Composition and application thereof

Abstract

The invention discloses a composition. The composition contains ozone micro-nano bubble water of epsilon-polylysine hydrochloride in a mass volume ratio of (0.05-1.0) g: 1.0 L, the concentration of the ozone micro-nano bubble water is 1.0 to 5.0 mg / L. The composition can effectively inhibit the growth of shewanella, pseudomonas, aeromonas and / or staphylococcus aureus, and when the composition is applied to the storage of aquatic products, not only can inhibit the growth of the bacteria, but also can improve the storage quality of the aquatic products, so that the water-holding capacity, hardness and / or elasticity of the aquatic products are better, and the aquatic products are better in storage effect. The invention further provides a method for inhibiting bacterial growth in the storage period of the aquatic products and / or improving the storage quality of the aquatic products.

Description

Technical Field

[0001] The present invention relates to the technical field of food processing, and specifically, to a composition and its application. Background Art

[0002] Ictalurus punctatus is a freshwater cultured fish, which is characterized by tender meat and rich in protein, unsaturated fatty acids and essential amino acids.

[0003] However, the characteristic of Ictalurus punctatus being rich in nutrients is conducive to the growth of microorganisms, resulting in a decline in the quality of fish meat during storage and a shortening of the shelf life, bringing huge economic losses to the fishery development. The dominant spoilage bacteria of Ictalurus punctatus mainly include Shewanella, Aeromonas and Pseudomonas, and there are significant differences in the composition of the dominant flora under different storage conditions, which also increases the difficulty of preserving Ictalurus punctatus.

[0004] Regarding the preservation technology of Ictalurus punctatus, the existing methods mainly focus on inhibiting the activity of dominant spoilage bacteria and regulating the storage environment. Currently, there is also a technology of placing fish meat in an ozone environment for preservation and anti-corrosion. Ozone micro-nano bubble water (OMNBW) is a bubble composite system formed by the combination of ozone gas and micro-nano bubble technology, and its characteristic is the tiny ozone bubbles wrapped by the gas-liquid interface. And due to the strong oxidizing property of ozone, it can destroy the cell wall, cell membrane and macromolecules inside the cell of spoilage bacteria, thereby effectively inhibiting the growth and reproduction of spoilage bacteria. However, in the complex microbial system of actual industrial production, the bactericidal efficacy of OMNBW is affected by various factors, and the use of ozone at high concentration and for a long time will cause irreversible oxidation of fish meat proteins and fats, destroying the texture characteristics such as the elasticity and tenderness of fish meat, and there are also certain safety hazards in long-term ozone treatment.

[0005] Therefore, how to improve the anti-corrosion and antibacterial effect of ozone, thereby enhancing the application efficacy of ozone and broadening the scope of application is an urgent problem to be solved at present. Summary of the Invention

[0006] The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art and provide a composition and its application.

[0007] The first object of the present invention is to provide a composition.

[0008] The second object of the present invention is to provide the application of the above composition in inhibiting bacteria.

[0009] The third object of the present invention is to provide the application of the above composition in improving the storage quality of aquatic products.

[0010] The fourth object of the present invention is to provide a method for inhibiting the growth of bacteria during the storage of aquatic products and / or improving the storage quality of aquatic products.

[0011] To achieve the above object, the present invention is realized by the following solutions:

[0012] A composition, the composition contains ozone micro-nano bubble water with ε-polylysine hydrochloride at a mass-volume ratio of 0.05-1.0 g: 1.0 L;

[0013] The concentration of ozone in the ozone micro-nano bubble water is 1.0-5.0 mg / L.

[0014] Preferably, the composition contains ozone micro-nano bubble water with ε-polylysine hydrochloride at a mass-volume ratio of 0.25-0.5 g: 1 L.

[0015] More preferably, the composition contains ozone micro-nano bubble water with 0.25 g: 1 L of ε-polylysine hydrochloride.

[0016] Further preferably, the concentration of ozone in the ozone micro-nano bubble water is 3.0 mg / L.

[0017] Among them, the ozone micro-nano bubble water is prepared by an ozone micro-nano bubble water machine.

[0018] The composition is prepared by mixing ozone micro-nano bubble water and ε-polylysine hydrochloride, and can effectively inhibit the growth of spoilage bacteria during the storage of aquatic products, and improve the water holding capacity, hardness and elasticity of aquatic products during storage.

[0019] Therefore, the present invention also claims the application of any of the above-mentioned compositions in antibacterial bacteria.

[0020] Preferably, the inhibited bacteria are Shewanella, Pseudomonas, Aeromonas and / or Staphylococcus aureus.

[0021] The present invention also claims the application of any of the above-mentioned compositions in improving the storage quality of aquatic products.

[0022] Preferably, the storage quality is water holding rate, hardness and / or elasticity.

[0023] Preferably, the aquatic product is catfish.

[0024] More preferably, the catfish is channel catfish.

