Background Art Recently in Korea as in the US and Europe, cake has continued to grow in importance as a dessert of preference among various food products classified as desserts such as ice cream, yogurt, cake, fruit, pudding, dairy products, jelly, etc. In the Korean food industry, techniques relating to the mass- production of cakes have developed following the lead of those countries with advanced technology in this area, such as European countries, the United States and Japan. At present, shortcakes, which are kept. in cold and/or frozen storage and mass-produced are popular as a preferred dessert especially in Europe and the United States. Viewing domestic circumstances, although rious bakeriA such as those in hotels, confectionee4 t Ua shops thatV make and sell {ttraditional. handmade calces are making good progress, such cakes have difficulties concerning individual packaging and distribution, as well as with inhibiting growth of microorganisms during distribution. For this reason, conventional cake-type desserts are usually baked and sold by local bakeries and are not mass-produced products. Furthermore, it is regarded that techniques for the mass-production of cakes through a continuous production process are substantially not proposed at present.

Practical examples of studies and developments, and techniques relating to the mass-production of desserts have been disclosed in Korea, but most of them are applied to only certain types of desserts, for example, fruit jelly, yogurt, fruit puddings, ice cream or cookies. However, actual cases regarding

the development of mass-production techniques for cake-type desserts suited to the varied tastes and eating habits of modern consumers are very rare.

Prior techniques have been proposed in the field of mass-producing desserts including, for example, Korean Patent Laid-Open No. KR 2002- 0069947 (J. Y Lee, et. al. Korean Patent Application. No. 2001-0010547), which disclosed a method for producing frozen desserts having various tastes and colors, Korean Patent Laid-Open No. KR 2000-0065637 (W. D. Chung, et. al. Korean Patent Application. No. 1999-0012084), which disclosed a method for producing acidic jelly desserts having improved flavor, and Korean Patent Laid-Open No. KR 2002-0046344 (D. Y Kwon, Korean Patent Application.

No. 2000-0075675), which disclosed a method for producing functional puddings, and other techniques to prepare ice cream, yogurt and the like.

Still needed however, are different kinds of desserts in consideration of the characteristics of desserts as a food product that usually requires greater variety in terms of satisfying lifestyle trends and the varied tastes of consumers.

Accordingly, the present invention aims to develop a novel method for mass-producing specific cake-type desserts that has never been previously proposed.

There are technical documents regarding cake-type desserts including, more particularly, JP Patent Laid-Open No. 1997-266749 (Tsuruta Takahiro, JP Patent Application. No. 1996-077839) and JP Patent Laid-Open No. 1995- 135922 (Ishi Akira, JP Patent Application. No. 1993-314481), which disclosed processes for preparing spongy cake and shortcake. However, sponge cake does not belong to the dessert classification, while shortcake with a topping of fresh cream is an ideal dessert but involves difficulty in ensuring the conditions and period of distribution when the above cakes are mass- produced and sold.

Among the cake-type desserts, cheese-cake has gained popularity with consumers in hotels, cafes and bakeries. Cheesecake has begun to occupy greater proportions of market share, that is, a 10 percent share in 2001 and a 20 percent share in 2002 of the 10 billion Korean won market for cake-type desserts in Korea, thereby taking a leading position among consumer preferences. However, as with other cake products mentioned above, the cheesecake market is also centered on bakeries that locally hand make and sell cakes to the consumer. This is the most common manner of sale, where the consumer directly comes to the bakery and gets the cake there.

Cheesecake is usually brought to the consumer at slightly higher prices, such as 3,500 to 4,000 Korean won per piece.

Therefore, the present invention provides a method for mass-producing cheesecake, which has advantages for the consumer in terms of lower prices, wider availability and convenience as far as how and when the product may be consumed. It also ensures mass-production and distribution together with being sanitarily safety. US Patent No. 4163806 owned by Callen Dennis M., et. al. disclosed a process for preparing unbaked cheesecake by mixing cream cheese with sugar and non-dairy whipped topping materials, refrigerating the mixture then ageing the resultant mixture. This process involves difficulty in assuring the period of distribution within a desirable time period on account of it not being accompanied by a heating and pasteurization process. US Patent No. 4425369 owned by Sakamoto Kenshi, et. al. disclosed an emulsion composition for producing cheesecake. However, the emulsion composition, which is only a raw material form useful for preparing a final cake product, does not relate to the completed product form in view of an industrial application.

