CN104089984A - Portable frozen fish flesh quality detection device and detection method using the same - Google Patents

Abstract

The invention discloses a portable frozen fish flesh quality detection device and a detection method using the same. The portable frozen fish flesh quality detection device comprises a detection probe, a miniature air pump, a gas chamber, an operational amplifier, a data acquisition card, a memory, a microprocessor, a display screen, an air pump flow-velocity regulating switch and several control buttons, and the miniature air pump and the gas chamber are connected to the detection probe. An output end of the operational amplifier is electrically connected to the data acquisition card. The microprocessor is electrically connected respectively to the data acquisition card, the display screen, the memory, the miniature air pump and all the control buttons. A free end of the detection probe is provided with an air inlet, and the air inlet is provided with a filter screen. A filter pad is arranged in the air inlet at the inner side of the filter screen. Multiple gas sensitive membranes are arranged in the gas chamber. All the gas sensitive membranes are electrically connected respectively to an input end of the operational amplifier. The portable frozen fish flesh quality detection device has the advantages of good economy, small volume, simple detection and fast rate, is suitable for household usage, and can provide reliable guarantee for improvement of safety of household food materials.

Description

Portable frozen fish meat quality detection device and detection method

technical field

The invention relates to the technical field of food quality detection, in particular to a portable frozen fish quality detection device and detection method that can accurately detect whether frozen fish is corrupt.

Background technique

Fish meat has the characteristics of rich nutrition and good taste, and is deeply loved by consumers.

However, during the frozen storage of fish meat, as the storage time increases, the fish meat is easily polluted and deteriorates. With the proliferation of microorganisms and a series of physical and chemical changes, the freshness of fish meat decreases. Rich nutrients such as protein, fat, and carbohydrates are utilized by bacteria and enzymes to produce acid gases such as ammonia, ammonia sulfide, aldehydes, aldehydes, ketones, ethyl mercaptans, alcohols, and carboxylic acids. Aldehydes, ketones, esters and other low-molecular compounds in metabolites cause fish to produce off-flavors.

People usually judge the quality of food through their senses, and this judgment is often highly subjective, and the results of evaluation and analysis often vary greatly with age and experience. Even the same person can get different results due to physical conditions and emotional changes. Moreover, olfactory identification is a process of inhalation of volatile substances. Long-term experiments will cause harm to human health, and some bad smells will make the judges particularly sensitive and cause errors in the results; The evaluation team is composed of personnel, the process is relatively cumbersome, and the evaluation results are often not repeatable.

And fish meat is a kind of food raw material, at present, there is no effective method to detect the quality of frozen fish meat.

Chinese patent authorization announcement number: CN101769889A, authorized announcement date July 7, 2010, discloses an electronic nose system for quality inspection of agricultural products, including a gas enrichment module that mainly completes the collection of low-concentration odors, and a main odor signal The gas chamber air circuit module and sensor array that converts electrical signals, a sensor conditioning circuit and data preprocessing module that mainly filter, analog-to-digital conversion, and feature extraction output signals from the sensor array, identify and judge a pair of signals, and bring An embedded system with data storage, a display and result output module; the gas enrichment module is composed of an adsorption tube filled with adsorbent, an electric heating wire and a temperature control device. The invention has the disadvantages of single function, long detection time and being unsuitable for household use.

Contents of the invention

The object of the present invention is to provide a portable frozen fish quality detection device and detection method that can accurately detect whether the frozen fish is spoiled in order to overcome the disadvantages of expensive and bulky detection devices in the prior art.

