Food or edible material: processes – compositions – and products – Products per se – or processes of preparing or treating... – Poultry egg is basic ingredient
Reexamination Certificate
1998-12-30
2001-04-03
Weier, Anthony J. (Department: 1761)
Food or edible material: processes, compositions, and products
Products per se, or processes of preparing or treating...
Poultry egg is basic ingredient
Reexamination Certificate
active
06210740
ABSTRACT:
REFERENCE TO RELATED APPLICATIONS
This application is the U.S. national stage of international patent application serial no. PCT/FR97/01200, filed Jul. 4, 1997 which is relied upon and incorporated in its entirety and is a continuation of French patent application serial no. 96/08356 filed Jul. 4, 1996.
The subject of the present invention is a process for treating fresh egg products comprising, after breaking the fresh eggs and separating the constituents, a heat treatment of the liquid egg white and packaging in air tight containers.
The liquid egg white in question in the present invention is a fresh or raw egg white, in the liquid state, obtained after separating the white and the yolk by mechanically breaking fresh eggs. It is therefore a non-fermented liquid product whose normal pH is of the order of 9 and which contains no additive for preservation.
Processes which make it possible to preserve egg products, and in particular egg white, for the longest possible period have been devised for a long time.
Accordingly, attempts have been made to pasteurize egg products in order to eliminate pathogenic microorganisms, in particular Salmonellae. Heat pasteurization has, however, considerable risks if it is desired to avoid degradation of the product. As regards egg white in particular, it is known that it coagulates from 57° C. Moreover, when egg white is heated above 56.7° C., substantial denaturation and in particular a decrease in its overrun or foaming capacity is observed. This denaturation can in particular be demonstrated by observing the volume of foam produced or the stability of foams produced from such a treated egg white. It has even been possible to observe a decrease in the foaming power during the rise in temperature to 49° C. for 1 hour or 43° C. for 6 hours (CUNNINGHAM in Egg Science and Technology 1977 page 166). COTTERILL and GLAUERT have shown since 1973 (Egg Science and Technology 1977) these thermal destructions which could be observed for various types of egg products and in particular for liquid egg white when the temperature is raised to 50° C. They observed that when the temperature increases, the time necessary to obtain complete destruction of microorganisms decreases and conversely. No measurement was however carried out for temperatures below 50° C.
In practice, it was recommended for the pasteurization of liquid egg white to use temperatures close to 55° to 56° C. However, at this temperature, a substantial impairment of the overrun capacity is observed (Aviculture Francaise 1988 page 790).
To carry out the heat treatments for the pasteurization, plate exchangers are used so as to maintain the pasteurization temperature for a very short period. The use of such plate exchangers allows a very rapid heating with a very short residence time. It has been observed that by flash heating, it was possible to treat liquid egg white up to 59° C. or even rising up to 62° C. without increasing turbidity (Egg Science and Technology 1977 page 166).
Such pasteurization processes at high temperature and for a very short period are known by the name HTST (High Temperature Short Time).
To avoid the risks of heat-degradation of the products, other processes have been devised which combine heat with another component. Accordingly, it was thought to reduce the pH to 7 by addition of lactic acid and aluminium sulphate and then to carry out a pasteurization at 60°-61.7° C. for 3 to 4 minutes.
Another method recommended was to add hydrogen peroxide which plays the role of bactericidal agent. After heating the egg white at 51.7°-53.3° C. for 1 min 30 sec, the hydrogen peroxide is added and left in contact with the egg white for 2 minutes.
Despite the commercial use of these processes, there is a need for a process of treatment which would not use a chemical additive which can cause various disadvantages including the risk of an additive residue remaining in the final product. Furthermore, these processes risk causing the undesirable modification of the natural properties of the egg.
U.S. Pat. No. 2,377,644 (PARSONS) describes a process for treating egg white which makes it possible to obtain a concentrated product which may then be reconstituted so as to resemble a natural liquid egg white. According to the process described, the natural liquid egg white is dried at a temperature below the coagulation temperature so as to reduce the quantity of water contained in the product and to obtain a dry matter concentration of between 25 and 60%. After this evaporation step, the product is maintained at a temperature of 7° to 10° C. for 12 to 14 hours. The concentrated egg white obtained can then be stored in refrigerated or frozen form.
French patent application 2,047,412 (PARKSON) also provides a process for treating egg white by concentrating the solid matter content, the heating being carried out under partial vacuum at a temperature of 30° to 35° C.
Such pasteurization under partial vacuum makes it possible to reduce the pasteurization temperature and the duration of heat treatment for obtaining the same bacteriological results. In practice, it is observed, however, that this type of process is difficult to carry out because it requires precise, constant and exact monitoring both of the temperature parameter and of the pressure parameter in the entire plant.
There has also been described in French patent 2,367,435 (LIOT) a process for treating liquid egg products, especially egg white, which may be in the concentrated or non-concentrated state, consisting in adding appropriate quantities of sugar or salt until an osmotic weight of at least 20 atmospheres is obtained. The dissolved gases are then eliminated until an oxygen content of less than 3 ppm is obtained. The elimination of the dissolved gases is carried out by bubbling an inert food gas, optionally under vacuum. The degassing can also be carried out by raising the temperature for a short period of time up to about 50° to 60° C., the temperature being chosen according to the degree of concentration and the quantity of sugar or salt added.
A subsequent heat treatment is applied to the product after packaging in a closed container or under circulating neutral gas at a temperature of 50° to 65° C. for a period of time of 4 hours to several days, and egg products are thus obtained, and in particular egg white in which the proteins are practically not denatured. The product obtained is practically sterilized in the sense that it contains less than 1000 microbes per gram.
This type of product, despite its advantages, cannot be used for all applications given that it contains, as additive for preservation, sugar or salt in substantial proportions. Furthermore, the products obtained are concentrated products which have to be diluted in order to reconstitute a liquid product similar to a natural product.
It can therefore be seen that there is a great need for a liquid egg product resembling as closely as possible a natural product, whose characteristics are those of a natural product and which can nevertheless be preserved, preferably at room temperature, for a long period.
It has now been discovered, surprisingly, that it was possible, by a specific combination of specific steps during the process for treating non-concentrated liquid egg white, to obtain such a liquid product free of any additive for preservation.
The subject of the invention is therefore a process for treating fresh egg products which comprises a heat treatment of the non-concentrated liquid egg white which makes it possible to obtain a liquid product which is in every respect identical to the liquid egg white obtained immediately after breaking a fresh egg.
The subject of the invention is in particular a process allowing the production of a non-concentrated liquid egg white free of additives for preservation and which can nevertheless be stored for at least three months in its packaging at room temperature.
The process for treating fresh egg products according to the invention which makes it possible to solve these problems comprises, after breaking fresh eg
Anza Laurence
Liot Roger
Liot Roger
Smith , Gambrell & Russell, LLP
Weier Anthony J.
LandOfFree
Method for treating liquid egg whites does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for treating liquid egg whites, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for treating liquid egg whites will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2555927