Under the above circumstances, the present inventors have intensively studied to find an improved cheesecake product that is suited to consumer

lifestyles and varied tastes, and that is convenient to carry and enjoy regardless of the consumer's location and that also easily assures the period of distribution thereof, as well as a method for mass-producing the same.

Brief Description of the Drawings Fig. 1 shows a graph of product temperature associated with baking time and variation in total number of microorganisms.

Disclosure of the Invention Technical Problem Accordingly, the present inventors attempted to solve the above problems involving previous techniques regarding the preparation of cheesecake such as inconvenience of carrying and shortness of the allowable period of distribution. They also intensively studied to find a specific combination ratio of cheese-based sheet as a raw material of cheesecake with the desired industrial manufacturing properties that would allow excellent taste of the product and, in addition, to develop a firing process ensuring pasteurization in the preparation of the cheesecake. As a result, the present invention has been completed.

Technical Solution The present invention relates to a method for mass-producing cheesecake.

More particularly, an object of the present invention is to provide cheese- based raw material with excellent taste and desired industrial manufacturing properties and a firing process that satisfies various consumer preferences simultaneously with safety in terms of microorganisms, thereby obtaining a novel cheesecake product suitable to lifestyle trends and the tastes of consumers with convenience for carrying and enjoying it, while also easily

ensuring the period of distribution.

The process according to the present invention comprises processes of admixing a body material containing cream cheese and eggs, etc. , and a sweetening material such as sugar or glucose; of charging the admixture in a pan then forming the filled admixture into a shaped material; of baking the shaped material in an oven, sterilizing the baked product, then plasticizing the treated product to keep the shape of the product; of cooling and refrigerating the plasticized product after removing heat to increase efficiency of cold storage; of dividing and packaging the cold product as a final step by cutting the product into 10 pieces of cake then packaging each of the cakes to assure the period of distribution.

Hereinafter, the present invention will be described in more detail. This description will explain, for example, 1. a study for cheese cake composition; 2. a study for the pasteurization/firing processes for assuring the period of distribution; and 3. a study associated with the mass-production process according to the present invention in the following experimental examples 1 to 3. Furthermore, the method for mass-producing cheesecake according to the present invention will be described in the following examples 1 and 2.

Advantageous Effects According to the method for mass-producing cheesecake using the present invention, the cheesecake that has excellent quality suited to lifestyle trends and tastes of consumers, favorable storage ability and safety to ensure the period of distribution produces varieties of cake-type dessert products.

Therefore, the present invention is effectively applicable in the food industry.

Mode for carrying out the invention Hereinafter, the present invention will be described in more detail by

reference to the following preferable experimental examples. However, it should be noted that the following examples are presented only as preferable embodiments for the purpose of illustration and are not intended to limit the invention thereto.

Experimental Example 1: Study for cheesecake composition The following experiment was carried out using Korean consumers, especially, women in theirs twenties who comprise the main consumer group for dessert products.

(1) Study for cheese-based material In order to investigate taste quality of the cheesecake as the important factor for evaluating the cheesecake involving women in theirs twenties, 200 panels among them were subjected to a survey of taste preferences regarding the cheese-based sheet of the cheesecake. From the survey, it was found that the most important taste qualities of the cheesecake, in order of preference, were <1> cheese flavor, <2> softness, and <3> moistness/texture. For satisfying such major qualities, it required selection of representative sensory properties capable of evaluating each of the taste qualities. For this experiment, the Descriptive Analysis technique was utilized. As a result of the above analysis, it was understood that sensory property components could be representative of different taste properties as shown in Table 1 below.

Other than the following taste properties, selected further were degree of yellow coloring, sweetness and tartness of taste.

