Capillary Extrusion Viscometer for the Viscosity Measurement of Fish Protein Paste

Abstract

To overcome various limitations of conventional viscometers in measuring salted or unsalted surimi paste, a capillary extrusion viscometer was developed. The viscosity of surimi paste was measured as a function of moisture content (MC) (75–80%), salt content (2–4%) and liquid egg white (LEW) content (2–4%). As moisture, salt and LEW contents increased, viscosity gradually decreased. The viscosity values, as affected by MCs, showed a highly negative relationship with fracture properties of surimi gel, especially shear stress from the torsion test, indicating that MC is linearly correlated to the strength of gels at fracture. This easy and quick viscosity measurement can effectively facilitate the production control of comminuted muscle foods, including surimi paste. PRACTICAL APPLICATIONS There had been a difficulty to measure the exact viscosity of comminuted muscle food pastes when conventional viscometers were used. This was due to the non‐linearity between dilution rates and viscosity of muscle paste, or limited range of shear rate during viscosity measurement. New developed small capillary extrusion viscometer can measure a wide range of comminuted muscle paste viscosity. When using this capillary viscometer, flow behavior of non‐Newtonian surimi paste and other comminuted muscle paste can be well defined.

Elucidating Factors Affecting Floatation of Fish Ball

“…With increased moisture content from 80% to 84%, apparent viscosity decreased. Similar trends were observed in the apparent viscosity of Alaska pollock, which proportionally decreased as moisture content increased from 76% to 86% (Kim and Park 2005). The effect of salt concentration, thawing conditions, and chopping temperature on the density of surimi paste is described in Figure 6.…”

“…Apparent viscosity of surimi paste was then determined by the slope of shear stress compared with shear rate. Possible slip at the tube wall was thought by Kim and Park (2005) in our first experiments. Preliminary experiments provided with a higher linearity between pressure (force value) and crosshead speeds.…”

“…Viscosity measurement was performed according to the method developed by Kim and Park (2005) using a Texture Analyzer (TA‐XT plus, Texture Technologies Corp.) fitted with a capillary fixture kit (TA‐525) having an extrusion tube of 30 mm long, piston dia of 38 mm, and nozzle dia of 6 mm. Surimi paste remaining after gel analysis was packed into the cylinder using a sausage stuffer (Sausage Maker).…”

“…Using power law, σ = C (−dv/dr) n, n (flow behavior index) and C (consistency coefficient) were obtained from the slope and yintercept in log σ and log (−dv/dr) graph. They were flow behavior index (n) = 0.262 and log C (consistency coefficient) = 3.14 (Kim and Park 2005). Apparent viscosity of surimi paste was then determined by the slope of shear stress compared with shear rate.…”

Extending the Shelf Life of Set Fish Ball

“…Viscosity measurement was performed according to the method developed by Kim and Park (2005) using a Texture Analyzer (TA‐XT plus; Texture Technologies Corp.) fitted with a capillary fixture kit (TA‐525) having an extrusion tube 30 mm long and a nozzle diameter of 6 mm. Surimi paste remaining after gel analysis was packed into the cylinder using a sausage stuffer (Sausage Maker).…”