Fishery Research

Pickling Technology Uses Ionic Strength to Plump Up Texture

Pickling technology is ordinarily used in food processing to flavor or remove smelliness from meat or fish ingredients that go into food products. Pickling can be done with seasonings, food ingredients or a pickling liquid containing a dissolved mineral. Pre-processing fishery products by pickling helps improve appearance, texture and overall flavor and create a tastier product.
Technology for boosting the water retention property of protein is often used when pickling fishery products. This technology is very effective for softening the meat but in the case of fishery products, it can lead to the loss of umami components, which changes the texture.
Nissui is developing technology focusing on the ionic strength of pickling liquids as a different method for controlling texture.
Pickling fishery products in a liquid with high ionic strength causes muscle fibers to loosen and retain water as it penetrates between the fibers. Unlike the change that occurs when using a pH adjuster, the usual method, the muscle fibers retain their shape and reduce loss of umami components. As a result, after heating, the product retains the original soft, plump texture of fish. In addition, the fish stays moist even some time after cooking, so it does not become dry or hard or otherwise change texture later.

Figure 1．State of Muscle Fibers when Pickled with High Ionic Strength Liquid (for illustrative purposes)

" Fukkura Kirimi"(Plump Filets) Series for Bulk Cooking and Retaining Texture after Cooking

For bulk cooking for school lunches or in institutional or commercial settings, users want to be able to cook filets efficiently without having to thaw them first. But cooking frozen filets creates drips that make the meat tough and dry, and the filets are not tasty.
To deal with this problem, we used pickling technology to adjust ionic strength and reduce dripping. This allows the fish's texture to remain plump without becoming tough or dry after cooking. Pickling also reduces weight change or shrinkage due to cooking. Our "Fukkura Kirimi" using pickling technology offers various kinds of fish in different formats, and we are also working on applying the technology to deep-fried and grilled fish products.

Figure 2. "Fukkura Kirimi" Product Characteristics and Examples of Commercialization

Shrimp that Looks and Tastes Real

Tasty shrimp is firm, fibrous and chewy, has contrasting bands of red and white, and has a characteristic sweet and umami. Nissui's pickling technology, which calibrates ionic strength, makes tasty shrimp possible. With pH adjusters, the pickling solution penetrates muscle fibers, blurring the boundary of the muscle fibers and giving the shrimp a limp texture. Moreover, pH adjusters cause loss of components like amino acids, weakening the shrimp's real flavor.
With our "Shrimp Pro" line of products made using our new pickling technology, the meat is moist but the fibers retain their crisp edges. The result is shrimp with a natural shrimp texture, opaque meat and authentic sweet flavor. The technology can also be used for various shrimp preparations, from shelled shrimp or seafood mix to breaded deep-fried shrimp and shrimp gratin, which consumers appreciate for their fine quality. (Patent pending)

Figure 3. Product Characteristics and Examples of Commercialization of Our New Pickling Technology