A composition for identifying the freshness of mussels and its use

Abstract

The application discloses a kind of composition for identifying mussel freshness and application thereof, belong to aquatic product preservation technical field.A kind of composition for identifying mussel freshness, including Camphene (camphene), 1-Penten-3-ol (1-pentene-3-alcohol), (E)-2-pentenal ((E)-2-pentenal), 1-penten-3-one (1-penten-3-ketone), Methyl butanoate (methyl butanoate), 5-Methylfurfural (5-methylfurfural).The composition can be applied in the freshness detection of fresh mussel production, transportation and sales process.The application uses flavoring substance to identify the freshness of mussel, to guide the packaging form of mussel transportation process, and lays a foundation for long-distance transportation of mussel.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of aquatic product preservation, and in particular relates to a composition for identifying the freshness of mussels and application thereof. BACKGROUND

[0002] Mussels are a high-quality marine product, and their characteristics of high protein, low fat and rich in various nutrients are widely recognized. The fresh sample protein content can reach 20%, which includes 7 essential amino acids and 4 umami amino acids, and the composition ratio of essential amino acids basically meets the FAO / WHO model. The ratio of copper (Cu), Fe and Zn among mineral elements is reasonable.

[0003] However, mussels are still in the primary processing stage, mainly sold in seafood markets, and sold around the production area. The high protein and fat content of mussels leads to a relatively fast product spoilage rate, which makes fresh mussels unable to be transported over long distances, greatly limiting the development of the mussel industry. At the present stage, it is urgent to establish a product quality confirmation method to guide the industrialization development of fresh mussels. SUMMARY

[0004] The purpose of the present application is to provide a composition for identifying the freshness of mussels, and another purpose is to provide specific applications of the composition to make up for the shortcomings of the prior art.

[0005] Gas chromatography-ion mobility mass spectrometry (GC-IMS) is an analytical technique that combines the high separation power of gas chromatography with the rapid detection capability of ion mobility spectrometry. It separates each component in the sample by gas chromatography, and then uses ion mobility mass spectrometry to quickly identify and quantify the separated components. In the food industry, GC-IMS is used to detect volatile organic compounds, residual pesticides, additives and flavor components in food. It can provide detailed chemical fingerprints of complex mixtures in food, which helps food quality control and safety evaluation. At present, with the progress of technology and the in-depth application, GC-IMS has begun to play a greater role in food traceability, authenticity identification and new ingredient discovery, especially in the fields of food safety supervision and functional food development.

[0006] To achieve the above purpose, the present application is realized by the following technical solutions:

[0007] A composition for identifying the freshness of mussels, comprising Camphene (Camphene), 1-Penten-3-ol (1-Penten-3-ol), (E)-2-pentenal ((E)-2-pentenal), 1-penten-3-one (1-penten-3-one), Methylbutanoate (Methylbutanoate), 5-Methylfurfural (5-Methylfurfural).

[0008] The composition for identifying the freshness of mussels can be applied to the freshness detection in the production, transportation and sales of fresh mussels.

[0009] The detection method for identifying whether the fresh mussels are fresh by the composition comprises the following steps:

[0010] (1) Sampling: sampling points are set at the four corners and the middle of the stacking space, and a small piece of sample is taken from each of the upper, middle and lower layers to mix into a sample of 500g-1500g.

[0011] (2) Sample preparation: the meat of the fresh sample is taken, frozen by liquid nitrogen, and crushed by a frozen grinder. 2g of the crushed mussel meat sample is placed in a 20mL headspace bottle and sealed.

[0012] (3) Determination by GC-IMS;

[0013] (4) OPLS-DA analysis is performed on the composition to determine the freshness of the mussels, and the composition is: Camphene (Camphene), 1-Penten-3-ol (1-Penten-3-ol), (E)-2-pentenal ((E)-2-pentenal), 1-penten-3-one (1-penten-3-one), Methyl butanoate (Methyl butanoate), 5-Methylfurfural (5-Methylfurfural).

[0014] Further, the GC-IMS method in step (3) is: the chromatographic column is MXT-WAX, 15m, 0.53mmID, 1.0μmdf; the column temperature is 60℃; the carrier gas / drift gas is N2; the IMS temperature is 45℃; in the automatic headspace sampling unit, the sampling volume is 0.5mL; the incubation time is 20min; the incubation temperature is 40℃; the sampling needle temperature is 45℃; the incubation rotation speed is 500rpm; the gas chromatography conditions are: E1 drift gas volume flow rate 0-30min, 150mL / min; E2 carrier gas volume flow rate 0-2min, 2mL / min; 2-10min, 2-15mL / min; 10-15min, 15-50mL / min; 15-20min, 50-100mL / min; 20-30min, 100-150mL / min. The total running time is 50min. To avoid cross contamination, before each analysis, the syringe is automatically flushed with nitrogen for 30s, and after each analysis, it is flushed for 5min. The positive ketone compounds C4-C9 are used as external references to calculate the retention index (RI) of each volatile compound. The volatile components are analyzed by the laboratory analysis viewer (Vocal) and the NIST database and IMS database search.

