title: Chemical properties of ω-3 fortified gels made of protein isolate recovered with isoelectric solubilisation/precipitation from whole fish.
abstract: Protein isolate was recovered from whole gutted fish using isoelectric solubilisation/precipitation (ISP). The objective was to determine chemical properties of heat-set gels made of the ISP protein isolate fortified with ω-3 polyunsaturated fatty acids (PUFAs)-rich oils (flaxseed, fish, algae, krill, and blend). The extent of the PUFAs increase, ω-6/ω-3 FAs and unsaturated/saturated FAs ratios, and the indices of thrombogenicity and atherogenicity depended on specific ω-3 PUFAs-rich oil used to fortify protein isolate gels. Lipid oxidation in ω-3 PUFAs fortified gels was minimal, although greater (P<0.05) than control gels (without ω-3 PUFAs fortification). However, all gels were in the slightly rancid, but acceptable range. The commonly used thiobarbituric-acid-reactive-substances (TBARS) assay to determine lipid oxidation in seafood may be inaccurate for samples containing krill oil due to its red pigment, astaxanthin. Protein degradation (total-volatile-basic-nitrogen) was greater (P<0.05) in ω-3 PUFAs fortified gels than control gels. However, all gels were considerably below the acceptability threshold for protein degradation. The shear stress of ω-3 PUFAs fortified gels was generally greater than the control gels and the shear strain was generally unchanged. This study demonstrates that ω-3 PUFAs fortification of protein isolates recovered with ISP from fish processing by-products or whole fish has potential application in the development of functional foods.
authors.affiliation: Oregon State University, Seafood Research and Education Center, 2001 Marine Dr., Astoria, OR 97103, USA.
authors.forename: Reza
authors.initials: R
authors.lastname: Tahergorabi
authors.forename: Sarah K
authors.initials: SK
authors.lastname: Beamer
authors.forename: Kristen E
authors.initials: KE
authors.lastname: Matak
authors.forename: Jacek
authors.initials: J
authors.lastname: Jaczynski
mesh_terms: D000818:Animals; D011232:Chemical Precipitation; D015525:Fatty Acids, Omega-3 / Q000032:analysis*; D005396:Fish Products / Q000032:analysis*; D029941:Fish Proteins / Q000737:chemistry* / Q000302:isolation & purification; D005399:Fishes; D005511:Food Handling; D055951:Functional Food / Q000032:analysis*; D005782:Gels / Q000737:chemistry; D008055:Lipids / Q000737:chemistry; D010084:Oxidation-Reduction; D011492:Protein Hydrolysates / Q000737:chemistry / Q000302:isolation & purification; D012995:Solubility
chemical_list: D015525:Fatty Acids, Omega-3; D029941:Fish Proteins; D005782:Gels; D008055:Lipids; D011492:Protein Hydrolysates