JPH0851940A - Rice treating agent and method for treating rice using the same - Google Patents

Abstract

PURPOSE:To obtain a rice treating agent capable of improving the taste of Japanese rice or foreign rice after cooked, by its contact with rice before cooked, and also capable of improving cooked rice preservabllity because of enabling the number of thermophilic bacteria to be reduced. CONSTITUTION:This rice treating agent contains at least one kind of surfactant selected from glycerin fatty acid esters with the number of carbon atoms in the fatty acid residue being 8-18, glycerin organic polycarboxylic esters or salts thereof, polyglycerin fatty acid esters, saccharides or sugar alcohol fatty acid esters, propylene glycol fatty acid esters and lecitin. Rice before cooked is washed using this treating agent followed by separating the washings off the rice.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a method for improving the quality of cooked rice,
More specifically, the present invention relates to a method of improving the quality of cooked rice, which allows the cooked rice to have good taste and storability by bringing the rice grains into contact with an aqueous solution of a specific rice treating agent prior to cooking rice.

[0002]

2. Description of the Related Art Conventionally, rice has been limited to rice cooked at homes, restaurants, restaurants, group lunch centers, etc., but the food service industry that handles large amounts of rice in response to recent changes in the social environment and lifestyle With the emergence of some companies, some of them specialize in supplying only cooked rice, and the demand for delicious cooked rice is increasing. In addition, the import of foreign rice has increased in recent years, and the needs for matching these rice with the tastes of the Japanese people are increasing, especially in the restaurant industry.

[0003] Ingenuity has been devised for tasting rice, which is the staple food of Japanese people, and in addition to how to sharpen rice before cooking rice, how much water is added, how long it is soaked, how to cook it, and how long it is steamed. The use of added rice quality improvers and additive formulations has been proposed and marketed [food and development, VOL. 29, N
O. 6,44-47 (1994); JP-A-6-4676.
No. 9, JP-A-53-145937, JP-A-SHO-6
0-75243]. These technologies and products are used for the purpose of adding a small amount when cooking rice to make sticky and glossy rice, suppressing mutual adhesion of rice grains and dryness when cooled, and the ingredients are large Oil and fat type,
There are enzyme type, starch type, and polysaccharide type. On the other hand, by using a surfactant, a technology relating to an additive for rice grains and a method of using the same, which prevents cracking of white rice due to rapid water absorption during water immersion and suppresses collapse and stickiness of cooked rice, is disclosed. (JP-A-2-35049, JP-A-1-350)
No. 312971, Japanese Patent Laid-Open No. 1-277463,
JP-A-1-269460, JP-A-1-22843
4, JP-A-1-141564 and JP-A-64
-80447 and JP-A-56-21563).

The above-mentioned techniques and products are added to the cooked rice to be added in advance during the process of drying, storing, processing such as rice polishing, which is carried out after the quality improving agent is harvested, or in water before cooking or when cooking. Since the quality improver remains, it does not fit the consumer's health, nature and safety orientation.
In addition, in addition to the fact that a specific device is required to add rice in the processing stage such as milled rice, mass production and distribution of rice in which specific additives are mixed in advance has individual differences in the taste of cooked rice. Not necessarily preferable. As described above, although technologies and products aimed at improving the quality of cooked rice have been actively developed, it cannot be said to be sufficient and further technical development is desired.

[0005]

DISCLOSURE OF THE INVENTION The present inventors have completed the present invention as a result of intensive research to improve the taste and storability of cooked rice. That is, the present invention has been made for the purpose of providing a method for easily improving the eating habit and preservability of cooked rice without remaining in cooked cooked rice.

[0006]

[Means for Solving the Problems] The inventors of the present invention have conducted intensive studies on a method for improving the quality of cooked rice in order to obtain the preferable cooked rice, and completed the present invention.

