Technical Field

The present invention relates to a method of preparing rice cake having prolonged storage stability, which makes possible mass production of traditional rice cake and allows the production of rice cake meeting the diverse tastes of modern people. More particularly, the present invention relates to a method of preparing rice cake, comprising milling rice at a milling degree exceeding 10, which is the general milling degree of white rice, in order to prevent the rice cake from decomposing, and dextrinizing the milled rice by heating in order to prevent rice flour from burning by increasing thermal conductivity during cooking (or steaming) after molding.

Background Art

Typically, rice has been commercialized in a variety of food items, mainly snacks, beverages and rice cakes. Recently, rice-based food products have been supplied to consumers in a wide variety of forms, including beverages prepared by mixing rice and several cereals, and noodles and hamburgers prepared using rice. Among the rice food products, rice snacks or rice beverages can easily be commercialized by mass production because they have long shelf lives, and are thus purchased by a broad range of consumers. However, conventional rice cake hardens due to aging of starch as time goes by and thus has a shorter shelf life than do rice snacks or rice beverages. For this reason, mass-produced conventional rice cake is difficult to transport to the market. Thus, consumers must purchase rice cake manually produced at a small scale and consume the rice cake as soon as possible. In addition, most traditional processes of producing rice cake are relatively complex, and many steps are performed manually, thereby making it difficult to mass- produce rice cake. These problems impede the growth of related industries. Rice cake is traditionally produced as follows. Rice is first washed with water and immersed in water for about eight hours to allow it to sufficiently absorb water. After being immersed in water, the rice is pulverized and mixed with several accessory materials. The mixture is passed through a sieve to homogenously blend the materials, and is steamed in a rice steamer. The thus prepared rice cake is cut to a desired size and packaged. In this traditional process of preparing rice cake, the steps of placing rice flour into a rice steamer, steaming, cutting into a desired size and packaging are separately and manually carried out, thereby making it difficult to mass produce rice cake and increasing the production cost of rice cake. Conventional rice cake generally has a shelf life of one day at room temperature, and hardens more rapidly when stored in a refrigerator to prevent its decomposition. In order to provide rice cake meeting the diverse tastes of modern consumers by solving the problems of conventional rice cake, including storage instability, short shelf life and limited taste, the present inventor studied rice cake for several years while serving as the director of the Korean Traditional Culture Research Center, which is a private nonprofit organization, and applied for patents for research results, including Korean Pat. Registration No. 0425415 (2004.03.19) titled "Rice Cake Sandwich Prepared Using Rice Cake and Preparation Method Thereof", Korean Pat. Registration No. 0446412 (2004.08.20) titled "Rice Cake as Snack and Preparation Method Thereof", Korean Pat. Laid-Open Publication No. 2004-0068095 (2004.07.30) titled "Method of Preparing Rice Cake", and Korean Pat. Laid-Open Publication No. 2003-0085422 (2003.11.05) titled "Container for Packaging Major and Accessory Materials for Rice Cake Preparation".

Disclosure of the Invention The present invention is one of the research results of the previous studies and is based on the Korean Pat. Application No. 2004-0021262 (2004.03.29) titled "Rice Cake as Meal and Snack and Preparation Method Thereof". It is therefore an object of the present invention to provide a method of preparing rice cake, which is capable of extending the storage period of the rice cake by removing the bran layer, which is liable to decay, through a milling step at a milling degree exceeding 10, which is the general milling degree of white rice. It is a further object of the present invention to provide a method of preparing rice cake comprising a dextrinization step of heating milled rice, which allows more rapid cooking by increasing thermal conductivity between particles in a subsequent cooking step and improves the taste of rice cake. It is yet another object of the present invention to provide a method of preparing rice cake, which is capable of producing a variety of rice cakes meeting the taste of modern people by adding various accessory materials, improving health by adding a functional liquid, and imparting a soft and sponge-like texture by sieving raw materials twice.

Brief Description of the Drawings The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. 1 is a graph showing the changes in bacterial cell number during storage of milled rice according to the milling degree of rice; and FIG. 2 is a graph showing the changes in bacterial cell number depending on whether rice is immersed in water containing an antiseptic additive.

