MXPA01001867A - Process for the production of partially gelatinized rice flour - Google Patents

Abstract

The invention is directed to a continuous process for the production of rice flour and dough. Rice flour and dough is made by hydrating rice flour or a blend of rice flour and other cereal components, tempering, and then cooking to partially gelatinize the starch in the flour.

Description

PROCESS FOR THE PRODUCTION OF PARTIALLY GELATINIZED RICE FLOUR Field of the Invention The present invention relates to the preparation of dough from rice flour. More particularly, this invention is directed to the production of partially gelatinized flour and dough which is made by physically mixing the flour with water, hydrating the flour, kneading the hydrated flour and cooking the kneaded flour to partially gelatinize the starch in the flour. Background of the Invention Flour and Dough Using and completely cooking rice flour limits the flexibility of any process where food products are custom-made snack foods and the like, which require a combination of flour or rice dough with other types of flour and dough, such as corn dough or wheat dough. Providing partially gelatinized rice flour using the process of the invention described herein allows the manufacture of a dough including rice dough tailored to a particular product, using a continuous process without extended downtime. An objective of this invention is to provide a new and flexible process for the production of partially gelatinized rice flour and dough. These and other objects, advantages, features and aspects of the present invention will become more apparent when considering the following description and claims. SUMMARY OF THE INVENTION This invention is directed to a continuous process for the production of partially gelatinized rice flour and dough. In the process, corn flour or a physical mixture of rice flour with other components of one or more grains of other grains is hydrated to provide a hydrated rice flour (or physical mixture of rice flour and one or more additional components of rice flour). cereal) having a moisture content of at least 20% by weight. Additional cereal components may include flour from other cereals, such as wheat flour and oatmeal. In an important aspect, during hydration, the rice flour is mixed with water having a temperature of at least about 10 * C, but not at a temperature that would substantially gelatinize the starch in the flour. Generally, the temperature of the physical water / flour mixture should not exceed about 60"C. The mixing of the physical water / flour mixture should be effective in substantially evenly distributing water throughout the entire physical mixture. moisture level of at least about 20% by weight In another important aspect, the physical mixture of hydrated rice flour has a moisture content of about 26 to about 30% by weight of water, based on the weight of rice flour and water After hydration, the hydrated rice flour is kneaded for a while to distribute moisture evenly throughout the flour.Mounting times usually vary from around 30 seconds to about 12 minutes, depending on the type and particle size of the flour in the hydrated flour After kneading, the kneaded flour enters a cooking device to cook it in a cooking process that uses lime or direct and indirect. The indirect heat maintains the cooking device and the dough at an elevated temperature which is effective to keep the cooking device clean of partially cooked residual dough. Direct heat, such as the injection of water vapor into the kneaded product, cooks the dough in combination with the indirect heat. The combination of direct and indirect heat brings the temperature of the kneaded product to a level of at least about 165 'F when leaving the cooking device and partially gelatinizes the starch in the flour and the starch in any other cereal components with which that the rice flour can be physically mixed or combined. After partial gelatinization, no more than about 90% by weight of the starch in the rice flour or the physical mixture of rice flour is gelatinized, and in an important aspect, no more than about 70% by weight of the starch in the rice flour or physical mixture is gelatinized. The kneaded product is exposed directly to water vapor for about 1 to about 10 minutes, and preferably about 1 to about 2 minutes, the cooking temperature also being potentially affected by a subsequent drying step. After cooking the rice flour or the physical mixture of cooked rice flour, the rice flour can be dried at a moisture content of no more than about 15% by weight at a temperature that is effective to not damage with heat or burn the product. Generally, during drying of the product, the temperature should not exceed 95 * F. After drying the rice flour or the dry physical mixture, it is sized, such as by grinding and sifting to a particle size of about 16 to about 65 mesh, depending on what type of food product will be made with the mixture. component physics. The process of the invention is effective to hydrate, knead and cook the physical mixture of rice flour or components, such that no waste water is created and the process can be carried out without removing water from the rice flour or the physical mixture of components after hydrating, kneading or cooking. Moreover, the process is effective to provide a product that does not require washing after the steps of hydration or cooking.