In order to achieve the above object, the present invention adopts the following technical solutions:

A portable frozen fish meat quality detection device, including a detection probe, a miniature air pump and an air chamber connected to the detection probe, an operational amplifier, a data acquisition card, a memory, a microprocessor, a display screen, an air pump flow rate adjustment switch and several control buttons The output terminal of the operational amplifier is electrically connected with the data acquisition card, and the microprocessor is electrically connected with the data acquisition card, display screen, memory, air pump and each control button respectively; A filter screen is provided on the gas port, and a filter pad is provided in the air inlet inside the filter screen; several gas-sensitive films are provided in the air chamber, and each gas-sensitive film is respectively electrically connected to the input end of the operational amplifier. The flow rate adjustment switch of the air pump is used to adjust the flow rate of the air flow, which is divided into three levels: strong, medium and weak, corresponding to the large, medium and small flow rates respectively. It can be used to control the flow rate of the gas flow during the detection process. The filter screen is used to prevent large-sized impurities from entering the detection probe, and the filter pad is used to prevent small-sized impurities from entering the detection probe.

During the measurement process, the measurer holds the detection probe with one hand, closes the air inlet to the fish to be detected, and performs a selection operation on the control button with the other hand, and the detection device starts to measure. The microprocessor calculates and analyzes the detected data, and when it is judged that the fish meat is spoiled, the microprocessor controls the touch screen to display the alarm information of the meat spoilage.

The frozen fish meat quality detection device of the present invention is economical, small in size, easy to carry, simple and fast in detection, suitable for home use, and can provide reliable guarantee for improving the safety of food materials.

Preferably, there are eight gas-sensitive membranes, which are respectively the first gas-sensitive membrane for detecting sulfide, the second gas-sensitive membrane for detecting hydrogen, and the third gas-sensitive membrane for detecting ammonia. The fourth gas sensitive membrane for detecting alcohol, toluene and xylene, the fifth gas sensitive membrane for detecting hydrocarbon gas, the sixth gas sensitive membrane for detecting methane and propane, and the sixth gas sensitive membrane for detecting nitrogen oxides The seventh gas sensitive membrane, the eighth gas sensitive membrane for detecting butane.

As a preference, the gas-sensitive film is in the shape of a hollow spindle with openings at both ends and a length of 12 to 15.5 mm, and a rectangular insulating circuit board is arranged in the gas chamber, and each gas-sensitive film is welded on the insulating circuit board at equal intervals. The diameter of the middle part of the gas sensitive film is 3.3 mm to 3.6 mm, the diameter of both ends of the gas sensitive film is 1.5 to 1.7 mm, and the thickness of the gas sensitive film is 1 mm to 1.3 mm; the cavity of the gas sensitive film is provided with a heating resistance wire, The two ends of the heating resistance wire are electrically connected to the power supply through the heating pins respectively. There are two detection pins and two fixed pins connected to the insulating circuit board on the gas sensitive film. The two detection pins are respectively connected to the operational amplifier. The non-inverting input terminal and the inverting input terminal are electrically connected.

The structure of the gas-sensitive film of the present invention helps to improve the gas detection accuracy. In the working state, the gas-sensitive film is heated to 300-480°C by the resistance wire. When the measured gas is carried to the surface of the sensor sensitive film, the gas molecules are It is oxidized under the action of high temperature, and the oxidation products are attached to the surface of the gas sensitive membrane, causing the change of the resistance of the gas sensitive membrane. According to the change of the resistance value, the gas concentration can be characterized. Different gas-sensitive films of the present invention are made of different materials, and each gas-sensitive film is only sensitive to a specific gas, that is, the gas-sensitive film has specificity.

Preferably, the air chamber has a width of 0.9 cm to 1.2 cm, a length of 1.5 cm to 1.9 cm, and a thickness of 0.35 cm to 0.5 cm. The advantage of the smaller size of the air chamber is that it avoids the existence of turbulent flow, has high detection accuracy, and requires a small amount of air intake.

As preferably, a detachable cover plate is also provided on the detection probe near the air inlet; a housing is also included, and the air chamber, operational amplifier, data acquisition card, memory and microprocessor are located in the housing, and the display screen and Each control button is located on the shell, and the length of the shell is 16 cm to 20 cm, the width is 6 cm to 8 cm, and the thickness is 1.5 cm to 2 cm.

Preferably, the operational amplifier is a UPC4570 low-noise operational patch amplifier, the data acquisition card is a low-power embedded data acquisition card based on MSP430F5438, and the microprocessor is an MSP430F149 low-power embedded MCU.

