Inedible seeds from fruits like apples, mangoes and oranges could be transformed into animal feed, biochar and bioenergy, helping to create more sustainable farming systems, say scientists.
Researchers in India said fruit seeds — often overlooked byproducts of fruit production — could have a number of practical uses for producers, helping to reduce waste, offer valuable new income streams and create more ‘circular’ farming businesses where waste is utilised.
In a paper published in Science of the Total Environment, researchers said fruit seeds from apples, papayas and mango can be processed into high-nutrient animal feeds for poultry, livestock and even aquaculture.
These seeds are rich in polyphenols and fatty acids, they explained, meaning they can provide a natural and cost-effective feed option. However, polyphenols can impact feed taste, they warned, so work needs to be done to understand their potential impact.
Fruit seeds can also be converted into biochar, which improves soil health by increasing moisture retention, reducing soil acidity and helping to capture carbon — making it especially valuable in regions with poor soils, they said.
For larger operations, fruit seeds can also be processed into biodiesel, providing an alternative energy source that can be used on the farm, the researchers added. Mango and avocado seeds in particular have shown promise in biodiesel production, helping to lower fuel costs and reliance on fossil fuels.
While work needs to be done to understand the best methods of processing and extraction, and farmers may need to partner with processors to utilise waste, the researchers said seeds could be “valuable products” with diverse applications across the farming sector.
“Fruit seeds [have been] previously overlooked and commonly discarded, but were known to comprise diverse chemicals with significant industrial applications,” they added.
“Non-edible seeds have demonstrated their potential as a rich reservoir of sustainable materials and compounds, presenting novel solutions to address environmental issues and promote the utilisation of resources.”