[Table 1] Correlation between taste properties of cheesecake and factors of description analysis Positive correlation Negative correlation Measuring Measuring Correlation faste factor Correlation factor constant properties (Description constant (Description (Description Analysis) analysis) Analysis) Caramel Cheese flavor 0. 92 Caramel-0. 73 flavor Cheese flavor Ripe milk Baked wheat taste 0. 74-0. 72 flavor flour flavor Lemon flavor 0. 84 Softness/Spreading 0. 84 Powdery-0. 84 moistness/ Oiliness 0. 86 Particulate-0. 80 texture

In order to practically apply the above taste properties in products, one of the most important parameters is the composition of the cheesecake blend. In the present study, selected were raw materials principally used in conventional cheesecakes available in bakeries in which products are handmade to accomplish the taste quality of the above cheesecake blend, while investigating the effect of each of the raw materials to the taste quality of the final cheesecake product.

Firstly, the raw materials essentially used in the cheesecake include cream cheese, wheat flour, sugar, salt, eggs, fresh cream, lemon juice and baking powder and the like, all of which are commonly used in the production of cheesecake. Although the final product has substantially different taste based on composition of (or contents) of the raw materials defined by manufacturers and/or processes for preparing the product, the composition of the cheesecake blend tends currently to be defined dependent on experiences and/or know-how of the manufacturers in the present dessert market.

In the present invention, the correlation between major raw materials of the cheesecake and the taste properties thereof was under investigation in

order to clearly understand the effects of the raw materials on the taste properties. As a result of the investigation, found out were factors of the raw materials mostly effective to the taste properties and the correlation thereof as shown in Table 2 below.

As shown in Table 2, the essential ingredient of the cheesecake, that is, cream cheese, exhibited'positive'correlation associated with overall coloring (degree of yellowness), tartness of taste, cheese flavor, ripe milk flavor, degree of moistness and spreading property while'negative'correlation concerning sweetness of taste and baked wheat flour flavor.

. [Table 2] Correlation between taste properties of cheesecake and composition of raw materials Fresh Basic taste Cream cheese Sugar Egg Lemon cream Yellowness degree + + Sweetness of taste--+ Acidic taste + - Fresh Cheese taste Cream cheese Sugar Egg Lemon cream Cheese flavor + + + Ripe milk flavor + Baked wheat flour flavor Lemon flavor Fresh Texture Cream cheese Sugar Egg Lemon cream Degree of moistness + + + Spreading + Particulate + Oiliness Powdery Note) (+): positive correlation, (-): negative correlation, none marked : substantial non-correlation

Based on the results from the above Table 2 ; obtained were not only excellent taste and texture quality by finely controlling the contents of the raw materials. The present study was repeatedly conducted for the composition of the cheesecake blend desirable to maintain original shape of the final product during distribution. As a result, obtained were compositions of the raw materials in numerical ranges desirably defined for mass-production and/or distribution of the final cheesecake product as shown in Table 3.

With the applied combination ratios shown in Table 3, it is possible to prepare cheesecake having excellent taste quality only by blending all of the raw materials in a mixer without alternative complicated mixing processes (such as the whipping process of cream).

[Table 3] Contents of raw materials applied in cheesecake and applicable ranges thereof Raw materials Applicable range (%) Cream cheese 40-55 Sugar 10-17 Fresh cream 3-8 Cake flour 0-6 Expanding agent 0-1 Lemon juice 0.5-1 Others Balance (2) Study for the composition of cheesecake The study of the above (1) concerns an invention only for the cheese- based sheet of the cheesecake product.

However, in order to embody uniqueness and variety of the cheesecake,

proposed and developed further was a method for producing cake with 4 layers comprising cookie, source, cheese-based sheet and sugar syrup, other than the cheesecake made of only cheese-based sheet.

Particularly, the cheesecake with 4 layers as an excellent dessert is formed by preparing a bottom base filled with cookie, charging the source and the cheese-based sheet in order, baking the prepared laminate in an oven and coating the baked cake with sugar syrup. Cookie is preferably used to present a variety of cheesecake by adding a crunchy property to the softness of the cheese-based sheet to provide the consumer with an unusual mouth feel.

