Low-nitrite natural pickling agent for meat products and preparation method of low-nitrite natural pickling agent

Abstract

The invention discloses a low-nitrite natural pickling agent for meat products and a preparation method of the low-nitrite natural pickling agent. The low-nitrite natural pickling agent is prepared from the following components: lycopene, celery powder, sodium erythorbate, citric acid, a natural perfume extract, a fermentation additive and a nanoscale chitosan microsphere complex. The invention provides an alternative healthy additive for nitrite-free meat products, the health of the products is effectively improved on the premise of not increasing the cost, the additive is wide in application, can be applied to current meat products and also can be applied to quick-frozen sausages, and various nitrite-free meat products have the advantages of low cost and low production cost under the condition that the existing formula is not changed. By adding the pickling agent disclosed by the invention, the health requirements of modern consumers can be met, and the product quality is obviously improved.

Description

Technical Field

[0001] The invention belongs to the technical field of meat products, in particular to a natural pickling agent for meat products with low nitrite and a preparation method thereof. Background Art

[0002] Meat products refer to cooked or semi-finished meat products made from livestock and poultry meat as the main raw material and seasoned, such as sausages, ham, bacon, marinated meat, barbecued meat, dried meat, etc. Meat products are one of the main products in my country's food industry, and they occupy an important position in the domestic market, foreign trade market and military food supply.

[0003] Nitrite is cheap and can not only give meat products a good appearance and color through coloring, enhance the pickled flavor of meat products, delay fat oxidation and rancidity, but also inhibit the growth and reproduction of spoilage bacteria, extend the shelf life of meat products, and prevent food poisoning caused by pathogenic bacteria. Therefore, it is widely used in the development of meat products. However, according to research, sodium nitrite reacts with amino acids in meat products to form nitrosamine compounds, which may induce cancer in humans, making pickled meat products unhealthy and unfit for long-term consumption.

[0004] Therefore, the present invention solves the corresponding problems by providing a natural pickling agent for meat products with low nitrite. Summary of the invention

[0005] The purpose of the present invention is to provide a natural pickling agent for meat products with low nitrite, so as to solve the deficiencies in the prior art.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A low-nitrite natural pickling agent for meat products, comprising the following ingredients by weight: 1.2-1.8 parts of lycopene, 13-17 parts of celery powder, 1.3-1.7 parts of sodium isoascorbate, 4-5 parts of citric acid, 0.2-0.4 parts of natural flavor extract, 0.8-1.2 parts of fermentation additives, and 0.12-0.15 parts of nano-chitosan microsphere complex. Under this optimized ratio, the ingredients work synergistically in terms of color development, anti-oxidation, anti-corrosion and flavor improvement, which can not only ensure efficient replacement of nitrite, but also significantly improve the quality indicators of meat products such as color, taste, safety and shelf life.

[0008] As a further technical solution, the preparation method of lycopene is as follows:

[0009] The cherry tomatoes were rinsed with clean water for 10 minutes, and then pulped at a speed of 1500 r / min for 10 minutes to obtain a pulp;

[0010] A mixed solvent of n-hexane and acetone was added to the slurry at a solid-liquid ratio of 1:10, and the mixture was stirred and extracted at 35°C for 3 hours, and then centrifuged at 4500 rpm for 15 minutes, filtered to obtain an extract, and then subjected to reduced pressure distillation and spray drying to obtain lycopene;

[0011] Wherein, in the mixed solvent of n-hexane and acetone, n-hexane and acetone are mixed in a volume ratio of 1:1.

[0012] As a further technical solution, the preparation method of the celery powder is as follows:

[0013] Choose fresh, disease-free and insect-free celery, rinse it 4-5 times, and remove the roots and leaves;

[0014] Then cut into 2.2-2.8 mm thin slices, and dry with hot air at 55-58°C for 12 hours, turning over every hour; after drying, crush and pass through a 85-95 mesh sieve to obtain.

[0015] As a further technical solution, the natural spice extract is a mixture of rosemary extract, clove extract and cinnamon extract in a weight ratio of 1: (0.2-0.5): (0.5-1.5). Rosemary extract is rich in various antioxidant ingredients and can effectively inhibit the oxidation and deterioration of meat products; clove extract not only has antibacterial and preservative effects, but also can give meat products a unique flavor; cinnamon extract can enhance the flavor of meat products, and the active ingredients it contains help to extend the shelf life of the product. The three can be mixed in a specific ratio to better play a role and optimize the quality of meat products.

