CN110089549A - The undamaged online preservation method of one seed oyster - Google Patents

Abstract

The present invention relates to the technical field of oyster preservation, in particular to an on-line freshness preservation method without damage to oysters. The freshness preservation method of the present application is to take fresh live oysters and remove their shells to remove the meat, put the oyster meat into A solution for cleaning, and then put the freshness preservation After soaking, the oysters were wrapped tightly with plastic bags. The oysters were sampled irregularly at room temperature, and the freshness of the oysters was tested with a near-infrared spectrometer, which can quickly distinguish whether the oyster meat is fresh and store them separately. The fresh-keeping at room temperature will not cause secondary pollution of oysters, will not damage oyster tissues, is simple to operate, does not require sample processing and expensive instruments, and can quickly achieve the distinction of oyster meat quality.

Description

A No-damage Online Fresh-keeping Method for Oysters

【Technical field】

The invention relates to the technical field of fresh-keeping oysters, in particular to an online fresh-keeping method without damage to oysters.

【Background technique】

Oyster, commonly known as oyster, also known as oyster yellow and sea oyster, is regarded as a delicious sea treasure and a bodybuilding food because of its delicious taste and complete nutrition. Therefore, among many marine treasures, many people have a soft spot for oysters. Due to the tenderness of oyster meat, if it is not properly preserved after harvest, it will deteriorate within 2 days. At present, domestic research on oyster preservation is frozen storage and controlled atmosphere storage. However, these two methods of storing oysters still have complex operations and a short shelf life. Technical defects; the general preservation period is about 7 days; although some preservatives are currently used in oyster preservation, due to their unreasonable ratio, the shelf life is often short, and oysters may cause secondary pollution. Freshness is the most important thing when adding other biological preservatives, which may cause it to be mixed with preservatives and taste bad; the index for measuring the freshness of oysters is TVB-N, which usually requires crushing of materials. The traditional chemical method will destroy the tissue structure of the oyster, the measurement process is troublesome, and it will also damage the oyster, which is not conducive to freshness monitoring. The applicant of this patent used the electronic nose method to test the freshness of oysters in the scheme "A Method for Preserving Oysters" filed on the same day. However, the freshness preservation agent of this scheme cannot realize the freshness of oysters at room temperature. Therefore, the applicant carried out After further research, it was found that adding the egg white of sea duck eggs to the preservative can prolong the shelf life of aquatic products to a certain extent, but in continuous practice, it was found that the use of sea duck eggs in the preservative would cause misjudgment by the electronic nose, resulting in ineffective detection Therefore, it is necessary to improve the freshness preservation method of oysters, which can simply and conveniently carry out freshness preservation and non-damage monitoring of oysters, and at the same time, the freshness preservation method will not destroy the taste of oysters.

【Content of invention】

In view of the above, it is necessary to provide an online fresh-keeping method for oysters without damage, which can keep oysters fresh at room temperature. The method will not destroy the taste of oysters.

In order to achieve the above object, the technical scheme adopted in the present invention is:

An on-line fresh-keeping method without damage to oysters, said method is: take fresh and live oysters, remove the shells and take the meat, put the oyster meat into solution A to wash, then put the oysters into the preservative and soak them for 90-120 minutes, after soaking the oysters After being fished out, put the fish in the refrigerator until the surface preservative layer becomes hard, wrap it tightly with a fresh-keeping bag, and keep it fresh at room temperature. The oyster meat is stored separately; the detection model of the near-infrared analysis method is: Y=0.7807X+0.6391, where Y is an approximate coefficient; X is the number of bands.

Further, the A solution is composed of the following components by weight: 13-17 parts of sodium chloride, 16-19 parts of trehalose, 4-9 parts of lemon juice and 120-150 parts of water.

Further, the antistaling agent is composed of the following components by weight: 7-14 parts of tea polyphenols, 5-9 parts of rosemary powder, 15-20 parts of chitosan, 12-18 parts Parts of egg white, 14 parts-19 parts of dragon fruit stem extract, 6 parts-11 parts of sodium alginate and 170 parts-180 parts of water.

Further, the egg white is separated from sea duck eggs.

