This application claims the benefit of U.S. Provisional Application No. 60/003,896, filed on September 18, 1995.

The present invention relates generally to a commercial method for making cheesecake and, more particularly, to an automated method for making cheesecake utilizing a baking oven having a controlled atmosphere.

Cheesecake is one type of food which has maintained its popularity amongst the baker and consumer alike. Cheesecake is typically made by the average baker by mixing a variety of ingredients including a major portion of milk or milk products into batter, placing the batter into a form, and placing the form into a oven at a desired temperature for a desired duration. As the demand for cheesecake has grown steadily with the growing population, commercial bakers have sought to mass produce the cheesecake making method and have therefore improved upon the simple methods of the common home baker.

Some of the techniques and equipment developed to mass produce cheesecake include: computer controlled industrial size ovens; automated on line mixing of ingredients; specialized baking forms and molds; automated packaging and labeling of baked goods; and automated transfer of ingredients throughout the baking method through the use of conveyors and other movers. Although these and other features have increased the speed by which cheesecake can be made, there is often a negative impact on the taste and quality of the cheesecake as a result of the increased speed.

A more serious problem inherent in the known commercial baking of cheese cake is the fact that the cake

thus baked is highly susceptible to spoilage, due to its milk and other highly perishable content. Thus, the commercial cake must either be frozen or kept under refrigeration. Freezing spoils the taste, while refrigeration must be carefully monitored. In either case, the shelf or storage life of commercial cake is rather short. There is a great deal of spoilage and return to the baker for credit or loss.

It is an object of the present invention to provide a baking system for cheesecake which results in a product of such purity and lasting characteristics that it may be stored, transported and displayed without refrigeration.

It is a further object of the present invention to provide a baked cheesecake having long shelf-life under normal atmospheric conditions.

Still another object of the invention is to overcome the aforedescribed quality and taste problems inherent in conventional commercial baking by providing a method for making cheesecake which controls the entire baking process to provide sterile air continually directed onto the baked cheesecake to thoroughly bake and cool the cheesecake. Yet another advantage of the present invention is that the environment of the cheesecake is continually vented to remove contaminated air. Still another advantage of the present invention is that the cheesecake making method is automated and electronically controlled.

The objects and advantages together with others will be apparent from the following disclosure of the present invention.

The present invention comprises a method for making cheesecake in which cheesecake batter is processed from formation of the batter, filling of baking cups, baking,

cooling and completion of packaging under controlled, time and regulated conditions, all while the atmospheric environment of the apparatus is controlled and the batter and incipient cake is maintained under a selected sterile HEPA atmosphere.

Briefly, the method is carried out employing an assembly line comprising an assembly line comprising a hopper for the temporary storage of batter. A dispensing device dispenses a plurality of empty containers onto a conveying device. The containers are moved via the conveying device to a position adjacent the hopper wherein each of the containers are filled with a predefined amount of batter. After a predefined amount of containers are filled, the filled containers are moved by the conveying device into an oven with a first temperature. The filled containers are baked with convection heat for a first period of time producing cheesecake within the filled containers. The conveying device next moves the filled containers to an enclosed cooling location. A HEPA filter then directs a volume of sterile air onto the filled containers to cool the cheesecake for a second period of time. During the second period of time, the atmosphere within the enclosed cooling location is continually vented at a first rate of exchange. Finally, during the above described steps, a control unit which is electrically linked to various components of an assembly line, controls the speed of the conveying device, the dispensing of the empty cups, the oven first temperature and first period of time, the directing of sterile air, and the venting of atmosphere.

Full details of the present invention are set forth in the following description of the invention.

The foregoing summary, as well as the following detailed description of preferred embodiments of the

invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawing equipment which is used in a preferred embodiment of the cheesecake making method. It should be understood, however, that the invention is not limited to the precise steps, arrangements and instrumentalities shown. In the drawings:

Fig. 1 is a top plan view of an apparatus by which the preferred method of the present invention may be effected; and

Fig. 2 is a perspective view of a baking cup employed.

Referring now to the drawing in detail, wherein like numerals are used to indicate like elements throughout, there is shown in Fig. 1 equipment used in a preferred method of making cheesecake in the form of an assembly line, generally designated 10. As shown in Fig. 1, the assembly line 10 comprises a series of conveyors which move items through the assembly line 10 in a generally left to right flow.

With continued reference to Fig. 1, empty cups 12 which may be plastic or metal foil are dispensed from cup dispenser 14 onto infeed conveyor 16 which travels transversely to the assembly line. The cups 12 are dispensed by cup dispenser 14 automatically at a preprogrammed rate within a defined cycle. The cup dispenser 14 is electrically linked to a control unit 18 located for convenience midway along the assembly line 10. The control unit 18 which is encoded with cycle programming data to regulate the timing and rate at which the cups 12 are dispensed from the cup dispenser 14. The control unit 18 is also electrically linked to other components of the assembly line 10 to control the timing

and rate of those components and maintain a defined operating cycle.

With continued reference to Fig. 1, empty cups 14 travel on infeed conveyor 16 and are filled with a predetermined amount of batter as they pass beneath the batter hopper 20. An electric eye which is electrically linked to the control unit 28 is disposed adjacent the hopper 20, and when occluded by an empty cup 12, signals the control unit 18 to in turn signal the hopper 20 to release a given amount of batter into an empty cup 12. The batter constituting conventional cheesecake batter, including milk, flavorings, sugars, etc. is premixed off¬ line and stored in hopper 20 in close proximity to the infeed conveyor 16. Filled cups 22 travel along the infeed conveyor 16 until such time as a given number of the cups are filled. When this occurs the given number of cups are translated in a file, onto a main conveyor 24 to move through oven 26 simultaneously from left to right. The given number of the filled cups 22, are sensed as by a photo eye which is electrically linked to the control unit 18 which in turn causes the translatory movement and commences a new cycle for filling empty cups with batter. Once in the assembly line, the filled cups 22 are moved by the main conveyor 24 into an oven 26. Oven 26 is also electrically connected to the control unit 18 and its operating panels are regulated according to preprogrammed baking criteria, for example, baking time and temperature.