[0016] As a further technical solution, the preparation methods of the rosemary extract, clove extract and cinnamon extract all adopt the following method:

[0017] Wash and dry the rosemary, clove or cinnamon raw materials respectively, and then crush them into a particle size range of 0.5-1mm to increase the contact area between the raw materials and the solvent and improve the subsequent extraction efficiency;

[0018] The crushed raw material is placed in a sealed extraction device, and ethanol and water solvents mixed in a volume ratio of 1:2 are added at a material-liquid ratio of 1:10, and a suitable solvent combination is used to better dissolve the target extract;

[0019] The extraction is carried out at a temperature of 50-60°C and a pressure of 0.3-0.5MPa for 4-5 hours, and then the product is subjected to high-speed centrifugation for 15 minutes, filtered to obtain a filtrate, and the filtrate is spray-dried to obtain a corresponding raw material extract.

[0020] As a further technical solution, the fermentation additive is prepared by the following method:

[0021] Raw material selection and processing: fresh green tea leaves, grape peels, and orange peels are rinsed with clean water for 5 times, then dried at 50°C for 10 hours, and then crushed to a particle size of 30-40 mesh to obtain the raw materials to be fermented; in order to increase the contact area between the raw materials and the fermentation bacteria and promote the fermentation process.

[0022] Preparation of fermentation strains: Select Lactobacillus plantarum and Lactobacillus acidophilus and mix them in a ratio of 1: (0.6-0.8) as the fermentation strains;

[0023] Fermentation process: put the raw materials to be fermented obtained above into a fermentation tank, add fermentation bacteria at 3%-4% of the weight of the raw materials, then add sterile water to make the water content reach 65%-70%, adjust the temperature of the fermentation tank to 30-34°C, and ferment for 4-6 days;

[0024] Post-fermentation treatment: After fermentation, take out the fermentation product, and then place it at 42-45℃ for low temperature drying for 18-20 hours, and then crush it to a particle size of 80-100 mesh, and store it in a sealed container.

[0025] As a further technical solution, the mass ratio of the fresh green tea leaves, grape peels and orange peels is: (1-2): (5-7): (2-3).

[0026] As a further technical solution, during the processing of meat products, the natural curing agent is mixed with the raw meat, the amount of the natural curing agent added is 0.25%-0.3% of the weight of the raw meat, and after adding, it is fully stirred, the stirring speed is controlled at 220-300 rpm, the stirring time is 10-15 minutes, and then it is marinated at low temperature for 6 hours and taken out; the low temperature is 8-10°C; the meat products treated with this curing agent can not only reduce the risk of nitrite intake, but also meet consumers' demand for high-quality meat products in terms of color, flavor, taste and safety.

[0027] As a further technical solution, the preparation method of the nanoscale chitosan microsphere complex is:

[0028] First, chitosan is dissolved in 1% acetic acid solution to prepare a chitosan solution with a mass fraction of 2.5%, and then a glutaraldehyde crosslinking agent is added to the chitosan solution, stirred at 55-60° C. for 2 hours, subjected to ultrasonic crushing for 15-18 minutes, and the precipitate is collected by centrifugation and freeze-dried to obtain nano-chitosan microspheres;

[0029] Among them, the mass ratio of chitosan to glutaraldehyde is 12:1;

[0030] The power of ultrasonic crushing is 250W and the frequency is 35kHz;

[0031] The nano-chitosan microspheres were uniformly dispersed in the ε-polylysine aqueous solution, and then ultrasonically dispersed for 20 minutes, and then stirred at 350 r / min for 30 minutes, centrifuged, filtered, and freeze-dried to obtain a nano-scale chitosan microsphere complex;

[0032] Wherein, the concentration of the ε-polylysine aqueous solution is 0.6-0.7 mg / mL;

[0033] The mixing ratio of the nano-chitosan microspheres and the ε-polylysine aqueous solution is 50-60 g:120 mL.

[0034] The method for preparing a natural pickling agent for meat products with low nitrite comprises the following steps:

[0035] Raw material preparation: weigh lycopene, celery powder, sodium isoascorbate, citric acid, natural flavor extract and fermentation additive according to respective weight portions;

[0036] Preliminary mixing: Add the weighed raw material components into the high-speed mixer in sequence, and stir at a low speed of 150 rpm for 10 minutes to preliminarily mix the raw materials;

[0037] Stir and mix thoroughly: After initial mixing, increase the mixer speed to 450 rpm and continue stirring for 20-25 minutes;

[0038] Aseptic packaging: Packing in a sterile environment.

