JP2012016326A - Method for producing rice protein composition improved in quality by temperature control and food product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a rice protein composition improved in texture and melting-in-the-mouth feeling, and to provide a food product.SOLUTION: The method for producing the rice protein includes the step of forming the aggregate of the rice protein in a state that the rice protein-containing extract liquid obtained by immersing rice or rice flour in an alkaline solution is placed at a predetermined temperature of not less than 40°C, and recovering the aggregate. The predetermined temperature is preferably not more than 80°C. The formation of the aggregate may be performed by neutralizing the rice protein-containing extract liquid, or also by introducing a divalent metal ion into the rice protein-containing extract liquid. The food product contains the rice protein composition produced by these production methods.

Description

  The present invention relates to a method for producing a rice protein composition and a food.

  Conventionally, rice protein has a cholesterol lowering effect and a lipid metabolism improving effect, and has attracted attention as a functional food material. It is disclosed that such rice protein can be recovered as a precipitate that is extracted by immersing rice or rice flour in an alkaline solution and neutralizes the extract to be aggregated (Patent Document 1), and the rice protein composition obtained by this method is disclosed. It is also disclosed that the product is excellent in nutritional value and excellent in digestion and absorption (Non-Patent Document 1 and Non-Patent Document 2).

JP 2006-273840 A

Kumagai et al., J Nutr Sci Vitaminol 52, 467-472 (2006). Kumagai et al., J Nutr Sci Vitamol 55, 170-177 (2009)

  However, the rice protein composition obtained by the conventional method is hard to pulverize because the constituent particles are hard and has a rough texture and a poor texture. For this reason, the conventional rice protein composition had the problem that the foodstuff which can be utilized was limited.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for producing a rice protein composition and a food product that are improved in touch and mouthfeel.

  The inventors of the present invention have found that the protein composition obtained exhibits an excellent touch and crispness by adjusting the temperature at which rice protein aggregates are produced, and have completed the present invention. Specifically, the present invention provides the following.

  (1) It has the process of producing | generating the aggregate of rice protein in the state which put the rice protein containing extract obtained by immersing rice or rice flour in an alkaline solution in the predetermined temperature of 40 degreeC or more, and collect | recovering this aggregate A method for producing a rice protein composition.

  (2) The manufacturing method according to (1), wherein the predetermined temperature is 80 ° C. or lower.

  (3) The production method according to (1) or (2), wherein the production of the aggregate is performed by neutralizing the rice protein-containing extract.

  (4) The production method according to (1) or (2), wherein the production of the aggregate is performed by introducing divalent metal ions into the rice protein-containing extract.

  (5) A food containing a rice protein composition produced by the production method according to any one of (1) to (4).

  According to the present invention, aggregates produced in a state at a predetermined temperature of 40 ° C. or higher are recovered, so that the resulting rice protein composition exhibits excellent touch and mouthfeel.

  Hereinafter, although one embodiment of the present invention is described, this does not limit the present invention.

  In the method for producing a rice protein composition according to the present invention, a rice protein-containing extract obtained by immersing rice or rice flour in an alkaline solution is used. The rice protein-containing extract is not particularly limited and can be produced according to a conventional method.

  The material of the rice protein-containing extract may be one or both of rice such as polished rice or pulverized rice flour, but rice flour is preferable in terms of extraction time and efficiency because of its fine particle size. Most rice proteins are present as protein granules in the rice or rice endosperm.

  The alkaline solution is preferably one that is generally used in the food field, such as a sodium hydroxide solution, in that the protein composition is useful as a food. In the case of a sodium hydroxide solution, an alkaline solution may be prepared so that the final concentration after extraction is 0.01 to 1.0% by weight from the viewpoint of extraction efficiency.

  When rice or rice flour is immersed in an alkaline solution, rice protein is released from the rice tissue and floats in the solution in a swollen state. Although it does not specifically limit at this time, rice or rice flour is immersed in the quantity of 5 to 40 weight% with respect to an alkaline solution, and a mixture is suspended and stirred. Such extraction can be performed at room temperature for 1 to 48 hours, but when the extraction time is long, the temperature of the extract should be controlled to 30 ° C. or less in order to reduce the risk of microbial contamination. Is preferred.

