The Secret to Superior Texture Lies in High Ionic Strength Solutions
In food processing, there are techniques to enhance flavor and preservation by soaking ingredients in certain liquids or seasonings for set periods. This "pickling technology," when used as a pre-treatment for marine products, leads to significant improvements in appearance, texture, and overall flavor, resulting in a much tastier final product. However, there are challenges, such as the loss of umami components and alterations to the natural texture. At Nissui, we focused on optimizing the ionic strength of pickling solutions. When marine products are immersed in high ionic-strength solutions, muscle fibers gently loosen, allowing water to enter the spaces between them and helping retain moisture. Unlike conventional pH adjustment methods, this technique preserves muscle fiber structure, preventing excessive loss of umami components. After heating, products retain their original texture and umami while becoming tender and plump. Furthermore, this hydrated state remains stable long after cooking, preventing texture changes such as drying or toughening over time.
Figure 1: Muscle fiber state in a high ionic-strength solution (illustrative diagram)
Research Approach
At Nissui, we expanded our research beyond fish fillets to explore applications for other ingredients, with a particular focus on shrimp. As researchers, we seriously considered questions like "What makes truly delicious shrimp?" and "Are customers satisfied with existing frozen peeled shrimp and processed shrimp products?" - driven by our passion to deliver authentic shrimp flavor. Through a detailed scientific analysis of different shrimp species and market offerings, we identified the essential qualities that make shrimp truly delicious:
- Firm, springy texture
- Distinct fibrous texture
- Clear red and white color contrast
- Strong natural sweetness and umami
To achieve these qualities, we applied our new pickling technology with adjusted ionic strength.
Figure 2: Product characteristics of new pickling technology
Figure 3: Consumer survey results and testing site
Research Results
School cafeterias, industrial facilities, and restaurants face challenges in efficiently cooking large quantities of frozen fish fillets. However, conventional cooking of frozen fillets results in drip loss, dry texture, and toughness. Our new pickling technology successfully prevents drip loss, weight changes, and shrinkage when cooking from frozen. Fish fillets remain plump and moist even several hours after cooking. This innovation led to the development of our "Fukkura Kirimi" (plump fillets) series, now commercialized across various fish species and widely applied in fried and grilled fish products.
Figure 4: Product characteristics and commercialization examples of "Fukkura Kirimi"
Shrimp processed with this technology preserves the distinct structure of muscle fibers while retaining moisture, resulting in natural texture, clear appearance, and authentic umami. This technology, branded as "Seafood Pro Method," is used in frozen peeled shrimp "SHRIMP PRO" series, peeled shrimp, seafood mix, and applied to fried shrimp and gratin dishes, consistently chosen by customers who value authentic quality.
Figure 5: Seafood Pro Method
This innovative ionic-strength pickling technology continues to find new applications across our product range. Nissui remains committed to developing advanced processing technologies that deliver the authentic taste of marine products.