[0025] The present invention also claims a method for inhibiting the growth of bacteria during the storage of aquatic products and / or improving the storage quality of aquatic products, specifically:

[0026] Mix the aquatic product with any one of the above-mentioned compositions at a ratio of 5 - 20 g : 50 - 200 mL, let it stand for 5 - 15 min, then take out the aquatic product and store it under vacuum.

[0027] Preferably, mix the aquatic product with any one of the above-mentioned compositions at a ratio of 1 g : 10 mL.

[0028] Preferably, let it stand for 10 min.

[0029] Preferably, the aquatic product is catfish.

[0030] More preferably, the catfish is channel catfish.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The present invention provides a composition, which contains ozonated micro-nano bubble water of ε-polylysine hydrochloride with a mass-volume ratio of 0.05 - 1.0 g : 1.0 L; the concentration of ozone in the ozonated micro-nano bubble water is 1.0 - 5.0 mg / L. The composition can effectively inhibit the growth of Shewanella, Pseudomonas, Aeromonas and / or Staphylococcus aureus, and when the composition is applied to the storage of aquatic products, it can not only inhibit the growth of the above bacteria, but also improve the storage quality of aquatic products, making the water-holding capacity, hardness and / or elasticity of aquatic products better, and based on this, a method for inhibiting the growth of bacteria during the storage of aquatic products and / or improving the storage quality of aquatic products is provided. Description of the Drawings

[0033] Figure 1 It is a graph showing the number of Shewanella colonies after treatment with the OMNBW / ε-PLH mixture containing different concentrations of ε-PLH in Example 1;

[0034] Figure 2 It is a graph showing the calculation result of the number of colonies in Example 1;

[0035] Figure 3 It is a graph showing the measurement results of extracellular nucleic acid and protein leakage in Example 1; A is the graph of nucleic acid leakage rate test results; B is the graph of protein leakage rate test results;

[0036] Figure 4 It is a graph showing the PI fluorescence intensity measurement results in Example 1;

[0037] Figure 5 It is a graph showing the conductivity measurement results in Example 1;

[0038] Figure 6 It is a graph showing the ROS measurement results in Example 1;

[0039] Figure 7It is the graph of the NPS fluorescence intensity measurement result in Example 1;

[0040] Figure 8 It is the graph of the colony count measurement result of each group of channel catfish meat during storage in Example 2;

[0041] Figure 9 It is the graph of the TVB-N measurement result in Example 3;

[0042] Figure 10 It is the graph of the pH value measurement result in Example 3;

[0043] Figure 11 It is the graph of the MDA measurement result in Example 3;

[0044] Figure 12 It is the graph of the texture measurement result in Example 3; A is the graph of the hardness measurement result; B is the graph of the elasticity measurement result;

[0045] Figure 13 It is the graph of the centrifugation loss test result in Example 3;

[0046] Figure 14 It is the graph of the cooking loss test result in Example 3. Detailed implementation manners

[0047] The present invention will be further elaborated in detail below in conjunction with the accompanying drawings of the specification and specific embodiments. The embodiments are only used to explain the present invention and are not used to limit the scope of the present invention. The test methods used in the following embodiments are all conventional methods unless otherwise specified; the materials, reagents, etc. used are commercially available reagents and materials unless otherwise specified.

[0048] The channel catfish used in the embodiments of the present invention was purchased from the Xiashan Aquatic Product Wholesale Market in Zhanjiang City, with an average weight of 550 ± 50 g and an average body length of 40 cm ± 5 cm.

[0049] Bactericidal effects of ozone micro-nano bubble water and ε-polylysine hydrochloride in Example 1

[0050] I. Experimental method

[0051] 1. Preparation of bacterial suspension

[0052] The channel catfish was killed by ice-water bath treatment, and the back muscle was taken and stored at 4 °C for 8 days to obtain channel catfish meat in the spoilage period. Weigh 10 g of channel catfish meat in the spoilage period and put it into a sterile homogenization bag, then add 90 mL of sterile normal saline and beat and homogenize for 1 min (12 times / s) to obtain a homogenate.

[0053] Next, take 1 mL of the homogenate and perform 10-fold serial dilutions with sterile normal saline to obtain the diluted solution. Then, take 100 μL of the diluted solution and spread it on Tryptic Soy Agar Medium (TSA). After the medium solidifies, incubate it upside down at 30 °C for 48 h. Then, select Shewanella colonies with typical Shewanella characteristics (the colonies are round, with neat or slightly irregular edges, medium in size, about 1-3 mm in diameter, mostly grayish-white to light brown in color, smooth, moist, shiny on the surface, relatively soft in texture, and with a moderate degree of elevation) from the medium and inoculate them into nutrient agar for three generations of purification culture. Inoculate the purified Shewanella into LB broth and culture it in a shaker at 30 °C until the logarithmic phase (cultivate for 8 h). Then, add an equal volume of 50% (v / v) glycerol to obtain Shewanella liquid. Use a 1 μL inoculation loop to pick up 1 loop of Shewanella liquid and perform streak plate subculture at 30 °C in nutrient agar medium for 48 h. Pick a single colony and inoculate it into LB broth, and culture it with shaking at 30 °C and 150 r / min for 8 h for activation. Repeat the activation process 2 times to obtain the activated Shewanella liquid.

