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Physicochemical Properties of Yellowfin Tuna ( T hunnus albacares ) Skin Gelatin and its Modification by the Addition of Various Coenhancers
Author(s) -
Karayannakidis Panayotis D.,
Zotos Anastasios
Publication year - 2015
Publication title -
journal of food processing and preservation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.511
H-Index - 48
eISSN - 1745-4549
pISSN - 0145-8892
DOI - 10.1111/jfpp.12258
Subject(s) - gelatin , yellowfin tuna , thunnus , chemistry , glycerol , fish processing , tuna , food science , fish <actinopterygii> , fishery , biology , biochemistry
A gelatin preparation was produced from yellowfin tuna ( T hunnus albacares ) skins and its physicochemical properties were evaluated against bovine skin gelatin. The fish gelatin obtained exhibited higher gel strength and similar viscosity when compared with its mammalian counterpart, but showed a significantly lower melting point than the latter. In a follow‐up study, four compounds ( NaH 2 PO 4 , MgCl 2 , CaCl 2 and glycerol) at various concentrations were investigated in order to improve fish gelatin's physical properties. Addition of NaH 2 PO 4 at concentrations of 0.3 and 0.5 mol/L yielded gelatin gels that exhibited the highest gel strength, while the highest viscosities were noticed for gelatin solutions containing 0.3 and 0.5 mol/L CaCl 2 . The highest melting points were observed in the sample gels containing glycerol, irrespective of glycerol concentration. Results suggested that selected physical properties of fish skin gelatin can be modified by the addition of the above compounds at the appropriate concentration levels. Practical Applications Yellowfin tuna ( T hunnus albacares ) skins are one of the major by‐products formed by the fish processing industries in the north central coastal region of G reece. Typically, fish skins along with other by‐products, such as bones, heads, scales and viscera, end up as low commercial value products (e.g., animal feed) or dumped into landfills having harmful environmental effects. Utilization of the above by‐products, especially of collagen‐rich fish skins for gelatin production, will not only increase their commercial value, but it will also open new market opportunities for the gelatin and fish processing industries.