Further, the preparation method of the pitaya stem extract is as follows: peel the pitaya stem and mash it directly, then add 2 times the volume ratio of water to mix, oscillate and suspend to obtain a suspension, and add and suspend to the suspension Extract equal volumes of absolute ethanol, and carry out reflux extraction in a constant temperature pot. After extraction for 2h-3h, take the filtrate and carry out rotary evaporation and concentration, evaporate the ethanol, and dry to obtain the dragon fruit stem extract.

Further, when the Y value is 0.218, the oyster meat is judged as fresh.

Further, the construction method of the near-infrared model is:

(1) Oyster sample collection and sample preparation: mince oyster meat with different rotten degrees, and then place it in a refrigerator at -4°C;

(2) Spectrum scanning: Use a near-infrared spectrometer to perform near-infrared spectrum scanning on each sample to be tested. The near-infrared spectrum scanning range of each sample is 120-1200nm, the resolution is 0.03-8.4nm, and the number of scans is 3;

(3) Spectral correction: use the formula R=(R ₀ -R _d )/(R _w -R _d )×100% to correct the obtained original spectral data, where R ₀ is the original hyperspectral image; R _d is a black board with 0% reflectance, and is a black reference image obtained by covering the lens with a fully opaque camera cover; _Rw is a white board with 99% reflectance, and is a white reference image obtained by reflecting off a white polytetrafluoroethylene calibration board ;

(4) Spectral image segmentation and feature extraction: In order to obtain the typical spectrum of the sample, remove the background from the original hyperspectral image in step (2); the removal method of the background is: subtract a low reflection band from the high reflection band to construct The mask of the image is then segmented by mask and threshold calculation; after image segmentation, the easily identifiable part of the frozen sample is placed in the area of the region of interest, and then the average of the spectrum in the region of interest is taken value as the spectrum of the sample;

(5) Spectrum model establishment: In the spectral data sets obtained at different sample temperatures, 2/3 of the data were randomly selected as calibration sets to establish spectral models; the remaining 1/3 were classified as verification sets for model testing; After the spectral model and the test model are completed, the statistical correlation coefficient R ² and the mean square error RMSECP are used for the detection and correction of the verification model, and the corrected model is used to quickly identify and classify the samples to be identified.

The present invention has following beneficial effects:

The present invention is a fresh-keeping method for oysters under normal temperature conditions. In the pretreatment process, it has similarities with "A Method for Fresh-keeping Oysters" filed on the same day: both use A solution and preservative, but the difference is that A The ratio of the solution is different, and the ratio of the antistaling agent is different; these differences are effective researches on the normal temperature preservation of oysters. In the continuous research of the applicant, it was found that: oysters should be kept fresh under normal temperature conditions. Just need to increase the consumption of sodium chloride, sodium chloride can play a bactericidal effect, but, in order to balance the discomfort that sodium chloride brings to oysters, need to increase trehalose and lemon juice, balance mouthfeel in turn, the application In order to keep seafood fresh at room temperature, it is necessary to add sea duck egg white to the ingredients. Compared with other egg whites, sea duck egg white has higher viscosity, better fluidity and coagulation, and chitosan in the diluted ingredients has good The role of the dispersing ability of the oyster, so that the preservative components can fully flow to all parts of the oyster, and the preservative components are attached to the surface of the oyster. The measured value of the electronic nose is higher than the actual TVB-N content, which may be caused by the volatilization of a certain component in sea duck egg white, which leads to the wrong signal from the probe and misjudgment of the TVB-N content; therefore, the applicant researched and used near-infrared analysis method to analyze the freshness of oysters; at the same time, in this scheme, the antistaling agent is composed of tea polyphenols, rosemary powder, chitosan, sea duck egg white, dragon fruit stem extract, sodium alginate and water, and the antistaling agent Chinese tea polyphenols have antibacterial effect. The pitaya stem extract contains a large amount of dragon fruit polysaccharides. In addition to the antibacterial effect, it can also form a film on the surface of the oyster meat, effectively isolating the oyster and the air; The antistaling agent components are effectively dispersed and tightly attached to the surface of the oyster meat to form a film. However, adding too much will also affect the oyster smell, and adding too little will not form a film, which will affect the fresh-keeping effect. Therefore, the applicant added chitosan to make the oyster meat The surface can effectively form a film; rosemary powder can not only play a role in sterilization, but also play a role in balancing the smell of preservatives; sodium alginate can play a role in balancing the cytoplasm of oyster meat and balancing the taste; in order to overcome the inaccurate test of electronic nose The applicant used near-infrared analysis to judge the freshness of oyster meat.

