AU597833B2 - A method of processing a seafood - Google Patents

Description

1Q3 COMMONWEALTH OF AUSTRALIA SPatents Act 1952-1969 COMPLE .E SPECIFICATION

(ORIGINAL)

Form nt. Class I FOR OFFICE USE: Class Application Number Lodged Complete Application No.

Specification Lodged Published Priority: ,,.Related art: b o 4 o r 0 4000 This do cotains (aendnielit made Under TO BE COMPLETED BRUCE KELLY BY APPLICANT SName of Applicant: DENNIS Address of Applicant:1 6 9 Three Chain Road, Port Pirie, State of South Australia, Commonwealth of Australia Actual Inventor: DENNIS BRUCE KELLY S Address for Service: COLLISON CO., Patent Attorneys, 117 King William Street, Adelaide, South Australia, 5000.

Complete Specification for the invention entitled: A METHOD OF PROCESSING A SEAFOOD The following statement is a full description of this invention, including the best method of performing it known to me: REPRINT OF RECEIPT AO0OOO.

2 1 5/ 0 6/88

PATENI~

DESIVI S SUB-OFFICE JUN 1988~ souTnq AAILIA __1 i 1 i

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4 o 9o oc aeoo o D o 0 o 0 0 0 0 00 oo 0 0 0 0 o «t o4 1 r 2 This invention relates to a method of processing of seafood for local sale or for export.

There is a considerable problem in packaging of seafoods and in particular crabs in that the seafood must be very fresh when served. As seafood can become infected by bacteria very quickly, carefully and hygienically processing of the seafood for sale is most important.

The types or seafood to which this invention may be directed cor, prise all the normal type of seafood such as crustacea, molluscs and fish but the invention will be particularly described in relation to crustacea. It s to be realised however that the invention is not limited thereto but may 15 be directed to other types of seafood.

Crustacea comprise, crabs, prawns, lobsters and the like and this present invention is particularly directed towards crustacea of a size where the crustacea can be handled individually and individual packing is an economic possibility.

One such seafood is the crab which at present has limited marketability because of the problems of handling and processing of crabs. The meat in the crab is present in the arms and the legs as well as in 25 portions within the body of the crab. Generally in the past, cooking of crabs has involved dropping the whole animal into boiling water for a short period of time and then eating the crab immediately. Clearly such a process is only applicable where live animals can be obtained easily and hence markets such as the export market for such crustaceans are 30 thereby limited. If the crab is then transported in a dead condition then problems such as arms and legs dropping off and rapid deterioration of the flesh may occur. It is to these problems therefore that the present invention is directed.

oo0 Q Q o 0 ooo So o 00 04 o 0 0 *0 4 4 0 4CC c 3 In one form therefore the invention is said to reside in a process for cooking and packaging crabs for sale comprising the steps of; cooking the seafood item whole in boiling salt water for a period of 3 to 10 minutes, immersing the seafood item in cold water to cool for a period of to 10 minutes, cleaning the seafood item by removing a shell of the seafood product and sluicing out the viscera and then replacing the shell, packaging the seafood item in an individual vacuum shrunk pack, chilling the packaged seafood item to a temperature of between 0 degrees centigrade to 2 degrees centigrade for a period of from 1 to 2 r 15 hours, snap freezing the packaged seafood item to give a core temperature in the seafood product of minus 40 degrees centigrade, 1 4 A n storing the packaged seafood item at a temperature of less than Sminus 25 degrees centigrade.

4 I o t I 0 I ^NT i 4 he The process of removing unwanted portions of -44-s- seafood product and cleaning of the product may be by means of de-scaling, deshelling and gutting or the like depending upon the type of seafood product. In the case of the crab for instance, the removal of unwanted portions during cleaning may comprise removal of the hard upper shell from the body of the crab and removing with the shell the anal flap and then removing the intestines by means of a jet of cold sea water directed along the length of the body. Further in the case of the crab, after the body cavity has been cleaned the iO shell or cap of the body cavity may be cleaned and then placed on the crab before packaging which will protect the crab and provide a 9 more decorative arrangement.

ooo The packaging of the seafood product into individual packets may 15 be by means of shrink wrapping plastic material around the body of the seafood product or may be by means of placing the individual portions of the seafood product into plastic containers or plastic bags. The placement of the individual portions into plastic bags may be accompanied by vacuum extraction of air from the inside of the plastic bag to cause the bag to be reduced in volume and hence save packaging space and to draw the bag closely around the seafood product.

