Natural preservative and preparation method thereof

Abstract

The invention relates to the technical field of preparation of natural preservatives, and discloses a natural preservative and a preparation method thereof.The natural preservative comprises, by mass, 50%-60% of litsea coreana extract, 10%-20% of vinegar powder, 10%-30% of cinnamon extract, 2%-15% of anise extract and 0.2%-3% of chitosan. The litsea coreana extract, the vinegar powder, the cinnamon extract, the anise extract and the chitosan are used as raw materials, and the prepared natural preservative has a broad-spectrum antibacterial effect, is safe and healthy, is simple and convenient in preparation process and relatively low in production cost, and has a wide market prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of natural preservative preparation, and in particular to a natural preservative and a preparation method thereof. Background Art

[0002] Although chemical preservatives have strong antibacterial effects, their toxic side effects, single antibacterial spectrum, and poor stability are becoming increasingly prominent. As people pay more and more attention to food safety and health, the use of chemical preservatives is gradually restricted. Therefore, the development of natural, safe, and efficient preservatives has become a hot topic in current research.

[0003] The above information is presented as background information only to assist with understanding the present disclosure and no determination or admission is made as to whether any of the above may be used as prior art with respect to the present disclosure. Summary of the invention

[0004] The invention provides a natural preservative and a preparation method thereof to solve the problems existing in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A natural preservative comprising the following raw materials in percentage by weight:

[0007] Eagle tea extract 50%~60%, vinegar powder 10%~20%, cinnamon extract 10%~30%, anise extract 2%~15%, and chitin 0.2%~3%.

[0008] Optionally, the chitin comprises chitosan and / or chitooligosaccharide.

[0009] The present invention also provides a method for preparing a natural preservative, which is used to prepare the natural preservative as described above, comprising the following steps:

[0010] Weigh the raw materials according to the following mass percentages:

[0011] Eagle tea extract 50%~60%, vinegar powder 10%~20%, cinnamon extract 10%~30%, anise extract 2%~15%, and chitosan 0.2%~3%; the error range of the raw material ratio is controlled within 5%;

[0012] The raw materials are mixed and sieved to obtain a finished natural preservative.

[0013] Optionally, the mixing speed is 300-350 r / min, and the mixing time is 10-20 minutes.

[0014] Optionally, when the mixed raw materials are sieved, the sieve specification used is 40 mesh.

[0015] Optionally, the preparation steps of the vinegar powder include:

[0016] The fermented raw materials are fermented in liquid form to produce concentrated vinegar with a solid content of 60% to 70%;

[0017] Processing the concentrated vinegar under spray drying conditions to obtain vinegar powder;

[0018] The processing technology of vinegar powder includes: inlet temperature of 150~170℃, material concentration of 15%~25%, maltodextrin addition of 25%~30%, roxburghii polysaccharide addition of 3%~5%, and feed rate of 5.2mL / min.

[0019] Optionally, the fermentation raw materials include: one or more of glutinous rice, red koji and sesame.

[0020] Optionally, the preparation steps of the eagle tea extract are as follows:

[0021] Remove impurities from the fresh leaves of Laoying tea, maintain the predetermined thickness, spread them out for a predetermined period of time at 21-28℃, and turn them over at least once during the process;

[0022] The tea leaves after being spread out to dry are spread out flat and steam-fixed at a predetermined thickness;

[0023] Rolling is performed using a rolling machine, first at a predetermined speed, then with pressure, and then dried until the moisture content is 10% to produce sun-dried green tea;

[0024] Mix a certain amount of sun-dried green tea with a certain proportion of water, inoculate a certain proportion of Aspergillus niger spore suspension, seal it, culture it under constant temperature for a period of time, and dry it to obtain fermented eagle tea;

[0025] The dried fermented eagle tea was ground into powder and sieved, extracted with 55%-75% ethanol for three times, the extracts were combined and centrifuged to obtain the supernatant, concentrated by rotary evaporation to a solid content of 60%-80%, and freeze-dried to obtain the eagle tea extract.

[0026] Optionally, the ethanol extraction comprises: extracting with 55% to 75% ethanol at 25 to 35° C. for 10 to 24 hours;

[0027] The rotary evaporation is carried out at a temperature of 45-50°C;

[0028] The temperature of the low-temperature freeze drying is -7 to -10°C, and the time is 25 to 40 minutes.