【Description of drawings】

Fig. 1 is the scanning chart of infrared spectrometer when modeling of the present invention; Among the figure, abscissa is band, and unit is nm; Ordinate is spectral absorption value approximation coefficient, has no unit.

Fig. 2 is predicted value and measured value correlation figure of the present invention, among the figure, abscissa is predicted value; Vertical coordinate is measured value; R ² is correlation coefficient.

【Detailed ways】

All features disclosed in this specification, or steps in all methods or processes disclosed, may be combined in any manner, except for mutually exclusive features and/or steps.

Unless expressly stated otherwise, any feature disclosed in this specification (including any appended claims, abstract) is only one example of a series of equivalent or similar features.

Example 1:

An on-line fresh-keeping method without damage to oysters, the method is: take fresh and live oysters and remove the shells to get the meat, put the oyster meat into a solution A to clean, then put it into a preservative and soak it for 90 minutes, remove the oysters after soaking Put the fish in the refrigerator until the surface preservative layer becomes hard, wrap it tightly with a fresh-keeping bag, and keep it fresh at room temperature. During the fresh-keeping period, samples are taken from time to time, and the samples are distinguished by near-infrared analysis to separate fresh and spoiled oyster meat deposit.

The preparation method of the A solution in the plan is: Weigh the following raw materials by weight: 13 parts of sodium chloride, 16 parts of trehalose, 4 parts of lemon juice and 120 parts of water; then fully mix the raw materials to obtain the A solution .

In the scheme, the antistaling agent is composed of the following components by weight: 7 parts of tea polyphenols, 5 parts of rosemary powder, 15 parts of chitosan, 12 parts of egg white, 14 parts of dragon fruit stem extract, 6 parts sodium alginate and 170 parts of water; wherein, the egg white is separated from sea duck eggs.

The preparation method of the dragon fruit stem extract in the preservative is as follows: directly smash the dragon fruit stem after peeling, then add 2 times the volume ratio of water to mix, shake and suspend to obtain a suspension, and add the suspension and the like to the suspension. Volume of absolute ethanol, reflux extraction in a constant temperature pot, after extraction for 2h, take the filtrate and carry out rotary evaporation concentration, evaporate ethanol, dry to obtain dragon fruit stem extract.

The preparation method of the antistaling agent in the scheme is: take the following raw materials by weight: 7 parts of tea polyphenols, 5 parts of rosemary powder, 15 parts of chitosan, 12 parts of egg whites, 14 parts of dragon fruit stems Extract, 6 parts of sodium alginate and 170 parts of water; then fully mix the raw materials, emulsify at a high speed to obtain a preservative.

Example 2:

A method for online preservation of oysters without damage. The method is as follows: take fresh and live oysters and remove the shells to get the meat, put the oyster meat into solution A to wash, then put the oysters in a preservative and soak them for 120 minutes, take out the oysters after soaking Put the fish in the refrigerator until the surface preservative layer becomes hard, wrap it tightly with a fresh-keeping bag, and keep it fresh at room temperature. During the fresh-keeping period, samples are taken from time to time, and the samples are distinguished by near-infrared analysis to separate fresh and spoiled oyster meat deposit.

The preparation method of the A solution in the scheme is: Weigh the following raw materials by weight: 17 parts of sodium chloride, 19 parts of trehalose, 9 parts of lemon juice and 150 parts of water; then fully mix the raw materials to obtain the A solution .

In the scheme, the antistaling agent is composed of the following components by weight: 14 parts of tea polyphenols, 9 parts of rosemary powder, 20 parts of chitosan, 18 parts of egg white, 19 parts of dragon fruit stem extract, 11 parts sodium alginate and 180 parts of water; wherein, the egg white is separated from sea duck eggs.

The preparation method of the dragon fruit stem extract in the preservative is as follows: directly smash the dragon fruit stem after peeling, then add 2 times the volume ratio of water to mix, shake and suspend to obtain a suspension, and add the suspension and the like to the suspension. Volume of absolute ethanol, reflux extraction in a constant temperature pot, after extraction for 3h, take the filtrate and carry out rotary evaporation concentration, evaporate ethanol, dry to obtain dragon fruit stem extract.