In the case of a crab, vacuum withdrawal of air around the body 9:25 and legs of the crab is used then the packaged crab will then have 940 considerably more strength for handling purposes as the plastic S"material drawn around the legs and arms of the crab will assist in preventing the legs and armnns falling off the body of the crab and make the crab easier to handle during various processes such as freezing and sale.

The snap freezing or rapid freezing of the seafood product, whether the product is cooked or not, may provide a seafood product which will have a long life provided it is maintained at a low temperature.

In a preferred embodiment of the invention, the snap freezing may be done in a chest or other freezer maintained at a temperature of minus 40 to minus 80 degrees centigrade and then the seafood

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P IN tl product can be stored in a freezer and be held at a temperature of below minus 30 degrees centigrade.

Alternatively the snap freezing may be done in a continuous cyrogenic chamber so that the product is cooled very quickly and then stored as discussed above at a temperature of below minus degrees centigrade. Before storage in a freezer the individual packages of seafood may be packed in cartons for transport.

This then generally describes the invention but a specific example of processing a seafood will now be discussed but as discussed above it is to realized that the invention is not limited to this particular seafood item but may be applicable to any seafood item of the general characteristics discussed above.

0 4 4444 4041 4 4 4.4, 4ra The invention is particularly discussed in relation to the blue swimmer crab (Portunus Pelagicus).

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The processing of the blue swimmer crab may be carried out on a ,20 catching boat or the first steps in the processing may be carried out I t on a catching boat so that the animal is very fresh when processing commences. Alternatively the animal may be kept alive by storing on ice or in sea water until the catching vessel or other transport means has reached a packaging factory so that as much as possible the crab is alive at the time of commencement of processing.

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It is not essential that the crab be alive at the time of processing but it is important that the crab is fresh. It may be killed by placing in chilled water or sea water and uhen processed.

The first step in the process of preparing the crab is to cook the crab whole in salt water. This is done by placing the crabs into boiling salt water and maintaining the salt water boiling after immersion of the crabs for a period of 3 to 10 minutes depending upon the size of the crab. Preferably the cooking time is 6 minutes.

The next step is to remove the crabs from the boiling water and immediately to immerse them in fresh cool salt water so as to cool them down to effectively room temperature as soon as possible.

This step in the process enhances flavour and quality of the crab.

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6 Preferably the cooling step is carried out for a period of up to minutes.

In the third step the crabs are cleaned. One preferred method of cleaning a crab is by removing the upper or top shell of the crab along with the anal flap and then by using a jet of v'water, preferably salt water, and a nylon brush so that the offal and gills of the crab, generally referred to as the the viscera, are removed. At the same time the top shell is quickly cleaned and replaced onto the crab.

This gives the crab its original appearance and hence a more presentable product and does supply some structural rigidity to the crab to assist with handling.

0 60-00 0- 00 0-0 0 0 00 *P 0 00*, 15 *0 o toe Next the crabs are individually placed into specifically designed vacuum packaging bags and then air is drawn from the individual bags to vacuum pack the crabs.

k S0 This process will not only increase shelf life but also enhance the appearance of the crab and allow for an increased volume without a corresponding increase in packaging costs. In an alternative process shrink wrapping of packaging onto the crabs may be used. The packaging material is drawn tightly around the body and claws of the crab and adds considerable strength and durability to the packages product. The individual packaged are then sealed, preferably by heat sealing to give a protective plastic coating around the crab which provides a hermetically sealed and hygienically sound package.

In the next step the crab is placed into a ciiller maintained at a temperature of between 0 degrees to 2 degrees centigrade and this will bring the product down to a uniform temperature before being placed into the snap freezing system. The crabs are maintained in the chiller for a period of 1 hour to 2 hours, preferably.