Description of the Drawing Figure 1 is a schematic illustration of a cooking device used in the process of the invention. Detailed Description of the Invention The process includes hydrating rice flour and / or hydrating rice flour with other components, such as components of other cereals, such as corn. In the case of corn, these components include (1) corn germ, or (2) half-milled corn and corn germ, or (3) half-milled corn, corn germ and corn bran, or (4) corn germ and corn bran, or (5) corn bran, or (6) half-milled corn and corn bran, or (7) whole milled corn, to provide a rice flour or a physical mixture of rice flour. The physical mixture of rice flour or components can be mixed dry and then mixed with water for hydration of the physical mixture or mixed separately in water for hydration of the physical mixture. Subsequently, the physical mixture of rice flour or components is hydrated with water to provide a physical mixture of hydrated corn components having a moisture content of at least about 20% by weight. After hydration, the process includes kneading the physical mixture of rice flour or hydrated components to provide a physical mixture of rice flour or kneaded components, cooking the physical mixture of rice flour or indirect heat kneaded components and steam direct. After cooking, the product cooked with the partially gelatinized starch can be used as a dough. However, in one important aspect, this cooked product is dried and optionally milled and sized. Hydration Step The rice flour or physical mixture of rice flour components is mixed with water in a high-speed mixer. The temperature of the hydration step varies between about 10 and about 60 * C. The temperature of the water of hydration depends on the time required for full hydration, and also on the size of the particles in the physical mixture. The time for hydration can vary between 5 minutes and 4 hours. The temperature of the water of hydration varies between about 10 and about 60"C, and preferably about 25 and about 60" C. Higher temperatures may be used, but they are not advisable because during mixing, heating may occur. Any heating that results in substantial gelatinization of the starch in the flour or in any component of the physical mixture should be avoided, because such gelatinization will not provide a uniform final product for the cooking step. In this regard, substantial gelatinization means that the structure of starch granules is not disturbed and there is no loss of bifringency before cooking, such that more than about 5% by weight of the starch in the flour or physical mixture is gelatinized.