[0029] Optionally, the preparation method of the Aspergillus niger spore suspension is:

[0030] Select Aspergillus niger strains from the slant culture medium, inoculate them into potato dextrose agar medium, and culture them at 28°C until Aspergillus niger grows all over the medium;

[0031] Use an inoculating loop to pick up the activated Aspergillus niger into sterile saline containing sterile glass beads and shake thoroughly;

[0032] The spore suspension was filtered through sterile cotton wool and the spore concentration was adjusted to 1.0 × 10 7 Pieces / mL.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The invention provides a natural preservative and a preparation method thereof, which uses eagle tea extract, vinegar powder, cinnamon extract, anise extract and chitosan as raw materials. The prepared natural preservative has a broad-spectrum antibacterial effect, is safe and healthy, has a simple preparation process, has a low production cost, and has broad market prospects.

[0035] The present invention has other features and advantages, which will be apparent from or will be described in detail in the accompanying drawings and the following detailed description incorporated herein, which together serve to explain the specific principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 It is a flow chart of a method for preparing a natural preservative provided by the present invention;

[0038] Figure 2 is a flow chart of the anti-corrosion application test in the present invention;

[0039] Figure 3 These are sample diagrams of Group 1 to Group 3 of the anti-corrosion application test of the present invention;

[0040] Figure 4 It is a comparison diagram of sample groups 1 to 4 of the anti-corrosion application test in the present invention. DETAILED DESCRIPTION

[0041] In order to explain in detail the possible application scenarios, technical principles, specific schemes that can be implemented, and the purposes and effects that can be achieved, the following is a detailed description of the specific embodiments listed in conjunction with the accompanying drawings. The embodiments described herein are only used to more clearly illustrate the technical solutions of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0042] Reference to "embodiment" herein means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The term "embodiment" appearing in various places in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or association with other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the various technical features mentioned in the embodiments can be combined in any way to form a corresponding implementable technical solution.

[0043] Unless otherwise defined, the technical terms used in this document have the same meanings as those generally understood by those skilled in the art to which this application belongs; the use of relevant terms in this document is only for describing specific embodiments and is not intended to limit this application.

[0044] In the description of this application, the term "and / or" is an expression used to describe the logical relationship between objects, indicating that three relationships may exist, for example, A and / or B, which means: A exists, B exists, and A and B exist at the same time. In addition, the character " / " in this article generally indicates that the objects before and after are in an "or" logical relationship.

[0045] In the present application, terms such as “first” and “second” are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship of quantity, priority or sequence between these entities or operations.

[0046] Without further limitations, in this application, the words "include", "comprises", "has" or other similar expressions used in the sentences are intended to cover non-exclusive inclusion. These expressions do not exclude the presence of additional elements in the process, method or product including the elements, so that the process, method or product including a series of elements may include not only those limited elements, but also other elements not explicitly listed, or also include elements inherent to such process, method or product.

[0047] Eagle tea (Litsea coreana var. lanuginosa) is a woody plant of the genus Litsea in the Lauraceae family. It has the effects of clearing away heat and detoxifying, relieving summer heat and stimulating appetite. Studies have shown that Eagle tea is rich in flavonoids and has multiple pharmacological effects such as antioxidant, anti-inflammatory, and antibacterial. In addition, Eagle tea has the characteristic of not going bad overnight in summer, indicating that it contains natural antibacterial ingredients and has important development prospects.

[0048] In the prior art, although there have been some studies on eagle tea extract, they mainly focus on anti-oxidation, anti-inflammatory and other aspects, and there has not been a systematic study on its use as a natural preservative. The purpose of the present invention is to provide a natural preservative containing eagle tea extract and a preparation method thereof, so as to solve the problems of limited antibacterial ability, large toxic and side effects, single antibacterial spectrum and poor stability of chemical preservatives in the prior art.

[0049] To achieve the above object, the present invention provides the following technical solutions:

[0050] In a first aspect, a natural preservative is provided, comprising the following raw materials in percentage by weight:

[0051] Eagle tea extract 50%~60%, vinegar powder 10%~20%, cinnamon extract 10%~30%, anise extract 2%~15%, and chitin 0.2%~3%.