Best Mode for Carrying Out the Invention

In order to accomplish the above objects, the present invention provides a method of preparing rice cake, comprising the steps of: (a) milling rice at a milling degree exceeding 10; (b) dextrinizing the milled rice; (c) immersing the dextrinized rice in water containing an antiseptic additive; (d) grinding the water-soaked rice; (e) molding the ground rice into a predetermined shape; and (f) cooking the molded rice. At the milling step (a), rice is milled at a milling degree exceeding 10, which is the general milling degree of white rice, to remove the bran portion which is liable to decay, thereby extending the storage period of rice cake. The rice milling may be carried out in such a way that rice is milled at a milling degree exceeding 10 according to the present invention, or may be carried out by further milling general white rice. Most preferably, the milling degree of rice is between 12 and 13 to extend the storage period of rice cake and prevent the waste of rice. The type of rice used may be non-glutinous rice or glutinous rice and is determined according to the kind and desired use of rice cake. When rice cake is made of non- glutinous rice, it has a sponge-like texture. When rice cake is made of glutinous rice, it has a chewy texture. At the dextrinization step (b), the dextrinization indicates the heating of starch at 160-1700C to degrade soluble starch to dextrin via several steps. Examples of dextrinized food products include Korean traditional snacks, such as parched barley powder and popped snacks preparing using grains, and popcorn. The dextrinization of milled rice is carried out by heating, for example, roasting, milled rice at 160-1700C until the milled rice has a smooth and slightly brown surface like a glossy coat. This dextrinization allows more rapid cooking at Step f. In particular, steaming simultaneously with sterilization in a Retort sterilizer makes cooking in a short time possible, thereby preventing excessive cooking leading to burning or taste change of the rice cake. At the immersion step (c), rice is allowed to absorb water. The immersion step is carried out in the presence of an antiseptic additive, preferably an acidic additive that has a disinfecting effect by acidifying the water and inhibiting microbial growth, and more preferably a natural additive selected from the group consisting of lactic acid, citric acid, grapefruit seed extract and combinations thereof. If desired, rice is washed to remove impurities before being soaked in water. The immersion step to allow rice to absorb water is introduced because it takes a lot of time for moisture and heat to penetrate into the rice at Step f due to the rice's properties of having low moisture content and its hard tissues. When rice is soaked in water in advance for a predetermined period of time, the rice tissues absorb water and becomes loose. In this state, rice is easily gelatinized by heating. When rice cake is made of rice soaked in water for about eight hours, it has the best taste when consumed. Also, with respect to color, softness, moistness, elasticity, etc., it is most preferable that rice cake be made of rice soaked in water for about eight hours. The combinations of natural additives are, for example, lactic acid and citric acid, or lactic acid and a grapefruit seed extract. To prepare the water in which the dextrinized rice is immersed, the lactic acid may be used in an amount of 0.5-0.6 wt%, and the citric acid or grapefruit seed extract in an amount of 0.1-0.2 wt%. The immersion is carried out for about 5-8 hours. These kinds of additives and their amounts should not affect the taste of prepared rice cake. At the grinding step (d), the water-soaked rice is placed into a basket to remove water and ground with a grinder. The rice is preferably ground along with 0.8-2 wt% of salt based on the weight of rice. In more detail, when rice cake is made of rice flour with a particle size of less than 10 mesh, it has a hard and tough texture. When rice flour exceeding 20 mesh is used, rice particles should be fine. In the latter case, a grinding process requires much longer time and higher cost. Thus, rice flour is preferably prepared at a particle size of about 10-20 mesh. The molding step (e) is introduced to prepare rice cake having a predetermined shape, and Step f is introduced to cook the rice flour. In particular, for mass production of rice cake, at Step e, rice flour is alternately layered with various accessory materials in a synthetic resin container having a predetermined shape, and is sealed with a packing paper. Step f is preferably carried out in a high-pressure high- temperature sterilizer, a so-called Retort sterilizer. In particular, when the sterilizer uses high- temperature water vapor, the container and the packing paper are preferably heat-resistant. Also, to cushion impact and prevent prepared rice cake from changing, the rice cake is preferably sealed after a gas is charged into the packing paper. The gas may be a mixture of carbon dioxide and nitrogen gas. The carbon dioxide and nitrogen gas are preferably mixed at a volume ratio of 2:7 to 5:5 taking gas cost into account and to validate the storage period of rice cake. Preferably, Step f is carried out at 115-125°C for 15-60 min to steam and disinfect rice flour at the same time. On the other hand, to provide a variety of rice cake, the present method of preparing rice cake further includes, between Step d and Step e, the steps of (dl) preparing accessory materials; (d2) preparing a natural colorant; (d3) preparing a functional liquid; (d4) mixing 40-75 wt% of the rice flour of Step d, 10-20 wt% of powdered materials among the accessory materials of Step dl, 0.5-2 wt% of salt and 10-20 wt% of sugar, based on the total weight of the mixture, and primarily passing the mixture through a 10-20-mesh sieve; and (d5) mixing 0.2-2 wt% of the natural colorant of Step d2 and 0.5-5 wt% of the functional liquid of Step d3 with the remaining amount of the primarily sieved mixture of Step d4, and secondarily passing the resulting mixture through a 10-20-mesh sieve. At the molding step (e), the sieved powdered ingredients are preferably layered alternately with the accessory materials of Step dl having particle sizes higher than 10 mesh. The accessory materials of Step dl may be selected from the group consisting of cowpea flour, chestnuts, jujubes, walnuts, beans, red beans, peanuts, pine nuts, various fruits, sweet potatoes, sesame, black rice, Cinnammomi Cortex, citron, pumpkins, pepper, honey, black soybeans, and combinations thereof. Various types of beans and red beans may be used at once, and the fruits may be raw or dried. Among the accessory materials, the cowpea flour functions to prevent rice flour from hardening in a short time and to maintain the rice flour in a soft state. The natural colorant of Step d2 may be any one of strawberry powder, green tea powder, mugwort powder or a gardenia seed extract. The natural colorant may be used in an amount ranging from 1 to 3 wt% at Step d5 according to the kind of rice cake. Strawberry powder is used to produce pink rice cake. Green tea powder or mugwort powder is used to produce green rice cake. To produce yellow rice cake, a gardenia seed extract is used. The functional liquid of Step d3 may be obtained by extracting 0.5-10 wt% of a functional ingredient, selected from among gardenia, a medical plant Acanthopanax senticosus, a medical plant Lonicera japonica, safflower seeds, an edible mushroom Hericiυm erinaceum, an edible mushroom Agaricus blazei, coffee, Astragali Radix, Grycyrrhizae Radix, grape powder and ginseng tea powder, in the remaining amount of water. If desired, the functional liquid may be milk or an aloe extract. The functional liquid is used to impart known pharmaceutical functions to the rice cake of the present invention, and to improve the flavor of finished rice cake by supplying moisture in the following steps in which raw materials are blended. At the primary sieving step (d4), powdered materials (rice flour, accessory materials and natural colorant) are mixed. At the secondary sieving step (d5), the primary sieved mixture of Step d4 is mixed with the functional liquid in order to impart pharmaceutical functions to rice cake, improve the flavor of rice cake and facilitate molding of the mixture. At the molding step (e), the powdered materials are stacked according to raw materials used and decorated with accessory materials having particle sizes higher than 10 mesh, thus generating rice cake in various forms. When the powdered materials are stacked in multiple layers and accessory materials having large particle sizes are placed between the powdered material layers, cooking is more rapidly achieved at Step f. A better understanding of the method of preparing rice cake according to the present invention may be obtained through the following test examples and preparation examples which are set forth to illustrate, but are not to be construed as the limit of the present invention. In the illustrative preparation examples, the name of each rice cake is arbitrarily assigned.