That is, according to the present invention, rice before cooking rice is prepared by using glycerin fatty acid ester having a fatty acid residue having 8 to 18 carbon atoms, glycerin organic polycarboxylic acid-ester or salt thereof, polyglycerin fatty acid ester, sugar. Alternatively, a rice treatment agent containing one or more surfactants selected from sugar alcohol fatty acid ester, propylene glycol fatty acid ester, and lecithin and a rice treatment before the rice is cooked using the treatment agent, and then the washing liquid is separated. The present invention relates to a characteristic rice processing method.

In the rice treating agent used in the present invention,
One or more selected from glycerin fatty acid ester having 8 to 18 carbon atoms of fatty acid residue, glycerin organic polyvalent carboxylic acid-ester or salt thereof, polyglycerin fatty acid ester, sugar or sugar alcohol fatty acid ester, propylene glycol fatty acid ester, lecithin Surfactants are used. As the fatty acid having 8 to 18 carbon atoms which constitutes the surfactant, caprylic acid, capric acid, lauric acid, myristic acid, stearic acid, isostearic acid,
It may be a saturated or unsaturated fatty acid residue such as oleic acid, or may be a linear or branched fatty acid.

When a hydrolase, polyphosphoric acid and / or its salt, organic carboxylic acid and / or its salt are contained together with the above-mentioned surfactant, a rice treating agent suitable for the present invention can be obtained.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the rice treating agent used in the present invention, glycerin fatty acid ester having a fatty acid residue having 8 to 18 carbon atoms, glycerin organic polycarboxylic acid-ester or salt thereof, polyglycerin fatty acid ester, sugar Alternatively, one or more surfactants selected from sugar alcohol fatty acid ester, propylene glycol fatty acid ester and lecithin are used.

As the glycerin fatty acid ester, those commercially available as distilled monoglyceride can be used. This is a mixed product of monoglyceride, diglyceride, and triglyceride obtained by direct esterification reaction of glycerin and fatty acid or transesterification reaction of glycerin and fat or lower alcohol ester of fatty acid so that monoglyceride becomes the main component by molecular distillation. It is purified.

Examples of the organic polycarboxylic acid-fatty acid ester and its salt include salts of glycerin succinic acid fatty acid ester and glycerin carboxylic acid fatty acid ester. Examples of the salt include alkali metal salts such as sodium salt and potassium salt, Examples thereof include alkaline earth metal salts such as magnesium salts, and ammonium salts.

The organic polycarboxylic acid-fatty acid ester such as glycerin succinic acid fatty acid ester and glycerin carboxylic acid fatty acid ester used in the present invention has 8 to 1 carbon atoms.
The fatty acid monoglyceride of 8 is obtained by reacting an organic polycarboxylic acid such as succinic acid or citric acid or an anhydride thereof, and the reaction molar ratio thereof may be appropriately selected,
In the case of C12 monoglyceride and succinic anhydride, 0.5 to 2 succinic anhydride is added to 1 mol of monoglyceride.
The one obtained by the molar reaction shows a good effect of improving the quality of rice. As the fatty acid monoglyceride, for example, one commercially available as distilled monoglyceride can be used.

These organic polycarboxylic acid-fatty acid esters such as glycerin succinic acid fatty acid ester and glycerin cenoic acid fatty acid ester are located at the position where succinic acid or citric acid is bonded to the 1-position or 2-position hydroxyl group of monoglyceride in the production process. An isomer or a product in which two molecules of the polycarboxylic acid are bound to a monoglyceride may be partially produced, but in the present invention, such a mixture may be used as it is. Furthermore, depending on the production conditions, unreacted monoglyceride remains, but there is no particular problem as long as it is the above reaction molar ratio. Also, monoglycerides having different fatty acids may be used in combination.

Further, the salts of glycerin succinic acid fatty acid ester and glycerin succinic acid fatty acid ester are sodium hydroxide in the organic solvent such as water, methanol, ethanol, acetone or the like or a mixed solvent thereof. Produced by preliminarily neutralizing with an alkaline substance such as potassium hydroxide, sodium carbonate, potassium carbonate, or 3Na phosphate, and then distilling off water or an organic solvent, or by using it with other alkaline components such as polyphosphate. It may be produced by a wadding reaction.

