Rheological and spectroscopic characterization of surimi under various comminuting and heating conditions

• Main Author: Poowakanjana, Samanan
• Other Authors: Park, Jae W., Goddik, Lisbeth, Penner, Michael H., Daeschel, Mark, Ingham, Russell E., Food Science and Technology, Oregon State University. Graduate School
• Format: Doctoral or Postdoctoral Thesis
• Language: English; unknown
• Published: Oregon State University
• Subjects: Fishery processing; Surimi > Analysis; Surimi; Pacific; alaska pollock; Theragra chalcogramma; Alaska
• Online Access: https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/6m311s676

Optimization of comminuting and heating conditions for surimi gel preparation obtained from three fish species: Alaska pollock (AP) (Theragra chalcogramma), Pacific whiting (PW) (Merluccius productus), and threadfin bream (TB) (Nemipterus spp.) was the focus of this study. Three parameters during comminution were separately evaluated: chopping time, chopping temperature, and salting time. Results from fracture gel analysis suggested a strong relation between the fish's environmental habitat and optimal final chopping temperature. Extending chopping time to 15 min under strictly controlled temperature at 0 °C was preferable for cold water fish AP surimi. Even though high chopping temperature (20 °C) for a shorter time (12 min) surprisingly resulted in strong gel texture similar to that of 0 °C for 15 min, high chopping temperature should not be employed for AP surimi. AP could set as a gel at this temperature within a shorter time in a holding tank which could subsequently cause a problem when extruded on the cooking belt. Temperate water fish Pacific whiting, demonstrated its maximum gel strength when chopped at 15-20 °C. The optimum comminution condition for warm water fish threadfin bream surimi was to chop the surimi until the paste temperature reached between 25-30 °C. Prolongation of chopping once the surimi hit its threshold (optimum) temperature diminished the quality of the resulting protein gel. Cooling system connected to the chopping bowl is strongly recommended as it will allow the comminution process to be extended as long as possible until the surimi paste reaches its target temperature. Raman spectroscopy disclosed the different level of protein unfolding based on secondary structure of α-helix and β-sheet during various comminuting conditions. Unfolding of protein was facilitated by increased chopping temperature to a greater degree than extended chopping time. Extending chopping could denature the light meromyosin structure as it could not form a semi gel-like structure at temperatures between ...