[0039] Beneficial effects:

[0040] The present invention provides an alternative healthy additive for nitrite-free meat products, effectively improves the health of products without increasing costs, and has a wide range of applications. It can be applied to current meat products and quick-frozen grilled sausages. Various nitrite-free meat products can meet the health needs of modern consumers by adding the pickling agent of the present invention while keeping the existing formula unchanged, thereby significantly improving product quality.

[0041] Among them, lycopene has the effect of antioxidant, which can delay its rancidity and inhibit the growth of microorganisms; it has the advantages of good coloring and good safety; the rich oil content in meat products can give lycopene good solubility stability; it has good dispersibility when applied, which can improve the coloring effect of cured meat products, and has good color stability. Celery powder can improve the nutritional value and antioxidant properties of meat. Celery powder not only adds a unique taste and flavor to meat products, but also its nutrients complement the nutrients in meat products, improving the overall nutritional value of food. In addition, celery powder has a scavenging effect on free radicals, including DPPH free radicals and NO-2, which shows that celery powder has certain antioxidant properties, which help to delay the oxidative deterioration of meat products, maintain their freshness and taste, thereby extending the shelf life and providing consumers with healthier food choices. As an antioxidant and color enhancer, sodium isoascorbate has a group that is easy to dehydrogenate in its molecular structure, so it hinders the action of oxygen and fat to achieve the purpose of deoxygenation, and can also reduce trivalent myoglobin to divalent myoglobin, so it can be used to stabilize the color and quality of meat products, and can replace nitrite. Natural spice extracts are mixed with rosemary, clove, and cinnamon extracts in a specific proportion, and have a good effect in antiseptic and antibacterial. Rosemary extract contains many antioxidant ingredients, which can effectively inhibit the oxidation and deterioration of meat products and fundamentally reduce the environment where microorganisms are easy to breed. Clove extract has antibacterial and antiseptic capabilities, and has an inhibitory effect on common microorganisms that cause meat products to spoil, such as Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. Cinnamon extract can enhance the flavor of meat products, and the active ingredients it contains also help to extend the shelf life of the product. Together with rosemary and clove extracts, it creates an environment that is not conducive to the survival of microorganisms, making the antiseptic performance of natural pickles better. Fermentation additives combine multi-source natural raw materials with directional fermentation technology, and cooperate with nano-scale chitosan microsphere complexes to show significant antiseptic and antibacterial effects in meat pickling. The preparation process of fermentation additives uses green tea leaves, grape peels and orange peels as raw materials. After scientific pretreatment, they are fermented by plant lactobacillus and acidophilus to generate a composite antibacterial system containing tea polyphenols, resveratrol and flavonoids. Under the action of nano-scale chitosan microsphere complexes, the antibacterial effect is greatly improved, and a variety of microorganisms can be inhibited. In addition, the organic acids (lactic acid and acetic acid) produced by fermentation reduce the pH of the system, breaking through the optimal growth environment of Escherichia coli. At the same time, bacteriocins and hydrogen peroxide play a synergistic antibacterial role by destroying the integrity of the cell membrane and interfering with energy metabolism. At the same time, the introduction of plant lactobacillus and acidophilus can significantly reduce nitrite.

[0042] The invention can produce a strong synergistic effect through the mutual cooperation of multiple components. Lycopene can resist oxidation, and together with rosemary extract, fermentation additives, nano-chitosan microsphere complexes, etc., it strengthens the inhibition of oxidation of meat products, reduces the risk of quality degradation and microbial growth caused by oxidation, and sodium isoascorbate, as an antioxidant, further strengthens the antioxidant system, and cooperates with lycopene and antioxidant components in natural spice extracts to improve the antioxidant and antiseptic capabilities of meat products. Citric acid adjusts the pH of meat products, creates an environment that is not conducive to the growth of microorganisms, and cooperates with other components to play a role in improving color. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a bar graph of the inhibition rate of Escherichia coli in each test group. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] Lactobacillus plantarum deposit number: CCTCC NO: M20221666;

[0046] Lactobacillus acidophilus preservation number: CGMCC No.19501;

[0047] The following are specific embodiments

[0048] Example 1

[0049] A low-nitrite natural pickling agent for meat products comprises the following ingredients by weight: 1.2 parts of lycopene, 13 parts of celery powder, 1.3 parts of sodium isoascorbate, 4 parts of citric acid, 0.2 parts of natural flavor extract, 0.8 parts of fermentation additives, and 0.12 parts of nano-scale chitosan microsphere complex.

