JPH11271298A - Method for measuring deterioration of quality of unpolished rice - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and economically prevent unpolished rice from molding by detecting the aroma component present in the unpolished rice before the molding is visually confirmed, or detecting the total weight of the aroma component. SOLUTION: The aroma component present in unpolished rice before molding is visually confirmed is collected, condensed, and detected and analyzed. The chemical materials contained in the aroma component include ethanol, 2- pentanone, 2-heptanone and the like. In the detection and analysis, according to a method using a gas chromatographic mass spectrometer, the chemical materials of the aroma component can be used as index component to easily and surely perform the quantitative detection and identification. According to a method using a conductive polymer sensor, the aroma component is detected by the sensor, the output is calculated by multivariate analysis, and the result is graphed and identified by the difference in pattern, whereby precise detection and identification can be performed. Since the possibility of molding can be detected and discriminated before the molding is visually confirmed, the molding can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring brown rice quality deterioration that can be used in the field of distribution and storage of brown rice.

[0002]

2. Description of the Related Art When storing rice, it is dried in the state of brown rice and stored in a brown rice storage, a prefabricated refrigerator, or the like in order to prevent deterioration in quality. However, it does not mean that the quality does not decrease at all even with brown rice, but when the humidity of rice is too high, white koji rice, bergimos rice,
Microorganisms including fungi such as yellowing rice bacteria are generated. The conventional method for inspecting brown rice is visual, so it depends heavily on experience, and cannot be quantitatively detected.

[0003] The inventors of the present invention have previously proposed a specific flavor component [eg, 3-methyl-1-butanol (3-methh), which is not present in brown rice having no mold, but present in brown rice having mold.
yl-1-butanol), 3-hydroxy-2-butanone,
1-octen-3-ol
Etc.] to detect and identify moldy brown rice (Japanese Patent Application No. 9-258979).
Specification).

[0004]

However, 1-octen-3-ol (1-octen-3-ol) which causes mold odor is caused.
ol) and the like, there was a problem that even if the occurrence of mold was visually observed, it was not detected for a certain period of time.
When distributing and storing brown rice and the like, harmful substances such as mold are generated, and the commercial value is reduced. Therefore, if it is possible to detect and identify before the occurrence of mold, it is very effective. The object of the present invention is to rely on visual observation and experience, and to quantitatively detect and identify the possibility of mold occurrence before the time when mold occurrence is visually observed, and to determine the occurrence of mold based on it. It is an object of the present invention to provide a method for measuring the deterioration of brown rice quality that can take measures such as taking preventive measures.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the conventional problems, and as a result, have detected the aroma components in brown rice before the time when the occurrence of mold was visually observed, or It has been found that by detecting the total amount of such aroma components, the possibility of mold generation can be reliably detected and identified quantitatively, and the present invention has been completed.

[0006] In order to solve the above-mentioned problems, the invention of claim 1 is a method for measuring the deterioration of brown rice quality, characterized by detecting an aroma component existing in brown rice before the time when mold is visually observed.

[0007] The invention of claim 2 of the present invention is a method for measuring brown rice quality deterioration, characterized by detecting the total amount of aroma components in brown rice before the time when the occurrence of mold is visually observed.

According to a third aspect of the present invention, there is provided the method for measuring the deterioration of brown rice quality according to the first or second aspect, wherein the aroma component is collected and concentrated, and analyzed and detected by a gas chromatograph mass spectrometer. It is characterized by doing.

According to a fourth aspect of the present invention, there is provided the method of measuring brown rice quality deterioration according to any one of the first to third aspects, wherein ethanol (Ethano) in the aroma component is used.
l), 2-Pentanone, 2
-Heptanone (2-Heptanone), 1-pentanol (1-Pentanol), 1-hexanol (1-Hexanol), octanoic acid (Octa)
Noic acid) is detected as an index component.

[0010]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, the detection of aroma components in brown rice before the time when mold generation is visually observed, or the detection of aroma components in brown rice before the time when mold generation is visually observed. It is characterized by detecting the total amount of
The detection method is not particularly limited. Usually, the above-mentioned aroma components are collected, concentrated, detected and analyzed. One preferred method for detecting and analyzing is a gas chromatograph mass spectrometer. The above-mentioned odor components contain many chemical substances, and among them, specific odor components such as ethanol (Ethanol), 2-pentanone (2-Pentanone) and 2-heptanone (2-H)
eptanone), 1-pentanol (1-Pent)
anol), 1-hexanol (1-Hexano)
l), Octanoic acid
It is preferable to use d) as an index component because it can be detected and identified quantitatively easily and reliably.

