Research & reports

U.S. Environmental Protection Agency (EPA) · U.S. Environmental Protection Agency, Office of Research and Development · United States

This EPA report (October 2023, EPA-600-R-23-065) introduces the 'Wasted Food Scale,' a new ranking of eleven food waste management pathways from most to least environmentally preferable, replacing the 1990s 'Food Recovery Hierarchy.' It finds source reduction, donation, and upcycling most preferable, and that sewer/wastewater treatment and landfill stand out for their sizeable methane emissions.

FAO, Rikolto, RUAF · Food and Agriculture Organization of the United Nations (FAO), Rikolto & RUAF · Global

A comprehensive guide co-published by FAO, Rikolto and RUAF for local decision-makers, urban planners and practitioners. It frames urban and peri-urban agriculture from production through to urban food systems and policy, promoting reduced food loss via short supply chains, biodiversity protection, social inclusion, and urban-rural linkages.

Nakamura K., Kojima D., Ando M. · Sustainability (MDPI), 14(6):3174 · Japan

Analyzes nationwide survey data to identify consumer attributes (gender, age, children in the household, safety awareness) and behaviors (checking labels, food management) associated with household food-waste generation and reduction in Japan. It shows that contributing factors differ between large cities, small cities, and rural areas, underscoring the need for region-specific measures.

Harvey S., Mount P., Valentine H., Gibson C. · Journal of Agriculture, Food Systems, and Community Development, 11(4):233-247 · United States

Interviewing 12 farmers who participated in a gleaning program and 16 who did not in the Greater Kansas City metro area, this study analyses motivations for and barriers to donating surplus produce to food-rescue organisations such as food banks. Participants cited ease of donating and tax incentives; non-participants cited safety and liability concerns. It informs the design of food-rescue schemes that redirect urban and peri-urban farm surplus to community food aid.

Rüschhoff J., Hubatsch C., Priess J., Scholten T., Egli L. · Renewable Agriculture and Food Systems · Germany (Leipzig)

A Leipzig case study assessing food self-sufficiency potential, finding that combining organic agriculture, reduced food loss, and a more plant-based diet could reach a mean self-sufficiency level of about 95%.

Fernandes L., Fernandes J.R., Tavares P.B. · Solar · Portugal

Builds and tests two indirect solar dryer prototypes for fruits and vegetables using low-cost, reused materials (wood, styrofoam, recycled aluminum cans). Reports drying kinetics comparable to a commercial electric dryer, cutting waste from domestic over-production.

· Journal of Food Processing and Preservation · Brazil

Designs, constructs, and applies a low-cost solar dryer, studying the drying kinetics of araticum fruit pulp. Demonstrates a self-built, inexpensive dryer for preserving and adding value to produce.

Dufera L.T. · Journal of Food Quality · Jimma, Ethiopia

Dries tomato slices in a twin-layer solar tunnel dryer under Ethiopian conditions, testing how different pre-drying treatments affect physicochemical quality and drying kinetics. Addresses low-cost tunnel-type solar drying for vegetable preservation.

· Agronomy · Global

Investigates replacing conventional hydroponic media such as cocodust with compost from locally sourced grocery waste, testing four mixtures (20–80% waste compost) on hydroponic lettuce over 35 days.

Sofia Kourmpetli, Natalia Falagán, Charlotte A. Hardman, Lingxuan Liu, Bethan R. Mead, Lael Walsh, Jessica Davies · International Journal of Postharvest Technology and Innovation · Global

This perspective paper presents 'rurbanisation' as a strategy for a resilient food system, focusing on postharvest benefits of urban agriculture for sustainable supply chains, enhanced nutrition, and access to fresh food. It identifies challenges for upscaling urban agricultural systems, including the need for improved technologies, local infrastructure, and knowledge transfer to new farmers. The paper also highlights research gaps in postharvest quality and safety.