The preferred mixer for the process is a turbulizer, supplied by Hosoka to Bepex, but other available high speed mixers can be used. It is important to mix during hydration to distribute water substantially evenly throughout the raw mix. The time is not critical as long as the moisture is distributed substantially evenly throughout the physical mixture of rice flour or components at a moisture level of at least about 20% by weight, in an important aspect in a range from about 23 to about 34% by weight, and preferably from about 26 to about 30% by weight, based on the weight of the hydrated physical mixture. Kneading After hydration, the physical mixture of rice flour or hydrated components is maintained or kneaded for a few minutes to ensure that moisture is evenly distributed throughout all the flour particles or components. This can be done by methods that include the use of a standard transport screw or a kneading container. It is not essential, but it is advisable to maintain a constant temperature during this process. Kneading times can vary between about 30 seconds and about 12 minutes. Long kneading times are not advisable as microbial growth may occur. Long kneading times are not required as the rice flour particles are small enough to ensure that all water is evenly distributed throughout the product and a uniform mixture is obtained for cooking. Cooking The cooking device cooks indirect and direct heat, such as a screw-type cooking device, and partially gelatinizes the starch in the physical mixture of rice flour or components. This cooking device, as shown in Figure 1, is an elongated heating device having a heat jacket surrounding a channel through which the kneaded product is transported. The hydrated and kneading product is moved forward, downwardly of the cooking device, by means of vanes in a hollow rotor in the device. The rotor is connected to a source of water vapor to transmit water vapor to the vanes that are hollow and are open to receive steam from the rotor. Water vapor enters the rotor and is transported therethrough to the blades having one or more holes from which steam is injected into the kneaded product. The vanes evenly distribute the water vapor in the product that is being cooked. Indirect heat is applied from the device jacket. The direct heat brings the kneaded product to a temperature, partially gelatinizing the starch, while the indirect heat maintains the cooking device and the dough at an elevated temperature, which is effective to keep the cooking device clean of partially cooked residual dough. The cooking conditions are controlled by selecting a specific length for the device, the number of open holes of water vapor in the vanes, the amount of indirect heat being applied and the speed at which the kneaded product is transported through the cooking device. Referring to Figure 1 for more detail, the kneaded product is fed to an elongated heating device 4, shown in Figure 1. The kneaded product is fed to the opening 8 for feeding the heating device to the channel 10. Kneading product is transported down channel 10 in the y direction. The channel 10 is surrounded by a steam jacket 12 through which water vapor is circulated. A hollow rod 14 extends longitudinally downwards in the center of the channel. A plurality of vanes 16 are mounted on the rod 14 down its length. The rod 14 is rotated and the vanes are angled such that when the vanes rotate the vanes, mix the kneaded product and push the product down the channel 10. The vanes have openings 18 that extend through the vanes to hollow center of the rod 14. These openings are for transmitting water vapor that goes through the rod and the vanes, so that the water vapor can be injected into the particulate food product that is being transmitted down the channel 10. As the rod rotates, the vanes push the product down the conduit to the outlet opening 20 through which the cooked mass flows. The openings in the vanes can be opened or closed to control the injection of water vapor towards the product that is being transmitted down the channel. The injected amount of water vapor is effective to heat and cook the product, such that a product with partially gelatinized starch is obtained. Additional indirect heating of the kneaded product and the cooking channel is carried out using indirect heat from the jacket of the device. Sufficient water vapor is injected to cook the kneaded product and gelatinize the starch therein and provide the cooked product with a temperature of at least about 165"F. A device that can be used to cook the kneaded product as described in present is available as Solidaire, model SJCS 8-4, from Hosokawa Bepex Corporation, 333 N.E. Taft Street, Minneapolis, Minnesota 55413, United States. Direct heat, such as the injection of water vapor into the kneaded product, boils the dough in combination with the indirect heat. Indirect heat can be provided by steam or oil. The combination of indirect and direct heat brings the temperature of the kneaded product to a value of at least about 165"F when leaving the cooking device.The kneaded product is directly exposed to water vapor for about 1 to about 10 minutes , and preferably from about 1 to about 2 minutes, the cooking time and temperature are also potentially affected by the temperature in the subsequent drying step.When lower temperatures are used during drying, higher temperatures are used during drying. cooking and vice versa The cooking temperature, as measured by the temperature of the product when leaving the cooking device, is a function of the type of product desired and the drying temperatures that are subsequent to the cooking step. lower drying temperatures, such as when the dryer inlet temperature is 370 * F, no significant cooking occurs in the dryer. or lower temperatures are used, the temperature of the cooked product, when leaving the cooking device, is at the upper end of the range of about 185 to about 210 * F. When higher temperatures are used, such as around 500"F for the intake air temperature, and the temperature of the dry product exceeds 85" C, the cooked product leaves the cooking device at the lower end of the designated range, around from 160 to about 200"F. Overcooking will result in a sticky dough when it is further processed In one important respect, the cooked product can be used directly in additional processing and cooking, such as in snacks. an extremely important aspect, the cooked product is dried to provide a product with partially gelatinized starch.

Drying Conventional techniques, such as a drip dryer or band dryer, can be used to dry the cooked mixture to provide a product with partially gelatinized starch and a product with a moisture level of no more than about 15% by weight. Alternatively, a Micron dryer, supplied by Hosokawa Bepex, or a drier may be used. In this system there is also a sorting system that grinds the cooked product in such a way that the correct final granulation of the dry flour is obtained for specific applications. For applications where thicker granulation is required, this air classification system can be reduced to a minimum level to ensure that the required coarse particles are still present. The temperatures used during drying depend on the temperatures and humidity used during the cooking stage. If a high temperature is used during cooking, a lower temperature can be used during the drying process. If lower temperature and lower humidity levels are used during cooking, higher temperatures are used during the drying step to ensure that some cooking is obtained during the drying step. However, a fine balance is maintained to prevent the product from suffering thermal damage during the drying process. Such thermal damage will result in a kneading which does not form an appropriate cohesive mass and which is discolored. Drying of the Dry Product The dry rice product is sifted in a standard sieve to obtain the correct granulation. Thick fractions can be removed and ground to a smaller granulation. The product too fine can be removed, if necessary. The following examples describe and illustrate the process of the invention and corn flour prepared by the process of the invention. Example I Rice flour is hydrated by mixing with water using a turbulizer. The hydrated product is then heated in a Solidaire 6 device from Hosokawa Bepex Corporation, open vanes for steam injection. The cooked product is then dried.