[0052] Optionally, the chitin comprises chitosan and / or chitooligosaccharide.

[0053] Please refer to Figure 1 In a second aspect, a method for preparing a natural preservative is provided, which is used to prepare the above natural preservative, comprising the following steps:

[0054] Weigh the raw materials according to the following mass percentages:

[0055] Eagle tea extract 50%~60%, vinegar powder 10%~20%, cinnamon extract 10%~30%, anise extract 2%~15%, and chitosan 0.2%~3%; the error range of the raw material ratio is controlled within 5%;

[0056] The raw materials are mixed with a double-shaft paddle mixer and then sieved, and then successively inspected and metered and packaged to finally obtain the finished natural plant food preservative.

[0057] Optionally, the mixing speed is 300-350 r / min, and the mixing time is 10-20 minutes.

[0058] Optionally, when the raw materials are sieved after mixing, the sieve size used is 40 mesh.

[0059] Optionally, the preparation steps of vinegar powder include:

[0060] The fermented raw materials are fermented in liquid form to produce concentrated vinegar with a solid content of 60% to 70%;

[0061] Processing the concentrated vinegar under spray drying conditions to obtain vinegar powder;

[0062] The processing technology of vinegar powder includes: inlet temperature of 150~170℃, material concentration of 15%~25%, maltodextrin addition of 25%~30%, roxburghii polysaccharide addition of 3%~5%, and feed rate of 5.2mL / min.

[0063] Optionally, the fermentation raw materials include one or more of glutinous rice, red koji and sesame.

[0064] Optionally, the preparation steps of eagle tea extract are as follows:

[0065] Remove branches, dead leaves and other debris from the fresh leaves of Laoying Tea, spread them out in a room with a temperature of 21-28℃, with a thickness of 12-14 cm, for 13 hours, turning them over once in the middle;

[0066] Spread the dried tea leaves on the steamer to a thickness of 5-6 cm and steam for 30 seconds;

[0067] Use a rolling machine to roll the tea leaves at a speed of 37 r / min for 15 minutes, then gently press and roll the tea leaves for 10 minutes, and dry the leaves until the moisture content of the tea leaves is about 10%, thus making sun-dried green tea.

[0068] Mix 500 g of sun-dried green tea with 30% water, inoculate with 1% Aspergillus niger spore suspension, shake well and seal, place in a 30°C constant temperature incubator for 3 days, and dry to obtain fermented eagle tea;

[0069] The dried fermented eagle tea is ground into powder, sieved, and extracted with 55%-75% ethanol, which is repeated three times. The extracts are combined and centrifuged to obtain the supernatant, which is concentrated by rotary evaporation to a solid content of 60%-80%, and then freeze-dried to obtain the eagle tea extract.

[0070] Optionally, the ethanol extraction comprises: extracting with 55% to 75% ethanol at 25 to 35° C. for 10 to 24 hours;

[0071] The rotary evaporation was carried out at a temperature of 45-50°C;

[0072] The temperature of low-temperature freeze-drying is -7~-10℃ and the time is 25~40 minutes.

[0073] Optionally, the preparation method of Aspergillus niger spore suspension is:

[0074] Select Aspergillus niger strains from the slant culture medium, inoculate them into potato dextrose agar medium, and culture them at 28°C until Aspergillus niger grows all over the medium;

[0075] Use an inoculating loop to pick up the activated Aspergillus niger into sterile saline containing sterile glass beads and shake thoroughly;

[0076] The spore suspension was filtered through sterile cotton wool and the spore concentration was adjusted to 1.0 × 10 7 Pieces / mL.

[0077] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0078] Example 1

[0079] A natural preservative containing eagle tea extract is composed of the following raw materials in percentage by mass: 60% of eagle tea extract, 10% of vinegar powder, 20% of cinnamon extract, 7% of anise extract and 3% of chitosan.