[0015] Compared with the prior art, the present application has the beneficial effects of:

[0016] The present application determines the standard of "fresh" of the fresh product by supervising the flavor substances of the commercialized fresh mussel product in different packaging forms. The present application uses flavor substances to identify the freshness of the mussel, so as to guide the packaging form of the mussel during transportation, and lay the foundation for long-distance transportation of the mussel. GC-IMS uses gas phase separation and detection technology, combines the high separation ability of GC and the rapid response of ion mobility spectrometry (IMS), has the advantages of no pretreatment and high sensitivity, has excellent identification ability for small molecules and low content volatile components, has been widely used in food flavor analysis, and has great significance for the development and upgrading of the industry. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is the fingerprint spectrum of the direct refrigeration group gas chromatography-ion mobility spectrometry analysis result in the example.

[0018] Figure 2 is the OPLS-DA analysis result spectrum diagram of the direct refrigeration group in the example.

[0019] Figure 3 is the typical flavor substance change heat map of the direct refrigeration group in the example.

[0020] Figure 4 OPLS-DA analysis of the third day sample of the oxygenation group.

[0021] Figure 5 Verification experiment of the moisture and oxygenation refrigeration group. DETAILED DESCRIPTION

[0022] The technical solutions described in the present application will be further described and explained in combination with the examples below.

[0023] Example 1:

[0024] In this example, 300 Mytilus coruscus with an average weight of 60 grams were collected from the sea area located in Lianyungang, Jiangsu Province (34°21'12.49''N, 119°17'2.13''E). The mussels were washed with seawater to remove pollutants and foot silk attached to the shell, and were divided into a blank control group and an experimental group. The experimental group was further divided into a direct refrigeration group, an oxygenation refrigeration group, and an oxygenation and moisture refrigeration group according to different storage methods. Each group was divided into three parallel test groups (i.e., 30 mussels in each test group).

[0025] Among them, the direct refrigeration group is self-sealing bag packaging mussels; the oxygenated refrigeration group is oxygenated bag packaging mussels, and the oxygenated and moisturized refrigeration group is oxygenated bag with seawater absorbing cotton packaging mussels. Mussels with different packaging forms are placed in a 1-4℃ refrigeration freezer for storage. Sampling is performed at the 0th day, 1st day, 3rd day, 5th day, and 7th day of storage, respectively, and volatile compounds and physical and chemical indicators are measured.

[0026] The direct refrigeration group (LC) is fresh mussels purchased, which are immediately transported from Lianyungang to Qingdao with ice after being removed from the ropes, with a total travel time of 3.5-4 hours. After arrival, the mussels are washed with seawater of 28 salinity to relax the stress state of the mussels. After washing, 80 mm±5 mm mussels are taken, 10 per bag, placed in 10 silk self-sealing bags, set with unique numbers, and placed in a 0-4℃ refrigeration cabinet for refrigeration. Sampling is performed according to the sampling date.

[0027] The oxygenated refrigeration group (CY) is fresh mussels purchased, which are immediately transported from Lianyungang to Qingdao with ice after being removed from the ropes, with a total travel time of 3.5-4 hours. After arrival, the mussels are washed with seawater of 28 salinity to relax the stress state of the mussels. After washing, 80 mm±5 mm mussels are taken, 10 per bag, placed in oxygenated bags, the oxygen concentration in the oxygenated bags is 90%, set with unique numbers, and placed in a 0-4℃ refrigeration cabinet for refrigeration. Sampling is performed according to the sampling date.

[0028] The oxygenated and moisturized refrigeration group (BS) is fresh mussels purchased, which are immediately transported from Lianyungang to Qingdao with ice after being removed from the ropes, with a total travel time of 3.5-4 hours. After arrival, the mussels are washed with seawater of 28 salinity to relax the stress state of the mussels. After washing, 80 mm±5 mm mussels are taken, 10 per bag, placed in oxygenated bags, a piece of water-absorbing cotton is added to the oxygenated bags, the water-absorbing cotton contains 100 mL of seawater, the oxygen concentration in the oxygenated bags is 90%, set with unique numbers, and placed in a 0-4℃ refrigeration cabinet for refrigeration. Sampling is performed according to the sampling date.

[0029] Gas chromatography analysis is performed on fresh mussels and the three groups of experimental mussels, including the following steps:

[0030] (1) The soft tissues of the three groups of mussels are separated from the shells, frozen in liquid nitrogen, then homogenized into powder and stored at -80℃ for standby use.

