Method for preparing yogurt using rice nuruk

Abstract

The present disclosure relates to a method for manufacturing yogurt using rice koji. A method for manufacturing yogurt using rice koji according to one embodiment comprises: (a) a step of preparing rice koji; (b) a step of gelatinizing and saccharifying soaked rice raw materials to produce a substrate for yogurt fermentation; (c) a step of inoculating the substrate with lactic acid bacteria to ferment; and (d) a step of cooling and aging the fermented mixture to complete vegan yogurt. It may include.

Description

Technology Field

[0001] The present disclosure relates to a method for manufacturing yogurt. More specifically, it relates to a method for manufacturing a fermented food that provides a flavor and nutrition similar to yogurt without using dairy products, by utilizing 'rice koji'. Background Technology

[0002] Yogurt is a representative probiotic food made by fermenting milk, offering various nutritional benefits including gut health. However, recently, there has been an increasing demand for fermented foods that exclude animal-derived ingredients due to factors such as veganism and lactose intolerance. Consequently, while some plant-based yogurts utilizing soy milk or almond milk have been developed and are on the market, the technology for manufacturing yogurt using grains remains limited.

[0003] Meanwhile, 'nuruk,' used in the production of traditional alcoholic beverages and fermented foods, plays a crucial role in aiding the saccharification of carbohydrates and promoting fermentation due to its abundance of fermentation microorganisms and enzymes. While wheat or rice nuruk is typically used in the production of makgeolli, yogurt derives its viscosity and acidity from lactic acid fermentation, unlike makgeolli; consequently, it has been difficult to produce non-dairy-based fermented grain yogurt. In particular, to achieve a smooth texture and sufficient lactic acid content without animal-derived ingredients, sufficient saccharification and an appropriate microbial environment must be established during the fermentation process.

[0004] In addition, rice nuruk is a traditional fermentation agent completed by inoculating rice flour with starter cultures (yeast, mold, lactic acid bacteria, etc.) and undergoing fermentation, drying, and aging processes. Although it has been used in various traditional fermented foods, including makgeolli and vinegar, there has not been sufficient technological accumulation regarding applications such as the production of vegan yogurt. Although methods for producing pseudo-yogurt using fermented grain and legume liquids have been attempted in some patents (Reference Patents 1 and 2, etc.), it was difficult to achieve taste, aroma, and viscosity comparable to animal-based ingredients, and there remained the problem of difficulty in ensuring fermentation stability.

[0005] With the recent convergence of health-oriented consumption trends, the rise of vegans and vegetarians, and movements to rediscover the value of traditional fermented foods, a new yogurt manufacturing technology utilizing rice koji that can satisfy taste, nutrition, and lactic acid bacteria activity without the need for dairy products is garnering attention. Accordingly, this invention requires the development of a manufacturing technology that effectively utilizes traditional rice koji to saccharify grain-based fermentation substrates and stably induce lactic acid bacteria fermentation, thereby enabling the realization of flavor and texture similar to conventional yogurt without using any animal-derived ingredients. The problem to be solved

[0006] According to one embodiment, a method for manufacturing yogurt using rice koji can be provided.

[0007] According to one embodiment, a method for manufacturing rice koji-based yogurt through cooling and aging can be provided. means of solving the problem

[0008] As a technical means for achieving the technical problem described above, according to one embodiment, a method for manufacturing yogurt using rice koji may be provided, comprising: (a) a step of preparing rice koji; (b) a step of gelatinizing and saccharifying soaked rice raw materials to produce a substrate for yogurt fermentation; (c) a step of inoculating the substrate with lactic acid bacteria to ferment; and (d) a step of cooling and aging the fermented mixture to produce yogurt. Effects of the invention

[0009] According to one embodiment, yogurt can be produced using entirely plant-based materials by using rice koji.

[0010] According to one embodiment, yogurt with a flavor and texture similar to dairy-based yogurt can be produced through saccharification and fermentation processes.

