Methods for maintaining the freshness of fresh fish and shellfish during long-distance maritime transport

Abstract

Long-distance transport of fresh seafood has traditionally been done by air freight to maintain its freshness without delay. As a result, there are few experimental studies demonstrating the effectiveness of extended sea transport and storage periods, and it is currently said that the limit for maintaining freshness is 10 days to Southeast Asia and 20 days including the best-before date for chilled salmon from Norway. [Solution] By setting the freshness preservation period to 30-50 days during sea transport, the storage period of fresh seafood is extended. The combined effect of materials effective for preserving freshness (nanobubble activated water, disinfectant activated hypochlorous acid water RUS water, nano silk ice) provides disinfection and sterilization effects on microorganisms attached to fresh seafood. Furthermore, the super chilling high freshness preservation effect of nano silk ice ensures the quality of the seafood before it is transferred to styrofoam boxes. As a result, bacterial growth is suppressed, and the seafood in the styrofoam boxes is managed at a temperature range of -1 to -3°C during sea transport and storage containers, preventing the seafood from freezing.

Description

Technical Field

[0001] Establish a method for controlling microorganisms adhering to and generated in seafood by the combined effect of effective materials for maintaining the freshness of fresh seafood during long-distance marine transportation.

Background Art

[0002] Mixed hypochlorous acid water (sterilizing active hypochlorous water RUS water) is a low-concentration, highly effective sterilizing and bactericidal water with hypochlorous acid (HClO) as the main component at a specified concentration (10 ppm to 80 ppm). It has a sterilization effect about 18 times that of sodium hypochlorite, the drug. (Approved by the Ministry of Health, Labour and Welfare, Food Safety Department) It is used for preventing food poisoning in food washing and sterilizing cleaning related to food, and is approved as a sterilizing agent for food additives such as sterilizing cleaning of cut vegetables, sterilizing cleaning of raw fresh seafood, and pre-treatment of container-packaged pressurized heat-sterilized foods.

[0003] The nanobubble water (ultra-fine bubbles) developed by the Tohoku University Future Science and Technology Joint Research Center has a very small environmental impact, very low irritation to the human body, and almost no cytotoxicity. Therefore, its applications are very wide-ranging, and wide-ranging applications such as cleaning various members, agriculture, fisheries, medical care, and prevention of infectious diseases are expected.

[0004] Until now, the method for maintaining the freshness of fresh fish has had the weakness that it cannot be processed in large quantities due to the "live tying" treatment for each fish. However, the seawater silk ice developed by Nichio Co., Ltd. is a sherbet-like ice with extremely fine particles at a minus temperature. It has a very fast cooling rate and can maintain a minus temperature for a long time. It can quickly cool the fish without wrapping and damaging it. Therefore, it is said that preventing the fish from thrashing and low-temperature storage are essential for delaying the "postmortem rigor" state (the state where the body becomes stiff after death). Since the freshness drops after passing through the "postmortem rigor" state, it is important to delay the postmortem rigor in maintaining freshness. (When the fish thrash, ATP in the body is consumed and fatigue substances such as lactic acid accumulate and deteriorate.)

Prior Art Documents

Non-Patent Documents

[0005] [Non-Patent Document 1] Nikko Co., Ltd. www.k-nikko.com / product / silk-ice / [Non-Patent Document 2] Tohoku University Joint Research Center for Future Science and Technology (NICHe) www.tohoku.ac.jp>japanese>newimg>pressimg>tohoku... [Non-Patent Document 3] Shinshokuken Cooperative Association Mixed Hypochlorous Acid Water (Disinfectant Activated Hypochlorous Acid Water RUS Water) Complies with the "Standards for Foods, Additives, etc." based on Article 11, Paragraph 1 of the Food Sanitation Act of the Ministry of Health, Labour and Welfare [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] Methods for preserving the freshness of fresh seafood have evolved over time. Previously, fish were packed in styrofoam boxes with ice on the bottom for shipping. Because the fish would discolor within a day, their nerves were severed ("ikejime"), and they were transported in cold temperatures to ensure freshness for more than two days. Subsequently, the use of slushy sea ice, which has a similar "ikejime" effect, became more common. The importance of low-temperature management was emphasized, and crushed ice was used to quickly cool the fish, preventing deterioration and allowing the fish to maintain its freshness for six days. Furthermore, as a measure against food poisoning, hygiene management was paramount, as well as the presence of norovirus, Vibrio parahaemolyticus, E. coli, and histamine in seafood. While hygiene management measures to prevent the proliferation and sterilization of such organisms are being questioned, and microorganisms attached to fish and shellfish are being disinfected on board ships and at fishing port market facilities, and the fish and shellfish are being transported in styrofoam boxes kept at supercooled temperatures, long-distance transport of fresh fish and shellfish has been done by air freight to maintain freshness without delay. Therefore, there are few conclusive experimental examples of extending the time required for sea transport and storage, and the scientific investigation is still ongoing. Currently, the limit for maintaining freshness is said to be 10 days to Southeast Asia and 20 days from Norway, including the best-before date for chilled salmon. [Means for solving the problem]