[0011] Other preferable methods for detecting the above-mentioned aroma components include a ceramic semiconductor type sensor, a quartz oscillator type sensor, a conductive polymer type sensor, a MIS type sensor and a BA type sensor.
W (Bulk Acoustic Wave) sensor, SAW (Surface A)
coustic Wave) type sensor, APM (Acoustic Plate Mod)
e) A method using a type sensor, an infrared absorption type sensor or the like, or a combination of these sensors can be used. All of these sensors can be purchased commercially,
Alternatively, it can be created and used easily. Among these sensors, a method using a conductive polymer sensor can be preferably used. The odor component is detected using a conductive polymer type sensor, the output data from this sensor is calculated by a known multivariate analysis method, and the calculation result is displayed on a graph to identify the difference based on the difference in the pattern. Can be detected and identified.

As an example of a device provided with a conductive polymer type sensor, specifically, for example, a movement in which a low ppb level volatile substance is adsorbed and desorbed on a semiconductor polymer type sensor array in which a plurality of specific semiconductor polymers are combined. Detects changes in electrical resistance caused by phenomena and enables mapping of chemical substances in graphic and digital formats (analysis,
Aroma Scan Technology (Aroma Scan plc., UK), which is capable of recognizing and discriminating.

In the present invention, the pretreatment of the brown rice sample is not particularly limited.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to embodiments, but the present invention can be variously modified without departing from the spirit of the appended claims. (Example 1) Brown rice with no visible mold (Koshihikari brown rice from Uonuma, Niigata Prefecture) was placed in a beaker, covered with a wrap film and stored at 25 ° C. After storage for 14 days, after storage for 16 days, After storage for 20 days and after storage for 25 days, sampling was performed, and aroma components were collected and concentrated by the following method, detection and analysis were performed, and mold detection of brown rice was visually detected by the following method.

(Collection / Concentration, Detection, and Analysis of Aroma Components) Brown rice before storage and 12 g of sampled brown rice are put into a 25 ml eggplant-shaped flask, kept at 25 ° C. for 3 minutes, and then nitrogen gas (50 cc) for 10 minutes. / Min) to introduce gas in the headspace to the Tenax collector (TENA).
XTA (80 mg, manufactured by GL Sciences Inc.) was adsorbed on a Tenax resin and collected. ThermalDesor
ption Cold Trap Injector
(CROMPACK) and analyzed using a GC / MS (gas chromatograph mass spectrometer 5972A, manufactured by Yokogawa Electric Corporation) (analysis conditions: Injection t).
emp. 250 ° C., detector temp. 25
Hold at 0 ° C and oven temperature of 40 ° C for 5 minutes.
The temperature was raised to 250 ° C at a rate of 250 ° C / min.
Minutes. Column used HP INOWAX 0.25
mm × 60 m × 0.25 μm).

(Method of Visually Detecting Mold in Brown Rice) 100 brown rice randomly picked from brown rice before storage and sampled brown rice were subjected to an Olympus stereo microscope (SZ-P).
T) was visually observed to determine whether mold had developed in the germ part, and the number of brown rice having mold had been measured.

Brown rice before storage and after storage for 14 days, after storage for 16 days, after storage for 20 days, after storage for 25 days (mold generation)
Table 1 shows the results of mold detection visually (the number of molds generated / 100 grains) for the brown rice sampled in FIG.

The brown rice sampled after storage for 14 days, after storage for 16 days, after storage for 20 days, and after storage for 25 days was evaluated for a specific odor component [ethanol (Eth).
anol), 2-Pentanon
e), 2-Heptanone, 1
-Pentanol (1-Pentanol), 1-hexanol (1-Hexanol), octanoic acid (O
ctanoicacid)] and the total amount of each flavor component are shown in Table 2.

FIGS. 1 (a) and 1 (b) show the results of quantifying the total aroma components of brown rice before storage and brown rice sampled after storage for 14 days, respectively. For brown rice sampled after 16 days storage and 20 days storage,
The results of quantifying the total odor components are shown in FIGS. 2 (a) and (b), respectively. FIG. 3 shows the results of quantifying the total aroma components of brown rice sampled with a large amount of mold after storage for 25 days. Brown rice before storage and after storage for 14 days, 16
For brown rice sampled after storage for 20 days, after storage for 20 days, and after storage for 25 days, specific flavor components [ethanol (Et)
hanol), 2-pentanone (2-Pentanon)
e), 2-Heptanone, 1
-Pentanol (1-Pentanol), 1-hexanol (1-Hexanol), octanoic acid (O
ctanoicacid)] is shown in FIG. 4 and FIG. FIG. 5 is a graph showing an enlarged vertical axis of the graph shown in FIG.

[0020]

[Table 1]

[0021]

[Table 2]

According to Table 1, no mold was observed visually until storage for 14 days, but after storage for 16 days, mold generation was observed in 1 out of 100 grains, and after storage for 20 days, 4 out of 100 grains. Mold was observed on the rice, and after storage for 25 days, 100
It turns out that mold generation was observed in 100 of the grains. Table 2, FIG. 1 (a), (b), FIG. 2 (a), (b), FIG.
From FIGS. 4 and 5, it can be seen that the aroma component did not rapidly increase until storage for 14 days, but the aroma component increased rapidly after storage for 16 days. Examples of specific aroma components that showed a sharp increase include ethanol (Ethanol),
2-pentanone (2-Pentanone), 2-heptanone (2-Heptanone), 1-pentanol (1-Pentanol), 1-hexanol (1-H
exanol), octanoic acid (Octanoic acid)
acid).

