Characteristics and Functional Properties of collagen extracted from Nile tilapia (Oreochromis niloticus) skin

Abstract

Tilapia skin might be used as a new source of collagen, therefore collagen obtained from Nile tilapia skin can be utilized as food product because of its good functional properties. Two extraction methods were applied to obtain acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) from Nile tilapia skin. In this study, collagen was characterized in terms of FT-IR Spectrum, amino acid analysis, SDS-PAGE and Thermal denaturation temperatures (Td). Also, some major functional properties including solubility, oil and water absorption, emulsifying activity, stability, foaming ability, foam stability, and gelation properties were determined. The results showed that the yields of ASC and PSC were 4.30% and 1.84 % (on a wet weight basis), respectively. Amino acid composition indicated that the imino acid content of ASC and PSC were found to be 172.10 and 164.18 residues per 1000 residues, respectively. The FTIR Spectrum confirmed that the presence of a triple-helical structure characteristic of ASC and PSC. SDS-PAGE results indicated that ASC and PSC were type I collagen. The denaturation temperature of ASC and PSC were 26⁰ C and 25⁰ C respectively. The solubility of ASC and PSC were highly solubilized in the pH range of 2-3. ASC and PSC had good water and oil absorption capacity. Gelation studies revealed that ASC and PSC have good gelation properties. Consequently, Nile tilapia skin could be used as a good source of collagen in the food industries.