[0050] The preparation method of lycopene is as follows:

[0051] The cherry tomatoes were rinsed with clean water for 10 minutes, and then pulped at a speed of 1500 r / min for 10 minutes to obtain a pulp;

[0052] A mixed solvent of n-hexane and acetone was added to the slurry at a solid-liquid ratio of 1:10, and the mixture was stirred and extracted at 35°C for 3 hours, and then centrifuged at 4500 rpm for 15 minutes, filtered to obtain an extract, and then subjected to reduced pressure distillation and spray drying to obtain lycopene;

[0053] Wherein, in the mixed solvent of n-hexane and acetone, n-hexane and acetone are mixed in a volume ratio of 1:1.

[0054] The preparation method of the celery powder is as follows:

[0055] Choose fresh, pest-free celery, rinse it 4 times, and remove the roots and leaves;

[0056] Then cut into 2.2 mm thin slices, dry with hot air at 55°C for 12 hours, turning over every hour; after drying, crush and pass through an 85-mesh sieve to obtain.

[0057] The natural spice extract is prepared by mixing rosemary extract, clove extract and cinnamon extract in a weight ratio of 1:0.2:0.5.

[0058] The preparation methods of the rosemary extract, clove extract and cinnamon extract all adopt the following method:

[0059] Wash and dry the rosemary, clove or cinnamon raw materials respectively, and then grind them into a particle size range of 0.5 mm;

[0060] The crushed raw material is placed in a sealed extraction device, and ethanol and water solvents mixed in a volume ratio of 1:2 are added at a material-liquid ratio of 1:10, and a suitable solvent combination is used to better dissolve the target extract;

[0061] The extraction was carried out at a temperature of 50°C and a pressure of 0.3 MPa for 4 hours, and then subjected to high-speed centrifugation for 15 minutes, filtered to obtain a filtrate, and the filtrate was spray-dried to obtain the corresponding raw material extract.

[0062] The fermentation additive comprises the following preparation method:

[0063] Raw material selection and processing: fresh green tea leaves, grape peels, and orange peels were washed with clean water for 5 times, then dried at 50°C for 10 hours, and then crushed to a particle size of 30 meshes to obtain the raw materials to be fermented;

[0064] Preparation of fermentation strains: Select Lactobacillus plantarum and Lactobacillus acidophilus in a ratio of 1:0.6 as the fermentation strains;

[0065] Fermentation process: put the raw materials to be fermented obtained above into a fermentation tank, add fermentation bacteria at 3% of the weight of the raw materials, then add sterile water to make the water content reach 65%, adjust the temperature of the fermentation tank to 30°C, and ferment for 4 days;

[0066] Post-fermentation treatment: After fermentation, take out the fermentation product, dry it at 42℃ for 18 hours, crush it to a particle size of 80 mesh, and seal it for storage.

[0067] The mass ratio of the fresh green tea leaves, grape peels and orange peels is 1:5:2.

[0068] The preparation method of nano-scale chitosan microsphere complex is as follows:

[0069] First, chitosan was dissolved in 1% acetic acid solution to prepare a 2.5% chitosan solution, and then glutaraldehyde crosslinking agent was added to the chitosan solution, stirred at 55°C for 2 hours, ultrasonically crushed for 15 minutes, and the precipitate was collected by centrifugation and freeze-dried to obtain nano-chitosan microspheres;

[0070] Among them, the mass ratio of chitosan to glutaraldehyde is 12:1;

[0071] The power of ultrasonic crushing is 250W and the frequency is 35kHz;

[0072] The nano-chitosan microspheres were uniformly dispersed in the ε-polylysine aqueous solution, and then ultrasonically dispersed for 20 minutes, and then stirred at 350 r / min for 30 minutes, centrifuged, filtered, and freeze-dried to obtain a nano-scale chitosan microsphere complex;

[0073] Wherein, the concentration of ε-polylysine aqueous solution is 0.6 mg / mL;

[0074] The mixing ratio of nano-chitosan microspheres and ε-polylysine aqueous solution is 50 g:120 mL.

[0075] After testing, the nitrite content in the meat product pickled with the natural pickling agent of this embodiment was 2.44 mg / kg.

[0076] Example 2

[0077] The difference from Example 1 is that the fermentation additive is prepared by the following method:

[0078] Raw material selection and processing: fresh green tea leaves, grape peels, and orange peels were washed with clean water for 5 times, then dried at 50°C for 10 hours, and then crushed to a particle size of 30 meshes to obtain the raw materials to be fermented;

[0079] Preparation of fermentation strains: Select Lactobacillus plantarum and Lactobacillus acidophilus in a ratio of 1:0.7 as the fermentation strains;

[0080] Fermentation process: put the raw materials to be fermented obtained above into a fermentation tank, add fermentation bacteria at 3.5% of the weight of the raw materials, then add sterile water to make the water content reach 68%, adjust the temperature of the fermentation tank to 32°C, and ferment for 4 days;

[0081] Post-fermentation treatment: After fermentation, take out the fermentation product, dry it at 43°C for 190 hours, crush it to a particle size of 80-100 mesh, and seal it for storage.