Ferdian Suprata, Christine Natalia, Djoko Setyanto, Budi Kartadinata, Victoria Principall · Jurnal Ilmiah Teknik Industri · Indonesia (Sampora Village)

This study in Sampora Village, Indonesia, aimed to reduce food losses by designing an affordable 4.77 m3 Modified Atmosphere Storage (MAS) cold-storage unit for horticultural products. Using a Design Thinking method and qualitative interviews, the design focused on temperature/humidity control, air circulation, and ventilation to extend product quality. The study proposed an affordable cold-storage technology.

Margaret Marcy Emerson · Digital Commons - LIU Promoting Scholarship and Creative Work of LIU Students, Faculty, and Staff (Long Island University) · United States

In 2019, an estimated 35% of all food was lost or wasted in the U.S., and organic waste in landfills generates methane, a potent greenhouse gas. Composting significantly cuts the amount of food going into landfills, reducing climate and environmental impacts. Compost enhances soil, reduces the need for chemical fertilizers, improves soil water retention, provides carbon sequestration, and local composting conserves energy and reduces transport emissions.

Minten B., Tamru S., Reardon T. · Food Policy · Ethiopia

Analyses self-reported post-harvest losses across farmers, wholesalers, processors, and retailers along rural-urban value chains for teff and liquid milk in Ethiopia.

Dsouza A., Price G., Dixon M., Graham T. · Sustainability · Canada

Presents a conceptual framework for incorporating composting into closed-loop urban controlled environment agriculture to recycle nutrients from organic waste streams.

Kulkarni I., Zang J., Leandro W., Parikh P., Adler I., Da Fonseca-Zang W., Campos L. · Water · Low- and middle-income countries (review)

A review of closed-loop biodigesters on small-scale farms in low- and middle-income countries, converting organic waste into energy and nutrient-rich digestate fertilizer integrated with food production.

Leena Erälinna, Barbara Szymoniuk · Sustainability · Finland

This article presents an experimental project in Turku, Finland, aimed at implementing a circular food system in sustainable urban farming. The project had two objectives: reducing food waste in Turku University Campus restaurants and supporting local nutrient recycling by composting food waste for urban farming. The resulting concept, based on two experimental studies, is globally replicable for managing local circular food systems.

Ferdian Suprata, Feliks Prasepta Sejahtera Surbakti, Victoria P.L.K Tampubolon · Jurnal Pengabdian Masyarakat Charitas · Indonesia

Challenges in urban farming include harvested vegetables being perishable before consumption, marketing, or distribution. This activity aimed to inform and share a cold storage design for storing produce from the "Mom's Farm" urban farming project in Nagrek Village. Monitoring and evaluation results indicated that factors such as electrical energy requirements and limited access to electricity should be added as design criteria for cold storage intended for remote areas.

Hope Baxter Chamdimba, Isaiah Omosa, Simon M. Wandera · Journal of Energy Environmental & Chemical Engineering · Kenya (Nairobi)

This review analyzed urban food waste in Nairobi City County, Kenya, which accounts for 64% of recoverable municipal solid waste, totaling 29.4 thousand tons annually. The study found that food waste has a biomethane potential of 508.45 ml CH4 /g VS, suggesting that the city's food waste could yield 10.5 million m3 of methane and 1.38 MW of electricity. While food waste is increasingly used for animal feed and composting, its application for energy recovery via anaerobic digestion is limited by a lack of source separation. Biogas is shown to be more economical than liquefied petroleum gas, but long-term methane generation requires supportive policies.

Corinna Schröder, Franziska Häfner, Oliver Christopher Larsen, Ariane Krause · Agronomy · Global

This pot trial with lettuce plants assessed the fertilizer value of composts derived from urban organic waste. Seven treatments, including food waste vermicompost and thermophilic compost from green waste and human feces, were investigated. Lettuce yield and total uptake of P, K, Ca, and Mg were highest with coir-based vermicompost, while fecal compost resulted in high shoot P and K but lower Ca and Mg uptake. All composts required additional nitrogen for lettuce growth, indicating a need for further research on macronutrient availability and alternative N sources.

