KR20030079351A - Method for detecting the volatile compounds of irradiated meat by using electronic nose - Google Patents

Abstract

PURPOSE: A method for detecting volatile compounds of irradiated meat by using an electronic nose is provided, thereby easily detecting off-flavor of the irradiated meat. CONSTITUTION: A method for detecting volatile compounds of irradiated meat by using an electronic nose comprises the steps of: introducing different kinds of irradiated meat into the electronic nose with a sensor array consisting of one or more metal oxide sensors; measuring the sensor resistance(Rgas) exposed to the volatile compounds of the irradiate meat; measuring the sensor resistance(Rair) in the air and determining a resistance ratio of Rgas/Rair; and applying the resistance ratio of Rgas/Rair to principal component analysis or neural network analysis, wherein the metal oxide sensor comprises a hydrogen sulfate sensor, an ammonia sensor, a hydrocarbon volatile steam sensor, an alcohol and organic solvent steam sensor, an air pollution sensor and a combustible gas sensor.

Description

Method for detecting the volatile compounds of irradiated meat by using electronic nose}

The present invention relates to a method for detecting volatile compounds of irradiated edible meat using an electronic nose. More specifically, the present invention relates to a method for detecting volatile compounds of irradiated edible meat using an electronic nose equipped with a sensor array consisting of six six metal oxide sensors.

Irradiation is well known for prolonging the shelf life of meat by protecting it against pathogenic bacteria and parasites. On the other hand, irradiation results in biochemical changes that can affect the nutritional and sensory acceptability of the treated food. For example, a lot of radiation increases unacceptable off-flavors due to radiolytic oxidation of lipids.

There are several ways to detect irradiated food. Physical methods include thermoluminescence (TL), photostimulated luminescence (PSL) and electron spin resonance (ESR). Chemical methods include the use of GC or GC / MS analyzers to detect hydrocarbons produced from fat-containing foods when exposed to radiation, and DNA, the microgel electrophoresis of single cells. “Comet” assays, TL for identifying irradiated species and agricultural products, and ESR spectroscopy for detecting irradiated chicken, pork, and beef. Through DNA methods, irradiated fruits, beef and grains can also be identified. Hydrocarbons are detected in irradiated pork, bacon and ham, and 2-alkylcyclobutanone in irradiated beef and chicken. This method is used in combination with mass spectroscopy, which in some cases is time consuming and requires pretreatment of the sample to remove particulate matter in advance. The methods also require expensive equipment and considerable technical skills.

Recently, electronic noses have been introduced that consist of an array of electrochemical sensors with partial specificity and an appropriate pattern-recognition system capable of recognizing a single or complex scent. Various applications of electronic noses in the food industry have been reported. These include quality assessment of ground meat, detection of differences in boar taint and meat in meat products, identification of producers for agricultural production, and monitoring of fragrance components in beer and sausages. ), And an estimate of the freshness of orange juice and milk.

Furthermore, the detection of irradiation treatment of red pepper and analysis of lipid oxidation of soybean oil using an electronic nose has been reported. This suggests that it is possible to measure fat oxidation and off-flavors after meat radiation using an electronic nose.

In the present invention, the possibility of identifying irradiated meat using an electronic nose was investigated. Principal component analysis and neural network systems have also been applied to the identification of irradiated meat.

In view of the above, the inventors of the present invention have measured the volatile compounds in the meat by using an electronic nose equipped with a sensor array composed of six metal oxide sensors after irradiating the meat. The present invention was completed by measuring the resistance ratio of the sensor and the resistance ratio when exposed to volatile compounds, and the change of the resistance ratio in the electronic nose according to hydrocarbon concentration, radiation dose, storage temperature and storage time.

Accordingly, an object of the present invention is to provide a method for detecting volatile compounds of irradiated edible meat using an electronic nose.

The object of the present invention is to detect the volatile compounds in the meat meat by using an electronic nose equipped with a sensor array consisting of six metal oxide (six metal oxide) sensors after irradiating the meat and the resistance of the sensor measured in the air and This was achieved by measuring the resistance ratio when exposed to volatile compounds and examining the change in resistance ratio in the electronic nose with the hydrocarbon concentration, radiation dose, storage temperature and storage time.