The polyglycerin fatty acid ester and sugar or sugar alcohol fatty acid ester used in the present invention are sugars such as polyglycerin, sucrose and glucose, or sugar alcohol such as sorbitan maltitol and fatty acid having 8 to 18 carbon atoms or fatty acid. It is desirable to appropriately select reaction conditions obtained by reacting a lower alcohol ester (methanol, ethanol, etc.), and polyglycerol mono-fatty acid ester or sucrose mono-fatty acid ester, sorbitan fatty acid ester, etc. as main products. The average degree of polymerization of polyglycerin is 2 to 20, preferably 4 to 10.
Is desirable.

The propylene glycol fatty acid ester is
It is preferable that the glycerin fatty acid ester produced by the same reaction as described above contains a monoester as a main component by a method such as molecular distillation or solvent extraction.

The lecithin preferably includes enzyme-decomposed lecithin and enzyme-transferred lecithin. The enzymatically decomposed lecithin is lysolecithin obtained by hydrolyzing the β-position of the two fatty acid residues of lecithin with an enzyme. The enzyme-transferred lecithin is a phosphatidylglycerol obtained by substituting the base bound to the phosphate of lecithin with glycerin by an enzyme.

In the rice treating agent of the present invention, a hydrolase, polyphosphoric acid and / or its salt, organic carboxylic acid and / or its salt can be used in addition to the above-mentioned surfactant.

As the hydrolase, those originating from any of plants, animals and microorganisms can be used. For example, protease, lipase, cellulase, amylase, papain,
Bromelain is exemplified, and those sold in Japan and overseas can be used. Papain is a peptide, amide, ester, especially basic amino acid bond hydrolase of precocious papaya origin, bromelain is an enzyme of plant origin,
Peptides that are commercially produced from pineapple,
Amide and ester hydrolase. These hydrolases may be used alone or in combination of two or more.

Polyphosphoric acid and / or its salt [hereinafter,
As a counter ion of polyphosphoric acid (abbreviated as “salt”), organic carboxylic acid and / or salt thereof [hereinafter referred to as “organic carboxylic acid (salt)”], an alkali metal or an alkaline earth metal is preferable. The polyphosphoric acid (salt) referred to in the present invention means pyrophosphate, tripolyphosphate, which are widely used industrially,
These include tetrapolyphosphoric acid salts and pentapolyphosphoric acid salts, which may be used alone or as a mixture. Commercially available polyphosphoric acid (salt) has tripolyphosphate as a main component (Sixth Edition, Official Guidebook for Food Additives, 1992, Hirokawa Shoten) and is suitable for the purpose of the present invention. Examples of the organic carboxylic acid (salt) include fumaric acid, succinic acid, maleic acid, adipic acid, lactic acid, malic acid, citric acid and the like.

Aqueous solution PH of rice treating agent used in the present invention
Is not particularly limited, but is preferably 6 to 8.5, and may be appropriately adjusted with an acidic or alkaline substance such as an inorganic or organic acid or a salt thereof, if necessary. Also,
The amount of the surfactant, hydrolase, polyphosphoric acid (salt), and organic carboxylic acid (salt) in the rice treatment agent is not particularly limited, but generally the surfactant is 1 to 90% by weight, Preferably 5 to 70% by weight, the hydrolase is 0.1
-30% by weight, preferably 0.5-20% by weight, polyphosphoric acid (salt) and organic carboxylic acid (salt) 1-90% by weight,
It is preferably 5 to 70% by weight.

For the rice treating agent used in the present invention, food additives such as those listed in the Officially Registered Food Additives and food materials such as starch and lactose are appropriately selected as desired within the range not impairing the object of the present invention. You may add it. Further, the form of the present quality improving composition is not particularly limited, such as powder, liquid and paste.

The method of improving the quality of cooked rice using the rice treating agent of the present invention is to mix and contact the aqueous solution of the present composition with the rice in the step of washing the rice before the rice is cooked, and thereafter to add the aqueous solution of the present composition. To separate from rice. It is desirable that this operation be repeated at least once, preferably several times, but once soaking is sufficient. The object of the present invention can be achieved by appropriately performing a normal washing operation before and after the operation of the present invention.