[0054] Centrifuge the activated Shewanella liquid at 4 °C and 8000 r / min for 10 min, discard the supernatant, wash the precipitate (bacteria) 2 times with 0.85% (w / v) normal saline, and resuspend it in normal saline to obtain a Shewanella suspension (8.49 lgCFU / mL).

[0055] According to the above method, pick Aeromonas colonies, Pseudomonas colonies, and Staphylococcus aureus colonies respectively, and prepare Aeromonas suspension, Pseudomonas suspension, and Staphylococcus aureus suspension.

[0056] 2. Preparation of Ozone Micro-Nano Bubble Water (OMNBW)

[0057] Use an ozone micro-nano bubble water machine (ZJ-NM002-C0032, Shanghai Zhongjing Environmental Protection Technology Co., Ltd.) to prepare ozone micro-nano bubble water (OMNBW) with an ozone concentration of 3 mg / L. The working conditions of the machine are: carrier gas pressure is 0.36 MPa; ozone inlet volume is 150 mL / min; water temperature is 4 °C.

[0058] 3. Determination of the Bactericidal Effect of ε-Polylysine Hydrochloride (ε-PLH) Combined with OMNBW against Shewanella

[0059] Weigh 0.05 g, 0.10 g, 0.25 g, and 0.50 g of ε-PLH, and add them to 1.0 L of OMNBW (3.0 mg / L) respectively to obtain OMNBW / ε-PLH mixtures with different concentrations of ε-PLH (including those with 0.05 g / L, 0.10 g / L, 0.25 g / L, and 0.50 g / L of ε-PLH).

[0060] Mix 1 mL of the Shewanella bacterium suspension obtained in Step 1 with 9 mL of the OMNBW / ε-PLH mixtures with different concentrations of ε-PLH respectively and mix them evenly. After treatment for 10 min, add 1 mL of a neutralizing agent (sodium thiosulfate at 10 g / L) to terminate the reaction, and obtain the treated Shewanella bacterium suspension.

[0061] Take 1 mL of the treated Shewanella bacterium suspension and place it in a petri dish. Then add 20 mL of nutrient agar and mix evenly. Place it at 20 °C and incubate for 72 h. Calculate the logarithm of the total number of Shewanella colonies in the petri dish (expressed as lg CFU / mL) to obtain the number of Shewanella colonies after treatment with the OMNBW / ε-PLH mixtures with different concentrations of ε-PLH.

[0062] For the blank group (CK), replace the OMNBW / ε-PLH with an equal volume of physiological saline for treatment, and keep the other treatments exactly the same to obtain the logarithm of the number of Shewanella colonies in the blank group.

[0063] For the control group (OMNBW), replace the OMNBW / ε-PLH with an equal volume of OMNBW (3.0 mg / L) for treatment, and keep the other treatments exactly the same to obtain the logarithm of the number of Shewanella colonies in the control group.

[0064] 4. Bactericidal effect test of the combination of ε-polylysine hydrochloride (ε-PLH) and OMNBW

[0065] (1) Calculation of the number of colonies

[0066] CK group: Mix 1 mL of the Shewanella bacterium suspension obtained in Step 1 with 9 mL of physiological saline and mix them evenly. After treatment for 10 min, add 1 mL of a neutralizing agent (sodium thiosulfate at 10 g / L) to terminate the reaction, and obtain the treated Shewanella bacterium solution. Take 1 mL of the treated Shewanella bacterium suspension and place it in a petri dish. Then add 20 mL of nutrient agar and mix evenly. Place it at 20 °C and incubate for 72 h.

[0067] The only difference between the OMNBW group and the CK group is that the physiological saline is replaced with an equal amount of OMNBW (3.0 mg / L), and the other treatments are exactly the same.

[0068] The only difference between the ε-PLH group and the CK group is that the normal saline was replaced with an equal volume of 0.25 g / L ε-PLH solution (using deionized water as the solvent), and the remaining treatments were exactly the same.

[0069] The only difference between the OMNBW / ε-PLH group and the CK group is that the normal saline was replaced with an equal volume of OMNBW / ε-PLH mixture (the concentration of ozone in OMNBW was 3.0 mg / L, and the concentration of ε-PLH was 0.25 g / L), and the remaining treatments were exactly the same.

[0070] After the culture of each treatment group was completed, the logarithm of the total number of Shewanella colonies in each culture dish was calculated (expressed as lg CFU / mL).

[0071] Then, the Shewanella suspensions in the CK group, OMNBW group, ε-PLH group, and OMNBW / ε-PLH group were successively replaced with equal volumes of the Aeromonas suspension, Pseudomonas suspension, and Staphylococcus aureus suspension obtained in step 1, and the remaining treatments were exactly the same, obtaining the logarithm of the number of Aeromonas colonies, the logarithm of the number of Pseudomonas colonies, and the logarithm of the total number of Staphylococcus aureus colonies after treatment of each group.