Hereinafter, the configuration of the present invention.

1 is a graph showing the change in resistance ratio measured by an electronic nose for volatile compounds of edible meat irradiated with different dosages.

Figure 2 is a graph showing the results of the principal component analysis of the resistance ratio measured by the electronic nose for the volatile compounds of edible meat irradiated with different dosages.

FIG. 3 is a graph showing the change in resistance ratio measured by an electronic nose for volatile compounds of edible meat irradiated at different dosages during storage at −20 ° C. FIG.

FIG. 4 is a graph showing the change in resistance ratio measured by electronic nose for volatile compounds of edible meat irradiated with different dosages during storage at 4 ° C. FIG.

The present invention comprises the steps of storing the food for 8 weeks after irradiation; Analyzing the volatile compounds of the edible meat in the electronic nose to obtain a ratio of the sensor resistance measured in the air and the sensor resistance measured in the state exposed to the gas; Investigating the influence of hydrocarbon concentration on the resistance ratio; Investigating the effect of radiation dose on the resistance ratio; Investigating the effect of storage temperature and storage time on the resistance ratio.

In the present invention, n-pentadecane, 1-hexadecene, 1-hexadecene, n-heptadecane (Acros, USA), and 1-tetradecene (1-tetradecene) (Aldrich Hydrocarbons such as USA, USA) were used as standard materials and analyzed by electronic nose under the same conditions as hydrocarbons in irradiated edible meat.

Data analysis in the present invention is principal component analysis (principle component analysis) performed using a multivariate statistics analysis program (MVSAP, version 3.1) developed by Lee, DS (Korea, Seoul, Seoul Women's University) Is applied to data obtained from sensors that detect irradiated edible meat. Lab windows / CVI (National Instrument Co., USA) was used to develop the neural network analysis program.

Hereinafter, the specific method of the present invention will be described in detail with reference to Examples, but the scope of the present invention is not limited only to these Examples.

Example 1 Irradiation and Storage of Edible Meat

Using ⁶⁰ Coγ- radiation irradiation ⁽⁶⁰ Co γ-irradiator) in; (Republic of Korea in Daejeon material Korea Atomic Energy Research Institute) 1, edible flesh (食用肉) [Van tendon shaped muscle (muscle semitendinosus)] 100g of Korea Atomic Energy Research Institute The radiation was irradiated at 3, 5 and 10 kGy. Ceric cerous dosimeters were used to confirm the absorbed dose (± 0.2 kGy).

The irradiated and non-irradiated control samples as described above were stored at −20 to 4 ° C. for 8 weeks prior to use in sealed PE / Nylon bags.

Example 2 Analysis by Electronic Nose

An electronic nose equipped with a sensor array consisting of six six metal oxide sensors (Table 1) used a product manufactured by Hanbit Instrument (Seoul, South Korea). Six sensors were purchased from Figaro Co. (Tokyo, Japan). A gas sample was injected at a defined time by opening a computer controlled valve. Data from metal oxide sensors was also collected by the computer. The ratio of resistance is defined as R _gas / R _air , where R _air and R _gas are the resistance of the sensor measured in air and exposed to gas, respectively.

Electronic Metal Sensors Sensor number Sensor model specification One TGS825 Hydrogen sulfide 2 TGS824 Ammonia 3 TGS880 Hydrocarbon volatile vapors 4 TGS822 Alcohol and organic solvent vapors 5 TGS800 Air contamination 6 TGS813 Combustible gas

For analysis, 10 g of irradiated edible meat was placed in a 325 ml glass jar sealed with polyethylene. Equilibration time for analysis was 3 minutes in the electronic nose. All measurements were performed at 30 ° C. The measurement process includes the steps of heater cleaning for 10 seconds, cleaning the sensors in the electronic nose, pumping clean air for 10 seconds and the upper space of irradiated edible meat for 60 seconds. (headspace) analysis.