The concentration of the composition used depends on the compounding amounts of the surfactant, hydrolase, polyphosphoric acid (salt) and organic carboxylic acid (salt), but is not uniquely determined, but is usually 0. 01-5% by weight, preferably 0.05-3
Weight percent is preferred. The contact time with the rice may be appropriately selected, but the time required for one washing with water, which is usually performed, is sufficient, and in the case of a composition to which a hydrolase is added, it is preferable to contact for at least about 30 minutes. The temperature of the aqueous solution of the composition at the time of contact can be room temperature or lower temperature to achieve the object of the present invention. Furthermore, mechanical force is preferably applied, and the method is not particularly limited. In the case of dipping, the object of the present invention can be further exerted by stirring during or after dipping.

[0026]

EFFECTS OF THE INVENTION By contacting the aqueous solution of the rice treating agent of the present invention with rice before cooking, the taste of Japanese rice or foreign rice after cooking can be improved, and the number of heat-resistant bacteria can be reduced. Because you can do it, it will last longer.

[0027]

The present invention will be described in more detail by way of examples, which should not be construed as limiting the invention thereto.

Example 1 An aqueous solution (wt%) containing each surfactant in the amount shown in Table 1 was prepared, and the rice was treated and cooked as follows.
The taste was evaluated. In addition, + in the column of PH adjuster indicates that the pH adjuster was added to adjust the pH to the value described in the table. 290 g of Thai long grain rice on the market
After being brought into contact with the above-mentioned aqueous solution of c (20 ° C.) for 30 seconds with light hand stirring, the aqueous solution is rinsed. Repeat this operation 1
Rinse the water after rinsing it gently with the same temperature and the same amount of tap water. The rice thus treated and 600 g of tap water were placed in a commercially available electric kettle to cook the rice, and then steamed for 20 minutes for evaluation. As a comparative example, rice washed with tap water three times was similarly cooked. Regarding the appearance and taste of cooked rice, a paired comparison of the product of the present invention with a comparative example by 7 panelists was carried out based on the following evaluation criteria, and the average score of 7 persons is shown in Table 1. 1 point: comparative example is better 2 point: comparative example is slightly better 3 point: equivalent to comparative example 4 point: slightly better than comparative example 5 point: better than comparative example

[0029]

[Table 1]

Example 2 An aqueous solution (wt%) containing a surfactant and a hydrolase in the amounts shown in Table 2 was prepared, and the rice was treated and cooked as follows,
The taste and storability of cooked rice were evaluated. In addition, + in the column of PH adjuster indicates that the pH adjuster was added to adjust the pH to the value described in the table. Thai long grain rice 29 on the market
After washing 0 g of rice twice with tap water, it is immersed in 500 cc of the above aqueous solution (20 ° C.) for 1 hour with occasional stirring. After that, the immersion water is drained and the rice is washed once with tap water. The thus treated rice and 600 cc of tap water were put in a commercially available electric kettle to cook the rice and then steamed for 20 minutes, and the taste was evaluated in the same manner as in Example 1. The results are shown in Table 2. In addition, the number of heat-resistant spore-forming bacteria in cooked rice immediately after cooking rice and the number of general viable bacteria in cooked rice 24 hours after cooking rice were measured. In case of thermostable spores, cooked rice 1
0 g and 90 ml of sterilized water were placed in a 100 cc Erlenmeyer flask, heat-treated at 85 ° C. for 15 minutes, and rapidly cooled. The mixture is aseptically placed in a homogenizer cup and finely pulverized, the solid matter is separated with a sterilized gauze, and the filtrate is used as a thermostable spore germ test stock solution. As for general live bacteria, 10 g of cooked rice and 90 ml of sterilized water are aseptically placed in a homogenizer cup and finely pulverized, a solid is separated with a sterilized gauze, and a filtrate is used as a general live bacteria test stock solution.

