Table 2. Overview of valorization technologies and their application

Technology	Target byproduct(s)	Products obtained	Industrial applications
Enzymatic hydrolysis	Blood, Offal	Bioactive peptides	Functional foods, nutraceuticals
Collagen extraction	Skin, Bones	Gelatin, collagen peptides	Food, pharma, cosmetics
Transesterification	Animal Fats	Biodiesel	Energy, industrial fuels
Fermentation	Protein hydrolysates	Single-cell proteins, enzymes	Feed, biotech industry
Supercritical fluid extraction	Fat, Skin	Bioactives, oils	Cosmetics, food supplements