Lipid Composition of Alaska Pink Salmon (Oncorhynchus gorbuscha) and Alaska Walleye Pollock (Theragra chalcogramma) Byproducts

In Alaska, over one million metric tons (MT) per year of fish processing byproducts are produced. The objective of this study was to determine the fatty acid profile and quantitate lipid classes in the extracted oils of byproducts from pollock (heads, frames, viscera, skins) and salmon (heads, viscera). In pollock, viscera had the highest percent lipid and in salmon, heads had the highest lipid content. All fish parts from both salmon and pollock were rich in omega-3 fatty acids, which ranged from 25% to 36% in the extracted oils. Differences among byproducts in fatty acid content and percent of lipid
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Calcium Compounds to Improve Gel Functionality of Pacific Whiting and Alaska Pollock Surimi

The effect of calcium compounds during three thermal treatments with or without setting was studied. Formation of cross-linking was investigated using SDS-PAGE. Solubility varied. Calcium acetate, chloride, and caseinate were extremely soluble. Calcium lactate had good solubility at 0.2% or higher, then in descending order were phosphate, citrate, sulfate, and carbonate. Effects of temperature on solubility were not measurable except for caseinate. When 25°C setting was applied to surimi, calcium was most effective. Effect of calcium on shear stress was dependent on species, setting temperature, and specific compound. SDS-PAGE indicated that improved gel functionality was likely due to Ca++-dependent trans-glutaminase.
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Characterization of rheological and physicochemical properties of Alaska walleye pollock (Gadus chalcogrammus) roe

Alaska walleye pollock (Gadus chalcogrammus) roe is a commercial product of the Alaska pollock fishery. Accordingly, the objective of this study was to determine functional properties of pollock roe through rheological and physicochemical analyses. Pollock roe rheological properties were determined by flow sweep and frequency sweep measurements. Zeta potential of the roe was measured at different pHs (2-12) and roe protein concentration of 0.05% (w/v). Protein solubility was determined by adjusting pH of the freeze-dried pollock roe powder between 2 and 12. Emulsion stability of the roe was determined by measuring creaming index at different oil:water ratios ranging from 5:95
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Effects of nano-scaled fish bone on the gelation properties of Alaska pollock surimi

Gelation properties of Alaska pollock surimi as affected by addition of nano-scaled fish bone (NFB) at different levels (0%, 0.1%, 0.25%, 0.5%, 1% and 2%) were investigated. Breaking force and penetration distance of surimi gels after setting increased significantly as NFB concentration increased up to 1%. The first peak temperature and value of storage modulus (G′), which is known to relate to the unfolding and aggregation of light meromyosin, increased as NFB concentration increased. In addition, 1% NFB treatment demonstrated the highest G′ after gelation was completed. The activity of endogenous transglutaminase (TGase) in Alaska pollock surimi increased as NFB
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Functional Protein Additives in Surimi Gels

Medium-grade Alaska pollock surimi was used to investigate the effects of functional protein additives on texture and colors. Torsion failure and differential scanning calorimetry tests were applied to measure gel strength, gel deformability, and calorimetric properties. CIE Lab color values were also measured. Shear stress values of gels and peak temperature of DSC thermograms were all increased. Shear strain, a good indicator of protein-protein interaction, was increased only by addition of egg white and beef plasma protein. Yellowness (b*) values were affected by all additives except frozen egg white. Whiteness index (L*-3b*) was a more effective indicator to differentiate additives.
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Physicochemical Changes in Alaska Pollock Surimi and Surimi Gel as Affected by Electron Beam

Alaska pollock surimi and surimi gels (cooked) were subjected to various doses of electron beam (e-beam). Shear stress of surimi gels increased as the dose increased up to 6 to 8 kGy and then decreased. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed gradual degradation of myosin heavy chain as the dose increased. The degradation was slower for frozen samples. The integrity of actin was slightly affected by high doses (25 kGy). The amount of sulfhydryl groups and the level of surface hydrophobicity of Alaska pollock surimi decreased as the dose increased, suggesting formation of disulfide bonds and hydrophobic interactions. The
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