Description
Method and Apparatus for Treatment of Meat Products
Technical Field This invention relates generally to agitating appa¬ ratus having a fixed receptacle and a rotatable stirrer disposed to rotate about a horizontal axis.
Background Art
Apparatus used in the curing and processing of meats by mechanical means generally may be classified in two categories. One is tumbling, and the other is massaging. Tumblers generally consist of a round drum into which meat and curing agents are placed. The drum generally rotates about, a horizontal axis and the meat pieces are mechanically worked through the process of falling from the top to the bottom of the drum as it rotates. Some ≠ tumblers also turn end over end. An example of such ~ process and apparatus so used are described in U.S. Patent No. 3,076,713. The massaging process is generally accomplished by placing the meat pieces in a stationary tub together with their curing fluids and stirring the mixture by a plural¬ ity of stirring arms mounted to rotate about a vertical axis. The massaging process is generally slower than tumbling and uses frictional energy as opposed to a more rapid kinetic energy of the tumblers. Examples of the process and apparatus for use in massaging are to be found in the Patents No. 3,775,134 to Michels et al and No. 3,934,860 to Michels and Langen. Tumblers generally are operated under a partial vacuum while massagers seldom if ever are so operated.
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The merits and limitations of the two processes are reported in the literature, e.g., in Western Meat Industry, October, 1974 and in The National Provisioner, June 18, 1977. Meat, processors commonly try to achieve one or more of the following objectives during the curing process:
(1) _ Obtain uniform absorption and distribution of the curing agents and other added substances into the meat tissue for uniform color and flavor. (2) Realize dissolution and extraction of some sol¬ uble proteins (i.e., yosin) to the meat surface to make the meat sticky to aid in further processing steps and also improve coherent properties of the finished product.
(3) Maximize processing yields through chemical bind- ing of protein to water, or create a matrix which retains water and other substances.
(4) Make meat more tender through loosening of tissue structure.
In addition, the meat processors seek to meet these objectives in a manner that is cost effective with regard to time and labor, and at the same time minimize damage or deformation of the meat shape and general appearance. This latter qualification is especially important in the case of bone-in, semi-boneless, or whole boneless pork or beef products.
Tumblers can be* used to a greater or lesser extent depending on the particular meat pieces as described, but only for a limited mechanical working cycle or else deformation or breakup tends to occur. Therefore, the general objectives of the process are accomplished to a less than optimum extent. Both bone-in and boneless meats can be processed in tumblers.
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The massaging process generally produces better curing results but in a relatively long time span, and generally only for boneless meats. It has been found that assagers cannot be used effectively for bone-in or semi-boneless pieces because the presence of the bones can damage the equipment as well as deform and breakup the meat struc¬ tures when the bones are present.
Disclosure of the Invention
This invention is designed for use in meat curing and processing of all types of red meats such as pork, beef, lamb and veal; poultry and fish; and products containing natural meat along with meat analogues or other added substances, such as flavorings, tenderizing agents, or phosphates. The method and apparatus of the present in- vention is particularly important in the processing of pork pieces such as hams and picnics, either bone-in, semi-boneless, or boneless; processed as water added or no water added; enclosed for processing and/or sale in casings, cans, molds, stockinette, or bare. It is an object of the present invention to provide a method and apparatus that constitutes an improvement over both the conventional tumbling and massaging processes. In particular, the apparatus of the present invention permits a long, slow mechanical working method similar to a massager to maximize curing objectives. In addition, the appratus does so without deforming or causing breakup of whole boneless, semi-boneless, or bone-in hams, picnics or other similar pieces.
It is an additional object to provide a method and apparatus which combines some of the kinetic energy of the tumbler with some of the frictional energy of the massagers to enable a long, slow mechanical working
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process for all types of boneless or bone-in meat products without breakup or deformation, thereby permitting optimization of the general curing objectives sought by all meat processors. It is a more particular object of the present inven¬ tion to provide a fixed cylindrical drum having its axis horizontal. A rotatable shaft is mounted within and colinear with the axis of the drum and has paddles attached at right angles to the shaft. The rotation of the shaft and the type of paddles imparts frictional energy to meat•in the drum as well as provides some kinetic energy as the meat pieces drop and slide from uppermost to lower positions within the drum as the paddles cause the meat to rise and fall. As described above, tumblers provide for a rotary drum which imparts only kinetic energy due to a falling action of the meat. As also pointed out above, the massagers provide only for frictional energy as a stirrin mechanism moves the meat pieces against each other and against the surfaces of the vat and stirring arms.