The preparation method of the antistaling agent in the scheme is: take the following raw materials by weight: 14 parts of tea polyphenols, 9 parts of rosemary powder, 20 parts of chitosan, 18 parts of egg whites, 19 parts of dragon fruit stems Extract, 11 parts of sodium alginate and 180 parts of water; then fully mix the raw materials, emulsify at a high speed to obtain a preservative.

Example 3:

A method for online preservation of oysters without damage. The method is as follows: take fresh and live oysters and remove the shells to get the meat, put the oyster meat into solution A to wash, then put the oysters in a preservative and soak them for 110 minutes, take out the oysters after soaking Put the fish in the refrigerator until the surface preservative layer becomes hard, wrap it tightly with a fresh-keeping bag, and keep it fresh at room temperature. During the fresh-keeping period, samples are taken from time to time, and the samples are distinguished by near-infrared analysis to separate fresh and spoiled oyster meat deposit.

The preparation method of A solution in the scheme is: Weigh the following raw materials by weight: 15 parts of sodium chloride, 18 parts of trehalose, 6 parts of lemon juice and 140 parts of water; then fully mix the raw materials to obtain A solution .

In the scheme, the antistaling agent is composed of the following components by weight: 10 parts of tea polyphenols, 7 parts of rosemary powder, 17 parts of chitosan, 14 parts of egg white, 17 parts of dragon fruit stem extract, 8 parts sodium alginate and 175 parts of water; wherein, the egg white is separated from sea duck eggs.

The preparation method of the dragon fruit stem extract in the preservative is as follows: directly smash the dragon fruit stem after peeling, then add 2 times the volume ratio of water to mix, shake and suspend to obtain a suspension, and add the suspension and the like to the suspension. Volume of absolute ethanol, reflux extraction in a constant temperature pot, after extraction for 2.5h, take the filtrate and carry out rotary evaporation concentration, evaporate ethanol, dry to obtain dragon fruit stem extract.

The preparation method of the antistaling agent in the scheme is: take the following raw materials by weight: 10 parts of tea polyphenols, 7 parts of rosemary powder, 17 parts of chitosan, 16 parts of egg whites, 17 parts of dragon fruit stems extract, 8 parts of sodium alginate and 175 parts of water; then, the raw materials are fully mixed, emulsified by high-speed oscillation to obtain a preservative.

In embodiment 1-3, the oyster used is near river oyster; The near-infrared analysis method of embodiment 1-3 is: the first 0-20d after fresh-keeping, detect once a day oyster meat sample, detect 3 groups of samples simultaneously every day; , put the meat sample directly into the near-infrared analyzer for scanning, bring the value into the detection model for calculation, and judge whether the oyster meat is fresh; the scanning range of the near-infrared spectrum is 120-1200nm, and the resolution is 0.03-8.4nm. The number of times is 3.

The freshness distinction model is: Y=0.7807X+0.6391,

In the formula, Y represents the approximation coefficient;

X indicates the band.

When Y is 0.218, it is judged as fresh.

The construction and verification process of the freshness discrimination model of near-infrared spectrometer:

1. Construction of near-infrared model:

Without any fresh-keeping treatment, the oyster meat samples from the nearby river were only tested at -4°C (continuous test for 10 days), and the corresponding data collected were sorted out to build a freshness discrimination model, as follows:

(1) Oyster sample collection and sample preparation: mince oyster meat with different rotten degrees, and then place it in a refrigerator at -4°C;

(2) Spectrum scanning: Use a near-infrared spectrometer to perform near-infrared spectrum scanning on each sample to be tested. The near-infrared spectrum scanning range of each sample is 120-1200nm, the resolution is 0.03-8.4nm, and the number of scans is 3;

(3) Spectral correction: Image calibration can eliminate interference from light intensity changes and reduce image noise. Calibration of the graph using the following equation:

R=(R0- _Rd )/( _Rw - _Rd )*100%.

where R0 is the original hyperspectral image;

Rd is a blackboard with 0% reflectance and is the black reference image obtained by covering the lens with a fully opaque camera cover;

Rw is a white board with 99% reflectance, and is a white reference image obtained by reflection from a white polyethylene calibration board.