More particularly, such cookies used include general plain cookies, or cookies containing at least one of chocolate, almond nut and oatmeal, etc. , to present various types of mouth feel. Further, the source includes, but is not especially limited to, fruit processed source comprising principally fruits such as blueberry, strawberry, apple, pear, mango, lime, lemon, orange, peach, mandarin, grapefruit, tropical fruits and citrus, and syrups such as maple syrup, coffee syrup and chocolate syrup that comprise maple, coffee and liquid chocolate, respectively, together with sugar. Alternatively, a plain cheesecake product without syrup is prepared for the consumer who prefers the inherent and rich taste of cheese.

Experimental Example 2: Study for firing process to assure the period of distribution Cheesecake is generally classified into souffle type and rare type cakes through the firing process. The souffle type cheesecake is formed by conducting the firing process in an oven. The firing process refers to baking of a mixed batter to give baked flavor, color and taste, and processing of liquid dough into a solid form product. The firing process can also produce texture of the product and, most of all, remove bacteria and/or

microorganisms through the pasteurization process.

Accordingly, the present invention used the firing process for preparation of cheesecake in order to control baked-like tastes and colors based on varied consumer preferences in development of the mass-produced cheesecake and, at the same time, to ensure the period of distribution as well as hygienic safety and generate texture preferable to mass-production and the distribution environment, (in consideration of the domestic distribution environment), and intensively studied the firing process.

(1) Effect of the firing process on taste quality In order to investigate the effect of the firing process on the taste quality and evaluation of the taste by the consumer, three products were formed by preparing three mixtures having the combination ratio of the composition proposed above then baking the mixtures under the same conditions of temperature and moisture but for different plasticizing times of 50,60 and 70 minutes, respectively. The obtained cheesecake products were presented to panels of consumers who test and describe the unpleasant properties and qualities of the products. As a result, the panels detected unpleasant tastes such as a scorched and bitter taste for the product with 70 minutes'firing, and a greasy taste for the product with 50 minutes'firing. However, for the product with 60 minutes'firing, no particularly unusual taste was detected by the panels.

Additionally, in order to identify the effect of the firing process on consumer preferences, 30 panels were individually given products to evaluate in terms of appearance quality, overall taste quality, and softness and moisture level of the cheesecake. After the evaluation, individual preferences of the panels were marked in accordance with a rating scale from 1 for the lowest grade to 5 for the highest grade.

From the results, the preferences of the overall taste quality tor the products were, in order of highest ratings, 3.89 for 60 minutes, 3.61 for 50 minutes and 2. 98 for 70 minutes of firing time. Such scores had 95% reliability with deviation. The evaluation of the appearance quality was carried out on surface color of the product depending on the firing time. As a result, the preferences of the appearance quality were, in order of highest ratings, 3.60 for 60 minutes, 3.52 for 50 minutes and 1. 96 for 70 minutes of firing time. Such scores had 95% reliability with deviation. From the result of the evaluation for softness of the product, the preferences of the softness were, in order of highest ratings, 4.00 for 50 minutes, 3.92 for 60 minutes and 3.25 for 70 minutes of firing time. Such scores had 95% reliability with deviation. In addition, as a result of the evaluation for moisture level of the product, the preferences thereof were, in order of highest ratings, 3.66 for 50 minutes, 3.52 for 60 minutes and 3.28 for 70 minutes of firing time. Such scores had 95% reliability with deviation.

Therefore, considering overall the above evaluations, the panels, that is, the consumers preferred the product fired for 60 minutes, next the products with 50 minutes and 70 minutes'firing process in that order.

(2) Effect of the firing process on safety against bacteria and/or microorganisms Since the firing process is important to the baked product as a sterilization process, a study regarding the effects of the firing process on safety against bacteria and/or microorganisms was also conducted simultaneously with the investigation of the preferences.