[0082] The mass ratio of the fresh green tea leaves, grape peels and orange peels is 1.5:6:2.2.

[0083] The preparation method of nano-scale chitosan microsphere complex is as follows:

[0084] First, chitosan was dissolved in 1% acetic acid solution to prepare a 2.5% chitosan solution, and then glutaraldehyde crosslinking agent was added to the chitosan solution, stirred at 58°C for 2 hours, ultrasonically crushed for 15 minutes, and the precipitate was collected by centrifugation and freeze-dried to obtain nano-chitosan microspheres;

[0085] Among them, the mass ratio of chitosan to glutaraldehyde is 12:1;

[0086] The power of ultrasonic crushing is 250W and the frequency is 35kHz;

[0087] The nano-chitosan microspheres were uniformly dispersed in the ε-polylysine aqueous solution, and then ultrasonically dispersed for 20 minutes, and then stirred at 350 r / min for 30 minutes, centrifuged, filtered, and freeze-dried to obtain a nano-scale chitosan microsphere complex;

[0088] Wherein, the concentration of ε-polylysine aqueous solution is 0.65 mg / mL;

[0089] The mixing ratio of nano-chitosan microspheres and ε-polylysine aqueous solution is 58 g:120 mL.

[0090] After testing, the nitrite content in the meat product pickled with the natural pickling agent of this embodiment was 2.35 mg / kg.

[0091] Example 3

[0092] The difference from Example 1 is that the fermentation additive is prepared by the following method:

[0093] Raw material selection and processing: fresh green tea leaves, grape peels, and orange peels were washed with clean water for 5 times, then dried at 50°C for 10 hours, and then crushed to a particle size of 30 meshes to obtain the raw materials to be fermented;

[0094] Preparation of fermentation strains: Select Lactobacillus plantarum and Lactobacillus acidophilus in a ratio of 1:0.8 as the fermentation strains;

[0095] Fermentation process: put the raw materials to be fermented obtained above into a fermentation tank, add fermentation bacteria at 4% of the weight of the raw materials, then add sterile water to make the water content reach 70%, adjust the temperature of the fermentation tank to 34°C, and ferment for 4 days;

[0096] Post-fermentation treatment: After fermentation, take out the fermentation product, dry it at 45℃ for 20 hours, crush it to a particle size of 80-100 mesh, and seal it for storage.

[0097] The mass ratio of the fresh green tea leaves, grape peels and orange peels is 2:7:3.

[0098] The preparation method of nano-scale chitosan microsphere complex is as follows:

[0099] First, chitosan was dissolved in 1% acetic acid solution to prepare a 2.5% chitosan solution, and then glutaraldehyde crosslinking agent was added to the chitosan solution, stirred at 60°C for 2 hours, ultrasonically crushed for 18 minutes, and the precipitate was collected by centrifugation and freeze-dried to obtain nano-chitosan microspheres;

[0100] Among them, the mass ratio of chitosan to glutaraldehyde is 12:1;

[0101] The power of ultrasonic crushing is 250W and the frequency is 35kHz;

[0102] The nano-chitosan microspheres were uniformly dispersed in the ε-polylysine aqueous solution, and then ultrasonically dispersed for 20 minutes, and then stirred at 350 r / min for 30 minutes, centrifuged, filtered, and freeze-dried to obtain a nano-scale chitosan microsphere complex;

[0103] Wherein, the concentration of ε-polylysine aqueous solution is 0.7 mg / mL;

[0104] The mixing ratio of nano-chitosan microspheres and ε-polylysine aqueous solution is 60 g:120 mL.

[0105] After testing, the nitrite content in the meat product pickled with the natural pickling agent of this embodiment was 2.28 mg / kg.

[0106] The preparation methods of the above embodiments all adopt:

[0107] The method for preparing a natural pickling agent for meat products with low nitrite is characterized by comprising the following steps:

[0108] Raw material preparation: weigh lycopene, celery powder, sodium isoascorbate, citric acid, natural flavor extract and fermentation additive according to respective weight portions;

[0109] Preliminary mixing: Add the weighed raw material components into the high-speed mixer in sequence, and stir at a low speed of 150 rpm for 10 minutes to preliminarily mix the raw materials;

[0110] Stir and mix thoroughly: After preliminary mixing, increase the mixer speed to 450 rpm and continue stirring for 25 minutes;

[0111] Aseptic packaging: Packing in a sterile environment.