[0011] According to one embodiment, the flavor of the fermented grain food can be enhanced by maintaining the unique aroma and nutrients of rice koji. Brief explanation of the drawing

[0012] FIG. 1 is a flowchart of a method for manufacturing yogurt using rice koji according to one embodiment. Figure 2 is a diagram showing the specific process of a method for preparing a substrate for yogurt fermentation according to one embodiment. Specific details for implementing the invention

[0013] In order to provide a detailed explanation sufficient for a person skilled in the art to easily implement the technical concept of the present invention, embodiments of the present invention will be described with reference to the accompanying drawings. However, the following embodiments are merely examples to aid in understanding the present invention and do not reduce or limit the scope of the rights of the present invention. Furthermore, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0015] FIG. 1 is a flowchart of a method for manufacturing yogurt using rice koji according to one embodiment.

[0016] Hereinafter, embodiments of the present invention will be described in more detail with reference to FIG. 1. FIG. 1 shows a flowchart of a method for manufacturing yogurt using rice koji according to one embodiment. First, rice koji is prepared in S100, and in S200, an initial fermentation base material may be prepared using a culture medium of a strain pretreated to inhibit alcohol production or a special lactic acid bacterium to replace or supplement it. This base material may undergo a sterilization or pasteurization process in advance to increase fermentation safety and prevent the occurrence of unwanted bacteria, and interacts with the enzymes and microbial community unique to rice koji to help facilitate the subsequent fermentation process.

[0017] According to the present invention, the step of preparing rice koji (S100) corresponds to step (a) of claim 1, and specifically, the rice koji comprises rice flour inoculated with starter culture and fermented at 30°C to 40°C for a certain period (claim 2). If the fermentation temperature is excessively high, there is a risk that the balance of microorganisms will be disrupted, and conversely, if it is too low, the fermentation time may be excessively long or the fermentation may be insufficient; therefore, a range of 30 to 40°C is appropriate. After fermentation is complete, it is preferable to refrigerate the rice koji (about 4°C to 10°C) to stabilize enzyme activity and microbial survival. Since the flavor may change depending on the aging period, the desired flavor profile may be obtained by varying the aging time.

[0018] In the subsequent S300, the soaked rice raw material is gelatinized and saccharified to produce a substrate for yogurt fermentation (step (b) of Claim 1). The soaked rice raw material may be selected from at least one of brown rice, black rice, glutinous rice, and non-glutinous rice (Claim 3). If a more complex flavor is desired, a mixture of brown rice and black rice, or glutinous rice and non-glutinous rice, may be used. Since the viscosity or color may vary depending on the mixing ratio, it can be adjusted to suit the purpose. In this step, the ratio of rice koji to rice raw material may be set in the range of 3 to 10 parts by weight relative to 100 parts by weight of rice raw material (Claim 5), which is a suitable level for properly saccharifying starch and increasing fermentation efficiency. For example, if 90 parts by weight of non-glutinous rice and 10 parts by weight of black rice are mixed and soaked for 2 to 3 hours, and then a rice koji of 5 parts by weight is added, a good degree of saccharification can be obtained while preserving the unique flavor of the grain. In the gelatinization process, the rice starch is swollen by heating at approximately 90°C to 100°C for a certain period of time (e.g., 20 to 60 minutes), and then in the saccharification process, the enzyme contained in the rice koji (or an externally added saccharification enzyme) is used to induce the formation of monosaccharides or disaccharides.