[0072] (2) Determination of extracellular nucleic acid and protein leakage

[0073] As shown in (1), the CK group, OMNBW group, ε-PLH group, and OMNBW / ε-PLH group were respectively set up, and the absorbance (OD 260处理前 and OD 280处理前 ) of the bacterial suspension before treatment in each group at 260 nm and 280 nm was measured. Then, the bacterial suspensions after 10 min of treatment in each group were respectively collected, centrifuged at 4 °C and 8000×g for 10 min, the supernatant was collected, and the absorbance (OD 260处理后 and OD 280处理后 ) at 260 nm and 280 nm was measured respectively. The nucleic acid leakage rate was calculated according to formula I, and the protein leakage rate was calculated according to formula II; among them, both the nucleic acid leakage rate and the protein leakage rate were based on the CK group, that is, the level of CK was recorded as 1.

[0074] Formula I: Nucleic acid leakage rate = OD 260处理后 / OD 260处理前 ;

[0075] Formula II: Protein leakage rate = OD 280处理后 / OD 280处理前 .

[0076] (3) Determination of propidium iodide (PI) fluorescence intensity

[0077] As shown in (1), the CK group, OMNBW group, ε-PLH group, and OMNBW / ε-PLH group were set up respectively. The bacterial suspensions after 10 min of treatment in each group were collected, centrifuged at 4 °C and 8000×g for 10 min, the supernatant was discarded, 1 mL of PBS buffer (0.1 mol / L) and 20 μL of PI staining solution with a final concentration of 10 μmol / L were added to the precipitates in each group, incubated at 37 °C in the dark for 30 min, then centrifuged at 4 °C and 8000×g for 2 min. After discarding the supernatant, it was washed twice with 0.85 (w / w) sterile normal saline and resuspended in normal saline. The fluorescence intensity was detected using a multifunctional microplate reader under the conditions of an excitation wavelength of 482 nm and an emission wavelength of 635 nm, and the fluorescence intensity (F 1 ) of each group was obtained, and the relative fluorescence intensity was calculated according to formula III.

[0078] Formula III: Relative fluorescence intensity (%) = (F 1 / F 0 ) × 100%;

[0079] where F 1 is the fluorescence intensity of each group; F 0 is the fluorescence intensity of the CK group.

[0080] (4) Determination of conductivity

[0081] As shown in (1), the CK group, OMNBW group, ε-PLH group, and OMNBW / ε-PLH group were set up respectively. The bacterial suspensions after 10 min of treatment in each group were collected, centrifuged at 4 °C and 8000×g for 10 min, the supernatant of each group was collected and the conductivity of each supernatant was measured using a DDB-303A conductivity meter.

[0082] (5) Determination of intracellular reactive oxygen species (ROS)

[0083] As shown in (1), the CK group, OMNBW group, ε-PLH group, and OMNBW / ε-PLH group were set up respectively. The bacterial suspensions after 10 min of treatment in each group were collected, centrifuged at 4 °C and 8000×g for 10 min, the supernatant was discarded, 2 mL of 2’,7’-dichlorofluorescein diacetate (DCFH-DA) with a concentration of 10 μmol / L was added to the precipitates in each group, and the reaction was carried out in the dark for 30 min. After the reaction, it was centrifuged at 4 °C and 8000×g for 2 min, the supernatant was discarded, and after adding an equal volume of PBS buffer, the fluorescence intensity (R 1 ) of each group was detected using a multifunctional microplate reader under the conditions of an excitation wavelength of 488 nm and an emission wavelength of 525 nm, and the relative expression level of ROS was calculated according to formula IV.

[0084] Formula IV: Relative expression level of ROS (%) = (R 1 / R 0 ) × 100%;

[0085] where R 1 is the fluorescence intensity of each group; R 0 is the fluorescence intensity of the CK group.

[0086] (6) Determination of fluorescence intensity of N-phenyl-1-naphthylamine (NPN)

[0087] As shown in (1), the CK group, OMNBW group, ε-PLH group and OMNBW / ε-PLH group were set respectively. The bacterial suspensions after 10 min of treatment in each group were collected, centrifuged at 4 °C and 8000 × g for 10 min, the supernatant was discarded, 1 mL of PBS buffer and 20 μL of NPN staining with a final concentration of 10 μmol / L were added to the precipitates in each group respectively. After mixing evenly, they were incubated in the dark for 10 min. Then, the fluorescence intensity of NPN in each group (N 1 ) was detected using a multifunctional microplate reader under the conditions of an excitation wavelength of 350 nm and an emission wavelength of 401 nm, and the relative fluorescence intensity of NPN was calculated according to Formula V.

[0088] Formula V: Relative fluorescence intensity of NPN (%) = (N 1 / N 0 ) × 100%;

[0089] where N 1 is the NPN fluorescence intensity of each group; N 0 is the NPN fluorescence intensity of the CK group.