A method and apparatus of the present invention is- intermediate between the two processes in that it provide both frictional and kinetic energy. The present apparatu does not cause breakup or deformation of the meat pieces that would occur within a tumbler within the same time span; and the apparatus does not encounter the potential of damage to equipment or meat that might occur when massagers are used.
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Brief Description of Drawings
Fig. 1 is a perspective, partially phantom view of the apparatus of the present invention; and
Fig. 2 is a cross-sectional view taken on line 2-2 of Fig. 1.
Best Mode for Carrying Out the Invention
The apparatus of the present invention is illustrated in Fig. 1 and is designated generally by the numeral 10. The apparatus 10 comprises a cylindrical drum 11 disposed with its axis horizontal, a rotatable drive shaft 12, a driving motor 13, and paddles 14 and 15. The drum 11 is stationary and is mounted on legs 16 so that its cylin¬ drical axis 17 is horizontal. The drum 11 preferably is constructed of stainless steel and may be built to with- stand pressures due to a partial vacuum within, and may be of any suitable length or diameter to accommodate the quantity of meat to be processed. The drive shaft 12 is rotatably mounted within the drum 11 with its axis coin¬ cident with the axis 17 of the drum. The paddles 14 and 15 have generally flat planar surfaces with one edge radially mounted on the shaft 12 on opposite sides there¬ of. The paddles are axially displaced and extend radially outward so that their outer edge is near the inner surface of the drum 11. The drive shaft 12 is adapted to be rotated by the driving motor 13 which may include a suit¬ able gear box not shown designed to give a desired speed of rotation.
Access to the interior of the drum 11 is provided by one or more lids or covers 18 and 19 which cover apertures formed in the side of drum 11. The lids 18 and 19 may be designed to withstand pressures due to a partial vacuum within the drum 11 and may be secured by clamps or hasps
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20 and 21. The interior of the drum 11 can be evacuated by any suitable means (not shown) .
In operation, lids 18 and 19 are opened and the drum 11 partially filled with meat pieces. The pieces may be pre-injected with such agents as flavorings, tenderizing compounds or phosphates, or curing substances. Free liquids or solids may also be introduced as required for absorption into the meat and the lids 18 and 19 closed. The drum 11 might then be partially evacuated if desired. The motor 13 is then energized causing the shaft 12 and paddles 14 and 15 to rotate at a relatively slow speed of approximately 6 rp for example. As the paddles 14 and 15 rotate, the pieces of meat are gradually raised to a higher elevation and are caused to slide either across the surfaces of the paddles 14 and 15 and shaft 12, or across the edges of the paddles.14 and 15. The mechanical motion imparted to the pieces of meat thus provides some of the frictional energy obtained in a massager, and at the same time imparts some of the kinetic energy as encountered in a tumbler. However, the action of machine 10 is such that the mechanical working takes place without the breakup and deformation encountered in a tumbler. At the same time, there are no projections present which might tend to damage the equipment when meat pieces which have bones are used. The invention thereby attains some of the desired properties of both the tumbler and the massager without the disadvantages of either.
It is to be understood that the invention shown and described is a preferred embodiment and that many changes and modifications may be made thereto without departing from the spirit of the invention. By way of further, working, examples the paddle means, while being oriented
generally radially outwardly from the axis of the drive shaft extending into the container means need not include the axis of the shaft; that is, the plane of the paddle, while it preferably includes the axis of the shaft (the paddle in the presently preferred embodiment being edge- mounted on the shaft) it need not include the entire axis of the shaft. In this alternate embodiment, the plane of the paddle is canted or turned with respect to the shaft axis and may be varied, for example, by angle adjustment means. The offset or axially displaced paddles may also be set at an included angle of less than 180° with respect to each other (when viewed end-on, i.e., along the shaft as in Fig. 2) and the paddle angle may be adjustable by appropriate angle adjustment means. Likewise, there may be 2 or more paddles on one "side" of the shaft and one or more on the other "side", offset, or partially offset or staggered with respect to each other. The process may be operated at positive pressure, atmospheric pressure, or at a partial or full vacuum. The gas within the vessel may be the atmosphere or may be some other gas or gas mix¬ ture to promote meat curing, prevent deterioration, or promote preservation of the meat, such as N~o, or an inert atmosphere (N2) .
It is to be understood that the invention is not to be considered limited to the embodiment shown and described except insofar as the claims need be so limited.
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