[0031] (2) Fresh mussel tissue (not subjected to storage treatment) is taken, frozen in liquid nitrogen, homogenized into powder and stored at -80℃ as a blank control group.

[0032] (3) Analysis using gas chromatography-ion mobility spectrometry (GC-IMS): Chromatographic column MXT-WAX, 15 m, 0.53 mm ID, 1.0 pm df; Chromatographic column temperature 60 °C; Carrier gas / drift gas: N2; IMS temperature: 45 °C; Injection volume in the auto headspace injection unit: 0.5 mL; Incubation time: 20 min; Incubation temperature: 40 °C; Injection needle temperature: 45 °C; Incubation rotation speed 500 rpm; Gas chromatography conditions: El drift gas flow rate 0-30 min, 150 mL / min; E2 carrier gas flow rate 0-2 min, 2 mL / min; 2-10 min, 2-15 mL / min; 10-15 min, 15-50 mL / min; 15-20 min, 50-100 mL / min; 20-30 min, 100-150 mL / min; Total run time 50 min. To avoid cross-contamination, the syringe was automatically flushed with nitrogen for 30 s before each analysis and for 5 min after each analysis, the positive ketone compounds C4-C9 were used as external references to calculate the retention indices (RI) of each volatile compound. The volatile components were analyzed by the laboratory analysis viewer (Vocal) and NIST database and IMS database search.

[0033] Results analysis:

[0034] Due to the high concentration of monomer ions and neutral molecules that can form dimers in the drift region, one compound can generate multiple signals, and monomers and dimers of the same compound can also be generated. In this example, the monomers and dimers formed are represented by the letters "M" and "D", respectively. Through the search of the NIST database and IMS database established by the qualitative software, a total of 72 volatile compounds were detected in the mussels, of which 63 volatile compounds were qualitatively detected (Table 1), including 20 alcohols, 16 aldehydes, 11 ketones, 5 esters, 3 sulfides and 3 terpenes, and 5 other volatile compounds.

[0035] During the storage of bivalves, various flavor compounds changed significantly, among which aldehydes and ketones: These compounds usually provide a fresh ocean flavor in the fresh state of bivalves. With the extension of storage time, the oxidation of fat can lead to the generation of aldehydes and ketones, which may enhance the flavor at the initial stage, but excessive oxidation can produce undesirable flavors, such as halitosis and sour odor. Alcohols: Unsaturated alcohols have a low threshold in bivalves and usually exhibit mushroom and metallic flavors, which contribute greatly to flavor. With the extension of storage time, the content of 1-penten-3-ol and other alcohols may increase, and the change of these substances can be used as an indicator of flavor deterioration. Sulfur-containing compounds: These compounds may promote the formation of flavor in fresh bivalves, but during storage, the increase in the concentration of sulfur-containing compounds can lead to unpleasant odors, such as sulfur odor.

[0036] As can be seen from Figure 1 It can be seen that compared with the blank control group, the content of most aldehyde compounds decreased significantly and the content of most alcohol compounds gradually increased on the fifth day of storage. These changes have important influence on the stability and quality of shellfish flavor. By controlling the storage conditions and monitoring the changes of flavor compounds, the flavor and quality of shellfish can be better maintained.

[0037] Table 1 Volatile flavor substances in mussels during storage detected by gas chromatography-ion mobility spectrometry (GC-IMS)

[0038]

[0039]

[0040] OPLS-DA is a supervised discriminant analysis statistical method, which combines partial least squares regression (PLSR) and orthogonal signal correction technology (OSC). This method can remove the data changes in the independent variable X that are irrelevant to the classification variable Y, so that the classification information is mainly concentrated in a principal component, effectively filtering out the noise irrelevant to the classification information, so that the model is simple and easy to understand, and the analytical ability and effectiveness of the model are improved. The goodness of the OPLS-DA model can be evaluated by parameters such as R2X, R2Y and Q2, among which Q2 represents the predictive ability of the model, Q2>0.5 is usually considered as an effective model, and Q2>0.9 indicates that the model is very good. The variable weight value (Variable Importance for the Projection, VIP) obtained by the OPLS-DA model is used to measure the influence strength and explanatory ability of the expression pattern of each metabolite on sample classification and discrimination, and metabolites with VIP>1 are considered to have significant contribution to the model explanation.

[0041] OPLS-DA analysis was performed on the direct cold storage group, such as Figure 2As shown, the samples can be effectively distinguished during different storage periods, which provides good support for subsequent model construction and sample analysis. According to the standard of P<0.05 and VIP>1, the flavor compounds were analyzed, and it can be seen from Table 2 that 27 kinds of different aroma substances were screened out in the refrigeration group, and the above 27 compounds were subjected to principal component analysis again, and the comprehensive score was calculated (Table 3), and 6 compounds with a score of 0.5 or more, Camphene, 1-Penten-3-ol, (E)-2-pentenal, 1-penten-3-one, Methyl butanoate and 5-Methylfurfural were selected as typical flavor compounds.