[0090] II. Experimental results

[0091] 1. Test results of killing Shewanella bacteria

[0092] The result graph of the number of Shewanella colonies after treatment with the OMNBW / ε-PLH mixture containing different concentrations of ε-PLH is as Figure 1As shown in the figure, the results show that the logarithm of the number of Shewanella colonies in the blank group is 8.80 lg CFU / mL, the logarithm of the number of Shewanella colonies in the control group is 4.60 lg CFU / mL, the logarithm of the number of Shewanella colonies after treatment with the OMNBW / ε-PLH mixture containing 0.05 g / L of ε-PLH is 4.25 lg CFU / mL, the logarithm of the number of Shewanella colonies after treatment with the OMNBW / ε-PLH mixture containing 0.10 g / L of ε-PLH is 3.74 lg CFU / mL, the logarithm of the number of Shewanella colonies after treatment with the mixture of OMNBW / ε-PLH containing 0.25 g / L of ε-PLH is 3.26 lg CFU / mL, and the logarithm of the number of Shewanella colonies after treatment with the OMNBW / ε-PLH mixture containing 0.50 g / L of ε-PLH is 3.22 lg CFU / mL.

[0093] Compared with the blank group, the number of Shewanella colonies after treatment with the OMNBW / ε-PLH mixture containing different concentrations of ε-PLH decreased significantly, all decreasing by more than 4 orders of magnitude; and compared with treatment with OMNBW alone, the number of Shewanella colonies treated with the OMNBW / ε-PLH mixture was also significantly less. When the concentration of ε-PLH in the OMNBW / ε-PLH mixture was 0.25 g / L, the number of Shewanella colonies was significantly lower, and with the continued increase of the ε-PLH concentration, the antibacterial effect against Shewanella did not show obvious changes anymore.

[0094] The results indicate that ε-PLH can enhance the antibacterial effect of OMNBW against Shewanella, and the antibacterial effect against Shewanella is the best when using the OMNBW / ε-PLH mixture (the concentration of ozone in OMNBW is 3.0 mg / L and the concentration of ε-PLH is 0.25 g / L).

[0095] 2. Bactericidal effect test

[0096] (1) The calculation results of the number of colonies are shown in Figure 2 the figure. The results show that the logarithm of the viable count of Shewanella in the CK group is 8.52 lg CFU / mL, while the number of Shewanella colonies in the ε-PLH group, OMNBW group, and OMNBW / ε-PLH group decreased to 4.40, 4.08, and 3.46 lg CFU / mL respectively; and for Pseudomonas, Aeromonas, and Staphylococcus aureus, the same antibacterial trend was also shown.

[0097] Treatment with OMNBW and ε-PLH together (i.e., the OMNBW / ε-PLH group) can effectively inhibit the growth of Shewanella, Aeromonas, Pseudomonas, and Staphylococcus aureus, and has a strong bactericidal effect on these four bacteria.

[0098] (2) The results of the determination of extracellular nucleic acid and protein leakage are shown in Figure 3 as follows. Figure 3 In Figure 3 A is the test result graph of nucleic acid leakage rate, and

[0099] In

[0100] B is the test result graph of protein leakage rate. The results show that compared with the CK group, the nucleic acid leakage rate and protein leakage rate of Shewanella, Aeromonas, Pseudomonas, and Staphylococcus aureus in the OMNBW group, ε-PLH group, and OMNBW / ε-PLH group are all significantly increased, indicating that these three treatments can effectively damage the cell membrane integrity of Shewanella, Aeromonas, Pseudomonas, and Staphylococcus aureus, causing the internal nucleic acids, proteins and other contents to flow out;

[0101] (3) The results of PI fluorescence intensity determination are shown in Figure 4 as follows. The results show that compared with the CK group, the relative fluorescence intensities of the four strains in the ε-PLH group, OMNBW group, and OMNBW / ε-PLH group are all significantly increased, and the relative fluorescence intensity of Staphylococcus aureus increases the most significantly. After treatment with ε-PLH, OMNBW, and OMNBW / ε-PLH, its relative fluorescence intensity increases by 662.18%, 1214.77%, and 1524.43% compared with the CK group; the same trend is also shown in Shewanella, Aeromonas, and Pseudomonas. Compared with the ε-PLH group and OMNBW group, the permeability of the bacterial cell membrane in the OMNBW / ε-PLH group is significantly increased (P<0.05).

[0102] (4) The results of conductivity determination are shown in Figure 5 as follows. The results show that compared with the ε-PLH group and OMNBW group, the conductivity of the four strains in the OMNBW / ε-PLH group is significantly increased, especially for Shewanella. The conductivity of the OMNBW / ε-PLH group increases to 3.32 ms / cm, which is significantly higher than 2.42 and 2.62 ms / cm of the ε-PLH group and OMNBW group (P<0.05).

[0103] (5) The results of ROS determination are shown in Figure 6As shown, the results showed that the expression levels of supernatant ROS in the ε-PLH group, OMNBW group, and OMNBW / ε-PLH group were 1.37 times, 1.86 times, and 2.19 times that of the CK group, respectively; compared with the OMNBW group, the treatment with OMNBW / ε-PLH also significantly increased the intracellular ROS content.