Next the packaged crabs are removed from the chiller and immediately placed into a snap freezing system where the crab in its individual package is rapidly reduced to a temperature of no higher then minus 40 degrees centigrade within a two hour period.

A snap freezing room to achieve this may be maintained at a temperature of down to minus 60 degrees centigrade. It is preferred that the chilling be carried out with the time discussed I 7 above to maintain the continued high quality of the processed product.

9 o ii 000 9*s ci 0 #009 As discussed above alternative methods of snap freezing such as through a continuous cyrogenic chamber may be used to chill the individual crabs as quickly as possible.

As a final step on the upon the temperature of the crabs reaching a temperature of minus 40 degrees centigrade the packaged crabs may be removed from the snap freezer and stored in a primary or holding freezer which has a steady air temperature of minus degrees centigrade to minus 30 degrees centigrade or lower.

This then generally describers the processing of the blue swimmer 415 crab but it is particularly noted that there are some important features in this present invention.

S The reason for placing the crabs into the 0 degrees centigrade to 2 degrees centigrade chiller before the snap freezing step is critical to the working of the present invention. To maintain the high quality of the seafood according to the present invention heavy reliance is placed on the freezing as this will minimize any negative physical, biochemical or microbiological changes in the product which will provide a deteriorating product. It is critical therefore to ensure that the product during the snap freezing stage passes through the temperature change of maximum crystalization of minus 1 degrees centigrade to minus 5 degrees centigrade, in the case of the crab for instance, as quickly as possible. This lessens the damage to body cells and gives a superior quality crab on defrosting and eating.

Ensuring a speedy transition through the crystaline stage is very important in seafoods, especially in crabs, due to their basic composition and amount of body fluid. Hence if the crab is at a temperature of 0 degrees centigrade throughout the animal before it enters the snap freezer then the whole body can be chilled to below the crystalization temperature very quickly thereby preventing deterioration of the crab meat.

Also the very low core temperature of the present invention during the snap freezing stage ensures a safety barrier against any temperature rise associated with final packaging and storage of the product.

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~f j, 1 8 It will be noted that in the preferred embodiments discussed above the use of fresh sea water has been discussed and generally this gives the product its higher quality in relation to texture and flavour.

The cleaning step ensures in both the chilled and frozen forms a product that is not only much more desirable but has a far longer shelf life. This is due to the absence of any offal or viscera which would contain many more bacteria than other portions of the crabs.

Such bacteria would of course accelerate the spoilage rate of most products especially seafoods.

The packaging of the seafood product into individual packages o o before sale may be in a package comprised of ionorner resin which offers an extremely tough and flexible film packaging product. This will enable the maintenance of the taste and freshness of the frozen seafood product for up to two years after harvesting.

In general the present invention provides a product in which there is increased interest and growing demand and in particular in the super-market frozen product shelves where seafood items have been considerably lacking owing to the difficulty of processing. This present invention provides a carefully produced and packaged frozen product with particular attention being placed on quality and presentation.

,j By providing a process which will give a very much extended shelf t ,g life without any loss in quality a high quality seafood product can be available all year round regardless of closed seasons or other seasonal fluctuations.

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Claims (3)

1. A process for cooking and packaging crabs for sale comprising the steps of; cooking the seafood item whole in boiling salt water for a period of 3 to 10 minutes, immersing the seafood item in cold water to cool for a period of to 10 minutes, cleaning the seafood item by removing a shell of the seafood product and sluicing out the viscera and then replacing the shell, i packaging the seafood item in an individual vacuum shrunk pack, chilling the packaged seafood item to a temperature of between 0 degrees centigrade to 2 degrees centigrade for a period of from 1 to 2 J hours, S(f) snap freezing the packaged seafood item to give a core temperature in the seafood product of minus 40 degrees centigrade, storing the packaged seafood item at a temperature of less than minus 25 degrees centigrade.

2. A crab prepared by the process of claim 1. i

3. A method of processing a crab substantially as hereinbefore described with reference to the examples. Dated this 8th day of March 1990 DENNIS BRUCE KELLY By his Patent Attorneys COLLISON CO. t.