  The resulting liquid is solid-liquid separated (for example, centrifugal separation, standing separation, filtration separation, membrane separation), and the starch particles and insoluble fibers that precipitate are removed, so that a clear solution in which rice protein is dissolved and / or suspended. Can be obtained. The rice protein extract used in the method of the present invention may be either before or after solid-liquid separation, but is preferably after solid-liquid separation from the viewpoint of improving the purity of rice protein.

  The rice protein extract contains impurities such as water-soluble fiber, solubilized starch, and oligosaccharide in addition to rice protein. For this reason, in order to raise the purity of rice protein, it is necessary to aggregate rice protein. Conventionally, rice protein precipitation is performed by adding an acid to the rice protein extract to neutralize it, and at this time, the temperature is not adjusted at all, and is performed at room temperature. The rice protein composition obtained by collecting and drying the aggregate had hard constituent particles, and had a poor touch and mouthfeel.

  On the other hand, the method of the present invention has a step of generating rice protein aggregates in a state where the rice protein-containing extract is at a predetermined temperature of 40 ° C. or higher, and collecting the aggregates. To do. The protein composition obtained from this aggregate exhibits a significantly superior touch and mouthfeel compared to conventional ones. This mechanism is presumed to be due to a change in the higher order structure of rice protein at a temperature of 40 ° C. or higher.

  The predetermined temperature is not particularly limited, and can be appropriately selected from a range of 40 ° C. or higher so that the function of rice protein is maintained to a desired level. However, if the predetermined temperature is excessive, the effect of improving the touch and the mouthfeel is lowered, so that the predetermined temperature is preferably 80 ° C. or lower, and more preferably 70 ° C. or lower. The predetermined temperature is preferably 60 ° C. or lower, more preferably 50 ° C. or lower, from the viewpoint of the balance between the improvement effect of tongue touch and mouthbreaking and the heat denaturation of rice protein accompanying an increase in the heating time. .

  The aggregates may be generated by neutralizing the rice protein-containing extract. The formation of aggregates by neutralization is a conventionally known method, and can be carried out by adding an acid such as hydrochloric acid, sulfuric acid, phosphoric acid, etc. suitable for use in the food field in an amount that makes the pH within a predetermined range. it can.

  Moreover, you may perform the production | generation of an aggregate by introduce | transducing a bivalent metal ion into a rice protein containing extract. The inventors of the present invention have found that the protein composition derived from the resulting aggregate exhibits a better touch and mouthfeel.

  The divalent metal ion is not particularly limited, but preferably includes one or both of magnesium ion and calcium ion in terms of being suitable for use in the food field. The introduction of a divalent metal ion is not particularly limited, but a physiologically acceptable salt of a divalent metal (eg, a halide (especially chloride), carbonate, bicarbonate) is directly (that is, the salt is converted into rice). It can be performed by adding to the protein extract) or indirectly (that is, adding an aqueous salt solution to the rice protein extract).

  The amount of divalent metal ions introduced may be appropriately set according to the type of divalent metal ions used and the like so as to obtain a desired aggregate yield. The specific introduction amount of the divalent metal ion is not particularly limited, but in the case of magnesium ion, it is 10 mM or more, preferably 15 mM or more in the extract, and in the case of calcium ion, 15 mM or more, preferably 20 mM or more in the extract. More preferably, it is 30 mM or more.

  Since the rice protein-containing extract is derived from an alkaline solution and exhibits alkalinity, it is desirable to adjust the pH when the aggregate is produced or after the aggregate is produced.

  The aggregate can be recovered as a solid by solid-liquid separation (for example, centrifugation, stationary separation, filtration separation, membrane separation). Since the aggregate whose pH has been adjusted contains a large amount of salt, desalting is preferably performed by suspending in water, performing solid-liquid separation again, and recovering. The recovered aggregate can be processed or processed to obtain a rice protein composition. Examples of the processing include, for example, subjecting the aggregate to hot air drying, freeze drying, or the like, or suspending in a small amount of water and spray drying, thereby obtaining a rice protein composition having excellent storage stability. it can.

  Such a rice protein composition can be usefully used as a food itself or as a food additive because it exhibits functions of rice protein such as cholesterol lowering action and lipid metabolism improving action while exhibiting excellent touch and mouthfeel.