[0104] It is shown that the treatment with OMNBW / ε-PLH induced the production of ROS (reactive oxygen species) in Shewanella, Aeromonas, Pseudomonas, and Staphylococcus aureus, resulting in the imbalance of intracellular redox balance, and then inhibited the growth of Shewanella, Aeromonas, Pseudomonas, and Staphylococcus aureus.

[0105] (6) The results of the NPN fluorescence intensity measurement are shown as Figure 7 As shown, the results showed that compared with the CK group, the relative fluorescence intensities of NPN in the OMNBW group, ε-PLH group, and OMNBW / ε-PLH group were significantly increased, by 370.34%, 578.06%, and 922.17% respectively, and the relative fluorescence intensity of NPN in the OMNBW / ε-PLH group was significantly increased compared with other groups.

[0106] Therefore, based on the above results, the use of the OMNBW / ε-PLH mixture (ozone concentration in OMNBW is 3.0 mg / L, ε-PLH concentration is 0.25 g / L) can effectively inhibit the growth of Shewanella, Aeromonas, Pseudomonas, and Staphylococcus aureus.

[0107] Example 2 Effect of OMNBW / ε-PLH mixture on colonies during the storage of channel catfish

[0108] I. Experimental method

[0109] 1. Treatment of experimental groups

[0110] After killing channel catfish by ice-water bath treatment, take the back muscle and cut it into channel catfish meat blocks of 40×30×15 mm; according to the description in step 3 of Example 1, prepare the OMNBW / ε-PLH mixture (ozone concentration in OMNBW is 3.0 mg / L, ε-PLH concentration is 0.25 g / L).

[0111] CK group 1: Mix 672 channel catfish meat blocks and deionized water at a ratio of 1 g:10 mL, soak for 10 min, then take out the channel catfish meat blocks and drain, divide them into 6 equal parts, pack them into sterile bags for vacuum packaging treatment, and then store them at 4°C.

[0112] The only difference between the OMNBW group 1 and the CK group 1 is that deionized water is replaced with an equal amount of OMNBW (ozone concentration is 3.0 mg / L), and the rest of the treatments are exactly the same.

[0113] The only difference between ε-PLH group 1 and CK group 1 is that deionized water is replaced by 0.25 g / L ε-PLH (using deionized water as the solvent), and the rest of the treatments are exactly the same.

[0114] The only difference between OMNBW / ε-PLH group 1 and CK group 1 is that deionized water is replaced by the OMNBW / ε-PLH mixture (the concentration of ozone in OMNBW is 3.0 mg / L, and the concentration of ε-PLH is 0.25 g / L), and the rest of the treatments are exactly the same.

[0115] 2. Determination of total number of colonies

[0116] During the storage of each group, 10 g of catfish meat from each group was taken on the 0th, 2nd, 4th, 6th, 8th, and 10th days respectively. The 10 g of catfish meat was put into a sterile homogenization bag containing 90 mL of sterile normal saline (0.85% NaCl, w / v). After homogenizing for 1 min using a sterile homogenization beater (BM-400HP, Shanghai Songbai Instrument Company), 1 mL of the homogenized liquid was taken and added to a glass test tube containing 9 mL of normal saline. After mixing evenly, 10-fold serial dilutions were made to obtain diluted liquids. Then, 1 mL of the diluted liquid was placed in a sterile petri dish, and plate count agar was poured. After the agar solidified, it was placed in an incubator at 30 °C for 72 h of incubation. After the incubation ended, the logarithm of the colony count (lg CFU / g) was recorded.

[0117] II. Experimental results

[0118] The results of the determination of the colony counts of catfish meat during storage in each group are shown as Figure 8 follows. The results show that the logarithms of the colony counts of catfish meat in each group on the 0th day of storage were 4.07 lg CFU / g (CK group 1), 3.35 lg CFU / g (ε-PLH group), 2.45 lg CFU / g (OMNBW group 1), and 2.08 lg CFU / g (OMNBW / ε-PLH group 1) respectively; and during the early stage of storage (days 0 - 4), the growth of the colony counts in each group was relatively slow, and during the middle and late stages of storage (days 6 - 10), the colony counts increased rapidly; and the colony count in OMNBW / ε-PLH group 1 was significantly less than that in the other three groups during storage.

[0119] On the 8th day of storage, the colony counts in CK group 1, ε-PLH group 1, and OMNBW group 1 increased to 7.53 lg CFU / g, 6.57 lg CFU / g, and 6.03 lg CFU / g respectively, all higher than the national standard limit (6.0 lg CFU / g), indicating that the channel catfish meat in these three groups had started to spoil on the 8th day of storage; while the colony count in OMNBW / ε-PLH group 1 was 5.54 lg CFU / g, and the channel catfish meat still maintained a good quality state.

[0120] Example 3 Effect of OMNBW / ε-PLH mixture on the texture of channel catfish during storage

[0121] I. Experimental method

[0122] According to the steps shown in step 1 of Example 2, CK group 1, OMNBW group 1, ε-PLH group 1, and OMNBW / ε-PLH group 1 were obtained respectively; each group contained 6 portions of channel catfish meat.