(4) Spectral image segmentation and feature extraction: In order to obtain a typical spectrum of a sample, the background of the image should be removed from the hyperspectral image. The background removal operation is a mask constructed by subtracting a low-reflection band from a high-reflection band, and then the image is segmented by masking and thresholding. After image segmentation, the pixels of the frozen sample can be easily identified as regions of interest, and then the spectra within the region of interest are averaged as the sample spectrum. Background segmentation and spectrum extraction were carried out using software ENVI14.8 (ITT America Visual Information Solution Company).

(5) Spectrum model establishment: the algorithm establishes a spectral model for measuring the temperature of the sample. In the spectral datasets obtained at different sample temperatures, 2/3 of the data were randomly screened as calibration sets to establish spectral models; the remaining 1/3 were classified as validation sets for model testing. The statistical correlation coefficients for evaluating model performance are R2 and mean square error RMSECP. Use the wavelet transform (Fourier transform) method to transform and analyze hyperspectral data. For wavelet transform, it is very important to determine the decomposition level of the signal. Usually, the decomposition level is calculated by referring to the following formula:

mdl=INT(log2(s)).

In the formula: md1 is the minimum description length;

INT is the decomposition series;

S is the transform wave number.

Using this formula to decompose the original spectrum, the analyzed wavelet coefficients (cA and cD) can be used as input variables of the calibration model for spectral modeling and prediction.

(6) Data processing method: SPSS 19.0 and Origin 8.5 were used for statistical analysis and graphing of the experimental data.

As shown in Figure 1, Figure 1 is the near-infrared response map of 0-10d. The hyperspectral data contains a lot of repetitive and redundant information, which is not convenient for data transmission and calculation. The difference between zombie meat and mature meat is more in details, and the difference in spectral reflectance value is not very obvious. If the wave number is deliberately compressed, a large amount of detailed information will be lost. Building a model based on the selected spectral values of several characteristic wavelengths will definitely reduce the prediction performance of the model. In this experiment, the Fourier-Popper transform was tried to transform the meat spectrum. The results show that the sample has a good near-infrared response and can extract feature information from hyperspectral images well. It is proved that real-time observation of oysters can be realized by using the test model constructed by the invention.

2. Verify the test model of the near-infrared spectrometer:

When using near-infrared spectrometer to test the freshness of oyster meat, chemical method is used to test TVB-N value at the same time, and TVB-N value is used to judge whether oyster meat is fresh. for fresh

(1) Sample pretreatment (the two methods were sampled under the same conditions): the oysters were shucked and stored in a constant temperature refrigerator at 4°C;

(2) Determination by chemical method: every 10 samples constitutes a group, and after sampling on the same day, the samples are continuously stored at 4°C; the continuous measurement lasts for 10 days. The specific measurement method is: accurately weigh 3g of minced meat and 10g of MgO powder and add them to the tube, then add 100mL of distilled water, and immediately put steam into the instrument to carry out distillation until the 25mL absorption liquid containing boric acid becomes 50mL Till now, add the indicator solution made up of methyl red and methylene blue, absorb the liquid with hydrochloric acid standard titration solution (0.010mol/L) to the end point, and carry out the titration operation to guide the end point. When testing, the value of TVB-N is controlled at ≤15mg/100g, and if it exceeds it, it can be judged as spoiled meat.

(3) Determination by near-infrared method: every 10 samples is a group, and the samples are stored at 4°C after sampling on the same day; continuous measurement is performed for 10 days; and the freshness of oysters is calculated using the above model.

Test Results:

The test results show that during the 10-day test of 100 oyster samples, only 2 samples were judged wrong by using the analysis model of near-infrared spectrometer, and the accuracy rate reached 98.00%. This shows that the near-infrared spectrometer analysis method has a high accuracy in testing the freshness of oysters, can realize non-destructive testing, and the testing method is simple and convenient.

Control group 1:

The fresh-keeping method of this control group is as follows: take fresh oysters and remove the shells to get the meat, take fresh oysters and remove the shells to get the meat, wash the oyster meat in physiological saline, and then soak it in the preservative for 90 minutes, after soaking the oysters After being fished out, put the fish in the refrigerator until the surface preservative layer becomes hard, wrap it tightly with a fresh-keeping bag, and keep it fresh under normal temperature conditions. During the fresh-keeping period, samples are taken from time to time, and the samples are detected by near-infrared spectrometer analysis. Wherein, the formula of preservative is completely consistent with embodiment 1.