From Table 2, FIG. 4, and FIG. 5, the total amount of a certain fragrance component alone or the total amount of two or more of these specific fragrance components is a predetermined value. If it exceeds, the occurrence of mold is not visually observed,
It turns out that the possibility of mold generation can be quantitatively detected and identified. From Table 2, FIG. 4 and FIG. 5, the above-mentioned predetermined value is, in terms of the output value (abundance) of GC / MS, Ethanol: 100.000 or more 2-pentanone: 1.000.000 or more 2- Heptanone: 1.000.000 or more 1-pentanol: 5,000.000 or more 1-Hexanol: 100.000 or more Octanoic acid: It is considered to be 1.000.000 or more. In other words, if changes in these odor components are detected, it is possible to predict a decrease in the quality of brown rice before the occurrence of mold, so that it is possible to take measures before the brown rice is contaminated with mold odor.
The method of detecting the odor component is not limited to GC / MS, but may be any semiconductor sensor, quartz crystal sensor, conductive polymer sensor, or any other device capable of detecting the odor component as described above.

1 (a), 1 (b), 2 (a),
(B) From FIG. 3, it can be seen that the total amount of the fragrance component including the specific fragrance component increases before the occurrence of mold. Therefore, by monitoring the increase in the total amount of not only the above-mentioned specific odor components but also the odor components including these specific odor components, it is possible to predict the deterioration of brown rice quality before the occurrence of mold. For example, FIG. 1 (a), (b), FIG. 2 (a),
(B) According to the result of GC / MS shown in FIG. 3, since mold is found at a total amount of about 100.000.000, an alarm is sounded at a total amount of 50.000.000, so that the mold is generated before the occurrence of the mold. The occurrence of mold can be easily and economically prevented by detecting the possibility of occurrence and taking measures.

[0025]

EFFECT OF THE INVENTION The present invention detects the fragrance component in brown rice before the time when mold generation is visually observed, or detects the total amount of fragrance components in brown rice before the time when mold generation is visually observed. Anyone can reliably and quantitatively detect the possibility of the occurrence of mold before the time when the occurrence of mold is observed, without relying on visual observation or experience, without relying on visual observation or experience. Based on this, it is possible to take measures such as taking measures to prevent the occurrence of mold, so that it is possible to easily and economically prevent the occurrence of mold in brown rice. Examples of the method for detecting the fragrance component include a method of collecting and concentrating the fragrance component, and analyzing and detecting the fragrance component with a gas chromatograph mass spectrometer. Ethanol, 2-pentanone (2-Penta) in the aroma components
none), 2-heptanone (2-Heptanon)
e), 1-Pentanol, 1
-If hexanol (1-Hexanol) or octanoic acid is detected as an index component, it can be easily and reliably quantitatively detected and identified, and mold can be generated before mold is visually observed. Sex can be easily known.

[Brief description of the drawings]

FIG. 1 (a) is a graph showing the results of quantifying the total aroma components of brown rice before storage, and FIG. 1 (b) is a graph showing the results of quantifying the total aroma components of brown rice sampled after storage for 14 days. .

FIG. 2 (a) is a graph showing the results of quantifying the total aroma components of brown rice sampled after storage for 16 days, and FIG. 2 (b) shows the results of quantifying the total odor components of brown rice sampled after storage for 20 days. It is a graph.

FIG. 3 is a graph showing the results of quantifying the total aroma components of brown rice sampled after storage for 25 days.

FIG. 4 shows a specific flavor component [ethanol (Etha) of brown rice before storage and brown rice sampled after storage for 14, 16 days, 20 days, and 25 days.
nol), 2-pentanone
e), 2-Heptanone, 1
-Pentanol (1-Pentanol), 1-hexanol (1-Hexanol), octanoic acid (O
10 is a graph showing the results of quantification of C. tanoicacid).

5 is a graph showing an enlarged vertical axis of the graph shown in FIG. 4;

Claims (4)

[Claims] 1. A method for measuring brown rice quality deterioration, comprising detecting an aroma component present in brown rice before the time when mold is visually observed. 2. A method for measuring brown rice quality deterioration, which comprises detecting a total amount of aroma components in brown rice before the time when mold is visually observed. 3. The method according to claim 1, wherein the flavor component is collected and concentrated, and analyzed and detected by a gas chromatograph mass spectrometer. 4. Ethanol (Eth) in the aroma component
anol), 2-Pentanon
e), 2-Heptanone, 1
-Pentanol (1-Pentanol), 1-hexanol (1-Hexanol), octanoic acid (O
The method for measuring brown rice quality deterioration according to any one of claims 1 to 3, wherein ctanic acid) is detected as an index component.