Six six metal oxide sensors were used for the analysis of volatile compounds in irradiated products. Therefore, the resistance ratio decreased below 1 as the gas concentration increased. As they were exposed to target gases (volatile compounds), the sensors indicated a change in resistance. This resistance change was used for subsequent data processing. The resistance ratio is significantly influenced by the sensing layer materials and the type of sensor selected. For the measurement of volatile compounds in irradiated edible meat using an electronic nose, conditions such as sample volume, extraction time and extraction temperature are utilized to the maximum as the resistance ratio is measured. lost. The resistance ratio was the lowest at 60 seconds. After 60 seconds the resistance ratio increased, presumably due to the dilution effect in the sample bottles. The introduced volatile compounds reacted with the metal oxide sensor, and the concentration of the absorbed compounds decreased after the maximum value due to the inflow of fresh air. Therefore, the reaction time of the metal oxide sensors was set to 60 seconds.

Experimental Example 1: Effect of hydrocarbon concentration on the resistance ratio in the electronic nose

When food is irradiated, many volatile compounds are formed. Such compounds are useful as markers for radiation treatment. The proportion of radioactive products from lipids such as volatile hydrocarbons, aldehydes or butanones is directly linked to the chemical constituents of the lipids. When fatty acids are exposed to high energy radiation, they undergo selective cleavage, unlike other treatments, which occur in the ester carbonyl region. Two types of hydrocarbons are produced prominently from irradiation of fatty acids. One having one carbon less than the parent fatty acid (C _n-1 ) and the other having two carbons less than the parent fatty acid and having an additional double bond at position 1 (C _n-2 , 1-ene).

In general, edible meats include palmitic acids, stearic acids, oleic acids and linoleic acids. Therefore, pentadecane (C15: 0) and 1-tetradecene (C14: 1) from palmitic acid, heptadecane (C17: 0) and 1-hexadecene (from stearic acid) 1-hexadecene) (C16: 1), 8-heptadecene (C17: 1) from oleic acid and 1,7-hexadecadiene (C16: 2), linoleic acid Edible from which 6,9-heptadecadiene (C17: 2) and 1,7,10-hexadecatriene (C16: 3) were irradiated from It is expected to be detected in the body. Therefore, an electronic nose was applied for the detection of these hydrocarbons.

As the concentration of hydrocarbons increased, the resistance ratio in the electronic nose decreased (Table 2).

Variation of Electronic Resistance Sensor Resistance Ratio for Hydrocarbons Ingredient Amount (μl) Ratio of resistance of sensor One 2 3 4 5 6 n-Pentadecane One 0.730149 0.789994 0.718620 0.769595 0.768724 0.717356 10 0.678543 0.703196 0.641649 0.687661 0.699985 0.661227 100 0.670634 0.705182 0.666492 0.684812 0.707993 0.666874 1-tetradeken (1-Tetradecene) One 0.723765 0.742420 0.689683 0.746177 0.744328 0.683364 10 0.576273 0.577400 0.611006 0.555427 0.597845 0.620125 100 0.343623 0.351991 0.481924 0.290678 0.380819 0.516689 n-heptadecane (n-Heptadecane) One 0.733449 0.787785 0.781527 0.736588 0.739035 0.745206 10 0.628989 0.647454 0.627126 0.612798 0.632104 0.643379 100 0.437414 0.452615 0.599648 0.397729 0.381146 0.616245 1-hexadecene (1-Hexadecene) One 0.676067 0.687073 0.624060 0.661934 0.678603 0.621314 10 0.584823 0.560031 0.539976 0.542876 0.579837 0.562437 100 0.563039 0.542602 0.628179 0.520841 0.583104 0.647084

Some sensors generally responded well to the hydrocarbons. The response of the sensor was correlated with the concentration of hydrocarbons. This indicates that the electronic nose can detect irradiated edible meat. Therefore, other volatile compounds as well as hydrocarbons from irradiated edible meat are due to the different types of sensors selected (Table 1).

Experimental Example 2: Effect of dosage on resistance ratio in electronic nose

Electronic noses with six metal oxide sensors were used to identify edible and unirradiated edible meats at 1, 3, 5 and 10 kGy. Sensor 4 showed the lowest resistance ratio in the electronic nose (FIG. 1). The resistance ratio in sensor 4 was 0.41 in unirradiated edible meat and 0.21 in edible meat irradiated at 10 kGy. As the dose increased, the resistance ratio decreased. Detection of irradiated red pepper by the nose showed a good segregated pattern of treated samples as the dose increased.

