Editorial: Sustainability in Integrated Food Systems for Biovalorization and Circular Bioeconomy

Saurabh Singh^1*Durgesh Kumar Jaiswal²Raj Morya³JAY PRAKASH VERMA⁴Rajesh K Sani⁵

• ¹School of Chemical & BioPharmaceutical Sciences, Technological University Dublin, Dublin, Ireland
• ²Graphic Era Deemed to be University, Dehradun, India
• ³INRAE Qualite des Produits Animaux, Saint-Genès-Champanelle, France
• ⁴Banaras Hindu University Institute of Environment & Sustainable Development, Varanasi, India
• ⁵South Dakota School of Mines and Technology, Rapid City, United States

Sustainability in integrated food systems is becoming increasingly critical, particularly in conjunction with biovalorization and the circular bioeconomy. The exponential increase in world population and rise in demand for food is putting overwhelming stress on the food production and waste management system (Sliveira et al., 2026). Globally, scientists are trying to tackle these challenges using. Novel bioprocessing techniques in agriculturae and food processing are now trying to address this problem through biovalorization of organic residues into valuable products like biofuels and bioproducts. These biovalorization waste aligns well with the circular bioeconomy concept, which primarily focuses on utilizing resources more efficiently, reducing waste, and maintaining a closed-loop material and energy flow with minimal environmental impact.The launch of this Research Topic within the Waste Management in Agroecosystems section of Frontiers in Sustainable Food Systems was intended to catalyze scientific advancements by integrating novel insights, methodologies, and applications that enhance knowledge and innovation in this domain. The call for papers sought submissions on waste management through biovalorization, shifts towards a circular economy in food production and processing, and the crucial role of policies in supporting these transitions. Key questions related to reducing greenhouse gas emissions through biovalorization include: Which strategies are most effective for implementing circular principles in food systems? How can governments and markets create conditions for these practices to thrive? The contributions that came into the collection provide answers to several of these points. They cover examples on lignin depolymerisation, nutrient recovery, and other technical advances, but also include reviews and discussions on the policy and social side of food system transitions. This underscores the necessity of integrated approaches that combine both science and policy-making to make circular food systems a reality. This collection of articles advances the vision of a circular bioeconomy that not only minimises waste but also regenerates products by integrating the waste streams into production systems, thereby reducing environmental pressures.Valorization of organic waste streams in soil-plant system Nicastro et al. (2024) explored how far human urine derivatives can be used in circular agriculture, and they tested this on lettuce in soilless systems. The idea is simple but at the same time very challenging. Urine contains nitrogen, phosphorus, potassium and other micronutrients, so if recovered properly, it can replace part of the synthetic fertilisers that are currently expensive and also damaging for the environment. In their study, they tested various urine derivatives, including K-struvite, urine precipitate with CaO, electrodialysis concentrate, aurin, hydrolysed urine, and several stabilised urine treatments. They compared them with the standard NPK fertiliser. They not only measured the biomass but also the biochemical and physiological changes inside the lettuce plants. The results demonstrated that certain treatments, such as K-struvite and urine precipitate amended with CaO, achieved plant growth performance comparable to the NPK control, indicating their potential as viable and sustainable nutrient alternatives. The study reveals both the potential and the limits, as optimisation is still necessary to balance growth and stress. The general message is that urine derivatives, when processed in the right way, can close the nutrient loop, reduce the reliance on Haber-Bosch nitrogen, and contribute to lowering greenhouse gas emissions from fertiliser production. focused on the topic of soil fertility in the vineyards, where there is an issue of sustainability and dependence on mineral fertilizers. The results revealed distinct patterns: compost (both PWC-Pruning waste compost and iPWC-inoculated (with fungal community) pruning waste compost) released nutrients more slowly but more stably in comparison to the mineral fertilizer inoculation. Enzymatic activities like urease, phosphatase, and arylsulfatase were enhanced in the soil, particularly when inoculated with compost, which suggests an improvement in nutrient cycling. Soil microbial community activity showed stronger metabolic responses under compost, especially iPWC, compared to the more basal activity under NPK. Interestingly, while compost increased microbial activity, mineral fertilizer was associated with higher Shannon diversity, likely due to carbon limitation and even distribution of species under inorganic inputs. Still, compost showed better improvement in soil functions, pointing to its potential as a tool for vineyard sustainability. This research aligns well with circular economy principles: pruning waste, a common byproduct from vineyards, is valorised into compost, reducing reliance on chemical fertilisers and lowering the environmental footprint. The benefit of compost inoculation is that it does not interfere with the microbial dynamics of the soil-plant system to a great extent. It also helps in ameliorating nutrient deficiencies and increases the organic content of the soil. In contrast, chemical fertilizers and certain microbial biofertilizers can have long-term impacts-the former by reducing microbial activity and the latter by interfering with existing microbial community dynamics. Cacace et al. (2025) explored the control of root-knot nematodes (Meloidogyne incognita), which are among the most damaging pests of tomato production, using wasted bread, brewers' spent grain, and spent coffee grounds either directly or after bioprocessing with enzymes, lactic acid bacteria, or compost tea. The results showed that all the residues, whether native or bioprocessed, significantly reduced nematode multiplication and root galling compared to untreated control soils. The most striking effect came from bioprocessed brewers' spent grain, which achieved suppression levels very close to the commercial nematicide used as reference.Wasted bread also suppressed nematodes, but its effect on plant growth was not as strong as for brewers' spent grain. This work highlights the dual functionality of food residues as soil amendments, providing nutrients and at the same time suppressing soil-borne pests. It links directly to circular economy ideas, as the by-products of the bakery, brewing, and coffee industries, which are otherwise difficult to dispose of, can be converted into resources for crop protection, highlighting the untapped potential of these resources. 