  The present invention also includes foods containing such rice protein compositions. The food may be, for example, rice confectionery, Japanese confectionery, Western confectionery, ice confectionery, seasoning, processed meat products, processed fish / fishery products, processed milk / eggs, processed vegetables, processed fruits, processed cereal products. Of these, Japanese-Western confectionery and kneaded products are preferred in that superior touch and superiority of mouthfeel are exhibited.

<Example 1>
4 kg of Koshihikari rice flour (purchased from Niigata Flour Milling Co., Ltd.) was immersed in 20 L of a 0.2 wt% aqueous sodium hydroxide solution and stirred at 25 ° C. for 16 hours. The obtained liquid was centrifuged (5,000 × g, 5 minutes), and about 15 L of a clear supernatant was recovered (rice protein-containing extract) and stored in a refrigerator.

  100 mL of the rice protein-containing extract was dispensed into 7 beakers, and each was kept at a temperature of 20 ° C to 80 ° C. The pH of the rice protein-containing extract was adjusted to 5.5 using dilute hydrochloric acid kept at the same temperature. The precipitates were collected by centrifugation (5,000 × g, 5 minutes), resuspended in 100 mL of water, and then centrifuged again to collect the precipitates as aggregates. The precipitate was freeze-dried to obtain about 0.8 g of rice protein composition. Each composition was subjected to sensory evaluation (assessment of tongue and mouthfeel in 6 levels of 0 to 5 points) by five well-trained panelists. The results are shown in Table 1. In addition, the score in Table 1 is an average score of five panelists.

  As shown in Table 1, when a rice protein aggregate is produced at a temperature of 40 ° C. or higher, a rice protein composition that exhibits a better texture and a better mouthfeel than a temperature of 20 ° C. or 30 ° C. Was found to be obtained. Further, at a temperature of 70 ° C. or lower, a better touch and mouthfeel than that at a temperature of 80 ° C. were obtained. Furthermore, at a temperature of 40 to 50 ° C., a tongue touch and a mouthbreak equivalent to or higher than those at a temperature of 60 ° C. to 70 ° C. can be obtained. A temperature of 0 ° C has been found to be most preferred.

<Example 2>
100 mL of the rice protein-containing extract obtained in Example 1 was dispensed into 7 beakers, and each was kept at a temperature of 20 ° C to 80 ° C. A 2M aqueous solution of calcium chloride kept at the same temperature was added and mixed so that the calcium ion concentration was 30 mM, and the pH was immediately adjusted to 5.5 with 1N hydrochloric acid. After that, the rice protein composition was obtained by the same procedure as in Example 1 and sensory evaluation was performed. The results are shown in Table 2.

  Comparing Tables 1 and 2, the rice protein composition obtained using calcium ion introduction exhibited a touch and a mouthfeel superior to those of the neutralization method at any temperature during the formation of aggregates. Moreover, when the aggregate was produced | generated at the temperature of 40 degreeC or more, the especially outstanding tongue touch and mastication were obtained.

<Example 3>
A rice protein composition was obtained in the same procedure as in Example 2, except that a 1M magnesium chloride aqueous solution was used instead of the 2M calcium chloride aqueous solution and the magnesium ion concentration was added to 0, 30 mM. Sensory evaluation was performed. The results are shown in Table 3.

  When Tables 1 and 3 were compared, the rice protein composition obtained by using calcium ion introduction also exhibited a touch and a mouthfeel superior to those of the neutralization method at any temperature during aggregate formation. Moreover, when the aggregate was produced | generated at the temperature of 70 degreeC, the especially outstanding tongue touch and prickling were obtained.

Claims (5)

  Rice protein composition having a step of producing rice protein aggregates in a state where a rice protein-containing extract obtained by immersing rice or rice flour in an alkaline solution is placed at a predetermined temperature of 40 ° C. or higher, and recovering the aggregates Manufacturing method.   The manufacturing method according to claim 1, wherein the predetermined temperature is 80 ° C. or less.   The production method according to claim 1 or 2, wherein the aggregate is generated by neutralizing the rice protein-containing extract.   The production method according to claim 1 or 2, wherein the aggregate is formed by introducing divalent metal ions into the rice protein-containing extract.   The foodstuff containing the rice protein composition manufactured with the manufacturing method in any one of Claim 1 to 4.