Dr.Sumanta Bhattacharya, H. B. Lal, Bhavneet Kaur Sachdev · Journal of Emerging Technologies and Innovative Research · India

India's horticulture industry has grown, contributing to GDP and employing 42% of the population. However, 60% of products rot due to a lack of cold storage, hindering the elimination of food shortages and export amplification. Floriculture has also improved, with women playing a role in rural economy and empowerment.

Jennifer Jevons · · New Zealand (Wellington)

The work of Kaicycle, an urban farming initiative located on Wellington City Council land in New Zealand, was spotlighted. This initiative aims to help the community by improving awareness of soil health, advocating for food waste minimization, growing produce, and practicing regenerative composting. Kaicycle recycles food scraps from the community, composts using anaerobic microbes, and produces vegetable boxes for sale.

Charles Karani, Eric Obedy Gido, Hillary K. Bett · DOAJ (DOAJ: Directory of Open Access Journals) · Global

This study surveyed 456 urban agro-producer households using an electronically-structured questionnaire to explore informal agro-food waste management and safety measures in low- and lower middle-income countries. Findings showed significant disparities in management and safety practices between participating and non-participating livestock and mixed producers. Waste reduction (86%), utilization (86%), segregation (63%), and composting (58%) were preferred, while disposal (18%) and mixing with salt/dry feeds (24%) were less preferred. Knowledge variables, such as waste sorting and urban agriculture knowledge, had a greater influence on these practices.

Mariana Cecilia Grohar, Barbara Gacnik, Maja Mikulič-Petkovšek, M. Hudina, Robert Veberič · Horticulturae · Global

A laboratory study measured caffeine content and phenolic profiles across three types of tea and coffee waste through two successive solvent extractions. The first extraction was far more efficient overall, though green tea retained high flavanol content and mate tea high phenolic-acid content in the second extraction, black tea had the highest caffeine content across both extractions, and water proved the most effective solvent in nearly all cases — a simple, accessible extraction method the authors note is relevant to urban horticulture as a potential alternative to conventional pesticides.

Julia Södergren, Christer Larsson, Lars Wadsö, Karl-Johan Bergstrand, Håkan Asp, Malin Hultberg, Jenny Schelin · Journal of Cleaner Production · Global

A study evaluating the microbiological food safety of using anaerobic digestate — a liquid residue from food-waste biogas production — as a fertilizer in hydroponic vegetable production. The biofertilizer's microbial community was analyzed via 16S rRNA gene amplicon sequencing, challenge-tested with Salmonella enterica, Listeria monocytogenes and Bacillus cereus, and assessed for microbial activity using isothermal calorimetry. The microbial community changed distinctly through a necessary initial nitrification process, with Mycobacterium as the most abundant genus. Deliberate contamination of the nitrified biofertilizer with 5 log10 CFU/mL of S. enterica or L. monocytogenes became undetectable by selective plating after 48 hours of incubation at 20°C. B. cereus was present naturally at low levels (~10 CFU/mL), and an inoculation of 5 log10 CFU/mL declined to these background levels within 24 hours at 20°C. The biofertilizer did not support microbial activity without an added external nutrient source containing an accessible carbon source and trace elements. The digestate type studied was judged microbiologically safe for hydroponic use, but the constant presence of viable B. cereus was noted as underscoring the need for continuous risk assessment whenever the fertilizer's production process is modified.

Sovová L., Veen E.J. · Sustainability (MDPI), 12(12):5134 · Europe

A comparative study of food self-provisioning in allotment gardens in the Netherlands and Czechia, drawing on social practice theory. It argues self-provisioning is neither merely a poverty response nor a trend, holding significant potential for food provisioning that can be supported within alternative food networks and urban sustainability frameworks.