[0123] (1) Determination of total volatile basic nitrogen (TVB-N)

[0124] The determination was carried out according to the records in GB 5009.228-2016 "National Food Safety Standard - Determination of Total Volatile Basic Nitrogen in Foods", specifically as follows: During the storage of each group, on the 0th day, 2nd day, 4th day, 6th day, 8th day, and 10th day, 10 g of channel catfish meat from each group was taken. The 10 g of channel catfish meat was mixed evenly with 70 mL of deionized water in a conical flask. After standing for 30 min, it was transferred to a digestion tube and 1.0 g of magnesium chloride was added. Record the mass m (g) of the sample in the digestion tube. Use a Vapdest Kjeldahl type automatic Kjeldahl apparatus for determination, and record the volume V 1 (mL) of the hydrochloric acid standard solution used in the determination process of each group; the instrument parameters were set as the distillation time of 180 s and the pH value at the titration end point of 4.65.

[0125] Then, calculate the content of total volatile basic nitrogen (mg / 100 g) according to formula VI.

[0126] Formula VI: TVB-N (mg / 100 g) = {(V 1 - V 2 ) × c × M} / m × 100;

[0127] Where c is the concentration of the hydrochloric acid standard solution (mol / L); V 1 is the volume of the hydrochloric acid standard solution used in the determination process of each group (mL); V 2 is the volume of the hydrochloric acid standard solution used in the determination process of CK group 1 (mL); M is the molar mass of nitrogen; m is the mass of the sample (g).

[0128] (2) Determination of pH value

[0129] According to the records in GB 5009.237-2016 "National Food Safety Standard - Determination of pH Value of Foods", the pH values of catfish meat in each group were determined on the 0th, 2nd, 4th, 6th, 8th, and 10th days during storage, respectively.

[0130] (3) Determination of malondialdehyde content

[0131] Using a malondialdehyde (MDA) content detection kit (purchased from Beijing Solarbio Science & Technology Co., Ltd.), according to the records in the kit instructions, the MDA contents of catfish meat in each group were determined on the 0th, 2nd, 4th, 6th, 8th, and 10th days during storage, respectively.

[0132] (4) Texture determination

[0133] During the storage of each group, on the 0th, 2nd, 4th, 6th, 8th, and 10th days, 15×15×15 mm catfish meat samples were taken respectively (sampled from 1 portion of catfish meat in each group every day), and the texture of catfish meat was determined (hardness and elasticity) using a texture analyzer (TMS-Pro, FTC, USA); the test conditions of the texture analyzer were: flat-bottom cylindrical probe P / 36R; the pre-test speed, post-test speed, and test speed were all 1.0 mm / s; the test interval was 5.0 s; the deformation amount was 40%; the trigger force was 5.0 g.

[0134] (5) Determination of centrifugal loss

[0135] During the storage of each group, on the 0th, 2nd, 4th, 6th, 8th, and 10th days, 5 g of catfish meat (denoted as M 1 ) was taken and placed in a centrifuge tube with two layers of filter paper, and centrifuged at 4°C and 5000 r / min for 10 min in a high-speed refrigerated centrifuge (3-30KS, Sigma, Germany). Then, the filter paper was removed and the mass of the sample in the centrifuge tube was weighed (denoted as M 2 ), and then the centrifugal loss rate of catfish meat in each group was calculated according to Formula VII.

[0136] Formula VII: Centrifugal loss rate (%) = M 2 / M 1 ×100%.

[0137] (6) Determination of cooking loss

[0138] During the storage of each group, on the 0th, 2nd, 4th, 6th, 8th, and 10th days, 5 g of catfish meat (the mass was denoted as C 1) Put the catfish meat into a sealed bag and steam it in a water bath at 100 °C for 10 min. After steaming, dry the surface moisture of the catfish meat with filter paper and weigh the mass of the steamed catfish meat (denoted as C 2 ), then calculate the cooking loss rate according to Formula VIII.

[0139] Formula VIII: Cooking loss (%) = (C 1 - C 2 ) / C 1 × 100%.

[0140] II. Experimental results

[0141] 1. The measurement results of TVB-N are shown as Figure 9 follows. The results show that: on the 0th day of storage, the TVB-N of catfish meat in CK group 1 was 9.87 mg / 100 g, the TVB-N of catfish meat in ε-PLH group 1 was 8.31 mg / 100 g, the TVB-N of catfish meat in OMNBW group 1 was 5.40 mg / 100 g, and the TVB-N content of catfish meat in OMNBW / ε-PLH group 1 was 4.56 mg / 100 g; the TVB-N level of catfish meat blocks treated with the OMNBW / ε-PLH mixture was significantly lower than that of other groups and remained at the lowest level during storage, and was significantly lower than other groups; on the 10th day of storage, the TVB-N of catfish meat in CK group 1 was 27.55 mg / 100 g, the TVB-N of catfish meat in ε-PLH group 1 was 22.42 mg / 100 g, the TVB-N of catfish meat in OMNBW group 1 was 16.52 mg / 100 g, and the TVB-N content of catfish meat in OMNBW / ε-PLH group 1 was 13.96 mg / 100 g.