Control group 2:

The fresh-keeping method of this control group is: take fresh and live oysters, remove the shell and take the meat, put the oyster meat into solution A to wash, then put it into the preservative and soak for 90 minutes, after soaking, fish out the oysters and put the fish in the refrigerator. Until the surface preservative layer becomes hard, wrap it tightly with a fresh-keeping bag and keep it fresh at room temperature. During the fresh-keeping period, samples are taken irregularly. The samples are distinguished by near-infrared analysis, and fresh and rotten oyster meat are stored separately. Wherein, the prescription of A solution is completely consistent with embodiment 1; Antistaling agent is made up of the composition of following parts by weight: the tea polyphenol of 7 parts, the rosemary powder of 5 parts, the chitosan of 15 parts, the egg white of 12 parts, 14 parts of dragon fruit stem extract, 6 parts of sodium alginate and 170 parts of water; wherein, the egg white is separated from eggs.

Control group 3:

The fresh-keeping method of this control group is: take fresh and live oysters, remove the shell and take the meat, put the oyster meat into solution A to wash, then put it into the preservative and soak for 90 minutes, after soaking, fish out the oysters and put the fish in the refrigerator. Until the surface preservative layer becomes hard, wrap it tightly with a fresh-keeping bag and keep it fresh at room temperature. During the fresh-keeping period, samples are taken irregularly. The samples are distinguished by near-infrared analysis, and fresh and rotten oyster meat are stored separately. Wherein, the prescription of A solution is completely consistent with embodiment 1; Antistaling agent is made up of the composition of following parts by weight: the tea polyphenol of 7 parts, the rosemary powder of 5 parts, the chitosan of 15 parts, the egg white of 12 parts, 6 parts of sodium alginate and 170 parts of water; wherein, the egg white is separated from sea duck eggs.

Control group 4:

The fresh-keeping method of this control group is as follows: take fresh oysters, remove the shells, and take the meat, and put them directly into a refrigerator at a temperature of -4°C for refrigeration.

Control group 5:

The fresh-keeping method of this control group is: take fresh and live oysters, remove the shell and take the meat, put the oyster meat into solution A to wash, then put it into the preservative and soak for 90 minutes, after soaking, fish out the oysters and put the fish in the refrigerator. Until the surface preservative layer becomes hard, wrap it tightly with a fresh-keeping bag, keep it fresh at room temperature, take samples from time to time during the fresh-keeping period, wash the oyster meat, grind it, and use the analytical method of chemical determination of TVB-N to test the sample. Wherein, A solution, antistaling agent are identical with embodiment 1.

Control group 6:

The fresh-keeping method of this control group is: take fresh and live oysters, remove the shell and take the meat, put the oyster meat into solution A to wash, then put it into the preservative and soak for 90 minutes, after soaking, fish out the oysters and put the fish in the refrigerator. Until the surface preservative layer becomes hard, wrap it tightly with a fresh-keeping bag and keep it fresh at room temperature. During the fresh-keeping period, samples are taken from time to time, and the freshness of the oysters is tested with an electronic nose. Wherein, A solution, antistaling agent are identical with embodiment 1.

The test results of embodiment 1 and control group 1-6 are shown in Table 1:

Table 1 Freshness test result table

As can be seen from the above table, the 1-10d uses the near-infrared spectrometer method measurement value of the present application to be consistent with the control group 5, but the method for the control group 5 to measure the freshness of the oyster meat needs to destroy the oyster meat tissue structure, while the near-infrared spectrometer method of embodiment 1 The infrared spectrometer test method can detect the oyster meat without damage, and will not cause meat quality waste; and the fresh-keeping time of the oyster meat in Example 1 is longer than that of the control group 1-4, and the fresh-keeping method of the control group 6 is the same as that of Example 1, Control group 5 is completely consistent, but the results of its measurement are inconsistent with those of Example 1 and control group 5. This is due to the misjudgment of the electronic nose by the duck eggs in the preservative. Therefore, the method of the present application can effectively prolong the normal temperature of oysters. The preservation period will not cause damage to the oyster meat; it is a non-destructive and online method for monitoring the freshness of the oyster meat.

