Sustainable Applications of Animal Waste Proteins

Abstract

Currently, the growth of the global population leads to an increase in demand for agricultural products. Expanding the obtaining and consumption of food products results in a scale up in the amount of by-products formed, the development of processing methods for which is becoming an urgent task of modern science. Collagen and keratin make up a significant part of the animal origin protein waste, and the potential for their biotechnological application is almost inexhaustible. The specific fibrillar structure allows collagen and keratin to be in demand in bioengineering in various forms and formats, as a basis for obtaining hydrogels, nanoparticles and scaffolds for regenerative medicine and targeted drug delivery, films for the development of biodegradable packaging materials, etc. This review describes the variety of sustainable sources of collagen and keratin and the beneficial application multiformity of these proteins.

Recent Advances in Bio-Based Smart Active Packaging Materials

“…Collagen is one of the main components of the extracellular matrix of animal connective tissue and is the most abundant and widely distributed functional protein in mammals [ 18 , 19 ]. Proline and hydroxyproline are amino acids that are unique to collagen, and the number of hydrogen bonds they form plays an important role in the stability of the collagen structure.…”

“…Proline and hydroxyproline are amino acids that are unique to collagen, and the number of hydrogen bonds they form plays an important role in the stability of the collagen structure. In the food industry, collagen is used both in its native form as a food additive and in the form of collagen biomaterials [ 18 ].…”

Organic waste valorisation towards circular and sustainable biocomposites

“…Cellulose and lignin conversion to biopolymers also reached Technology readiness levels (TRLs) higher than 5, 235,297 and carrageenans in hydrogels also represent an interesting alternative to an integral valorisation of disposals, currently only used as fertilizing purposes. 298 A variety of sustainable sources of collagen and keratin and the beneficial multiform application of these two proteins have been also extensively reviewed. In all the cited cases, we should, however, keep in mind that production is economically viable and cost-competitive in the market only if, in parallel, and regardless of the easy scaling of the procedures and the yield in marketable products, it represents an industrial activity with no considerable environmental impacts.…”

Preparation Methods and Functional Characteristics of Regenerated Keratin-Based Biofilms

“…Keratin-based biofilms possess high biodegradability, compared to native fur and hair. The degraded keratin can serve as a C and N source for soil micro-organisms [ 140 , 141 , 142 ]; in particular, the degraded keratin can strengthen the soil respiration of micro-organisms, as well as adjust the pH and expand the cation exchange capacity of the soil. Based on this, keratin-based biofilms have great potential for conversion into biofertilisers.…”