島根県産業技術センター研究報告第56号(2020)

特別寄稿

Highly Water Pressurized Broun Rice and Its Characteristics
Katsumi Yoshino＊, Yoshiaki Nagata＊, Takuya Katsube＊, Hitoshi Kinoshita＊＊,
Tatsushi Matsuda＊＊ and Tadashi Inoue＊＊＊
Abstract
Upon application of high water pressure up to 600MPa, brown rice exhibits various excellent characteristics compared to usual brown rice and also white rice. For example compared to usual brown rice, cooking of highly waterpressurized brawn rice becomes much easier and because of enhanced digestion and absorption of nutrients it exhibits excellent characteristics as healthy food. Specific smelling of brawn rice also disappears. Because of completely
free from spore-forming bacteria, highly water pressurized brown rice is totally suppressed from the oxidation andcorruption, and can be brought in the factories for further treatments. Therefore various new types of products canbe formed, such as highly water pressurized brown rice powder which exhibits much excellent characteristics compared with conventional cooking powder of wheat.
By applying water pressure of 600MPa on long period stored rice which was kept in a tinplate can for 45year byus, specific smelling of long-stored rice disappeared.

１. Introduction

２. Material

Brown rice (BR) is known to be good for health be-

High pressure treatment of foods is known as a non-cause it contains various types of mineral and vitamins

thermal food processing technique. Highly water pres-in bran. However it is not widely used because of diffi-

surized brown rice (HPBR) was prepared by applying

culty of cooking and non-good feeling of chewing.

water pressure of 600MPa for 5sec on brown rice

However upon application of high water pressure up to(BR) using a hydrostatic pressurizer specially designed.

600MPa corresponding to the depth of 60000m below

Non-pressurized brown rice

sea level, brown rice can be well cooked utilizing nor-area of Shimane prefecture was used as starting mate-

mal electric steam rice cooker.1,)2) Because of enhanced

rial. For comparison white rice (polished rice,PR) pre-digestion and absorption of nutrients it exhibits excel-

pared by threshing BR to reduce bran and others waslent characteristics as healthy food. Specific smelling ofalso studied.

brawn rice also disappears upon application of high(BR) obtained in Iinan

３. Highly Water Pressuring Apparatuspressure. Because of completely free from spore-

Specially designed hydrostatic pressuring apparatus

forming bacteria, highly water pressurized brown rice
(HPBR) is totally suppressed from the oxidation andwas used in this study. Brown rice

corruption, and can be brought in the factory for fur-a pressure chamber and ultra-high water pressure up

ther treatments. Therefore highly water pressurized

to 600MPa was applied for 5 second and after releasing

brown rice powder

the pressure the sample was used as highly water(HPBRP) exhibits much excellent

characteristics compared with conventional wheat cook-pressurized brawn rice(HPBR) .

The hydrostatic pressuring apparatus for food engi-ing powder and various new types of products can befabricated.

neering and cross-section figure of the central pressuring area are shown in Figure l.

＊

Shimane Institute for Industrial Technology, 1
Hokuryo-cho, Matsue, Shimane 690-0816 Japan,＊＊
Satoyama food corporation, 1664 Kamiakana,Iinan-cho, Iishi-gun 690-3512 Japan,＊＊＊
Kadomasaya Co.Ltd., 397 Ohno,
Koyaguchi-cho, Hashimoto 649-7207 Japan(BR) was put in

Detailed design ofpressurizing part and schematic explanation of procedure are shown in our previous papers1) ,2) .
W and W, B area in these figures are filled withwater and also with water and working material, in
this case brawn rice. Then these parts were introduced― 32 ―

Yoshino・Nagata・Katsube・Kinoshita・Matsuda・Inoue：Highly Water Pressurized Broun Rice and Its Characteristics

Figure１. Highly water pressurizing apparatus for Food Processing
A：Photograph of apparatus.
B：Cross section figure of the part of pressuring chamberin 10a. Then the piston of 11a is inserted a little in 10a.

may be due to the enhanced water absorbency ofAfter this process, the large size of the jack of 11c1 is

HPBR. After soaking in water for 1 hour, the weight

operated so that the part of 10b will be pressed up

increased by 24.0% in HPBR , 20.5% in PR and, 9.3%

word from the bottom. Then the piston of the 11a willin BR. Because of enhanced digestion and absorption

contact to the fixed part of 11b and then the piston 11a

characteristics, effectively nutrition will be enhanced

will be inserted in 10a and the water filled part will bein HPBR.

pressurized.

It should be noted that free ferulic acid of HPBR
and BR was as high as 17.3mg/100g and much

４. Results and discussion

higher than that of PR. On the other hand upon fer-

4.1 Properties of Highly Water Pressurized Brown Ricementation of HPBR by the usual process of Sake fer-

Fundamental analyses of nutritional composition werementation the free ferulic acid of HPBR in sake lees

performed at Shimane Institute for Industrial Techno-waslogy and additional analyses were also performed atFermentation process in HPBR seems to influence on

Shimane Environment and Health Public Corporation.

formation of free ferulic acid. The mechanism of thisThe nutrient composition in PR, BR and HPBR ismuch

enhancedupto51.8mg/100g

enhancement is now under study.

summarized in Table 1.
Though carbohydrate and protein did not differ
among these samples, there were more dietary fiberand larger amounts of vitamins in HPBR and BR.
These facts suggest that high pressure treatment
does not damage any nutrients. That is because theheat treating process is not applied in this case, excellent staffs such as minerals and vitamins in branremain.
It should be noted that a cooking of HPBR by theusual rice cooker became much easier than BR. This― 33 ―

Table１. Nutrient composition(per 100g)in polishedrice(PR), brown rice(BR)and highly waterpressurized brown rice(HPBR).

