Gelation properties of Alaska pollock surimi with functional ingredients under ohmic heating

• Main Author: Pongviratchai, Panida
• Other Authors: Park, Jae W., Food Science and Technology, Oregon State University. Graduate School
• Format: Master Thesis
• Language: English; unknown
• Published: Oregon State University
• Subjects: Surimi > Effect of temperature on; Gelation; Surimi > Mechanical properties; Walleye pollock > Processing; Surimi > Electric properties; alaska pollock; Alaska
• Online Access: https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/c534fr63n

The rheological, color, micro-structural, and electrical properties of surimi seafood gels were investigated. Various starches and protein additives at different ratios were evaluated with Alaska pollock surimi under ohmic heating at different heating rates to determine their functional properties and further to compare these properties with those of conventionally cooked gels. Native starches at low concentration were able to enhance rheological properties due to their gelatinization during heating. Pregelatinized starch decreased texture properties; however, it could suppress the undesirable appearance of the final product because its granules could absorb the surrounding water during chopping and perform a higher degree of retrogradation when cooling. A mixture of native and pregelatinized starches showed a positive trend at high concentration. The more starch added, the lower the L* and b* values of the gels. Protein additives improved textural properties, but negatively affected gel colors. Lower moisture content of the final products showed higher strength in texture, but lower lightness values. Gels cooked under ohmic heating with a slow heating rate mostly exhibited better texture properties than conventionally cooked gels. Electrical conductivities increased when temperature increased, resulting in a linear relationship. Electrical conductivity also significantly increased with moisture content, and slightly increased with applied frequency and voltage. There were some changes in the magnitude of electrical conductivity of surimi-starch paste when temperature increased, most obviously seen at a high concentration of native starch with slow ohmic heating. This indicated that starch gelatinization affected the electrical conductivity of surimi-starch paste while heating.