TEST EXAMPLE 1: Evaluation of changes in bacterial cell number according to the milling degree of rice

In order to investigate the changes in bacterial cell number during storage of milled rice according to the milling degree of rice, general rice was milled at a milling degree of 7, 9, 11 or 13. 300 g of the milled rice were stored for a predetermined period of time, and bacterial cells were counted. The results are given in FIG. 1. As apparent in the graph of FIG. 1, as the milling degree of rice increases, a greater portion of bran was removed, thereby prolonging the storage period of milled rice.

TEST EXAMPLE 2: Evaluation of changes in bacterial cell number according to the use of a natural antiseptic additive The natural acidic additives used in the aforementioned immersion step (c) were evaluated for disinfecting action and inhibitory action on microbial growth, as follows. 200 g of nonglutinous rice were immersed in each of 500 g of water containing 2.5 g of lactic acid and 1.0 g of citric acid and 500 g of water containing 2.5 g of lactic acid and 1.0 g of a grapefruit seed extract. At each given time point, bacterial cells were counted. The results are given in FIG. 2 as a graph. Sample A was a control group using rice immersed in water not containing an additive. Sample B is rice cake prepared using rice immersed in water containing 2.5 g of lactic acid and 1.0 g of citric acid. Sample C is rice cake prepared using rice immersed in water containing 2.5 g of lactic acid and 1.0 g of a grapefruit seed extract. As shown in the graph of FIG. 2, when rice cake was prepared by employing an antiseptic additive, the storage period of the prepared rice cake was extended.