[0112] The method of using the natural pickling agent of the embodiment is:

[0113] During the meat processing, the natural curing agent is mixed with the raw meat, the amount of the natural curing agent added is 0.3% of the weight of the raw meat, and after adding, it is fully stirred, the stirring speed is controlled at 220 rpm, the stirring time is 15 minutes, and then marinated at low temperature for 6 hours, taken out, and the low temperature is 10°C.

[0114] Comparative Example 1:

[0115] Based on the technical solution of Example 1, the difference from the technical solution of Example 1 is that lycopene is not added.

[0116] After testing, the nitrite content in the meat product pickled with the natural pickling agent in this comparative example was 3.88 mg / kg.

[0117] Comparative Example 2:

[0118] Based on the technical solution of Example 1, the difference from the technical solution of Example 1 is that celery powder is not added.

[0119] After testing, the nitrite content in the meat product pickled with the natural pickling agent in this comparative example was 3.62 mg / kg.

[0120] Comparative Example 3:

[0121] Based on the technical solution of Example 1, the difference from the technical solution of Example 1 is that no natural flavor extract is added.

[0122] After testing, the nitrite content in the meat product pickled with the natural pickling agent in this comparative example was 3.17 mg / kg.

[0123] Comparative Example 4:

[0124] Based on the technical solution of Example 1, the difference from the technical solution of Example 1 is that no fermentation additives are added.

[0125] After testing, the nitrite content in the meat product pickled with the natural pickling agent in this comparative example was 6.33 mg / kg.

[0126] Comparative Example 5:

[0127] On the basis of the technical solution of Example 1, the difference from the technical solution of Example 1 is that Lactobacillus plantarum and Lactobacillus acidophilus are not added during the preparation of the fermentation additive.

[0128] After testing, the nitrite content in the meat product pickled with the natural pickling agent in this comparative example was 5.12 mg / kg.

[0129] Comparative Example 6:

[0130] Based on the technical solution of Example 1, the difference from Example 1 is that no nano-scale chitosan microsphere complex is added.

[0131] After testing, the nitrite content in the meat product pickled with the natural pickling agent in this comparative example was 4.06 mg / kg.

[0132] By comparing the nitrite content in the meat products pickled with the pickling agents in the examples and the comparative examples, it can be seen that the introduction of Lactobacillus plantarum and Lactobacillus acidophilus can significantly reduce the effect of nitrite.

[0133] test:

[0134] Preparation of bacterial suspension: Escherichia coli, Staphylococcus aureus and Bacillus subtilis were inoculated into the same culture medium and cultured in a constant temperature shaker at 37°C for 18-24 hours until the bacterial suspension concentration reached 1.2×10 7 CFU / mL (determined by counting using the dilution spread plate method).

[0135] Medium Preparation:

[0136] Natural pickling agent culture medium: Weigh an appropriate amount of agar culture medium, heat to dissolve, cool to 50-55° C., add 0.3% of the natural pickling agents of the embodiments and comparative examples, stir well, and then pour into sterile culture dishes, about 15-20 mL per dish, and wait for solidification.

[0137] Traditional pickling medium: Prepared in the same way, except adding an equal amount of traditional nitrite pickling medium.

[0138] Blank control medium: agar medium without adding any pickling agent.

[0139] Inoculation and culture: Use a sterile pipette to draw 0.1 mL of bacterial suspension and evenly spread it on the surface of the above culture medium. Set up 3 replicates for each bacterial species and each culture medium. Place the inoculated culture dish upside down in a 37°C constant temperature incubator and culture for 48 hours.

[0140] Colony count: After the culture is completed, take out the culture dish and count the colonies on the plate; calculate the average number of colonies on each plate and calculate the inhibition rate according to the formula.

[0141] The formula for calculating the antibacterial rate is: antibacterial rate (%) = ((the number of colonies in the blank control group - the number of colonies in the experimental group) / the number of colonies in the blank control group) × 100%;

[0142] Table 1 Escherichia coli

[0143] Antibacterial rate% Example 1 88.7 Example 2 88.0 Example 3 87.6 Comparative Example 1 80.8 Comparative Example 2 85.5 Comparative Example 3 80.0 Comparative Example 4 74.4 Comparative Example 5 83.6 Comparative Example 6 75.7 Traditional pickles 85.3

[0144] It can be seen from Table 1 that the natural pickling agent prepared by the present invention has a high antibacterial effect on Escherichia coli, and it can be seen from experiments that the introduced fermentation additive has the highest antibacterial effect on Escherichia coli.