At first, in order to examine raw materials frequently contaminated during production of the cheesecake and the species of microorganisms concerned and select the microorganisms as a reference used in the research and study,

all of the raw materials before the firing process were cultured at elevated temperature to separate and identify the microorganisms existing in the cultured solution. As a result of the separation and identification, detected were bacteria that survived, including, for example, Bacillus subtilis, Staphylococcus epidermis, Straphylococcus scuiri were detected from grains such as wheat flour as heat-resistant microorganisms; 41tenaria alternate, Penicillium aurantiogriseum, Rhizopus oryzae and Aspergillus oryzae belonging to fungi present in soil and grains such as wheat flour; Penicillium expansum and Cryptococcus infirmo-miniatus which are a source of cheese; and the microorganism Penicillium expansum, derived from fruit sources.

From the results of the above study, it was found that the main raw materials contaminated in the cheesecake mixture were wheat flour, cheese and fruit sources while the main contaminant of the heat-resistant microorganisms was wheat flour. Also, it was understood that Bacillus was preferably the reference microorganism useful for determining the pasteurization effect of the firing process.

Next, a temperature profile varied during the firing process was investigated by setting the temperature of an oven to 165°C on the top side and 150°C on the bottom side on an experimental basis, then measuring variation of the temperature at the center portion of the product at different times using both the k-type heat-resistant thermometer and data logger. The results are shown in Fig. 1.

With the firing times of 50,60, 70 and 80 minutes, determined was the effect for extinction of microorganisms depending on the firing time at the above temperature by comparing the total number of bacteria in the cheesecake batter before the firing process with that in the cheese cake product before the firing process. The total number of bacteria in the batter was 1,250 cfu/g before the firing process. When the batter was in the firing

process for 50,60, 70 and 80 minutes, it exhibited a bacteria number ot 3U or less, 0 to 10,0 to 10, and 0 to 10 cfulg, respectively.

More particularly, after contamination of the mixture with Bacillus as fungi strains, observed was the extinction degree of Bacillus obtained through the firing process. From the observed results, it was found that the number of Bacillus after the 50-minute firing process varied little, while in case of 60- and 70-minute firing process, the number was reduced to about 10 cfu/g by a 1 log cycle. Such a reduced Bacillus count did not increase any more during storage of the product. Consequently, in consideration of consumer preferences (such as overall taste quality, appearance, softness and moisture resulted from the evaluation) and conditions for microbial extinction, it is expected that the firing time for the cheesecake product is preferably about 60 minutes.

More particularly, the microbial level was 10 cfu/g or less in terms of total the number of the microbial strains when the cheesecake product with a 60-minute firing process was held in refrigeration storage at 10°C for two weeks. However, as the product was stored in the refrigerator at 10°C for three weeks, the microbial level was 10,000 cfu/g or less, thereby exhibiting rapid increase of the strains around two weeks at the same temperature of 10°C (see Table 4).

[Table 4] Variation of microbial level depending on preservation period after firing process Preservation period (day) Repeated number Mesophile Mold 1 10 0 20 0 1 00 1 0 0 7 2 0 0 14 1 0 0 2 0 0 11. 8x10 1. 2x10 2 1.5 x 103 1.2 x 103

Experimental Example 3: Study on production process suitable to industrial application The method for producing the cheese according to the present invention suitable to the industrial application was developed, which comprised the mixing, charging, firing, cooling and refrigerating, cutting and packaging processes. Each of the processes will be particularly described in order of treatment as follows.

(1) Mixing Process Raw materials including cream cheese, wheat flour, sugar or glucose- based sweetener, eggs, flavoring agents and so forth are introduced in a mixer.

After closing the mixer, it is under agitation at a high velocity. The mixing process is divided into a first mixing process to emulsify at least two among the raw materials naturally immiscible together, and a second mixing process to further at least one among the raw materials easy to foam during the mixing process other than the first mixing step to thereby control specific gravity and viscosity of the mixture.

The first mixing process comprises agitation treatment that is divided into low-velocity agitation and high-velocity agitation processes. The low- velocity agitation process reduces the viscosity by softening the raw materials and emulsifies the raw materials with minimum addition of air. The high- velocity agitation process is for completing the mixing process while maintaining balance of temperature of the mixture.