SMD amplifier, low-power embedded data acquisition card based on MSP430F5438, MSP430F149 low-power embedded single-chip microcomputer and touch screen selection make the detection device of the present invention small in size, light in weight, easy to carry, and more suitable for home use.

A detection method of a frozen fish meat quality detection device, comprising the steps of:

(7-1) A cascaded bistable stochastic resonance system model is provided in the memory, and the cascaded bistable stochastic resonance system model includes a first-order bistable stochastic resonance system model: and the second-order bistable stochastic resonance system model with the output x(t) of the first-order bistable stochastic resonance system model as the input signal: Among them, V(x) and V(y) are nonlinear symmetric potential functions, ξ(t) is Gaussian white noise, a and b are the input signal strength, _f0 is the modulation signal frequency, D is the noise strength, is the phase, x and y are the motion displacement of the particle, and t is the time;

The memory is also equipped with the single-stage stochastic resonance system model and the calculation formula of the signal-to-noise ratio: $\mathrm{SNR}=2\[\underset{\mathrm{\Δ\ω}\&Right\; Arrow;0}{\lim }\underset{\mathrm{\Ω}-\mathrm{\Δ\ω}}{\overset{\mathrm{\Ω}+\mathrm{\Δ\ω}}{\∫}}S\left(\mathrm{\ω}\right)\mathrm{d\ω}\]/S_N\left(\mathrm{\Ω}\right)$ ; Wherein ω is the signal frequency, Ω is the angular frequency, S (ω) is the signal spectral density, S _N (Ω) is the noise intensity in the signal frequency range; The mildew threshold N of fish is provided with in the microprocessor;

(7-2) Take the frozen fish sample out of the freezer, place it at room temperature for 30 minutes to 1 hour, put the air inlet of the detection probe close to the fish sample, and the microprocessor controls the detection probe to evaporate the volatile gas emitted by the meat. The volatile gas is inhaled into the air chamber for 5 to 20 seconds, the volatile gas is in contact with each gas sensitive film installed in the air chamber, and each gas sensitive film generates a response signal respectively, and the microprocessor calculates the average signal of each response signal to obtain the detection signal I(t).

(7-3) Input I(t) into the cascaded bistable stochastic resonance system model, adjust the values of a and b, so that the cascaded bistable stochastic resonance system model resonates, and the microprocessor will resonate a and b values are stored in memory;

(7-4) The microprocessor sets a set of f ₀ , and t value to get a set of parameter values x ₁ , y ₁ , and substitute a, b and x ₁ , y ₁ into the formula Calculated in Set the recovery signal of the detection signal I(t) as Input h(t) into the single-stage bistable stochastic resonance model to make the single-stage bistable stochastic resonance model resonate;

(7-5) Microprocessor utilization formula Calculate the excitation noise signal-to-noise ratio SNR, the microprocessor draws the output signal-to-noise ratio spectrum diagram of the stochastic resonance system model, selects the signal-to-noise ratio spectrum characteristic value noise width W in the signal-to-noise ratio spectrum diagram, and sets the signal-to-noise ratio spectrum characteristic value The value noise width W is compared with the mildew threshold N of fish meat; when |W|≥|N|, the microprocessor controls the display screen to display the alarm information of fish meat corruption.

The portable fish meat detection device of the present invention has small volume, small air chamber volume, limited gas flow rate of the micro-air pump adopted, short detection time, and less data length collected by the data acquisition card, usually requiring more than 1000 pieces of data to be collected. Accurate detection results can be obtained, but the data collected in the data acquisition card is only 80 to 110, and the low number of collected data will lead to a decline in detection accuracy. Therefore, the present invention adopts a unique data recovery method to perform non-destructive recovery on low-sampled data, and turns limited sampled data into unlimited data, thus ensuring the requirement of detection accuracy.