[0145] Table 2 Staphylococcus aureus

[0146]

[0147]

[0148] It can be seen from Table 2 that the natural pickling agent prepared by the present invention has a high antibacterial effect on Staphylococcus aureus, and it can be seen from experiments that the introduced lycopene has a significant promoting and improving effect on the antibacterial effect of Staphylococcus aureus.

[0149] Table 3 Bacillus subtilis

[0150]

[0151]

[0152] It can be seen from Table 3 that the natural pickling agent prepared by the present invention has a high antibacterial effect on Bacillus subtilis, and it can be seen from the test that the antibacterial effect of the introduced natural flavor extract on Bacillus subtilis can be more significantly improved.

[0153] Meat product preservation test:

[0154] Raw meat: Fresh pork, cut into small even pieces, each piece is about 100g.

[0155] Marinade:

[0156] Example 1 Natural pickling agent: prepared according to the given recipe.

[0157] Traditional pickles: pickles containing a standard amount of nitrite (as a control).

[0158] Marinated meat:

[0159] Natural curing agent group: weigh the natural curing agent, add 0.3% of the weight of the raw meat, put it into a stirring container together with the raw meat, stir at 300 rpm for 15 minutes to ensure that the curing agent and the raw meat are fully mixed, and then marinate the meat in a low temperature environment of 10°C for 6 hours.

[0160] Traditional marinade group: The raw meat was treated with traditional marinade in the same way.

[0161] Blank control group: No marinade was added to the raw meat, and only the same stirring and low-temperature storage treatment was performed.

[0162] Packaging and storage: After marinating, the three groups of meat products were vacuum packed in sterile plastic bags, 10 bags per group, and the packaged meat products were placed in a constant temperature and humidity incubator with the temperature set at 25°C and the relative humidity set at 75% for storage experiments.

[0163] Index detection:

[0164] Microbiological indicators: Randomly select 2 bags of meat products from each group on the 0th, 3rd, 7th and 14th days of storage, take meat samples by aseptic operation, and conduct microbiological testing. The testing method refers to the national standard GB4789 series of national food safety standards for food microbiology testing methods:

[0165] Table 4

[0166]

[0167] It can be seen from Table 4 that the natural pickling agent of the present invention has a sustained antiseptic and antibacterial effect. In the short term, the antiseptic and antibacterial effect is not as good as that of the nitrite pickling agent, but over a longer period, the antiseptic and antibacterial effect is more lasting.

[0168] The above description is only a preferred embodiment of the present invention, but the present invention is not limited to the scope of implementation shown. Any changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments with equivalent changes, which still do not exceed the spirit covered by the specification, should be within the protection scope of the present invention.

Claims

1. A natural pickling agent for meat products with low nitrite, characterized in that: The invention comprises the following ingredients by weight: 1.2-1.8 parts of lycopene, 13-17 parts of celery powder, 1.3-1.7 parts of sodium isoascorbate, 4-5 parts of citric acid, 0.2-0.4 parts of natural flavor extract, 0.8-1.2 parts of fermentation additives, and 0.12-0.15 parts of nano-scale chitosan microsphere complex.

2. The low-nitrite natural pickling agent for meat products according to claim 1, characterized in that: The preparation method of lycopene is as follows: The cherry tomatoes were rinsed with clean water for 10 minutes, and then pulped at a speed of 1500 r / min for 10 minutes to obtain a pulp; A mixed solvent of n-hexane and acetone was added to the slurry at a solid-liquid ratio of 1:10, and the mixture was stirred and extracted at 35°C for 3 hours, and then centrifuged at 4500 rpm for 15 minutes, filtered to obtain an extract, and then subjected to reduced pressure distillation and spray drying to obtain lycopene; Wherein, in the mixed solvent of n-hexane and acetone, n-hexane and acetone are mixed in a volume ratio of 1:

1.

3. The low-nitrite natural pickling agent for meat products according to claim 1, characterized in that: The preparation method of the celery powder is as follows: Choose fresh, disease-free and insect-free celery, rinse it 4-5 times, and remove the roots and leaves; Then cut into 2.2-2.8 mm thin slices, and dry with hot air at 55-58°C for 12 hours, turning over every hour; after drying, crush and pass through a 85-95 mesh sieve to obtain.