[0080] The preparation method of the natural preservative comprises the following steps:

[0081] (1) Preparation of vinegar powder: glutinous rice, red koji, sesame, etc. are used as raw materials, and concentrated vinegar with a solid content of 60-70% is prepared through liquid fermentation. The concentrated vinegar is processed under spray drying conditions. The specific process is as follows: inlet temperature 150-170°C, material concentration 15-25%, maltodextrin addition amount 25-30%, roxburghii polysaccharide addition amount 3-5%, and feed rate 5.2 mL / min to obtain natural fermented vinegar powder;

[0082] (2) Preparation of Eagle Tea Extract: Remove the impurities from the fresh Eagle Tea leaves and spread them out to air in a room at 21-28℃ for 13 hours, with a thickness of 12-14 cm. Turn them over once, spread them flat on a steamer for 30 seconds to kill the green leaves with steam, roll them for 15 minutes (37 r / min), press and roll them lightly for 10 minutes, and air them until the moisture content is 10% to obtain sun-dried green tea; mix 500 g of sun-dried green tea with 30% water, inoculate them with 1% Aspergillus niger spore suspension, shake them well and seal them, place them in a 30℃ constant temperature incubator for 3 days, and dry them to obtain fermented Eagle Tea; crush the fermented Eagle Tea into 60 mesh, extract them with 55-75% ethanol, extract them at 25-35℃ for 10-24 h, repeat the extraction 3 times, combine the extracts, centrifuge and take the supernatant, evaporate them by rotary evaporation at 45-50℃, concentrate them to a solid content of 60-80%, and freeze-dry them at low temperature to obtain Eagle Tea Extract;

[0083] (3) 60 g of eagle tea extract, 10 g of vinegar powder, 20 g of cinnamon extract, 7 g of anise extract, and 3 g of chitin are mixed in proportion using a double-shaft paddle mixer at a speed of 300-350 r / min for a mixing time of 10-20 minutes until they are evenly dispersed, and then sieved through a 40-mesh sieve to obtain a natural preservative.

[0084] Example 2

[0085] A natural preservative containing eagle tea extract is composed of the following raw materials in percentage by mass: 50% of eagle tea extract, 15% of vinegar powder, 18% of cinnamon extract, 15% of anise extract and 2% of chitosan.

[0086] The preparation method of the natural preservative comprises the following steps:

[0087] (1) Preparation of vinegar powder: glutinous rice, red koji, sesame, etc. are used as raw materials, and concentrated vinegar with a solid content of 60-70% is prepared through liquid fermentation. The concentrated vinegar is processed under spray drying conditions. The specific process is as follows: inlet temperature 150-170°C, material concentration 15-25%, maltodextrin addition amount 25-30%, roxburghii polysaccharide addition amount 3-5%, and feed rate 5.2 mL / min to obtain natural fermented vinegar powder;

[0088] (2) Preparation of Eagle Tea Extract: Remove the impurities from the fresh Eagle Tea leaves and spread them out to air in a room at 21-28℃ for 13 hours, with a thickness of 12-14 cm. Turn them over once, spread them flat on a steamer for 30 seconds to kill the green leaves with steam, roll them for 15 minutes (37 r / min), press and roll them lightly for 10 minutes, and air them until the moisture content is 10% to obtain sun-dried green tea; mix 500 g of sun-dried green tea with 30% water, inoculate them with 1% Aspergillus niger spore suspension, shake them well and seal them, place them in a 30℃ constant temperature incubator for 3 days, and dry them to obtain fermented Eagle Tea; crush the fermented Eagle Tea into 60 mesh, extract them with 55-75% ethanol, extract them at 25-35℃ for 10-24 h, repeat the extraction 3 times, combine the extracts, centrifuge and take the supernatant, evaporate them by rotary evaporation at 45-50℃, concentrate them to a solid content of 60-80%, and freeze-dry them at low temperature to obtain Eagle Tea Extract;

[0089] (3) 50 g of eagle tea extract, 15 g of vinegar powder, 18 g of cinnamon extract, 15 g of anise extract, and 2 g of chitin are mixed in proportion using a double-shaft paddle mixer at a speed of 300-350 r / min for a mixing time of 10-20 minutes until they are evenly dispersed, and then sieved through a 40-mesh sieve to obtain a natural preservative.

[0090] Example 3

[0091] A natural preservative containing eagle tea extract is composed of the following raw materials in percentage by mass: 50% of eagle tea extract, 10% of vinegar powder, 30% of cinnamon extract, 8% of anise extract and 2% of chitosan.