Then, input h(t) into the single-stage bistable stochastic resonance of the fish, so that the single-stage bistable stochastic resonance resonates; the microprocessor draws the output signal-to-noise ratio spectrum of the stochastic resonance system model. Select the signal-to-noise ratio spectrum eigenvalue noise width W in the ratio spectrum, and compare the signal-to-noise ratio spectrum eigenvalue noise width W with the mildew threshold N of fish meat; when |W|≥|N|, the microprocessor The control touch screen displays the alarm information of the corruption of this kind of meat.

Preferably, the detection signal includes 80 to 110 detection data.

Preferably, the single-stage bistable stochastic resonance model is Among them, V(x) is the nonlinear symmetric potential function, ξ(t) is Gaussian white noise, a ₁ is the input signal intensity, f ₀ is the modulation signal frequency, D is the noise intensity, is the phase, x is the motion displacement of the particle, and t is the time.

Therefore, the present invention has the following beneficial effects: (1) good economy, small size, simple and rapid detection; (2) suitable for family use, and can provide reliable guarantee for improving the safety of fish.

Description of drawings

Fig. 1 is a kind of functional block diagram of the present invention;

Fig. 2 is a kind of flowchart of the embodiment of the present invention;

Fig. 3 is a kind of structural representation of insulating circuit board and gas-sensitive film of the present invention;

Fig. 4 is a kind of structural representation of the present invention;

Fig. 5 is a schematic structural view of the detection probe of the present invention.

In the figure: detection probe 1, air pump 2, air chamber 3, operational amplifier 4, data acquisition card 5, memory 6, microprocessor 7, display screen 8, control button 9, insulating circuit board 10, adjustment switch 11, Air port 12, filter screen 13, filter pad 14, cover plate 15, housing 16, heating pin 17, detection pin 18, fixing pin 19, gas sensitive film 20.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

The embodiment shown in Fig. 1, Fig. 4, Fig. 5 is a kind of portable frozen fish meat quality detection device, comprises detection probe 1, the miniature air pump 2 that is connected with detection probe and air chamber 3, operational amplifier 4, data acquisition card 5 , memory 6, microprocessor 7, display screen 8, air pump flow rate adjustment switch 11 and 7 control buttons 9; the output end of the operational amplifier is electrically connected with the data acquisition card, and the microprocessor is respectively connected with the data acquisition card, display screen, The memory, the air pump and 6 control buttons are electrically connected; the free end of the detection probe is provided with an air inlet 12, the air inlet is provided with a metal filter 13, and the air inlet inside the filter is provided with a sponge filter pad 14; Eight gas-sensitive films 20 are arranged in the chamber, and the eight gas-sensitive films are respectively electrically connected to the input terminals of the operational amplifier.

As shown in Figure 3, the eight gas-sensitive membranes are respectively the first gas-sensitive membrane for detecting sulfide, the second gas-sensitive membrane for detecting hydrogen, the third gas-sensitive membrane for detecting ammonia, and the third gas-sensitive membrane for detecting ammonia. The fourth gas-sensitive membrane for detecting alcohol, toluene, and xylene, the fifth gas-sensitive membrane for detecting hydrocarbon gas, the sixth gas-sensitive membrane for detecting methane and propane, and the sixth gas-sensitive membrane for detecting nitrogen oxides Seven gas-sensitive membranes, eighth gas-sensitive membranes for detecting butane.

The gas-sensitive film is in the shape of a hollow spindle with two ends openings with a length of 15.5 mm. The gas chamber is provided with a rectangular insulating circuit board 10, and each gas-sensitive film is welded on the insulating circuit board at equal intervals. The diameter of the middle part of the gas-sensitive film is 3.6 mm, the diameter of both ends of the gas sensitive film is 1.5 mm, and the thickness of the gas sensitive film is 1 mm; a heating resistance wire is arranged in the cavity of the gas sensitive film, and the two ends of the heating resistance wire pass through the heating pin 17 and the power supply wire respectively. connection, two detection pins 18 and two fixed pins 19 connected to the insulating circuit board are provided on the gas sensitive film, and the two detection pins are respectively electrically connected to the non-inverting input terminal and the inverting input terminal of the operational amplifier. The air chamber has a width of 1 cm, a length of 1.7 cm, and a thickness of 0.4 cm.

