From Bean to Pond: Coffee Parchment Emerges as Sustainable Feed for Tilapia Farming

A new scientific breakthrough has uncovered a novel use for one of coffee’s most overlooked by-products. Researchers from Chiang Mai University have demonstrated that coffee parchment, the papery husk surrounding coffee beans, can serve as a functional feed additive in aquaculture — with significant benefits for Nile tilapia.

Published in the peer-reviewed journal Scientific Reports, the study shows that incorporating modest amounts of coffee parchment into fish feed not only improves growth and feed efficiency but also strengthens the immune system and enhances gut microbiota. The findings align with broader sustainability goals by transforming coffee waste into a valuable asset for the aquaculture sector.

Turning Coffee Waste into Aquafeed

Coffee parchment, a fibrous layer removed during the post-harvest process, makes up around 12% of the coffee cherry’s weight and is typically discarded. Despite its rich content of fiber and bioactive compounds such as polyphenols, caffeine, and flavonoids, its potential applications have remained largely untapped — until now.

In this eight-week feeding trial, scientists evaluated the effects of varying levels of parchment (0, 5, 10, 20, and 40 grams per kilogram of feed) on 300 Nile tilapia fingerlings reared in a biofloc system, an environmentally friendly aquaculture method that recycles organic matter through microbial activity.

Growth and Immunity Enhanced at Optimal Doses

The results were striking. Fish that received 5 g/kg of coffee parchment (CP5 group) exhibited:

• Significant increases in weight gain and feed conversion efficiency

• Higher survival rates

• Upregulation of genes linked to growth, such as ghrelin and galanin

Importantly, the CP5 group also showed marked improvement in immune responses:

• Elevated lysozyme and peroxidase activity in both skin mucus and blood serum

• Enhanced expression of immune-related genes including IL-1β, TNF-α, NFkB, and MHC II-α

Regression analysis identified an optimal dosage range of 15.06–19.86 g/kg, beyond which the benefits declined, likely due to the high fiber content limiting nutrient absorption.

A Healthier Gut Microbiome

The study also revealed profound effects on the fish gut microbiome. Notably:

• The CP10 group displayed the highest microbial diversity

• A significant reduction in Proteobacteria, a phylum associated with inflammation

• An increase in Cetobacterium, a beneficial genus linked to vitamin B12 production and improved digestion

These changes suggest that coffee parchment may act as a prebiotic, supporting a healthier intestinal environment — a key determinant of fish health and performance.

Environmental and Economic Implications

With global coffee production expected to exceed 172 million 60-kg bags in 2024–25, the industry generates an estimated 6 million tons of organic waste each year. The majority of this by-product ends up in landfills or is incinerated.

By repurposing parchment for aquaculture feed, this research offers a scalable solution that:

• Reduces environmental waste

• Cuts feed costs in fish farming

• Supports a circular economy by reintegrating agro-industrial by-products

The Role of Biofloc Systems

The integration of coffee parchment was especially effective in the biofloc system, which is gaining popularity for its ability to minimize environmental impact while improving nutrient cycling.

In this study, coffee parchment not only served as a feed additive but also contributed carbon to the floc environment, stimulating microbial activity and reducing nitrogen waste — reinforcing its role as a dual-function input.

Next Steps for Validation

While the results are promising, the authors note that further studies are needed:

• In commercial aquaculture settings

• Over longer production cycles

• Including pathogen challenge tests to confirm disease resistance benefits

They also recommend exploring higher dosage thresholds and metabolomic analyses to better understand how coffee parchment modulates fish physiology.

Conclusion

This pioneering research opens the door to a sustainable, science-backed application of coffee waste — one that benefits aquaculture, reduces environmental burden, and adds value to the global coffee supply chain. Coffee parchment, once a discarded husk, may soon find itself at the center of a greener, more efficient food system.

Study Reference:
Hien Van Doan et al., “Impacts of coffee parchment on growth, immunity, and gut microbiota of Nile tilapia in biofloc system,” Scientific Reports (2025) 15:25057. https://doi.org/10.1038/s41598-025-03109-1