In a preferred method of the present invention, a CTX™ electric convection oven is used. The CTX™ oven is approximately 3' x 12' long and has a temperature range of 100-700 degrees Fahrenheit. The oven 26 is covered by a conventional hood 28 enclosing the cups 22 while the batter is being baked. The main or oven conveyor 24 is driven at a controlled speed to move he filled cups through the oven at a rate timed to insure sufficient

dwell time in the oven to complete baking. The oven heat is applied convectionally.

To prevent uneven heating of the batter in the cup, and scorching of the bottom of the cup as it lies on the oven conveyor 24, the cup can be shaped so as to have a peripheral rim 30 (Fig. 2) on its bottom wall raising the bottom wall itself so that the wall does not fit flat against the surface of the conveyor. The conveyor may be made with an array of small pedestals or the like on which the cups rest above the surface of the conveyor. The conveyor may also be made in the form of a chain link so as to avoid a completely solid surface.

After a set period of baking (generally about twenty minutes) , the main conveyor 24 has moved the cups 22 now containing the baked batter out of the downstream end of the oven 26 onto a separate cooling table 34. The cooling table 34 is preferably formed by a plurality of freely rotatable rods, spaced parallel to each other, so that each cup can rest and move freely over two or more rods simultaneously. The spacing of the rods permits heat and air to flow freely up, about and over the cups 22. The table 34 is covered by a hood 36 of at least a foot or more in height and may preferably be made of clear plastic so that the completed baked product is visible.

Mounted above the oven hood 28 is a HEPA filter 38 venting the air from within the oven. A duct 40 extends from the filter 38 into the top of the cooling hood 36 to introduce sterile air to the oven. The operation of the HEPA filter controlled by the control unit is caused to continuously feed sterile atmosphere to the interior of the hood 36 on the baked goods on the table 34. While on the cooling table 34, the sterile air flowing from HEPA filter 30 and passing through duct 40 is directed onto the baked cups 22 on the cooling table 34 preferably at a rate

of five-hundred cubic feet per minute. Thus, the product is processed from cup filling to cup sealing under a virtual sterile atmosphere.

The cups 22 cooling on the table 34 are pushed forward as the cup 22 containing the baked cheesecake disgorge from the oven 26. The rest or dwell time on the cooling table is sufficient to allow the baked cheesecake to cool to the touch and to be fully treated by the HEPA, the sterile atmosphere "curing" the perishable contents of the batter. As the cups 22 containing the baked cheesecake leave the table 32 they are pushed onto a motor driven turntable 42. Turntable 42 spins in a clockwise direction at a rate controlled by control unit 28, is provided with guide means spaced above its upper surface to arrange the cups into a single file for transfer onto a single line conveyor 44. Single line conveyor 44 advances the filled cups to an infeed device 46 of a foil applicator 48. Infeed device 46 controls the spacing of the filled cups as they are advanced so that the foil applicator 48 may apply a sized piece of foil 50 cut from an endless roll 52 onto the top of the filled cup 22 after which the foil 50 is sealed onto the filled cup 44 by a heating device 54. The sealed cups are then moved by the single line conveyor 46 past a vacuum waste removal device 56 which suctions spilled batter, foil and the like from the exterior of the sealed cups.

The sealed cups containing the baked cheesecake are then transferred onto an accumulating conveyor 58 to move to a labeling machine 62 which automatically places a label onto the foil of sealed cup 22. The accumulating conveyor 60 moves the sealed cups 58 to a packing station where the sealed cups are manually removed from the conveyor 58 and packaged, a plural number at a time, in a shipping carton and finally placed on platform 64.

Preferably, the apparatus and cups are selected to process 3 oz. of batter 18 in each cup 22. However, it is understood that the quantity of batter, and size of cup, may be varied and other quantities and sizes are suitable as well. It will also be appreciated that the operating cycle can be adjusted via programming of the control unit 28 to bake different sizes and types of cheese cake, for example, the temperature of the oven can be increased and the speed of the main conveyor increased, depending on the contents of the batter to be baked.

In any event, the present process and apparatus insures baking of cheesecake with the highest purity and with an extended virtually indefinite shelf life. The processing of the baked cheesecake under , the sterile, HEPA atmosphere acts to kill bacteria and cure the batter.

It has been found, for example, that when an acidified dough mass containing 24% milk solids and saturated butter fat is heat-treated in individual ther o- formed plastic cups, under predetermined time/temperature conditions according the foregoing process, a complete kill of all bacteria is obtained. Furthermore, proper flavor and texture development occurs. The hot, cooked mass in the individual portion size cups is cooled in a cabinet through which sterile air is circulated. When most of the sensible heat has been dissipated, a film is heat-sealed to the rim of the thermo-formed cup.

This film is permeable to oxygen in order to prevent growth of anaerobic bacteria such as Botulinus. After 14 months of storage at normal office ambient conditions, the head-space under the film still contains an oxygen level in excess of 90% of the level present in the atmosphere showing the absence of growth.

During this latter cooling phase, some moisture condenses on the inside of the film. This water is later reabsorbed into the cooked cake. The product has a minimum shelf life of six months at normal retail ambient conditions.

From the foregoing description, it can be seen that the present invention comprises a method for making cheesecake. It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but is intended to cover modifications within the spirit and scope of the present invention as defined in the appended claims.