IE84475B1 - Process for preparing minced meat - Google Patents

Description

Process for preparing minced meat Introduction The present invention relates to a process for preparing minced meat and to minced meat products produced by the process.

In meat cutting, deboning and trimming operations, there is production of off—cuts which do not form suitable cuts for sale on their own. There are also other portions of beef carcasses which, while suitable and edible, are not, of themselves, sold as prime cuts.

As prime cuts are deboned in accordance with whatever specifications are required, such off-cuts of relatively good meat can be described as such. There are also other prime cuts which again are useful for many purposes, although not necessarily for sale as individual cuts. Thus, they are usually coarsely chopped, packed and then subsequently minced.

These are usually vacuum packed as mussels and trims during the deboning and cutting operations in the particular processing plant or indeed, are transferred from other processing plants to a central mincing station. There are some particularly important circumstances which must be considered when dealing with minced meat.

Firstly, it is necessary to ensure that there has been no microbiological spoilage due to incorrect refrigeration during the time the meat has been removed from a carcass and when it is sent for mincing. Thus, the raw materials need to be sampled for both TVC and E-coli. Subsequently, the meat must be held at a suitable temperature. Finally, the mince has to be conditioned to be suitable for human consumption.

One of the problems encountered when mincing meat is the fact that the mincing operation increases the temperature of the mince by two or three degrees which can adversely effect the quality and storage of the mince. Further, there is a need to condition mince in the sense that it has to be in a form suitable for consumption with the necessary organoleptic properties.

Further, after the mince has been prepared, it is necessary to pack the mince in a way that it will be suitably protected from contamination, while at the same time, it will continue to condition within the packaging. Generally, some form of vacuum packing is used in the industry.

There are many forms of mincing machines such as disclosed in US Patent Specification No. 4036442 (O|dham) and indeed various other devices have been proposed for forming and treating minced meat. However, heretofore, it is suggested that not enough attention has been paid to preventing spoilage of the meat during such mincing operations.

The present invention is directed towards providing a process for overcoming some of the aforesaid problems.

Statements of Invention According to the invention, there is provided a process for preparing minced meat comprising:- receiving a batch of chopped meat; checking the temperature of the meat and rejecting meat at a temperature greater than 4°C; loading the batch of chopped meat into a mincer in-fill hopper; delivering the meat into the mincer and mincing the meat; transferring the minced meat into a conditioning bin; sealing the conditioning bin; mixing the mince in the conditioning bin in steps of duration 10 to 20 seconds, interposed with rest intervals of between 10 and 20 seconds; during mincing, injecting CO2 at a pressure of between 16 and 20 bar pressure to reduce the temperature of the mince to between +1 °C and -2°C; sending the mince to a mince storage area; delivering the mince from the mince storage area to an extruder; extruding the mince as a continuous cylindrical tube; cutting the tube into discrete lengths to form desired portions as it is extruded; weighing each extruded portion on a belt weigher; feeding the weight to a controller; feeding a signal from the controller to control the operation of the extruder to change the frequency with which the extruded meat is cut in response to the weight sensed; transferring each portion to a container; sending the filled container to a container sealing chamber; closing the container sealing chamber; delivering oxygen and CO2 to the container sealing chamber; sealing the container; and removing the sealed containerfrom the conditioning chamber.

Ideally, in this process, the total mixing time is between 45 and 75 seconds and approximately 60 seconds, with 15 seconds rest intervals and the additional steps are performed of:- delivering the mince to a mince storage area; and maintaining the storage area air temperature at less than 3°C.

Preferably, the CO2 is injected at approximately 18 barpressure, the total cooling time is between 60 seconds and 180 seconds and generally approximately 120 seconds and the final temperature of the mince is between 0°C and -1°C.

In another method according to the invention, the oxygen and CO2 in the container sealing chamber is between 60% and 85% CO2 and generally, approximately 75% CO2.