[0019] Next, in S400, lactic acid bacteria are inoculated into the saccharified substrate to carry out fermentation (step (c) of Claim 1). The lactic acid bacteria used at this time may be one or more strains selected from the genus Lactobacillus, the genus Streptococcus, or the genus Bifidobacterium (Claim 4), and an example in which multiple strains are mixed and inoculated to diversify fermentation characteristics is also possible. For example, using a 1:1 mixture of Lactobacillus plantarum and Streptococcus thermophilus has the advantage of balanced acidity control and flavor formation. In addition, as mentioned in Claim 6, by adding a saccharifying enzyme prior to this fermentation and reacting for a certain period of time, a sweetness and sugar content suitable for fermentation can be secured. Specifically, by adding glucoamylase, etc., to a mixture of rice raw materials and rice koji at a concentration of 0.1% to 0.5% and reacting it for about 30 minutes to 1 hour at a temperature of 55°C to 65°C, it is possible to produce monosaccharides that are suitable for use by lactic acid bacteria. The mixture after saccharification can be stored for several hours to tens of hours at an aging temperature of 30°C to 40°C, and during this period, auxiliary operations can also be performed to suppress the growth of unwanted bacteria in the substrate and increase the stability of lactic acid bacteria fermentation.

[0020] Finally, in step S500, the fermented mixture is cooled and aged to produce the final yogurt (step (d) of Claim 1). Typically, after fermentation, the mixture is rapidly cooled to a temperature of 4°C to 10°C to stop or delay fermentation, and aged for a certain period to allow the flavor to settle more smoothly. The aging time is usually set from 6 hours to 24 hours or more; during aging, lactic acid bacteria activity continues, albeit weakly, resulting in a gradual change in flavor, a more stable texture, and an increase in viscosity. The finished yogurt may be sold in a separate packaging container, or various additives such as fruit syrup or grain flakes may be added to enhance functionality and palatability.

[0021] Thus, the present invention relates to a method for producing cereal-based vegan yogurt by utilizing rice koji as a key medium for saccharification and fermentation. First, the rice koji is stably fermented and aged (a); the soaked rice raw material is gelatinized and saccharified to create a substrate for yogurt fermentation (b); lactic acid bacteria are inoculated and fermented into the substrate (c); and the fermented mixture is cooled and aged to obtain the final yogurt (d). The rice koji is refrigerated after fermentation at 30°C to 40°C, and suitable rice raw materials for soaking include brown rice, black rice, glutinous rice, non-glutinous rice, etc. The lactic acid bacteria used for fermentation may be selected from one or more strains of the genera Lactobacillus, Streptococcus, and Bifidobacterium. In addition, during the gelatinization and saccharification process, the ratio of rice koji to rice raw material is set to 3 to 10 parts by weight per 100 parts by weight of rice raw material to increase fermentation efficiency, and if necessary, saccharification enzymes are added to ensure sufficient sugar content that lactic acid bacteria can utilize.

[0022] Consequently, according to the present invention, it is possible to achieve quality similar to or better than conventional yogurt in terms of viscosity, taste, and nutritional value without containing any dairy products, and provides a fermented grain food that is highly suitable for consumers who wish to avoid animal-derived ingredients due to allergies, vegetarianism, or religious reasons. In particular, by utilizing the enzyme community and fermentation microorganisms unique to rice koji, yogurt with rich flavor and health benefits can be produced conveniently and stably, and it holds great significance as a modern application of traditional fermentation technology.

[0024] Figure 2 is a diagram showing the specific process of a method for preparing a substrate for yogurt fermentation according to one embodiment.

[0025] Next, referring to FIG. 2, this illustrates a specific process for preparing a substrate for yogurt fermentation according to one embodiment. First, in S210, the rice raw material and rice koji prepared in step (b) (e.g., the substrate preparation step) are mixed and stirred. This is a specific implementation of the “step of mixing the rice raw material and rice koji” according to claim 6. After gelatinizing and soaking the rice raw material, it is added in an appropriate ratio (e.g., 3 to 10 parts by weight of rice koji relative to 100 parts by weight of rice raw material) and stirred sufficiently, thereby homogenizing the entire substrate and creating an environment where enzymes and microorganisms within the rice koji can function smoothly.