The data collected by the electronic nose was used to identify irradiated edible meat for PCA. Irradiated edible meat at different doses was sorted through PCA (FIG. 2). The first principal component score was 0.980 and the second principal component score was 0.01. PCA of irradiated edible meat showed a characteristic occurrence of off-flavor at different dose levels. As the dose increased, the PCA plot expanded from the left (negative value of the first principal component) through the middle to the right (positive value of the first principal component). As the irradiated meat was detected, it was found that the first principal component was related to the dose or the degree of off-flavor.

A neural network analysis has been developed to identify irradiated edible meat and applied to unknown samples. Known data of irradiated edible meat was used as data for understanding neural networks. On the basis of the database, an input pattern and a target pattern were set up for the back propagation learning algorithm. After supervised learning, unknown sample data was entered into the learned neural network system and analyzed to detect the dose. Output patterns analyzed through the neural network analysis system showed the dose of unknown samples. Table 3 shows the exact probability of predicting the dosage of an unknown sample in the electronic nose. It was found that an unknown irradiated sample was successfully detected.

Classification of Edible Meats Irradiated at Different Radiation Dose by Electronic Nose Resistance Ratio and Artificial Neural Network Progran Irradiation Predicted dose (kGy) Correct probability (%) Actual dose (kGy) 0 One 3 5 10 0 8/8 100 One 8/8 100 3 1/8 6/8 1/8 75 5 7/8 1/8 87.5 10 2/8 6/8 75

Experimental Example 3 Effects of Storage Temperature and Storage Time on the Resistance Ratio in Electronic Noses

When the irradiated edible meat was stored at -20 ° C, the resistance ratio increased at low dose levels. However, the refraction ratio was similar to the initial resistance ratio at 10 kGy (FIG. 3). When the dose is 10 kGy, the electronic nose can detect the deteriorating fragrances generated by radiation, not through rancidity. When the irradiated edible meat was stored at 4 ° C., the resistance ratio rapidly decreased in the unirradiated edible meat. The resistance ratios of the edible meats irradiated at 1, 3 and 5 kGy were lower than the non-irradiated edible meats (FIG. 4). When the dose was low and the storage temperature was high, the electronic nose was able to detect altered perfume from irradiated and rancid samples. Therefore, storage temperature is very important for the detection of irradiated meat.

Electron nose analysis can be used as a very effective way to detect radiation treatment for edible meat. The invention, which uses an array of gas sensors and pattern recognition together, has the advantages of being faster, nondestructive, simple and cheap compared to other methods including GC / MS. The present invention can be further developed for use in the electronic nose for the purpose of quality assessment in the food industry.

As described above, the method for detecting the volatile compounds of irradiated edible meat using the electronic nose of the present invention as described through the above embodiment is to detect the volatile compounds of the irradiated edible meat using the electronic nose and measured in the air. Irradiated edible meat can be identified by obtaining the ratio of the sensor resistance measured in the state exposed to the sensor resistance and the volatile compound, which is a very useful invention for the livestock industry.

Claims (2)

Placing the irradiated edible meat at different doses inside the electronic nose equipped with a sensor array comprising one or more metal oxide sensors; Measuring a sensor resistance (R _gas ) in a state of being exposed to volatile compounds emitted from irradiated edible meat; Measuring a resistance ratio R _gas / R _air resistance of the sensor (R _air) been measured at the sensor resistor (R _gas) and air been measured in the above step; A method of detecting volatile compounds of irradiated edible meat, characterized in that the step of applying the resistance ratio according to the different doses obtained in the step to principal component analysis or neural network analysis. The method of claim 1, wherein the metal oxide sensor is a sensor for detecting hydrogen sulfide, a sensor for detecting ammonia, a sensor for detecting hydrocarbon volatile vapor, a sensor for detecting alcohol and organic solvent vapor, a sensor for detecting air pollution and a flammable gas Method for detecting volatile compounds of irradiated edible meat, characterized in that the group consisting of sensors for detecting.