Effects of the low-agitation time on the properties of the mixture and the

finished product are shown in the following Table 5. As shown in Table 5, when the agitation time increases at a constant low-agitation velocity, the viscosity is reduced. It is expected that such reduction of viscosity is caused by a variation of the physical properties of the high-viscosity liquid as a result of the emulsification.

[Table 5] Property variation of the mixture according to a mixing time at a constant agitation velocity of 180 rpm Mixing time Specific Viscosity Temperature of Taste quality of (minute) gravity (dPas) mixture (°C) final product 0--15 5 0.97 120 18 + 10 0.95 85 20 ++ 15 0.93 70 21 +++ 20 0. 91 55 21 ++ Note) in sensory inspection, +++ excellent, ++ good, + ordinary (2) Charging Process In this process, an idea for formation of the cheesecake product with 4 layers comprising laminates of cookie, source, cheese-based sheet and sugar syrup is derived from the present invention to allow the consumer to enjoy uniqueness and variety of the product only by the present invention. Such cheesecake of 4 layers can be prepared and shaped with mechanically applicable properties using the charging process, which comprises steps of charging the raw materials in order as follows: 1. Charging of cookie On a round pan a diameter of 180mm, a round cookie with a diameter of 176mm is charged. The cookie can be prepared by admixing artificial butter,

so-called margarine, refined sugar, kitchen salt and a flavoring agent together to form cream ; adding cake flour through a sieve-type mesh then kneading the mixture into a batter; rolling and spreading the batter using a bar to form a plain sheet of 4mm thickness; stamping out the sheet in a circular mold frame with a diameter of 176mm to obtain a round cookie base; and finally baking the cookie base in the oven.

2. Charging of fruit source The fruit source is effective at removing the greasy taste caused by the cheese and to endow variety to the cheesecake. The fruit source is preliminarily treated using starch, a gelling agent to control the viscosity in a range of about 4-7cm measured by means of a BOST-BIG viscometer sufficient to mechanically charge the fruit source. Fruit flesh is crushed into pieces with a size that easily passes through nozzles of a charging device.

3. Charging of cheese-based sheet The cheese-based sheet has a specific gravity ranging from 0.93 to 0.95 by controlling the agitation time of a high-velocity agitator. The cheese- based sheet also has the viscosity ranging from 70 to 100 dPas possible to be mechanically charged. In the round pan, charged are the cookie, the fruit source and the cheese-based sheet prepared as described above in order.

Controlling the specific gravity and the viscosity in the defined range thereof, it is possible to maintain the shape of the cheesecake of 4 layers without intermixing of the fruit source and the cheese-based sheet and/or separation of the layers from one another.

In mass-production of the cheesecake product, a lot of samples can have the same height by controlling the specific gravity of the cheese-based sheet at a constant level. Such specific gravity can be managed by controlling the

mixing velocity and the mixing time and by managing the temperature of the high-velocity agitator.

4. Charging of sugar syrup The sugar syrup provides visually moist and glistening effect on the surface of the cheesecake product for greater eye appeal and also forms a coating layer over the surface of the product to inhibit contamination by microorganisms and growth thereof. The sugar syrup may include commercially available processed sugar products usually obtained adding a gelling agent such as pectin gel to a sugar solution then curing the solution.

The combination ratio of water and the sugar solution is freely controlled within a range of 1: 0.5 to 2 to obtain desirable viscosity. Additionally, in order to remove yeast usually growing in a sugar solution, the above mixture is further subjected to post-treatment consisting of heating at 85°C for 15 minutes or more, sterilizing and maintaining the temperature to reduce the viscosity, then injecting the hot diluted solution over surface of the cheesecake to be coated by spray nozzles.

(3) Firing process The firing process of the present invention using a typical industrial oven or so-called'tunnel oven'is accomplished by the introduction of vapor into the tunnel oven.

