The “settling” of fish paste varies significantly depending on the fish species due to differences in protein properties, resulting in distinct optimal temperatures and times. In particular, Alaska pollock and threadfin bream are the two most common raw materials in kamaboko production, yet their properties are contrasting.
1. Alaska Pollock (Cold-Water Fish)
Alaska pollock inhabits the cold northern seas, so its proteins begin reacting at relatively low temperatures.
• Optimal Settling Temperature: 10°C to 20°C (Low-Temperature Settling)
• Caution is needed as temperatures above 30°C can cause a phenomenon called “reversal,” where the mesh structure breaks down.
• Optimal time: * Around 10°C: Overnight (12–24 hours).
* Around 20°C: Approximately 2–4 hours.
* Characteristics: Slow, extended processing at low temperatures creates a supple, resilient texture (“ashi”).
2. Threadfin (Temperate/Tropical Fish)
Threadfin inhabit warm seas, making them more heat-stable than Alaska pollock and better suited to higher temperatures.
• Optimal Setting Temperature: 30°C to 40°C (High-Temperature Setting)
• The temperature range where Alaska pollock struggles is where threadfin most efficiently develops elasticity.
• Optimal time: Approximately 30 minutes to 2 hours.
• Due to the higher temperature, coagulation progresses faster than with Alaska pollock.
• Characteristics: Prone to developing very strong elasticity (firm texture), making it useful for adjusting texture when blended with Alaska pollock.
Comparison Summary Table
Comparison Item
Habitat
Alaska pollack surimi
Cold water areas (northern seas)
Itoyori surimi
Temperate to tropical zones
Primary Settling Temperature
Alaska pollack surimi
10°C to 20°C (low temperature range)
Itoyori surimi
30°C to 40°C (high temperature)
Time Required
Alaska pollack surimi
Longer (several hours to overnight)
Itoyori surimi
Shorter (30 minutes to 2 hours)
Recrystallization Phenomenon
Alaska pollack surimi
Prone to occur around 30℃
Itoyori surimi
Occurs at 50℃ to 60℃
Texture Characteristics
Alaska pollack surimi
Supple, soft elasticity
Itoyori surimi
Firm, springy elasticity
Practical Considerations
In actual production settings, these are often mixed and used together. In such cases, it is common to set the temperature to **around 30°C**, though fine adjustments may be necessary depending on the blend ratio.
Note: The “return” varies by fish species. For walleye pollock-based products, the key to preserving elasticity is to quickly pass through the 30–40°C temperature range.