PREPARATION EXAMPLE 1: Preparation of pumpkin rice cake

"Pumpkin rice cake" may be effective in reducing the swelling of underweight people having lowered stomach functionality, recovering patients and pregnant women, and may have therapeutic efficacy treating diabetes mellitus, hypertension and enlargement of the prostate gland. The pumpkin rice cake contains abundant carotin, the precursor of vitamin A, and is thus effective in preventing nyctalopia and xerophthalmia and suppressing carcinogenesis caused by carcinogens. Also, the pumpkin rice cake contains a diuretic that is effective in removing excess water from the body. A gardenia seed extract, used as a functional liquid to be at Step d3, was prepared by boiling 9 wt% of gardenia seeds in 91 wt% of water for 24 hrs at a low temperature. The gardenia seed extract thus obtained served as a natural colorant. The pumpkin rice cake was prepared as follows. 55-60 wt% of nonglutinous rice flour was mixed with 0.5-1 wt% of salt, 8-10 wt% of sugar, 23-26 wt% of cowpea flour and 5-8 wt% of fresh cream and primarily sieved (Step d4). The primarily sieved mixture was mixed with the gardenia seed extract by hand while not agglutinating and was secondarily sieved (Step d5). The secondarily sieved mixture was homogenously mixed with 5-9 wt% of steam-cooked pumpkin based on the total weight of the mixture of Step d4 (Step e), and was placed into a tray and steamed in a Retort sterilizer for 20-30 min during which time disinfection was carried out.

PREPARATION EXAMPLE 2: Preparation of mugwort rice cake "Mugwort rice cake" contains a large quantity of mugwort, and thus may be effective in preventing and treating colds and improving the physical constitution and may have a therapeutic effect on skin diseases. The mugwort rice cake also contains a medical plant Lonicera japonica, which has a variety of effects, including immune system stimulation, antiviral activity, antipyretic and antipoisoning activity, antibacterial activity, anti-inflammatory activity, analgesic effect, urination stimulation and anticancer activity. The mugwort rice cake was prepared as follows. First, a L. japonica extract was prepared by boiling 0.8 wt% of the medical plant L. japonica in 99.2 wt% of water for 1 hr at a low temperature and then for 2 hrs at a high temperature (Step d3). 55-60 wt% of nonglutinous rice flour was mixed with 23-26 wt% of cowpea flour, 2-5 wt% of mugwort, 1-2 wt% of salt, 8-12 wt% of sugar and 5-8 wt% of fresh cream, and the mixture was primarily passed through a sieve (Step d4). The primarily sieved mixture was blended with the L. japonica extract by hand while not agglutinating and was secondarily passed through a sieve (Step d5). The secondarily sieved mixture (Step d4) was homogeneously mixed with 2-5 wt% of black soybeans and 1-4 wt% of red beans, based on the total weight of the mixture, was placed into a tray, and was packaged (Step e). Then, the mixture of rice flour and auxiliary materials was steamed in a Retort sterilizer for 20-30 min during which time disinfection was carried out (Step f).

PREPARATION EXAMPLE 3: Preparation of strawberry rice cake

"Strawberry rice cake" functions to supply plenty of calcium, which is an essential element for bone formation. The strawberry rice cake also contains safflower (Carthamus tinctorius L.) seeds that increase bone mineral density, and thus may be effective in preventing osteoporosis. The strawberry rice cake was prepared as follows. First, a safflower seed extract was prepared by boiling 0.8 wt% of safflower seeds in 99.2 wt% of water for 1 hr at a low temperature and then for 2 hrs at a high temperature (Step d3). 55-60 wt% of nonglutinous rice flour was mixed with 20-25 wt% of cowpea flour, 1-2 wt% of salt, 8-12 wt% of sugar, 1-3 wt% of strawberry powder, 3-8 wt% of strawberries and 6-9 wt% of fresh cream, and the mixture was primarily passed through a sieve (Step d4). The primarily sieved mixture was blended with the safflower seed extract and secondarily passed through a sieve (Step d5). The secondarily sieved mixture was placed into a tray and packaged (Step e), and was steamed in a Retort sterilizer for 20-30 min and disinfected at the same time (Step f). PREPARATION EXAMPLE 4: Preparation of coffee rice cake