RVA; quick visco-analyzer. Equipment to measure the viscosity. A solution is made by varying the percentage of dry solids solutions and the viscosity is measured over a period of 12.5 minutes. The viscosity is expressed in cPoises.

Example II Example III Example IV Example V SI and S5 are simple flour, not treated according to the invention. S2, S3, S6, and S7 are partially cooked rice flour, processed according to the invention.

Example VI Example VII Example VIII EXAMPLE IX Coarse, partially cooked RVA rice flour: 20% d.s.

Claims (10)

1. CLAIMS 1. A process for making rice dough that has partially gelatinized starch, the process comprising: hydrating the rice flour with water at a moisture level of at least about 20% by weight, based on the weight of the flour and water to provide a hydrated flour; knead the hydrated flour for at least about 30 seconds to provide a kneaded flour; cooking the kneaded flour with indirect heat and the direct application of steam to bring the kneaded flour to a temperature of at least about 165 * F to provide a cooked rice flour having no more than about 90% by weight of the starch what is in the same gelatinized.
2. 2. The process as defined in claim 1, further comprising drying the cooked rice flour to a moisture content of no more than about 15% moisture by weight to provide a cooked, dry rice flour.
3. 3. A process as defined in claim 1, wherein the water during hydration of rice flour has a temperature of at least about 10'C and the rice flour and water are mixed at a rate that is effective for distribute the water substantially uniformly throughout the physical mix of rice flour.
4. 4. A process as defined in claim 1, wherein the rice flour is brought to a temperature of at least about 165"F.
5. 5. A process as defined in claim 1, wherein not more than about 70 % by weight of the starch in the rice flour is gelatinized 6.
6. A process for making rice dough that has partially gelatinized starch, the process comprising: physically mixing rice flour and a second cereal component selected from the group consisting of flour of wheat, oatmeal, and mixtures thereof, to provide a physical mixture of rice flour and cereal components, to hydrate the physical mixture of rice flour and cereal components with water, at a moisture level of at least about 20% by weight, based on the weight of the physical mixture of rice flour and cereal and water to provide a hydrated physical mixture of rice flour and cereal components, to knead the hydrated physical mixture of rice flour and cereal for at least about 30 seconds to provide a kneaded physical mixture of rice flour and cereal components; cooking the kneaded physical mixture of rice flour and cereal components with indirect heat and the direct application of steam to bring the blended physical mixture of rice flour and cereal components to a temperature of at least about 165 'F to providing a cooked physical mixture of rice flour and cereal components having no more than about 90% by weight of the starch in the same gelatinized.
7. The process as defined in claim 6, further comprising drying the physical mixture of rice flour and cereal components at a moisture content of no more than about 15% moisture by weight to provide a dry physical mixture, cooked rice flour and cereal components.
8. A process as defined in claim 6, wherein the water during hydration of the physical mixture of rice flour and cereal components has a temperature of at least about 10"C and the physical mixture of flour components of rice and cereal and water are mixed at a rate that is effective to distribute the water substantially uniformly throughout the physical mixture of rice flour and cereal components
9. 9. A process as defined in claim 6, wherein the physical mixture of rice flour and cereal components is brought to a temperature of at least about 165 * F
10. 10. A process as defined in claim 6, wherein not more than about 70% by weight of the starch in The physical mixture of rice flour and cereal components is gelatinized. The invention is directed to a continuous process for the production of flour and rice dough. The flour and rice dough are made by hydrating rice flour or a mixture of rice flour and other cereal components, kneading, and then cooking to partially gelatinize the starch in the flour.