RU2704824C1 - Method for preparation of bivalves for transportation and storage (versions) - Google Patents

Abstract

FIELD: fishing and fish farming.

SUBSTANCE: method includes maintenance of oysters in pools of 7–8 hours without water and 7–8 hours in flowing sea water with flow rate providing replacement of 1/3 of water volume per hour, repeating cycle of preparation three times within 48 hours. In another version, method includes content of mussels in pools 2–3 hours without water, and 2–3 hours in flowing sea water at flow rate, providing replacement of 1/3 of water volume per hour, repeating preparation cycle 3-4 times within 24 hours.

EFFECT: method provides longer storage life of live shellfish.

2 cl, 2 tbl, 2 ex

Description

The invention relates to the field of marine aquaculture of bivalves in the Black Sea and is intended for the technological preparation of live mollusks for long-term transportation and storage.

The technologies for growing bivalve mollusks (mussels, oysters) have been developed in detail and are widely used in various regions of the oceans. Their main difference is the location of marine farms - in the tidal zone or in the thickness of sea water, the so-called "deep water". There are no tidal phenomena in the Azov-Black Sea basin and cultivated mollusks are always under the surface of the water. This ensures their constant growth, but at the same time weakens the muscle-closure of the valves. During transportation and storage, such mollusks easily release water from the valves, which leads to their quick drying and death.

Industrial cultivation of mussels and oysters in the Black Sea was actively developed only a few years ago. With the expansion of sales markets and an increase in the range of transportation of live seafood, the problem arose of weak closure of the shell flaps, rapid dehydration (loss of mantle liquid) and the death of mollusks. Therefore, the search for solutions to strengthen the muscle-closure of bivalve mollusks grown in the water column is an urgent problem.

Closest to the claimed method is a method of strengthening the muscle-closure of bivalve mollusks, described in the literature [1]. In the known method, it is recommended that marine farmers conduct special preparation of live mussels before packing and transporting them. The preparation consists in alternately extracting the mussels from the water and immersing them again in water. Pure mussels are kept in the air for an hour, and then immersed in water for 1-2 hours. This procedure is repeated three times, as a result of which the mussels are “trained" not to release water. This method is not clearly and phased described, quite time-consuming, requiring the use of lifting mechanisms, and is applicable for a limited volume of mussels. With this method, sashes can be damaged, they can be pressed and fragments of the edges occur, while the mussels themselves experience stress, which significantly reduces their viability or leads to death. Live mussels are considered a product with a short shelf life of not more than 72 hours. The use of this method in working with another type of bivalve mollusks - oysters, is also ineffective.

The objective of the invention is the creation of conditions for the development and sustainable consolidation of cultivated bivalve mollusks (oysters and mussels) the ability to tightly close the valves for a long time.

The technical result of the use of the invention will be a stable response of live mussels and oysters to a long stay without water, consisting in a tight closure of the leaves, resistance to long transportation and an increase in shelf life: for mussels up to 5-7 days, for oysters - up to 15-17 days Technical result also is improving the quality of marketable bivalve mollusks.

The claimed technical result is achieved by the fact that oysters are kept in pools with running seawater, at a flow rate that provides 1/3 volume of water per hour, for 7-8 hours without sea water, and then 7-8 hours in sea water, repeating the preparation cycle 3 times within 2 days.

The claimed technical result in another embodiment of the invention is achieved by the fact that mussels are kept in pools with running sea water, at a flow rate that provides 1/3 volume of water per hour, for 2-3 hours without sea water, and then 2-3 hours in seawater, repeating the preparation cycle 3-4 times in 24 hours.

After analyzing the work experience of marine mussel and oyster farms in the tidal zones, in particular on the coast of France, the author noted that the mollusks grown in such conditions have a strong muscle-closure, keep the flaps tightly closed for a long time and carry 24 hours transportation and storage, remaining in excellent condition. This is due to the fact that these mollusks are drained daily for 6-8 hours at low tide, then again covered with tidal seawater. Thus, the muscle-closure is able to tightly close the leaflets for a long time.

Our proposed method consists in the short-term (2-3 days) content of bivalve mollusks under conditions that simulate the frequency of tides, excluding the effects of stress and injury to shells. In other words, the development consists in modeling the behavior of bivalves in a certain way and fixing the required reaction to drainage, i.e. mollusks develop a reflex of tight closure of the shell and prolonged work of the muscle-closure to keep the flaps closed for 2 or more weeks.

To work with live mollusks, it is proposed to organize a “mini-sea" - pools with running sea water, to create the same conditions for mollusks to be found in the natural environment. The “Mini-Sea" serves for the temporary storage of marketable mussels and oysters, preserving them alive and in good quality. A canopy of any design should be installed above the pools to prevent the ingress of rainfall and direct sunlight. A perforated “false bottom” should be arranged in the pool, located at a height of 10-15 cm from the bottom of the pool to ensure access of fresh sea water to the lower layers of mollusks, to collect and remove biological deposits. The flow rate should ensure a change of 1/3 of the volume of water in the pool with shellfish in 1 hour. So in a pool with a capacity of 6 m ^{3 the} flow rate of water should be at least 2 m ³ / hour.

The implementation of the method for oysters.

