Food waste represents a major environmental and economic challenge affecting global food security [1]. Agriculture and livestock consume vast amounts of land and water, contributing to deforestation, biodiversity loss, pollution, and greenhouse gas emissions, while food insecurity and diet-related diseases persist worldwide [2]. Addressing these challenges requires a responsible food system capable of recovering value from resources lost along the food chain.

In this context, agro-industrial and fruit/vegetable residues emerge as a potential high-value source, being rich in fibers, polyphenols, pigments, vitamins, and other bioactive compounds. Fermentation techniques offer a powerful biotransformation pathway to valorise these materials into high-value nutraceuticals and functional ingredients. By properly matching microbial strains with specific substrates and optimizing key process parameters, fermentation can turn food industry by-products into valuable resources, opening up new opportunities for the development of highly efficient bioprocesses.

From agricultural by-products to fermentation bioprocesses

Fruit and vegetable by-products mainly originate from the fresh produce and food-processing industries due to aesthetic or processing-related constraints, leading to the frequent discard of peels, seeds, cores, stalks, pulp, and damaged items [3, 4]. However, these residues represent a highly valuable source of bioactives, being exceptionally rich in dietary fibers, pectin, polyphenols, flavonoids, carotenoids, vitamins, and anthocyanins [5, 6, 7].

When waste cannot be avoided, such agro-industrial matrices can be upcycled into high-value ingredients through targeted valorisation technologies, including extraction, enzymatic treatments, and bioprocesses [8, 9]. Among these, fermentation stands out as a key transformation pathway. Depending on the nature of the substrate matrix, the collection state, and the target end-product, fermentation can be tailored using Solid-State Fermentation (SSF) or Submerged Fermentation (SmF) [7, 10].

Through these specific bioprocesses, selected microorganisms break down and convert the rich substrate matrices into aroma compounds, organic acids, enzymes, pigments, peptides, and other bioactive metabolites. Ultimately, this biotransformation yields functional ingredients, nutraceuticals, natural colorants, and antioxidants with broad applications across the food, pharmaceutical, and cosmetic industries [5, 7, 11].

Microbial strain selection and bioprocess optimization

Successful targeted fermentation requires matching microbial strains with optimal substrates, as synthesis capabilities and cell growth phases directly govern product yields [11]. Furthermore, optimizing process parameters (pH, temperature, shear stress, oxygen, inoculum size, and time) enables a controlled bioprocess [12, 13] that maximizes the recovery of enzymes, proteins, vitamins, and bioactive metabolites from food residues.

At ROELMI Biotech, this principle lies at the core of our approach: by gaining a deep understanding of the microorganism, characterizing its metabolic pathways, and optimizing process parameters, we harness the full potential of each substrate to produce high-quality functional ingredients designed for different market needs. By applying targeted fermentation to food-processing by-products, we aim to valorise their untapped potential, transforming them into high-value resources and creating new opportunities for the development of innovative ingredients. 

Through strategic collaborations with local companies, we can develop custom bioprocesses that actively reduce food waste while accelerating the transition toward a circular food economy. For our company, fermentation is more than a technique; it is a conscious innovation, turning what was once left behind into high value solutions for our future.

🖋️ Zanchetta, Ylenia; Tritto, Aurora; Avanzini, Francesca; Trejo, Cesar Francisco

Bibliography

  1. United Nations Environment Programme (UNEP). (2024). Food Waste Index Report 2024: Think Eat Save—Tracking Progress to Halve Global Food Waste. Nairobi: UNEP. https://wedocs.unep.org/20.500.11822/45230.
  2. De Oliveira, D. E. P., Miranda, A. C., Junior, M. V., Santana, J. C. C., Tambourgi, E. B., Facchini, F., Iavagnilio, R., & Pinto, L. F. R. (2024). Economic and environmental feasibility of cogeneration from food waste: A case study in São Paulo City. Sustainability, 16(7), 2979. https://doi.org/10.3390/su16072979.mdpi
  3. Laufenberg, G., Kunz, B., & Nystroem, M. (2003). Transformation of vegetable waste into value added products: (A) The upgrading concept; (B) Practical implementations. Bioresource Technology, 87(2), 167–198. https://doi.org/10.1016/S0960-8524(02)00167-0.10)
  4. Salas-Millán, J. Á., & Aguayo, E. (2024). Fermentation for Revalorisation of Fruit and Vegetable By-Products: A Sustainable Approach Towards Minimising Food Loss and Waste. Foods, 13(22), 3680. https://doi.org/10.3390/foods13223680
  5. Naqash, F., Masoodi, F. A., Rather, S. A., Wani, S. M., & Gani, A. (2017). Emerging concepts in the nutraceutical and functional properties of pectin—A review. Carbohydrate Polymers, 168, 227–239. https://doi.org/10.1016/j.carbpol.2017.03.058.
  6. Teng TS, Chin YL, Chai KF, Chen WN. Fermentation for future food systems: Precision fermentation can complement the scope and applications of traditional fermentation. EMBO Rep. 2021 May 5;22(5):e52680. https://doi.org/10.15252/embr.202152680. Epub 2021 Apr 27. PMID: 33908143; PMCID: PMC8097352.
  7. Marcelli A, Osimani A, Aquilanti L. Vegetable By-Products from Industrial Processing: From Waste to Functional Ingredient Through Fermentation. Foods. 2025 Jul 31;14(15):2704. https://doi.org/10.3390/foods14152704. PMID: 40807640; PMCID: PMC12345998. 
  8. Corrado, S., & Sala, S. (2018). Food waste accounting along global and European food supply chains: State of the art and outlook. Waste Management, 79, 120–131. https://doi.org/10.1016/j.wasman.2018.07.032.5) 
  9. Sharma, R., Dhir, A., Talwar, S., & Kaur, P. (2021). Over-ordering and food waste: The use of food delivery apps during a pandemic. International Journal of Hospitality Management, 96, 102977. https://doi.org/10.1016/j.ijhm.2021.102977.mendeley 
  10. Cassani, L. V., & Gomez-Zavaglia, A. (2022). Sustainable food systems in fruits and vegetables food supply chains. Frontiers in Nutrition, 9, 829061. https://doi.org/10.3389/fnut.2022.829061. 
  11. Hadj Saadoun, J., Bertani, G., Levante, A., Vezzosi, F., Ricci, A. M. G., Bernini, V., & Lazzi, C. (2021). Fermentation of agri-food waste: A promising route for the production of aroma compounds. Foods, 10(4), 707. https://doi.org/10.3390/foods10040707.
  12. Tornuk F, Akman PK. Recent developments in the valorization of agri-food waste and byproducts by fermentation. J Sci Food Agric. 2026 Mar 30;106(5):2567-2577. https://doi.org/10.1002/jsfa.70160. Epub 2025 Sep 2. PMID: 40891501.
  13. Sabater, C., Ruiz, L., Delgado, S., Ruas-Madiedo, P., & Margolles, A. (2020). Valorization of vegetable food waste and by-products through fermentation processes. Frontiers in Microbiology, 11, 581997. https://doi.org/10.3389/fmicb.2020.581997.