Isolation, characterization and valorizable applications of fish scale collagen in food and agriculture industries

Collagen has enormous applications in food, biomedical and pharmaceutical industries; but its high cost severely limits its use. Fish processing waste is a promising and cost efficacious source of collagen, which otherwise stated as an earnest environmental pollutant. Carp (Cyprinus carpio) is one of the main species of freshwater fish consumed in India. Acid-soluble collagen (ASC) was isolated from scales of Cyprinus carpio. Scales were demineralized by EDTA treatment and ASC was extracted from the demineralized scales. The yield of scale ASC was 9.79% (on the wet weight basis). SDS–PAGE and FTIR corroborated the isolated protein as collagen. Denaturation temperature (Td) of isolated collagen was found to be 37 °C. Considering bioactive properties of collagen, a milk based food product – paneer was developed by incorporation of the extracted collagen. Composed paneer was found to be acceptable with good sensorial and textural attributes. Same scales were further treated enzymatically and the released metabolites were tested for their competency to promote the plant growth. Released metabolites showed excellent plant growth promotion and hence could be successfully employed as an economic source of nitrogen fertilizers for plants.

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