experimental data to the differential equation obtained using the Runge–Kutta algorithm. The decrease of the TOC in water samples exhibited reaction orders of 0.95 for the TOC concentration and 0.628 for the oxygen concentration. The activation energy was 83.018 kJ/mol.

A new paradigm for sustainable, integrated, water resources management is emerging from international conferences around the world. Its most succinct description is ‘the water–food–energy nexus for a green economy’. The water, food and energy nexus aims at the most efficient, best practice principles applied throughout the full food supply chain. This includes consideration of reducing wastage of the food for various reasons in the supply chain. This paper describes the global opportunities for better efficiency and resources conservation in the water, food, and energy supply chains with examples from Australia. Food wastage equates on average to 243 l day⁻¹ of water per person in the food they throw away, which is 1.5 times the daily water use per person in the UK. The concepts of virtual water and water footprint can help in identifying opportunities to save water by targeting reduction of wastage of food that has the highest virtual water content. A green economy aims at achieving optimised supply chain objectives in a manner that espouses the sustainability principle, gives due attention to environmental concerns and helps with eradication of poverty and hunger.