2025) conducted a study on the biofortification of oyster mushrooms (Pleurotus djamor and P. florida) with zinc oxide nanoparticles (ZnONPs). The study's academic significance is highlighted by the potential to contribute to the field of mycology. The authors aimed to investigate whether the addition of ZnONPs into the substrate at the spawning stage could enhance the growth, biochemical quality, and nutrient content of these mushroom species. The results showed improved growth and yield compared to the control, with the 20 ppm treatment showing the most promising results in stimulating mycelial radial growth and final yield. Higher concentrations (40 ppm) were found to enhance biochemical properties such as phenolic and flavonoid content, as well as antioxidant activity, suggesting a potential dosedependent effect. Enzymatic assays indicated that ZnONPs triggered antioxidant responses, potentially by activating oxidative stress defence systems. Macronutrients (N, P, K, S) and micronutrients (Zn, Fe, Mn, Cu) also increased in the fruiting bodies, indicating that nanoparticle supplementation can significantly enhance the nutritional value of mushrooms and potentially contribute to the field of mycology. 2024) reviewed cocoa by-products with a multidimensional lens, combining bibliometric and patent analyses to understand both the science and technology outlook for these residues. They have shown that most scientific work to date has focused on agricultural and biological sciences, often assessing the nutritional and bioactive potential. At the same time, patents have concentrated on food ingredients, functional foods, and beverages. The review highlights the potential for value-added applications of cocoa by-products, inspiring us to explore the possibilities beyond animal feed or low-value composting. 2024) reviewed how small-scale coffee producers in Oaxaca can access the speciality coffee market. This manuscript analysed 38 publications to examine how quality is influenced by altitude, temperature, soil, and genetic factors. The review also delved into the complexities of coffee production, highlighting the crucial role of farm practices and post-harvest methods. Socioeconomic barriers, such as limited financial resources, weak market access, and a lack of organisation, were found to restrict smallholders from fully benefiting. The review concludes that collective models and community-based enterprises could be more sustainable pathways for development. 2024) examined the sustainability, recycling, and circular economy themes that have been addressed in the global beer industry from 1972 to 2022. This is a bibliometric study and includes the analysis of 417 publications. It observes that while technical research on fermentation, yeast, and brewing dominates, the explicit focus on sustainability is very much limited. The study highlights the growing role of brewers' spent grain (bagasse) as a key byproduct, a beacon of hope with its potential for valorisation through energy recovery, bioprocessing, and applications in the food and pharmaceutical sectors. It also reveals regional collaborations, especially between Europe and the Americas, and underscores that, despite growing academic attention, sustainability in brewing remains at an early stage, with future opportunities in linking circular economy practices more directly to industrial innovation and policy frameworks. Experimental studies by Nicastro et al. and Lucchetta et al. show that nutrient recovery can be done from human urine and vineyard residues which complement mineral fertilisers, closes nutrient loops and consequently supporting soil health. Bioprocess innovations, including the publications from Cacace et al. on suppression of soil-borne nematodes with food residues, and the work of Kumari et al. on nanoparticle-enriched mushrooms, show how residues can be reimagined as resources for crop protection and nutritional enhancement. Other works extend the perspective to the system level, showing both the promise and the challenges and limitations. Overall, these studies emphasise that biovalorization and circular bioeconomy are not abstract ideas but emerging practices, though still unevenly distributed.Across these published studies, one thing is evident. Waste streams from different scenarios are being pulled back into production either through human-derived fertilisers or composted residues, which ultimately close nutrient loops. The future works must push technological boundaries and focus on developing advanced methods for lignin depolymerisation and tackling the complexity of diverse residues. Also, beyond laboratory studies, focus should be on shaping cross-sectoral policies that integrate agriculture, energy, and waste streams. Further, the social dimension cannot be ignored either. So robust life-cycle and systems assessments are equally needed to weigh true environmental gains against hidden trade-offs. Overall, this collection emphasises that there is a growing momentum of research and practice at the intersection of food sustainability, waste valorisation, and circular bioeconomy. The range of studies, from vineyards and mushrooms to coffee, cocoa, and beer, demonstrates that existing challenges can be multifaceted and complex. However, the solutions are equally diverse and adaptable, offering inspiration for the potential of circular farming. If implemented appropriately, these solutions could pave the way for a sustainable future. The collective insights from this Research Topic are essential for researchers working in the area of food system sustainability, as they explore sustainable solutions across various industries.