According to the usual method, 1 ml of each sample stock solution and each diluted 10 times, 100 times, and 1000 times with sterile physiological saline were dispensed into a sterile petri dish, and after high pressure sterilization, preheated to about 50 ° C. Standard agar medium that has been kept warm 1
Pour 5 to 20 ml into the Petri dish and immediately pour it so that the sample solution and the medium are well mixed, and leave still until the medium is completely solidified. After coagulation, culturing at 35 ° C. for 2 days, diluting undiluted solution and sterilized physiological saline 10 times, 100 times according to a conventional method,
The average value of the number of settlements of 1000 times the product is measured. The results are shown in Table 2. The number of bacteria is 1 g of cooked rice.

[0032]

[Table 2]

Example 3 An aqueous solution (wt%) containing a surfactant, Na polyphosphate and an organic carboxylic acid in the amounts shown in Table 3 was prepared, and the rice was treated and cooked as follows, after which the appearance and taste of cooked rice were treated. Was evaluated. still,
The + in the column of the pH adjusting agent indicates that the pH adjusting agent was added to adjust the pH to the value described in the table. After washing 310 g of commercially available voluntary rice produced in Japan twice with tap water, 600 g
The aqueous solution of cc (20 ° C.) is brought into contact with the solution for 30 seconds with light hand stirring to rinse the aqueous solution. Then, wash the rice once with tap water. The rice thus treated and 430 ml of tap water were placed in a commercially available electric kettle to cook the rice, and then steamed for 20 minutes, and Example 1
The sensory evaluation was performed in the same manner as in. As a comparative example, rice that had been washed four times with tap water was cooked in the same manner. The evaluation results are shown in Table 3.

[0034]

[Table 3]

Example 4 Glycerin Succinic acid monolauric acid ester 15 parts by weight of a heated melt was added to a powdery mixture of 65 parts by weight of anhydrous sodium sulfate and 15 parts by weight of sodium polyphosphate, and homogenized while appropriately heating. To knead. After cooling to room temperature, it was pulverized to obtain a rice treating agent used in the present invention. Thai rice was treated and cooked in the same manner as in Example 1 using a 0.15 wt% tap water solution of this composition. Similarly, cooked rice treated only with water was prepared as a comparative example. Table 4 shows the results of the sensory evaluation performed in the same manner as in Example 1.

[0036]

[Table 4]

Example 5 Sucrose monolaurate 5 parts by weight, ethanol 1
0 parts by weight, 5 parts by weight of the hydrolase shown in Table 5 and 80 parts by weight of water were mixed and dissolved to prepare a rice treating agent used in the present invention. Using this 0.3% tap water solution, Thai rice was treated and cooked in the same manner as in Example 3, and the appearance, aroma, and taste of the cooked rice were sensory-evaluated in the same manner as in Example 1, and the rice was washed only with water and cooked. The product of the present invention was better than the product of the present invention.

Claims (4)

[Claims] 1. A glycerin fatty acid ester in which a fatty acid residue has 8 to 18 carbon atoms, and a glycerin organic polycarboxylic acid-
A rice treating agent containing one or more surfactants selected from fatty acid esters or salts thereof, polyglycerin fatty acid esters, sugar or sugar alcohol fatty acid esters, propylene glycol fatty acid esters, and lecithin. 2. The rice treating agent according to claim 1, further comprising one or more compounds selected from hydrolases, polyphosphoric acid and / or salts thereof, organic carboxylic acids and / or salts thereof. 3. The rice before cooking rice has 8 carbon atoms in the fatty acid residue.
~ 18 glycerin fatty acid ester, glycerin organic polycarboxylic acid-ester or salt thereof, polyglycerin fatty acid ester, sugar or sugar alcohol fatty acid ester,
A method for treating rice, comprising washing the rice with a rice treating agent containing one or more surfactants selected from propylene glycol fatty acid ester and lecithin, and separating the washing liquid. 4. A rice washing liquid is separated after washing with a rice treating agent containing one or more compounds selected from hydrolases, polyphosphoric acid and / or salts thereof, organic carboxylic acids and / or salts thereof. The method for treating rice according to claim 3, characterized in that