The detection probe near the air inlet is also provided with a detachable cover plate; it also includes a housing 16, the air chamber, operational amplifier, data acquisition card, memory and microprocessor are located in the housing, and the display screen and each control button are located in the housing. On the casing, the length of the casing is 18 cm, the width is 6.8 cm, and the thickness is 1.7 cm.

The 7 control buttons are power button, measure button, reset button and 4 direction buttons. When the detection probe touches the detection sample, the measurement button is pressed, and the detection device starts to measure. When the test is over, press the measurement button again, the test stops and the data is automatically saved and analyzed, and the result is given. The reset button is used for reset and reset, which is the system reset process to prevent the system from crashing and malfunctioning.

The 4 direction buttons are used to operate the menu. You can flexibly move the cursor up, down, left, and right according to the menu information on the touch screen. If you want to enter the menu in any direction, just press and hold the button in that direction. Left is to exit, right to enter the menu, up and down to select the menu of the same level.

The operational amplifier is a UPC4570 low-noise operational patch amplifier, the data acquisition card is a low-power embedded data acquisition card based on MSP430F5438, and the microprocessor is an MSP430F149 low-power embedded MCU.

A kind of detection method of frozen fish meat quality detection device as shown in Figure 2, comprises the steps:

(7-1) A cascaded bistable stochastic resonance system model is provided in the memory, and the cascaded bistable stochastic resonance system model includes a first-order bistable stochastic resonance system model: and the second-order bistable stochastic resonance system model with the output x(t) of the first-order bistable stochastic resonance system model as the input signal: Among them, V(x) and V(y) are nonlinear symmetric potential functions, ξ(t) is Gaussian white noise, a and b are the input signal strength, _f0 is the modulation signal frequency, D is the noise strength, is the phase, x and y are the motion displacement of the particle, and t is the time;

The memory is also equipped with the single-stage stochastic resonance system model and the calculation formula of the signal-to-noise ratio: $\mathrm{SNR}=2\[\underset{\mathrm{\Δ\ω}\&Right\; Arrow;0}{\lim }\underset{\mathrm{\Ω}-\mathrm{\Δ\ω}}{\overset{\mathrm{\Ω}+\mathrm{\Δ\ω}}{\∫}}S\left(\mathrm{\ω}\right)\mathrm{d\ω}\]/S_N\left(\mathrm{\Ω}\right)$ ; Wherein ω is the signal frequency, Ω is the angular frequency, S (ω) is the signal spectral density, S _N (Ω) is the noise intensity in the signal frequency range; The mildew threshold N of fish is provided with in the microprocessor;

In this embodiment, the mildew threshold of fish meat N=-45.63dB.

Step 100, take the frozen fish sample out of the freezer, place it at room temperature for 30 minutes, put the air inlet of the detection probe close to the fish sample, and the microprocessor controls the detection probe to suck the volatile gas emitted by the meat into the air chamber In 20 seconds, the volatile gas is in contact with each gas-sensitive film arranged in the gas chamber, and each gas-sensitive film generates a response signal respectively, and the microprocessor calculates the average signal of each response signal to obtain the detection signal I(t);

Step 200, input I(t) into the cascaded bistable stochastic resonance system model, adjust the values of a and b, so that the cascaded bistable stochastic resonance system model resonates, and the microprocessor will resonate a=7.5 and b=2.4 values are stored in memory;

Step 300, the microprocessor sets a group of cascaded bistable stochastic resonance system models and t=1.5 value, get a set of parameter values x ₁ =0.58, y ₁ =1.14, put a=7.5, b=2.4 and x ₁ =0.58, y ₁ =1.14 into the formula Calculated in get Set the recovery signal of the detection signal I(t) as h(t)=-0.98t+0.9t ³ , and input h(t) into the single-stage bistable stochastic resonance model of fish In the process, the single-stage bistable stochastic resonance model is resonated; the single-stage bistable stochastic resonance models of different meats are different;

Step 400, the microprocessor utilizes the formula Calculate the excitation noise signal-to-noise ratio SNR, the microprocessor draws the output signal-to-noise ratio spectrum diagram of the stochastic resonance system model, selects the signal-to-noise ratio spectrum eigenvalue noise width W in the output signal-to-noise ratio spectrum diagram, and converts the signal-to-noise ratio spectrum The eigenvalue noise width W is compared with the mildew threshold N of fish; when |W|≥|N|, the microprocessor controls the touch screen to display the alarm information of fish corruption.