[0142] It shows that the OMNBW / ε-PLH mixture can effectively inhibit bacteria in aquatic products and thus achieve the fresh-keeping effect.

[0143] 2. The measurement results of pH value are shown as Figure 10 follows. The results show that: during storage, the pH values of the catfish meat in the 4 groups all showed a trend of first decreasing and then increasing, and the pH value of the catfish meat in the OMNBW / ε-PLH group 1 during storage was significantly lower than that of the catfish meat in other groups. It shows that the OMNBW / ε-PLH mixture can better inhibit the growth and metabolism of microorganisms during the storage of aquatic products, delay the decomposition rate of proteins and thus reduce the production of alkaline substances.

[0144] 3. The measurement results of MDA are shown as Figure 11As shown in the figure, the results show that the MDA content of catfish meat in each group gradually increases with the extension of storage time. Among them, the catfish meat in the OMNBW / ε-PLH group 1 has a lower MDA content than that in the OMNBW group 1 and the CK group 1 during the late storage period (from the 6th to the 10th day of storage), indicating that the treatment with the OMNBW / ε-PLH mixture (the ozone concentration in OMNBW is 3 mg / L and the ε-PLH concentration is 0.25 g / L) can reduce the lipid oxidation during the storage of catfish meat with ozone.

[0145] 4. The results of texture measurement are shown in Figure 12 as follows. Figure 12 Figure A in Figure 12 is the result graph of hardness measurement, and

[0146] Figure B in

[0147] is the result graph of elasticity measurement; the results show that during the storage period of catfish meat in each group, with the increase of storage time, the hardness and elasticity of catfish meat both show a downward trend; while during the storage period of catfish meat in the OMNBW / ε-PLH group 1, the degree of decrease in hardness and elasticity of catfish meat is significantly lower than that of the other 3 groups of catfish meat. Figure 13 This indicates that the treatment of catfish meat with the OMNBW / ε-PLH mixture (the ozone concentration in OMNBW is 3 mg / L and the ε-PLH concentration is 0.25 g / L) and then preservation can significantly improve the texture level of catfish meat during storage, making the texture level of stored catfish meat closer to that of fresh catfish meat.

[0148] 5. The results of centrifugation loss test are shown in Figure 14 as follows. The results show that with the increase of storage time, the centrifugation loss rate of catfish meat in each group shows an increasing trend; while the centrifugation loss rate of catfish meat in the OMNBW / ε-PLH group 1 is significantly lower, indicating that the treatment with the OMNBW / ε-PLH mixture (the ozone concentration in OMNBW is 3 mg / L and the ε-PLH concentration is 0.25 g / L) can reduce the water loss of catfish meat during storage.

[0149] Based on the above results, treating catfish meat with the OMNBW / ε-PLH mixture (the ozone concentration in OMNBW is 3 mg / L and the ε-PLH concentration is 0.25 g / L) can effectively improve the quality of catfish meat during storage, making the stored catfish meat closer to fresh catfish meat.

[0150] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description and ideas. It is not necessary and impossible to list all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A composition, characterized in that The composition contains ozone micro-nano bubble water of ε-polylysine hydrochloride at a mass volume ratio of 0.05-1.0 g:1.0 L; The concentration of ozone in the ozone micro-nano bubble water is 1.0-5.0 mg / L.

2. The composition according to claim 1, characterized in that The composition contains 0.25-0.5 g / 1 L of ozone micro-nano bubble water of ε-polylysine hydrochloride.

3. The composition according to claim 2, characterized in that The composition contains 0.25 g:1 L of ozone micro-nano bubble water of ε-polylysine hydrochloride.

4. The composition according to claim 3, characterized in that The concentration of ozone in the ozone micro-nano bubble water is 3.0 mg / L.

5. Use of the composition according to any one of claims 1 to 4 in inhibiting bacteria.

6. The use according to claim 5, characterized in that: The inhibiting bacteria are Shewanella, Pseudomonas, Aeromonas and / or Staphylococcus aureus.

7. Use of the composition according to any one of claims 1 to 4 in improving the storage quality of aquatic products.

8. The use according to claim 7, characterized in that: The storage qualities are water holding capacity, hardness and / or elasticity.

9. A method for inhibiting bacterial growth during storage of aquatic products and / or improving the storage quality of aquatic products, characterized in that: Specifically: The aquatic product and the composition according to any one of claims 1 to 4 are mixed in the ratio of 5 to 20 g: 50 to 200 mL, and the mixture is allowed to stand for 5 to 15 minutes, and then the aquatic product is taken out and stored in a vacuum.

10. The method according to claim 9, characterized in that The aquatic product and the composition according to any one of claims 1 to 4 are mixed at a ratio of 1 g:10 mL.

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