[0007] Currently, long-distance transport of fresh seafood is handled by air freight to minimize transit time. However, there is no proven method to maintain the freshness of seafood for more than 20 days. Aiming to reduce logistics costs and increase the added value of products, and to expand sales channels for fresh seafood overseas, we aim to ensure the freshness of fresh seafood during long-distance sea transport through the combined effects of effective materials for freshness preservation. Since the target trans-Pacific sea transport takes 15-20 days, the period including transport and shelf life will be 30-50 days. We will use the sterilizing effect of activated hypochlorous acid water (RUS water) with a nanobubble water mechanism to disinfect microorganisms attached to fresh seafood, and maintain the high-freshness temperature range with nano-ice super chilling. To ensure the quality of the seafood, after landing, the seafood is immersed in a disinfection and sterilization washing box containing nanobubble activated water (ultrafine bubbles) and mixed hypochlorous acid water (disinfectant activated hypochlorous acid water) to disinfect microorganisms attached to the seafood on board the ship and at the fishing port market facilities, in order to prevent spoilage. The seafood is washed to remove microorganisms attached to the skin, gills, and especially the internal organs. Mixed hypochlorous acid water is then added to nano-silk ice, which provides the shortest possible freshness preservation effect, and the seafood is wrapped tightly in the ice for rapid cooling before being transferred to a styrofoam box. This suppresses bacterial growth, and the seafood in the styrofoam box is managed at a storage temperature of -1 to -3°C to prevent freezing inside the container during sea transport and storage. [Effects of the Invention]

[0008] The current state of freshness preservation for fresh fish and shellfish is as described in

[0006] , and the means to solve this problem is as described in

[0007] , in which the activity of bacteria that attach to and grow on fish and shellfish is controlled by the combined effect of effective materials for freshness preservation measures. [Modes for carrying out the invention]

[0009] After being landed, the seafood is disinfected on board the vessel and at the fishing port market to prevent spoilage. To do this, the seafood is immersed in a disinfection and sterilization washing box containing nanobubble activated water (ultrafine bubbles) and mixed hypochlorous acid water (disinfectant activated hypochlorous acid water). This washes off microorganisms attached to the skin, gills, and especially the internal organs. The seafood is then rapidly cooled by wrapping it tightly in nano-silk ice (fine ice) made by adding mixed hypochlorous acid water to the disinfection and sterilization washing box, achieving the shortest possible time to maintain freshness. In transport and storage containers, styrofoam boxes containing the freshness-preserving seafood are stacked, and the storage temperature is set to -1 to -3°C to prevent the seafood from freezing. [Industrial applicability]

[0010] This invention aims to provide fresh seafood raw materials and their products to their destinations by enabling long-distance maritime transport while maintaining freshness, in accordance with national policies that encourage the expansion of sales channels for fresh seafood both domestically and internationally, thereby reducing the burden of logistics costs and increasing the added value of marine products.

Claims

[Claim 1] Currently, long-distance transport of fresh seafood is handled by air freight to minimize travel time. However, there is no proven method to maintain the freshness of seafood for more than 20 days. In order to expand the sales channels for fresh seafood overseas, a combination of effective materials for freshness preservation is needed. The target trans-Pacific sea transport takes 15 to 20 days, so the total period including transport and shelf life should be 30 to 50 days. To ensure the quality of seafood, the working mechanism of nanobubble water is used to eliminate live bacteria attached to fresh seafood, and the sterilizing effect of activated hypochlorous acid water (RUS water) and the super chilling of nano silk ice are used to maintain a high temperature range for preserving freshness. Furthermore, in the facilities of the fishing port market, in order to disinfect and prevent the decay of fish and shellfish by removing microorganisms attached to them, the fish and shellfish are immersed in a disinfection and sterilization washing box containing nanobubble activated water (ultrafine bubbles) and mixed hypochlorous acid water (disinfectant activated hypochlorous acid water) to wash and remove microorganisms attached to the fish's skin, gills, and especially internal organs. Mixed hypochlorous acid water is then added to nano silk ice, which provides a freshness preservation effect in the shortest possible time, and the fish are wrapped tightly in it, rapidly cooled, and then transferred to a styrofoam box. As a result, bacterial growth is suppressed, and the fish and shellfish in the styrofoam box are managed by setting the storage temperature inside the container for sea transport and storage to -1 to -3°C, which prevents the fish and shellfish from freezing.