In the present embodiment, the microprocessor draws the output signal-to-noise ratio spectrogram of the detected fish meat, and makes a straight line whose ordinate is equal to -90dB in the output signal-to-noise ratio spectrogram, and obtains the two near peaks and valleys of the straight line and the curve. The abscissas of the intersection points are W ₁ =107dB and W ₂ =206dB, W=W ₂ -W ₁ =99dB.

In this embodiment, W=99dB of frozen fish, and the mildew threshold N=-45.63dB of frozen fish; therefore, |W|>|N| of frozen fish, then the microprocessor controls the touch screen to display the alarm information of frozen fish corruption .

It should be understood that this embodiment is only used to illustrate the present invention but not to limit the scope of the present invention. In addition, it should be understood that after reading the teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

Claims (9)

1. a portable freezing flesh quality pick-up unit, it is characterized in that the micro air pump (2) that comprise detection probe (1), is connected with detection probe and air chamber (3), operational amplifier (4), data collecting card (5), storer (6), microprocessor (7), display screen (8), air pump flow velocity transfer switch (11) and several control knobs (9); The output terminal of operational amplifier is electrically connected to data collecting card, and described microprocessor is electrically connected to data collecting card, display screen, storer, air pump and each control knob respectively; The free end of detection probe is provided with air intake opening (12), and air intake opening is provided with screen pack (13), in the air intake opening of screen pack inner side, is provided with filter pad (14); In described air chamber, be provided with several gas sensitization films (20), each gas sensitization film is electrically connected to the input end of operational amplifier respectively.

2. portable freezing flesh quality pick-up unit according to claim 1, it is characterized in that, described gas sensitization film is 8, be respectively the first gas sensitization film for detection of sulfide, the second gas sensitization film for detection of hydrogen, the 3rd gas sensitization film for detection of ammonia, for detection of alcohol, toluene, the 4th gas sensitization film of dimethylbenzene, the 5th gas sensitization film for detection of hydrocarbon component gas, the 6th gas sensitization film for detection of methane and propane, the 7th gas sensitization film for detection of oxides of nitrogen, the 8th gas sensitization film for detection of butane.

3. portable freezing flesh quality pick-up unit according to claim 1, it is characterized in that, it is the both ends open hollow spindle shape of 12 to 15.5 millimeters that described gas sensitization film is length, in described air chamber, be provided with on rectangle insulating circuit board (10), each gas sensitization film is uniformly-spaced welded on insulating circuit board, gas sensitization film middle part diameter is 3.3 millimeters to 3.6 millimeters, gas sensitization film two ends diameter is 1.5 to 1.7 millimeters, and the thickness of gas sensitization film is 1 millimeter to 1.3 millimeters; In the cavity of gas sensitization film, be provided with resistive heater, resistive heater two ends are electrically connected to power supply by heating pin (17) respectively, gas sensitization film is provided with two and detects pins (18) and two that are connected with insulating circuit board fixing pins (19), and two are detected pins and are electrically connected to in-phase input end and the inverting input of operational amplifier respectively.

4. portable freezing flesh quality pick-up unit according to claim 1, is characterized in that, the width of described air chamber is 0.9 centimetre to 1.2 centimetres, and length is 1.5 to 1.9 centimetres, and thickness is 0.35 centimetre to 0.5 centimetre.

5. according to the portable freezing flesh quality pick-up unit described in claim 1 or 2 or 3 or 4, it is characterized in that, near in the detection probe of air intake opening, be also provided with dismountable cover plate (15); Also comprise housing (16), described air chamber, operational amplifier, data collecting card, storer and microprocessor are positioned at housing, described display screen and each control knob are positioned on housing, the length of housing is 16 centimetres to 20 centimetres, width is 6 centimetres to 8 centimetres, and thickness is 1.5 centimetres to 2 centimetres.