"Coffee rice cake" emits a sweet coffee fragrance, which may make the spirit clear by stimulating the central nervous system, and facilitates the elimination of urine by promoting urination. The coffee rice cake also contains additional milk and thus supplies abundant nutrients. The coffee rice cake was prepared as follows. First, milk was prepared and used as a functional liquid (Step d3). 55-60 wt% of nonglutinous rice flour was mixed with 1- 2 wt% of salt, 8-12 wt% of sugar, 1-3 wt% of coffee powder, 18-23 wt% of cowpea flour and 5-6 wt% of fresh cream, based on the total weight of rice cake, and the mixture was primarily passed through a sieve (Step d4) . The primarily sieved mixture was blended with 20 g of milk and secondarily passed through a sieve (Step d5). The secondarily sieved mixture was placed into a tray and packaged (Step e), and was steamed in a Retort sterilizer for 20-30 min and disinfected at the same time (Step f).

PREPARATION EXAMPLE 5: Preparation of ginseng rice cake

"Ginseng rice cake" contains ginseng, thereby supplying consumers with healthy food with various effects provided by the added ginseng. Ginseng has therapeutic efficacy on stress, fatigue, depression, renal failure, hypertension, arteriosclerosis, anemia, diabetes mellitus and developed tumors, has a skin softening effect by preventing the skin from drying, and improves hepatic functions. The ginseng rice cake was prepared as follows. First, ginseng tea powder was suspended in water and used as a functional liquid (Step d3). 55-60 wt% of nonglutinous rice flour was homogeneously mixed with 18-23 wt% of cowpea flour, 1-2 wt% of salt, 10-14 wt% of sugar, 3-5 wt% of ginseng, and 4-7 wt% of fresh cream, based on the total weight of the mixture, and the mixture was primarily passed through a sieve (Step d4). The primarily sieved mixture was blended with a suitable amount of the ginseng tea solution (Step d3) and was secondarily passed through a sieve (Step d5). The secondarily sieved mixture was homogeneously blended, placed into a tray and packaged (Step e), and was steamed in a Retort sterilizer for 20-30 min and disinfected at the same time (Step f).

PREPARATION EXAMPLE 6: Preparation of sweet potato rice cake

"Sweet potato rice cake" contains resin-containing high-fiber sweet potatoes, which promote the excretion of excrement and soften the skin. The sweet potato rice cake was prepared as follows. First, a variety of raw materials was prepared: 45-55 wt% of nonglutinous rice flour, 18-23 wt% of cowpea flour, 10-15 wt% of steamed sweet potato, 8-12 wt% of sugar, 2-3 wt% of fresh cream, 1-2 wt% of a gardenia seed extract, 1-3 wt% of red sweet potato powder, 0.5-1 wt% of salt, and 0.5-1 wt% of strawberry powder (Steps a, dl, d2 and d3). Nonglutinous rice flour was mixed with edible salt, sugar, steamed sweet potato, a gardenia seed extract, cowpea flour and fresh cream, and passed through a sieve (Step d3). Separately, nonglutinous rice flour was mixed with salt, sugar, red sweet potato powder, strawberry powder and cowpea flour, supplemented with a gardenia seed extract, and passed through a sieve (Step d4). After cowpea flour was placed into a tray, the sieved mixture obtained at Step d3 and another sieved mixture obtained at Step d4 were sequentially layered on the cowpea flour (Step e), followed by simultaneous steaming and disinfection in a Retort sterilizer (Step f).

PREPARATION EXAMPLE 7: Preparation of nutritious black rice potato rice cake

"Nutritious black rice potato rice cake" contains black rice that has taste and flavor, and is beneficial to individuals having weak renal functions. The nutritious black rice potato rice cake was prepared as follows. First, a variety of raw materials was prepared: 28-35 wt% of glutinous rice flour, 28-33 wt% of black rice flour, 0.5-2 wt% of salt, 7-10 wt% of sugar, 3-6 wt% of black soybeans, 1-2 wt% of jujubes, 1-3 wt% of peanuts, 1-3 wt% of walnuts, and 15-20 wt% of cowpea flour (Steps a and dl). Glutinous rice flour was mixed with black rice flour, salt and sugar (Step d4), and was supplemented with various functional liquids or water, sieved and mixed with black soybeans, jujubes, peanuts and walnuts (Step d5). After cowpea flour was placed into a tray, the mixture obtained at Step d5 was placed onto the cowpea flour and packaged (Step e), followed by simultaneous steaming and disinfection in a Retort sterilizer (Step f).