A conventional tunnel oven is applicable in continuous mass-production of products but has a defect in that moisture in the product vaporizes faster and/or easier than with a conventional sealed and non-continuous oven, since the oven has an inlet in which the round pan is entered and an outlet through which the product is discharged after the firing process, both of them being not closed.

However, in order to obtain a moist and soft mouth teel as natural properties required for the dessert, the product requires greatly inhibited vaporization of moisture as much as possible. In this regard, such a tunnel oven with a high degree of vaporization is restricted in the technical aspect to embody the product only by applying the oven as it is. Accordingly, the present invention involves a design method that introduces vapor at the inlet of the oven opened during the firing process, whereby the method was adapted to minimize vaporization of moisture contained in the cheese cake product.

In order to analyze the effect of the vapor on the cheesecake in the firing process, compared were moisture amounts vaporized during the firing process in two cases, one of which does not introduce vapor during the firing process and the other of which introduces vapor at the input of the oven. For the first case involving the firing process without supplying vapor, the moisture amount vaporized from the product during the firing process was about 8 to 9% by weight based on the total weight of the initial product before the firing process. On the other hand, in the second case with the introduction of vapor through the inlet of the oven, the moisture amount was 4 to 5% by weight based on the total weight of the initial product.

As mentioned above, by introducing vapor at the inlet of the oven, it leads to a decreased amount of moisture vaporization to result in achieving a higher yield of the product. Also, the dessert product suited to the various taste preferences of modern consumers can be obtained because the product provides a soft, moist mouth feel.

Introduction of the tunnel vapor oven gives a few advantages as follows: First, when the amount of industrial water supplied is greatly reduced in the production of the dessert product in the form of heating-in-water bath, it is possible to prevent contamination of the product by the industrial water,

thereby achieving hygienic production. Second, by adjusting the pressure and amount of vapor flow in the tunnel oven, water content and mouth feel created by the water content can be easily controlled. Third, the vapor is introduced into the oven and allows the firing process using moist-heat, in contrast to traditional ovens that use dry-heat.

The moist-heat gradually heats the product and provides a moist feel to the product in contrast to the dry-heat, whereby the firing process using the moist-heat is preferable to produce delicate desserts with higher moisture content such as cheesecake, souffle, pudding and so forth.

On the contrary, dry-heat rapidly raises the temperature faster than moist- heat so that it controls the surface colors of the product and expands the product, providing the desired final product form.

Surface colors of desserts such as cake are substantially determined by the browning reaction caused from heat-decomposed and/or heat-oxidized materials formed through the heating of sugars. Such browning reaction usually generates when sugars or aqueous solutions containing sugars are heated at high temperature. Thus, if required for baked colors of the cake, a mixture in a liquid state should pass the firing, curing and drying steps and, in the final step, have its surface colored in the oven at 165°C or more on the top side, sufficient to generate, for example, the browning reaction. The temperature on the topside of the oven for color formation of cheesecakes preferably ranges from 165 to 180°C.

(4) Cooling/refrigerating process The cooling/refrigerating process is for removing heat from the cheesecake after the firing process and rapidly decreasing the temperature to the refrigeration temperature sufficient to keep the cheesecake under refrigeration, and for preventing the growth of microorganisms.

This process consists of moving the cheesecake atter the tiring process into a cooling room and keeping it there for about 30 minutes and removing the pan used in the firing process to accelerate cooling. After that, the cheesecake is placed into a refrigerator at 5°C or less under the main cooling step for about 1 hour, resulting in production of the final product in the refrigerated state with a temperature of 10°C at the center portion with ideal physical properties and hardness.

(5) Cutting process The cutting process consists of dividing the final round-shaped product having a diameter of 18cm into pieces under sterilized conditions to obtain individual pieces. As a result, each of the cheesecake pieces is individually packaged in a disposable receptacle and provided to the consumer, so that the consumer can conveniently enjoy the cake regardless of time and/or occasion.