Generally speaking, the sealing chamber is continuously monitored to maintain an atmosphere containing 80% 1 2% CO2, nitrogen less than 2%, with the balance oxygen.

Further, the vacuum applied is of the order of 680 millibars.

Detailed Descrijflm of thgmvention The invention will be more clearly understood from the following description of an embodiment thereof, given by way of example only, with reference to the accompanying drawing showing a layout of a meat mincing plant according to the invention.

Referring to the drawing, there is provided a mince processing plant, indicated generally by the reference numeral 1, comprising a mincing station 2, a buffer chill/storage station 3 and a packaging/final processing station 4.

The mincing station 2 comprises an infeed hopper 10 feeding through a conveyor 11, a mincer 12 which in turn feeds through further screw conveyors 15, two conditioning bins 13 which in turn feed output hoppers 14. The conditioning bin has a C02 inlet and includes a mixer and also has means for sealing the bin. The mincer 12 is a conventional meat mincer, generally in two stages. The buffer chill station 3 forms a mince storage area.

The packaging station 4 comprises an infeed station 20 having a portioning machine 21 feeding a check weigher 22 in turn feeding a cross conveyor 23. A suitable controller is provided which is connected to the check weigher 22 and the portioning machine 21.

This controller, with feedback from the check weigher, controls the frequency at which the extruded meat is cut. The cross conveyor 23 feeds a packing line 24 which includes a container sealing chamber 25 which then feeds a metal detector 26, a labelling station 27 and a final packing station 28.

The portioning machine 21 is an extruder having a cutting knife which is set to cut a tube of extruded mince into a desired portion, the setting of the knife being controlled by the check weigher 22. In this particular embodiment, the packing line 24 includes a machine for forming a container into which the extruded mince is dropped. The container sealing chamber 25 is a totally enclosed chamber and has means for injecting oxygen and CO2 into the chamber and also for sealing any packages therein, thus vacuum packing and sealing the meat in the particular container. The rest of the line is of conventional construction.

In operation, a batch of previously chopped meat is received which has already been checked for various microbiological contamination and has been stored at a temperature not greater than 3°C. The temperature of the meat is checked and rejected if the temperature is greater than 4°C. Generally. it will be rejected if it is greater than 3°C. The temperature of the meat is usually of the order of 1 to 2°C. This is done by taking samples of the meat and checking the internal temperature. A batch of chopped meat is then loaded into the mincer, minced in conventional fashion and transferred into the conditioning bin 13. In the conditioning bin 13, CO2 is injected at approximately 18 bar pressure into the bin 13 while the mince is mixed, usually in relatively short 15 second mincing cycles, followed by a 15 second time interval which forms a rest interval.

Generally, the incoming product to the conditioning bin 13 can be of the order of 5°C as it will normally have been heated by between 2°C and 3°C during the mincing cycle.

While the mince is being mixed in the conditioning bin, the CO2, as mentioned above, is injected at approximately 18 bar pressure in short bursts during the mixing. The CO2 performs two functions. Firstly, it acts as a general conditioning to kill many bacteria and further adds to conditioning of the meat and then generally chills the meat to somewhere between 0 and -1°C. Then the meat is delivered to the output hoppers 14 and may be sent either directly to the packaging station 4 or may be sent to a mince storage area, that is to say, the buffer chill/storage station 3, which storage area is maintained at an air temperature of less than 3°C. Subsequently, the minced meat is delivered from the buffer chill/storage station 3 to the packaging/final processing station 4 where it is delivered through the portioning machine 21, check weigher 22 and cross conveyor 23 to the vacuum packing station 24. The container sealing chamber 25 is closed and oxygen and CO2 is injected into the container sealing chamber so that the filled containers therein are vacuum packed and sealed with an atmosphere containing 75% CO2 and 25% 02. Then the normal metal detection, packing operations, etc. are carried out.

