Many biological residues generated by food production systems contain significant amounts of proteins that can serve as valuable sources of polypeptides. Instead of being treated solely as waste, these materials can be transformed into useful resources through appropriate processing technologies.
Fish processing residues, for example, often contain large quantities of structural proteins such as collagen. Materials such as fish bones and scales are therefore valuable sources of protein that can be converted into peptide fractions through controlled processing methods.
Poultry by-products such as feathers are another example of protein-rich residues. Feathers are composed primarily of keratin, a durable structural protein that gives feathers their strength and resilience. Although keratin is naturally resistant to degradation, specialised processing techniques can break it down into smaller peptide fragments that can be used in different applications.
Dairy by-products also represent an important source of proteins. Cheese whey, which is generated during cheese production, contains soluble proteins that can be recovered and transformed into bioactive peptides through enzymatic processes.
Recovering polypeptides from these materials contributes to the concept of residue valorisation, where underutilised biological resources are transformed into valuable products. By extracting useful compounds from materials that would otherwise remain underused, it becomes possible to improve resource efficiency and reduce waste within food production systems.
This approach is increasingly recognised as an important component of the circular bioeconomy, which aims to maximise the value of biological resources while minimising environmental impact.