When cutting the round cheesecake, skill is required to divide the cake equally in straight lines from the center point thereof while rotating a circular turntable at a constant angle. For example, in order to divide the cake into 8 pieces, the turntable should rotate at a 45-degree angle. Likewise, the round cake is divided into 10 pieces if the turntable rotates at an angle of 36 degrees while rotating the turntable at a 30-degree angle to provide 12 pieces of short cake.

(6) Packaging process The completed cheesecake product after the cooling and cutting processes is packaged in a triangular plastic receptacle under sterilized conditions then sealed. Herein, when aid materials for enhancing microbial safety such as an oxygen scavenger are entered together with the cheesecake into the package, the product can be safe for at least two weeks even during distribution in a

refrigerated state.

As described above, the method of the present invention comprising the processes of (1) to (6) leads to mass-production of cheesecakes, for example, at least 3,000 pieces per hour with relatively reduced manual labor through automation. As a result, triangular pieces of cheesecake that maintain microbial safety for two weeks under refrigerated conditions and are economically preferable, can be produced by the present invention method.

EXAMPLE 1 This example illustrates a method for producing a genuine cheesecake having rich cheese flavor and taste using cookie after kneading the cheese- based sheet in the combination ratios shown in the above Table 3.

First of all, a cookie was charged in a pan with paper put thereon. The cookie includes, but is not limited to, general plain cookie and other cookies containing some materials well-matched with cheese such as chocolate, almond, nuts and so on. Other materials, such as pie, tart, etc. can be used instead of the cookie.

In preparation of the cheese-based sheet, cream cheese was prepared by cutting it into pieces of even size desirable for admixing. Lemon juice was diluted with water. A flour blend was prepared by admixing cake flour, sugar, salt and an expanding agent together in a powdery form without agglomerate after weighing each of them. In the mixing process, the prepared cream cheese, yolks, whole egg, sugar as well as the prepared flour blend and the diluted lemon juice were all poured in a mixer equipped with an agitator under low-velocity agitation. After completion of the agitation, further agitation at high velocity was carried out for several seconds. Then, the rest of the raw materials and fresh cream were added into the mixer and then placed under high-velocity agitation for about 2 minutes. After the

agitation, the mixture was charged into the pan containing the cookie as well as the blueberry fruit source. Thereafter, the pan was placed in an oven at 150°C on the topside and 160°C on the bottom side and under the firing process for about 60 minutes. After the firing process, the obtained product was left to be cooled for 30 minutes then force cooled after spraying a topping gel over the surface of the product. The cold product was divided into pieces, which were in turn filled into small plastic receptacles together with introduction of an oxygen scavenger, packaged and sealed. The obtained cheesecake pieces exhibited a rich cheese flavor with stable safety after storage for two weeks.

[Table 6] Combination ratios of raw materials used in EXAMPLE 1 and EXAMPLE 2 Raw material Content in example 1 (%) Content in example 2 (%) Cream cheese 40 50 Sugar 12 17 Egg 16 14 Fresh cream 5 8 Cake flour 2 1 Expanding agent 0. 5 0 Blueberry source 0 6 EXAMPLE 2 This example illustrates a method for producing blueberry cheesecake containing a blueberry fruit source between a cookie layer and a cheese-based sheet layer.

First of all, a cookie was charged in a pan with a paper placed thereon.

Over the cookie, the desired amount of blueberry fruit source was poured around the center portion of the pan with a diameter of 5cm. The blueberry fruit source has a viscosity controlled to 4 to 7cm measured by a BOST-BIG

viscometer using a gelling agent.

According to the same procedure as described in Example 1, the cheese- based sheet prepared was placed over the blueberry fruit source. Thereafter, the laminated material left gently at room temperature for about 10 minutes to allow the blueberry fruit source to penetrate evenly between the cookie layer and the cheese-based sheet layer, then subjected to the firing process and others under the same conditions as described in Example 1 to produce the final product.

The blueberry fruit source can be of course replaced with other fruit sources including, but not particularly limited to, apple, strawberry, lemon, orange, mandarin, mango, cherry, black cherry, apricot, peach, grapefruit, lime and so forth, and/or syrups such as chocolate syrup, coffee syrup, maple syrup and the like.