[0026] Next, in S220, a saccharification enzyme is added to the mixture to perform a saccharification reaction for a certain period of time. This is a process to form a sugar content favorable for lactic acid fermentation by breaking down the starch in the rice raw material into monosaccharides or disaccharides. Specifically, glucoamylase or alpha-amylase is added at a level of 0.1% to 0.5%, and the reaction is carried out for about 30 to 60 minutes in a range of about 55°C to 65°C to significantly improve saccharification efficiency. During the saccharification reaction, it is advisable to maintain a uniform temperature while constantly mixing the mixture using a stirring device or a circulation pump, and in some embodiments, the reaction is stopped at a necessary point while simultaneously measuring the sugar content.

[0027] Next, in S230, the mixture after saccharification is stored at an aging temperature to complete a substrate suitable for fermentation. At the point where the saccharification reaction is finished, the mixture is in a state where carbohydrates have been sufficiently converted into monosaccharides. If the mixture is maintained at a stable temperature in the range of 30°C to 40°C for several hours to several tens of hours, the microbial activity conditions become more homogeneous, and the fermentation stability can be increased while suppressing the growth of unwanted bacteria. Since the aging temperature and time are directly related to the taste, aroma, and acidity of the final yogurt, they can be set in various ways depending on the purpose. For example, aging at around 35°C for about 6 hours can yield a state where rapid fermentation is possible, whereas aging at a low temperature (e.g., 25-28°C) for a long time results in a slower fermentation speed but has the advantage of forming a unique flavor smoothly.

[0028] The fermentation substrate completed through the process (S210, S220, S230) of Fig. 2 is subsequently incorporated into the fermentation step (S400) described in Fig. 1, and full-scale yogurt fermentation proceeds after inoculation with lactic acid bacteria. In particular, by finely controlling the temperature, time, and enzyme amount for each step of Fig. 2, the enzymatic interaction between the rice koji and the rice raw material is optimized, and the degree of saccharification is secured in advance, thereby creating a favorable environment in which lactic acid bacteria can actively proliferate from the beginning of fermentation. In conclusion, the present invention applies the traditional fermentation method using rice koji to the field of vegan yogurt, while separately coordinating saccharification and maturation through a specific process as shown in Fig. 2, thereby realizing a new fermented food that preserves the unique taste and aroma of grains.

[0029] Although embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention.

Claims

Claim 1 A method for manufacturing yogurt using rice koji, comprising: (a) a step of preparing rice koji; (b) a step of gelatinizing and saccharifying soaked rice raw materials to produce a substrate for yogurt fermentation; (c) a step of inoculating the substrate with lactic acid bacteria to ferment; and (d) a step of cooling and aging the fermented mixture to produce yogurt. Claim 2 A method for manufacturing yogurt according to claim 1, characterized in that the rice koji of step (a) is used after inoculating rice flour with starter culture and fermenting it at 30°C to 40°C, and then storing it in a refrigerator for stabilization. Claim 3 A method for manufacturing yogurt according to claim 2, characterized in that the rice raw material soaked in step (b) is at least one of brown rice, black rice, glutinous rice, and non-glutinous rice. Claim 4 A method for manufacturing yogurt according to claim 3, characterized in that the lactic acid bacteria inoculated in step (c) above are one or more strains selected from the genus Lactobacillus, the genus Streptococcus, or the genus Bifidobacterium. Claim 5 A method for manufacturing yogurt according to claim 4, characterized in that the ratio between rice koji and rice raw material during the saccharification reaction in step (b) is set to 3 to 10 parts by weight relative to 100 parts by weight of rice raw material. Claim 6 A method for manufacturing yogurt according to claim 3, wherein the step of preparing the substrate for yogurt fermentation comprises: a step of mixing and stirring the rice raw material and rice koji prepared in step (b); a step of adding a saccharifying enzyme to the mixture and performing a saccharification reaction for a certain period of time; and a step of storing the mixture after saccharification is completed at an aging temperature to complete a substrate suitable for fermentation.

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