1. Mollusks intended for placement in a “mini-sea" are pre-sorted by size, specimens with whole flaps and marketable shells are selected, cleaned of fouling, dirt, silting, etc.

2. Prepared oysters are placed in clean perforated plastic boxes in no more than 2-3 layers, with a strictly deep leaf down.

3. The first 7-8 hours of oysters are in pools without water (taking into account the time taken to sort and clean the mollusks), then the “mini-sea” is filled with sea water for 7-8 hours. After that, the supply of sea water is stopped, the pools are drained for the next 7-8 hours. The cycles of the processes of drainage and immersion in water are repeated 3 times for at least 2 days.

5. When placing a new batch of oysters, the entire preparation cycle with a change in the processes of drainage and immersion in water begins again. Pools are cleaned as needed.

Example 1

The inventive method with simulated tides was tested on industrial marine farms of Lake Donuzlav (Crimea). For the experiment, 200 copies of commercial oysters were selected. In the pool No. 1, mollusks (100 pieces) were kept in running seawater, in the pool No. 2 (100 pieces) - in the conditions of artificial tides according to the proposed scheme. The flow rate of 2 m ³ / hour. The duration of the experiment was 2 days. The first 7-8 hours of the oyster were in pools without water (taking into account the time taken to sort and clean the mollusks), then the pool was filled with sea water for 7-8 hours. After that, the supply of sea water was stopped, the pools were drained for the next 7-8 hours. The processes of drainage and immersion in water were repeated three times over 2 days. Further, all mollusks were placed in labeled thermal boxes and stored in a refrigerator at a temperature of 5 ° C. After 3, 5, 10 and 15 days the oysters were examined, the number of dead and ajar mollusks was recorded. At the same time, closed oysters (10 pieces each) were randomly selected, opened, and the internal contents of the shell were examined. The results are presented in table 1.

After 3 days, up to 60% of the examined unprepared oysters were dehydrated. In the upright position of the mollusk, there was a loss of fluid from the interstitial fissure. With further storage, the percentage of low-quality oysters increased. On day 10, all mollusks were in poor condition, dehydrated, ajar and subject to disposal. When examining and opening the “prepared” mollusks, the shell was well filled with intramantine liquid, the edges of the mantle reacted to touch, which indicated the viability of the oyster. On the 15th day, everyone remained alive and of high quality. Thus, the state and duration of storage of commodity oysters increases sharply after they are kept under artificial tides according to the recommended scheme.

The implementation of the method for mussels.

1. Mollusks intended for placement in the “mini-sea" are pre-sorted by size, specimens with whole leaves are selected, cleaned of fouling, dirt, etc.

2. Commodity mussels are placed in clean plastic boxes of 20-25 kg, the height of the mussel layer should not exceed 20-25 cm. Mussels are sensitive to drainage and its duration. The periods of drainage and immersion in water are 2-3 hours.

3. The first 2-3 hours of mussels are in pools without water (taking into account the time taken to sort and clean the mollusks), then the “mini-sea” is filled with sea water for 2-3 hours. After that, the supply of sea water is stopped, the pools are drained for the next 2-3 hours.

4. For a full pre-sale preparation of mussels, it is necessary to conduct at least 3-4 repetitions of these procedures within 24 hours.

5. When placing a new batch of mussels, the entire preparation cycle with a change in the processes of drainage and immersion in water begins again. Pools are cleaned as needed.

Example 2

The proposed ebb-tide simulation technology has been tested on production marine farms of Lake Donuzlav (Crimea). For the experiment, 400 copies of marketable mussel were selected. In the pool No. 1, mollusks (200 pieces) were kept in running sea water, in the pool No. 2 (200 pieces) - in the conditions of artificial tides according to the proposed scheme. The flow rate of 2 m ³ / hour. The duration of the experiment was 1 day. The first 2-3 hours of mussels were in pools without water (taking into account the time taken to sort and clean the mollusks), then the “mini-sea” was filled with sea water for 2-3 hours. After that, the supply of sea water was stopped, the pools were drained for the next 2-3 hours and repeated 3 times within 24 hours. Further, all mollusks were placed in labeled thermal boxes and stored in a refrigerator at a temperature of 5 ° C. After 1, 3, 5, and 7 days, the mussels were examined, the number of dead and ajar mollusks was recorded. The results are presented in table 2.

The use of a “mini-sea" for training the muscle-closure of mollusks is possible throughout almost the entire year. Drainage is recommended in the daytime and immersion in water at night.

List of references taken into account:

1. Kholodov V.I., Pirkova A.V., Ladygina L.V. Growing mussels and oysters c. Black Sea / under. ed. V.N. Eremeeva; National Academy of Sciences of Ukraine, Institute of Biology of the South Seas named after A.O. Kovalevsky. - Sevastopol. - 2010 .-- 424 p.

Claims (2)

1. A method of preparing bivalve mollusks for transportation and storage, characterized in that the oysters are kept in pools for 7-8 hours without water and 7-8 hours in running sea water at a flow rate that provides 1/3 volume of water per hour, repeating the cycle prepare three times in 48 hours. 2. A method of preparing bivalve mollusks for transportation and storage, characterized in that the mussels are kept in pools for 2-3 hours without water, and 2-3 hours in running sea water at a flow rate that provides 1/3 volume of water per hour, repeating preparation cycle 3-4 times in 24 hours.