Process for the filleting, treating, packaging, freezing, and thawing of varying types of tuna and other pelagic species

Abstract

A method of treating fish to maintain freshness after freezing and thawing. A whole fish is chilled and cut into four loins, each with two flat sides forming a corner. The loins are chilled and either sliced cross sectionally to form steaks or sliced parallel to one of the flat sides to form sashimi slabs. If sashimi slabs are formed, the slabs are then preferably dipped in a warm flavor enhancing solution. The steaks or slabs are then sealed in non-permeable bags, preferably in a "puzzle pack" configuration that maximizes density and minimizes interstices. The bag with the steaks or sashimi slabs is then submerged in a brine solution. A treatment gas is then injected into the bag. After a treatment time, the gas is removed and the bag is vacuum packed. The bags are then frozen for shipping and storage. When needed, the bags can be thawed in a brine solution.

Description

[0001] This invention relates to a process for the filleting into steaks and sashimi slabs, treating, packaging, freezing, and thawing of varying types of tuna and other pelagic species including swordfish and marlin.[0002] For hundreds of years varying types of fresh tuna-yellowfin, bigeye, bluefin, skipjack, and albacore--served as raw sashimi have become a staple of the Japanese diet. Over generations, as the population of Japan has grown, the market for raw tuna has grown in both fresh and frozen form with a premium going to the characteristics of a bright red color for appearance and high oil content for flavor. This Japanese sashimi market draws the highest quality and highest value tuna in the world and affects the parameters of international tuna exporters and the U.S. domestic market.[0003] Tuna is an important commodity in the international market, far dwarfing the volume and value of any other species. According to the U.S. National Marine Fisheries Service the total worl...

AI Technical Summary

Benefits of technology

[0033] The process of this invention is to efficiently fillet, treat, package, freeze, and thaw varying types of tuna and other pelagic species. Each whole tuna is first ice brine chilled and then filleted into four loins--left back, right back, left belly, and right belly. A majority of the loins go to the steaking fillet process, while a minority of the loins go to the sashimi slab fillet process.

Problems solved by technology

However, because of the high cost of air freight and fluctuating market conditions in Japan, only 30% to 80% of any given catch can profitably go to the Japanese fresh sashimi market.

However, such processing has often resulted in unsightly brown freezer burn making the resultant frozen tuna steaks less marketable and marginally profitable as a product distributed to the U.S. market.

Since the primary fresh tuna market is in Japan, the U.S. fresh tuna market suffers from having a lower quality, lower value product facing the same high costs of international air freight as the higher value imports to the Japanese market.

This results in lower profit margins and lower volumes for fresh tuna in the U.S. market.

Thus, the large potential U.S. market for "previously frozen" tuna steaks has not yet been profitably developed because of (1) a lack of sufficient raw material until now; and (2) a lack of technology that efficiently fillets, treats packages, freezes, and thaws the product while maintaining the bright red color and the appearance of freshness after thawing without unsightly browning.

No one until now has developed a process that controls the primary aspects that allows previously frozen tuna to appear fresh-color, texture, and the ability to maintain its freshness for a period of time after thawing.

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