To sum up, using the fresh-keeping method of the present application can effectively improve the fresh-keeping period of oyster meat without polluting the oyster meat, and at the same time, it is convenient and quick to perform online non-destructive detection of the oyster meat.

The above-mentioned embodiments only express several implementations of the present invention, and the description thereof is relatively specific and detailed, but should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims (7)

1. A non-damaging online fresh-keeping method for oysters, characterized in that, the method is: take fresh and live oysters and remove the shells to get the meat, put the oyster meat into solution A for cleaning, and then put it into the antistaling agent and soak for 90min- After soaking for 120 minutes, remove the oysters and put the fish in the refrigerator until the surface preservative layer becomes hard, wrap it tightly with a fresh-keeping bag, and keep it fresh at room temperature. , fresh and rotten oyster meat are stored separately; the detection model of the near-infrared analysis method is: Y=0.7807X+0.6391, where Y is an approximate coefficient; X is a wave band. 2. The fresh-keeping method for oysters according to claim 1, wherein the A solution is composed of the following components by weight: 13-17 parts of sodium chloride, 16-19 parts of trehalose, 4-9 parts part lemon juice and 120-150 parts water. 3. The fresh-keeping method for oysters according to claim 1, wherein the fresh-keeping agent is composed of the following components by weight: 7-14 parts of tea polyphenols, 5-9 parts of rosemary powder, 15-20 parts of chitosan, 12-18 parts of egg white, 14-19 parts of dragon fruit stem extract, 6-11 parts of sodium alginate and 170-180 parts of water. 4. The fresh-keeping method for oysters according to claim 1, characterized in that, the egg white is separated from sea duck eggs. 5. the fresh-keeping method of oyster according to claim 1, is characterized in that, the preparation method of described pitaya stem extract is: directly smash after the pitaya stem is peeled, then add the water mixing of 2 times of volume ratio After oscillating and suspending to obtain the suspension, add anhydrous ethanol equal to the volume of the suspension to the suspension, and carry out reflux extraction in a constant temperature pot. After extraction for 2h-3h, take the filtrate and concentrate it by rotary evaporation, evaporate the ethanol, and dry to obtain the fire dragon Fruit Stem Extract. 6. The fresh-keeping method for oysters according to claim 1, wherein the oyster meat is judged as fresh when the Y value is 0.218. 7. the fresh-keeping method of oyster according to claim 1, is characterized in that, the construction method of described near-infrared model is: (1) Oyster sample collection and sample preparation: mince oyster meat with different rotten degrees, and then place it in a refrigerator at -4°C; (2) Spectrum scanning: Use a near-infrared spectrometer to perform near-infrared spectrum scanning on each sample to be tested. The near-infrared spectrum scanning range of each sample is 120-1200nm, the resolution is 0.03-8.4nm, and the number of scans is 3; (3) Spectral correction: use the formula R=(R ₀ -R _d )/(R _w -R _d )×100% to correct the obtained original spectral data, where R ₀ is the original hyperspectral image; R _d is a black board with 0% reflectance, and is a black reference image obtained by covering the lens with a fully opaque camera cover; _Rw is a white board with 99% reflectance, and is a white reference image obtained by reflecting off a white polytetrafluoroethylene calibration board ; (4) Spectral image segmentation and feature extraction: In order to obtain the typical spectrum of the sample, remove the background from the original hyperspectral image in step (2); the removal method of the background is: subtract a low reflection band from the high reflection band to construct The mask of the image is then segmented by mask and threshold calculation; after image segmentation, the easily identifiable part of the frozen sample is placed in the area of the region of interest, and then the average of the spectrum in the region of interest is taken value as the spectrum of the sample; (5) Spectrum model establishment: In the spectral data sets obtained at different sample temperatures, 2/3 of the data were randomly selected as calibration sets to establish spectral models; the remaining 1/3 were classified as verification sets for model testing; After the spectral model and the test model are completed, the statistical correlation coefficient R ² and the mean square error RMSECP are used for the detection and correction of the verification model, and the corrected model is used to quickly identify and classify the samples to be identified.