It is envisaged that the total mixing time of the mince, after it exits the mincing operation, can be any time between 45 and 75 seconds but is generally approximately, as mentioned above, 60 seconds, with 15 second rest intervals. The purpose of this is to ensure a cohesive mixture. As stated above, the CO2 is generally injected at 18 bar pressure but can be at any pressure between 16 and 20 bar pressure. It will reduce the temperature of the mince to between +1°C and -2°C. Therefore generally, the final temperature of the mince is between 0°C and -1°C.

While it has been stated above that oxygen and CO2, in the final vacuum packing, are present in the atmosphere in the ratio 75% CO2 and 25% 02, this can vary from between 60% to 85% CO2 and thus from between 40% and 15% 02. However, a ratio of 3:1 has been generally found satisfactory.

When vacuum packing, the initial gas analysis is carried out to ensure that the levels of CO2 are of the order of 80% plus or minus 2%, the amount of oxygen is not greater than 25% and that nitrogen is less than 2%.

Normally, the vacuum is a 680 millibars, the sealing time is set to between 0.7 and 0.9 milliseconds so that a suitably modified atmosphere is produced inside the pack.

In this specification the terms "comprise, comprises, comprised and comprising" or any variation thereof and the terms "include, includes, included and including’' or any variation thereof are considered to be totally interchangeable and they should all be afforded the widest possible interpretation and vice versa.

The invention is not limited to the embodiment hereinbefore described, but may be varied in both construction and detail within the scope of the appended claims.

Claims (2)

1. A process for preparing minced meat comprising:- receiving a batch of chopped meat; checking the temperature of the meat and rejecting meat at a temperature greater than 4°C; loading the batch of chopped meat into a mincer in—fill hopper; delivering the meat into the mincer and mincing the meat; transferring the minced meat into a conditioning bin; sealing the conditioning bin; mixing the mince in the conditioning bin in steps of duration 10 to 20 seconds, interposed with rest intervals of between 10 and 20 seconds; during mincing, injecting CO2 at a pressure of between 16 and 20 bar pressure to reduce the temperature of the mince to between +1°C and -2°C; sending the mince to a mince storage area; delivering the mince from the mince storage area to an extruder; extruding the mince as a continuous cylindrical tube; cutting the tube into discrete lengths to form desired portions as it is extruded; weighing each extruded portion on a belt weigher, feeding the weight to a controller; feeding a signal from the controller to control the operation of the extruder to change the frequency with which the extruded meat is cut in response to the weight sensed; transferring each portion to a container; sending the filled container to a container sealing chamber; closing the container sealing chamber; delivering oxygen and CO; to the container sealing chamber; sealing the container; and removing the sealed container from the conditioning chamber. A process as claimed in claim 1, in which the total mixing time is between 45 and 75 seconds, with 15 seconds rest intervals and the additional steps are performed of:- delivering the mince to a mince storage area; and maintaining the storage area air temperature at less than 3°C. A process as claimed in claim 2, in which the mixing time is approximately 60 seconds. A process as claimed in any preceding claim in which:- the CO2 is injected at approximately 18 bar pressure; the total cooling time is between 60 seconds and 180 seconds ; and the final temperature of the mince is between 0°C and -1°C. A process as claimed in claim 4, in which the cooling time is approximately 120 seconds. A process as claimed in any preceding claim, in which the oxygen and CO2 in the container sealing chamber is between 60% and 85% CO

2. A process as claimed in claim 6, in which there is approximately 75% CO2. A process as claimed in claim 6, in which the sealing chamber is continuously monitored to maintain an atmosphere containing 80% 3 2% CO2, nitrogen less than 2%, with the balance oxygen. A process as claimed in any of claims 6 to 8 in which a vacuum of the order of 680 millibars is applied. A process as claimed in any preceding claim, in which the meat is rejected when the temperature of the meat exceeds 3°C. A process for producing minced meat substantially as described herein with reference to and as illustrated in the accompanying drawing. Minced meat produced in accordance with the method of any" preceding claim.