島根県産業技術センター研究報告
It should be also pointed out that GABA of HPBR
was much higher than that of PR.

第56号(2020)

ten, and therefore can be used for persons who are
suffering from allergy instead of the powder fromIt should also be mentioned that the residual bac-wheat.

teria became non-detectable after high pressure treat-

Figure 3 indicates examples of products obtained

ment as shown in Figure 2. That is, as evident infrom the powder of highly water pressurized brown

this figure, residual bacteria in BR was as high asrice ( HPBRP) .

50,000,000 CFU/g, but that in HPBR becomes ex-

4.3 Effects of highly water pressurized brown rice on

tremely low of about 300CFU/g.

dementia

4.2 Powder of highly water pressurized brown riceWehavedevelopedwater

Highly water pressurized brown rice HPBR is ex-pressurized

pected to be effective for improvement of dementia( HPBRP) utilizing super powderand Alzheimer s disease. We are collaborating withmill SPM-R430 of Nishimura Machine Works Co. Ltd.

two groups, one is Doshisha University leadered byby using HPBR as starting material. Usual processing

Prof. Hachiro Sugimoto and the other is Shimaneof the powder formation can be applied in this case.

University leadered by Prof. Michio Hashimoto. Details

As explained in the former section high water

will also be discussed in this conference. Parts of thebrown rice powder

highlypressure sterilize spore-forming bacteria and therefore

result were reported in the papers previously 3) ,4) .

the powder from HPBR was not-contaminated and5. Effect of high water pressure on old rice
kept in a tinplate can for 45 years

can be brought in any factory for further processing,because free from bacteria.
Due to decrease of lipid and spore-forming bacteria,
the oxidation and corruption of the powder fromHPBR is also highly suppressed.
That is, this new type of powder have following
specific properties.
１ ) Specific nutrition of HPBR will be effectively absorbed. ２ ) Characteristic smelling specific to brownrice was totally suppressed. 3) Enhanced food texture
will satisfy eating. HPBR gives us chewy and also
crisp feeling. 4) HPBR powder can be mixed withother complementally powder to enhance its utility.
5) It should be stressed that HPBR is free from glu-Figure２. Effect of high water pressure on theresidual bacteria
sample１：Brown rice without treatment ofhigh water pressure (BR)sample２：Brown rice with treatment of highwater pressure (HPBR)

Figure３. Examples of products made of HPBRP(a)Powder of highly pressurized brown rice(HPBRP)(b)Cake made of HRBRP(c)Pan-cake mix made of HRBRP(d)Noodle prepared from HPBRP― 34 ―

Yoshino・Nagata・Katsube・Kinoshita・Matsuda・Inoue：Highly Water Pressurized Broun Rice and Its Characteristics
By applying water pressure of 600MPa on long

45years old rice, I have no difficulty in my stomach.

stored-old rice which was kept in a tinplate box for
45year by us, specific smelling of long-stored rice disap-Summarypeared and upon cooking the pressurized rice becomes

Highly water pressurized brown rice by 600MPs iseatable.

totally different from usual brown rice and exhibits ex-Figure 4 indicates the result of GCMS analysis ofcellent characteristics as healthy food.

volatile components derived from rice samples.
GCMS analysis was carried out as follows; 1g of sam-References

ples and 1ml of water were sealed into HS vials and in-１) Katsumi Yoshino ;Tadashi Inoue. Ultra-high Hydros-

cubated at 95 degree for 45 minutes. Then volatiletatic Pressurizing and Food Process Engineering, J.

components from samples were trapped by SPME

Highly Water Pressurized Food Engineering. 2016,

method for 30 minutes. Concentrated components onvol.1, p.6

SPME fiber were injected into GCMS instrument by２) Tadashi Inoue, Ultra-high pressurized grains andsplitless mode.

its preparation method, Patent No.1885894, 1994

As evident in this figure the intensity of peak No.11３) Michiaki Okuda,; Yuki Fujita; Takuya Katsube; Hiromasa

indicated by an arrow which was considered as n-Tabata; Katsumi Yoshino; Michio Hashimoto andNonaldehyde by MS spectral library, was decreased by

Hachiro Sugimoto,BMCComplementaryand Alternative

high pressure treatment. The n-Nonaldehyde is known

Medicine, 2018,vol.18,p.110
４) Michio Hashimoto; Kentaro Matsuzaki:; Shozo Yano;

as one of the components of old rice odor.
Non-smelling pressurized old rice could be cooked

Eri Sumiyoshi; Osamu Shido; Takuya Katsube;

just like an old rice. The smelling totally disappeared

Mitsumasa Tabata and Katsumi Yoshino, Phanna-and it tasted just like not-so old rice. Though I ate thecometris ,2017,vol.92, p.69-73

Figure４. The result of GCMS analysis of volatile components derived from rice samples.
The intensity of Peak NO.11, which was considered as nonanal (n-Nonaldehyde) by MS spectral library, wasdecreased by high pressure treatment. The nonanal is one of the components of old rice odor.

― 35 ―