4. The low-nitrite natural pickling agent for meat products according to claim 1, characterized in that: The natural spice extract is prepared by mixing rosemary extract, clove extract and cinnamon extract in a weight ratio of 1:(0.2-0.5):(0.5-1.5).

5. The low-nitrite natural pickling agent for meat products according to claim 1, characterized in that: The preparation methods of the rosemary extract, clove extract and cinnamon extract all adopt the following method: Wash and dry the rosemary, clove or cinnamon raw materials respectively, and then grind them into particle sizes ranging from 0.5 to 1 mm; The crushed raw material is placed in a sealed extraction device, and ethanol and water solvents mixed in a volume ratio of 1:2 are added at a material-liquid ratio of 1:10, and a suitable solvent combination is used to better dissolve the target extract; The extraction is carried out at a temperature of 50-60°C and a pressure of 0.3-0.5MPa for 4-5 hours, and then the product is subjected to high-speed centrifugation for 15 minutes, filtered to obtain a filtrate, and the filtrate is spray-dried to obtain a corresponding raw material extract.

6. The low-nitrite natural pickling agent for meat products according to claim 1, characterized in that: The fermentation additive comprises the following preparation method: Raw material selection and processing: fresh green tea leaves, grape peels, and orange peels were washed with clean water for 5 times, then dried at 50°C for 10 hours, and then crushed to a particle size of 30-40 meshes to obtain the raw materials to be fermented; Preparation of fermentation strains: Select Lactobacillus plantarum and Lactobacillus acidophilus and mix them in a ratio of 1: (0.6-0.8) as the fermentation strains; Fermentation process: put the raw materials to be fermented obtained above into a fermentation tank, add fermentation bacteria at 3%-4% of the weight of the raw materials, then add sterile water to make the water content reach 65%-70%, adjust the temperature of the fermentation tank to 30-34°C, and ferment for 4-6 days; Post-fermentation treatment: After fermentation, take out the fermentation product, and then place it at 42-45℃ for low temperature drying for 18-20 hours, and then crush it to a particle size of 80-100 mesh, and store it in a sealed container.

7. The low-nitrite natural pickling agent for meat products according to claim 1, characterized in that: The mass ratio of the fresh green tea leaves, grape peels and orange peels is: (1-2): (5-7): (2-3).

8. The low-nitrite natural pickling agent for meat products according to claim 1, characterized in that: During the meat processing, the natural curing agent is mixed with the raw meat, the amount of the natural curing agent added is 0.25%-0.3% of the weight of the raw meat, and after adding, it is fully stirred, the stirring speed is controlled at 220-300 rpm, the stirring time is 10-15 minutes, and then marinated at low temperature for 6 hours, and then taken out; The low temperature is 8-10℃.

9. The low-nitrite natural pickling agent for meat products according to claim 1, characterized in that: The preparation method of the nanoscale chitosan microsphere complex is as follows: First, chitosan is dissolved in 1% acetic acid solution to prepare a chitosan solution with a mass fraction of 2.5%, and then a glutaraldehyde crosslinking agent is added to the chitosan solution, stirred at 55-60° C. for 2 hours, subjected to ultrasonic crushing for 15-18 minutes, and the precipitate is collected by centrifugation and freeze-dried to obtain nano-chitosan microspheres; Among them, the mass ratio of chitosan to glutaraldehyde is 12:1; The power of ultrasonic crushing is 250W and the frequency is 35kHz; The nano-chitosan microspheres were uniformly dispersed in the ε-polylysine aqueous solution, and then ultrasonically dispersed for 20 minutes, and then stirred at 350 r / min for 30 minutes, centrifuged, filtered, and freeze-dried to obtain a nano-scale chitosan microsphere complex; Wherein, the concentration of the ε-polylysine aqueous solution is 0.6-0.7 mg / mL; The mixing ratio of the nano-chitosan microspheres and the ε-polylysine aqueous solution is 50-60 g:120 mL.

10. The method for preparing the low-nitrite natural pickling agent for meat products according to any one of claims 1 to 9, characterized in that: The following steps are involved: Raw material preparation: weigh lycopene, celery powder, sodium isoascorbate, citric acid, natural flavor extract and fermentation additive according to respective weight portions; Preliminary mixing: Add the weighed raw material components into the high-speed mixer in sequence, and stir at a low speed of 150 rpm for 10 minutes to preliminarily mix the raw materials; Stir and mix thoroughly: After initial mixing, increase the mixer speed to 450 rpm and continue stirring for 20-25 minutes; Aseptic packaging: Packing in a sterile environment.

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