6. according to the portable freezing flesh quality pick-up unit described in claim 1 or 2 or 3 or 4, it is characterized in that, operational amplifier is UPC4570 low noise computing paster amplifier, data collecting card is the low-power-consumption embedded data collecting card based on MSP430F5438, and microprocessor is the low-power-consumption embedded MCU of MSP430F149.

7. a detection method for portable freezing flesh quality pick-up unit according to claim 1, is characterized in that, comprises the steps:

(7-1) in storer, be provided with cascade bistable-state random resonance system model, described cascade bistable-state random resonance system model comprises one-level bistable-state random resonance system model: with using the output x (t) of one-level bistable-state random resonance system model as the secondary bistable-state random resonance system model of input signal: wherein, V (x) and V (y) are non-linear symmetric potential function, and ξ (t) is white Gaussian noise, and a and b are input signal strengths, f ₀be frequency modulating signal, D is noise intensity, for phase place, x and y are particle movement displacement, and t is the time;

In storer, be also provided with and single-stage stochastic resonance system model and snr computation formula: $\mathrm{SNR}=2\[\underset{\mathrm{\Δ\ω}\→0}{\lim }\underset{\mathrm{\Ω}-\mathrm{\Δ\ω}}{\overset{\mathrm{\Ω}+\mathrm{\Δ\ω}}{\∫}}S\left(\mathrm{\ω}\right)\mathrm{d\ω}\]/S_N\left(\mathrm{\Ω}\right)$ ; Wherein ω is signal frequency, and Ω is angular frequency, and S (ω) is signal spectral density, S _n(Ω) be the noise intensity in signal frequency range; In microprocessor, be provided with the threshold value N that goes mouldy of the flesh of fish;

(7-2) freezing flesh of fish sample is taken out from refrigerating plant, at room temperature place 30 minutes to 1 hour, by the close flesh of fish of the air intake opening of detection probe sample, microprocessor is controlled escaping gas that detection probe gives out meat and is sucked in air chamber 5 to 20 seconds, escaping gas contacts with each gas sensitization film in being located at air chamber, each gas sensitization film produces respectively response signal, and microprocessor calculates the average signal of each response signal, obtains detection signal I (t):

(7-3) by I (t) input cascade bistable-state random resonance system model, regulate the numerical value of a and b, cascade bistable-state random resonance system model is resonated, a and the b value of microprocessor when resonating is stored in storer;

(7-4) microprocessor is set one group of f in cascade bistable-state random resonance system model ₀, with t value, obtain one group of parameter value x ₁, y ₁, by a, b and x ₁, y ₁substitution formula middle calculating the restoring signal of setting detection signal I (t) is by in h (t) input single-stage bistable-state random resonance model, single-stage bistable-state random resonance model is resonated;

(7-5) microprocessor utilizes formula calculate excitation noise signal to noise ratio snr, microprocessor draws the output signal-to-noise ratio spectrogram of stochastic resonance system model, in signal to noise ratio (S/N ratio) spectrogram, choose signal to noise ratio (S/N ratio) spectrum signature value noise width W, and signal to noise ratio (S/N ratio) spectrum signature value noise width W is compared with the threshold value N that goes mouldy of the flesh of fish; When | W|>=| during N|, microprocessor is controlled the warning message that display screen shows that the flesh of fish is corrupt.

8. the detection method of portable freezing flesh quality pick-up unit according to claim 7, is characterized in that, described detection signal comprises that 80 to 110 are detected data.

9. according to the detection method of the portable freezing flesh quality pick-up unit described in claim 7 or 8, it is characterized in that, described single-stage bistable-state random resonance model is wherein, V (x) is non-linear symmetric potential function, and ξ (t) is white Gaussian noise, a ₁input signal strength, f ₀be frequency modulating signal, D is noise intensity, for phase place, x is particle movement displacement, and t is the time.