[0042] Table 2 Compound score table of refrigeration group

[0043]

[0044] Table 3 Principal component analysis comprehensive score table

[0045]

[0046] According to the results of the comprehensive principal component analysis, Camphene, 1-Penten-3-ol, (E)-2-pentenal, 1-penten-3-one, Methyl butanoate and 5-Methylfurfural were selected as typical flavor substances, including 2 kinds of aldehydes, 1 kind of alcohol, 1 kind of ketone, 1 kind of ester and 1 kind of terpenoid compound. The concentration changes are shown in Table 3. Figure 3 Through the color change, it can be seen that with the extension of the storage time, several typical flavor substances have changed to different degrees.

[0047] Example 2:

[0048] The oxygen-filled packaging samples were selected for storage period experiment, and the samples of different days were taken for freshness discrimination verification, Camphene, 1-Penten-3-ol, (E)-2-pentenal, 1-penten-3-one, Methyl butanoate and 5-Methylfurfural were used as indexes, and OPLS-DA analysis was carried out as in Example 1, as shown in Table 4. Figure 4As shown, the freshness of the oxygenated preservation sample on the 3rd day was similar to that of the direct refrigeration group on the 1st day, and oxygenated preservation could preserve freshness to a certain extent, which also showed that the OPLS-DA analysis using the six flavor substances could determine the freshness of live mussels.

[0049] Example 3:

[0050] The moisturizing oxygenated packaging sample was selected for the storage period experiment, and samples of different days were taken for freshness discrimination verification. Camphene, 1-Penten-3-ol, (E)-2-pentenal, 1-penten-3-one, Methyl butanoate, and 5-Methylfurfural were used as indicators for OPLS-DA analysis as in Example 1, as shown in Figure 5 As shown, the freshness of the moisturizing oxygenated group sample on the 3rd day was similar to that of the direct refrigeration group on the 3rd day, and the preservation ability of moisturizing oxygenated preservation was better than that of the oxygenated group, which also showed that the OPLS-DA analysis using the six flavor substances could determine the freshness of live mussels in different preservation states.

[0051] Finally, through experimental analysis, several markers related to the quality of mussels during preservation were obtained: Camphene, 1-Penten-3-ol, (E)-2-pentenal, 1-penten-3-one, Methyl butanoate, and 5-Methylfurfural can be used to identify the composition of fresh mussel freshness, which can be applied to the freshness detection of fresh mussel production, transportation, and sales process.

[0052] Finally, although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for clarity. The skilled person should consider the specification as a whole, and the technical solutions in each example can be appropriately combined to form other embodiments that the skilled person can understand.

Claims

1. Use of a composition in the detection of freshness of live mussels during production, transportation and sale of live mussels; the composition comprises camphene, 1-penten-3-ol, (E)-2-pentenal, 1-penten-3-one, methyl butanoate, 5-methylfurfural.

2. A detection method for identifying whether a live fresh mussel is fresh, characterized in that, The method comprises the following steps: (1) Take a sample of live mussels; (2) Prepare the sample: remove the meat from the sample of live mussels, freeze in liquid nitrogen, and crush using a cryogenic grinder; (3) Perform the determination using GC-IMS; the GC-IMS method: the chromatographic column is a MXT-WAX capillary chromatographic column, 15 m x 0.53 mm, 1.0 μm; the column temperature is 60°C; the carrier gas / drift gas is N2; the IMS temperature is 45°C; the injection volume is 0.5 mL; the incubation time is 20 min; the incubation temperature is 40°C; the injection needle temperature is 45°C; the incubation rotation speed is 500 rpm; the gas chromatography conditions: E1 drift gas volume flow rate 0-30 min, 150 mL / min; E2 carrier gas volume flow rate 0-2 min, 2 mL / min; 2-10 min, 2-15 mL / min; 10-15 min, 15-50 mL / min; 15-20 min, 50-100 mL / min; 20-30 min, 100-150 mL / min, total running time 50 min; (4) Analyze and determine the freshness of the mussels using OPLS-DA with the composition; the composition comprises camphene, 1-penten-3-ol, (E)-2-pentenal, 1-penten-3-one, methyl butanoate, 5-methylfurfural.

3. The detection method of claim 2, wherein, In step (1), sample points are set at the four corners and the middle of the sample stacking space, and a number of small pieces are taken from the upper, middle and lower layers of each point to mix a sample; each sample is 500 g-1500 g.

4. The detection method of claim 2, wherein, In step (2), 2 g of crushed mussel meat sample is placed in a 20 mL headspace bottle and sealed.

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