PREPARATION EXAMPLE 8: Preparation of intelligence rice cake

"Intelligence rice cake" contains various nuts, and thus is nutritious and effective in activating brain functionality of students. The intelligence rice cake was prepared as follows. First, a variety of raw materials was prepared: 60-65 wt% of glutinous rice flour, 0.5-1 wt% of salt, 8-12 wt% of sugar, 3-6 wt% of black soybeans, 3-6 wt% of red beans, 1-3 wt% of chestnuts, 1-3 wt% of jujubes, 0.5-1.5 wt% of pine nuts, and 8-13 wt% of cowpea flour (Steps a and dl). Glutinous rice flour was mixed with salt and sugar (Step d4), and was supplemented with various functional liquids or water, sieved and mixed with black soybeans, red beans, chestnuts, jujubes and pine nuts (Step d5). After cowpea flour was placed into a tray, the mixture obtained at Step d5 was placed onto the cowpea flour and packaged (Step e), followed by simultaneous steaming and disinfection in a Retort sterilizer (Step f).

PREPARATION EXAMPLE 9: Preparation of Duteop rice cake

"Duteop rice cake" is a Korean traditional rice cake which was produced to celebrate the king's birthday. The Duteop rice cake was prepared as follows. First, a variety of raw materials was prepared: 60-65 wt% of glutinous rice flour, 0.5-1 wt% of salt, 2-5 wt% of sugar, 3-5 wt% of honey, 0.01-0.05 wt% of pepper, 0.1-0.3 wt% of Cinnamomi Cortex, 1-3 wt% of thick soy sauce, 2-4 wt% of jujube paste, 2-4 wt% of citron, 4-7 wt% of chestnuts, 4-7 wt% of jujubes, 0.1-0.5 wt% of pine nuts, 1-2 wt% of walnuts, and 8-12 wt% of cowpea flour (Steps a and dl). Glutinous rice flour was mixed with salt, sugar, honey, jujube paste, Cinnamomi Cortex, pepper and thick soy sauce (Step d4), and was supplemented with various functional liquids or water, sieved and mixed with citron, chestnuts, jujubes, pine nuts and walnuts (Step d5). Another accessory material, cowpea flour (Step dl), was roasted along with edible salt, sugar, pepper, Cinnamomi Cortex and thick soy sauce. After the roasted cowpea flour was placed into a tray, the mixture obtained at Step d5 was placed onto the cowpea flour and packaged (Step e), followed by simultaneous steaming and disinfection in a Retort sterilizer (Step f).

PREPARATION EXAMPLE 10: Preparation of glutinous sesame rice cake

"Glutinous sesame rice cake" has an effect of preventing aging. The glutinous sesame rice cake was prepared as follows. First, a variety of raw materials were prepared: 70-78 wt% of glutinous rice flour, 1-1.5 wt% of salt, 7-10 wt% of sugar, 12-16 wt% of white sesame seeds, and 1-4 wt% of black sesame seeds (Steps a and dl). Glutinous rice flour was mixed with salt and sugar (Step d4), and was supplemented with various functional liquids or water and sieved (Step d5) . The prepared materials were placed into a tray in the order of white sesame seed powder, rice flour, black sesame seed powder, rice flour and white sesame seed powder and were packaged (Step e), and simultaneously steamed and disinfected in a Retort sterilizer (Step f).

In the final products prepared using the aforementioned process, no bacterial growth was found for a storage period of three months. Also, when the rice cake was heated for 30 sec to 3 min in an electric oven or for 10-30 min in a steamer or with boiled water vapor, the rice cake maintained its initial taste and shape.

Industrial Applicability

As described hereinbefore, the present method of preparing rice cake supplies rice cake having an extended storage period of three months at room temperature, thereby increasing the shelf life of rice cake and expanding the marketability of rice cake, as well as enabling consumers to store purchased rice cake until eating. Also, unlike the traditional method of preparing rice cake including placing in a rice steamer, steaming, cutting into a desired size and packaging, the present invention provides a simplified process, including placing rice flour into a synthetic resin container, sealing the container and simultaneously steaming and disinfecting the rice flour, thereby making it possible to develop an automatic production system for rice cake and to mass-produce rice cake.