[0092] The preparation method of the natural preservative comprises the following steps:

[0093] (1) Preparation of vinegar powder: glutinous rice, red koji, sesame, etc. are used as raw materials, and concentrated vinegar with a solid content of 60-70% is prepared through liquid fermentation. The concentrated vinegar is processed under spray drying conditions. The specific process is as follows: inlet temperature 150-170°C, material concentration 15-25%, maltodextrin addition amount 25-30%, roxburghii polysaccharide addition amount 3-5%, and feed rate 5.2 mL / min to obtain natural fermented vinegar powder;

[0094] (2) Preparation of Eagle Tea Extract: Remove the impurities from the fresh Eagle Tea leaves and spread them out in a room at 21-28℃ for 13 hours to a thickness of 12-14 cm. Turn them over once and spread them flat on a steamer for 30 seconds to kill the green leaves with steam. Roll them for 15 minutes (37 r / min), press and roll them lightly for 10 minutes, and dry them until the moisture content is 10% to obtain sun-dried green tea. Mix 500 g of sun-dried green tea with 30% water, inoculate them with 1% Aspergillus niger spore suspension, shake them well and seal them. Place them in a 30℃ constant temperature incubator and culture them for 3 days. Dry them to obtain fermented Eagle Tea. Grind the fermented Eagle Tea into 60 mesh, extract them with 55-75% ethanol, extract them at 25-35℃ for 10-24 h, repeat the extraction three times, combine the extracts, centrifuge and take the supernatant, evaporate them at 45-50℃, concentrate them to a solid content of 60-80%, and freeze-dry them at low temperature to obtain Eagle Tea Extract.

[0095] (3) 50 g of eagle tea extract, 10 g of vinegar powder, 30 g of cinnamon extract, 8 g of anise extract, and 2 g of chitin are mixed in proportion using a double-shaft paddle mixer at a speed of 300-350 r / min for a mixing time of 10-20 minutes until they are evenly dispersed, and then sieved through a 40-mesh sieve to obtain a natural preservative.

[0096] Comparative Example 1

[0097] The preparation method of the natural preservative and the specific ratio of raw materials provided in this comparative example are substantially the same as those in Example 1, with the main difference being that this comparative example does not contain cinnamon extract.

[0098] Comparative Example 2

[0099] The preparation method of the natural preservative and the specific ratio of raw materials provided in this comparative example are substantially the same as those in Example 1, with the main difference being that this comparative example does not contain anise extract.

[0100] Comparative Example 3

[0101] The preparation method of the natural preservative provided in this comparative example and the specific ratio of raw materials are substantially the same as those in Example 1, the main difference being that this comparative example does not contain vinegar powder.

[0102] Comparative Example 4

[0103] The preparation method of the natural preservative provided in this comparative example and the specific ratio of raw materials are substantially the same as those in Example 1, the main difference being that chitosan is not contained in this comparative example.

[0104] Effect test

[0105] The natural preservatives prepared by Examples 1 to 3 of the present invention are respectively recorded as Example 1 to 3 groups; the natural preservatives prepared by Comparative Examples 1 to 4 are recorded as Comparative 1 to 4 groups; and then the performance of equal amounts of natural plant food preservative samples in each group is tested.

[0106] Test 1: Antibacterial test and result analysis

[0107] The 7 groups of natural preservatives prepared were prepared into solutions and subjected to the inhibition zone test. The test method is as follows:

[0108] (1) Sample dissolution: Pipette or weigh the raw materials according to the corresponding proportion and dissolve them in 50 mL of 50% alcohol-water solution, then stir to mix.

[0109] (2) Preparation of culture medium: Prepare the corresponding plate count medium and potato culture medium according to the recommended ratio in the culture medium, sterilize at 121℃ for 15 min, and cool to about 50℃ for later use.

[0110] (3) Antibacterial test: ① Take 300 μL of bacterial / mold solution in a clean plate and pour it into plate count agar medium (bacteria) and potato dextrose agar medium (mold, yeast) respectively; ② After the culture medium solidifies, mark the back of the plate; ③ Place the Oxford cup according to the plate mark and let it stand for half an hour; ④ Take 275 μL of solution from each test group into the corresponding Oxford cup; ⑤ Place the culture base of mold and yeast in a 28℃ incubator for 2-5 days and observe; place the culture base of bacteria in a 37℃ incubator for 1-3 days and observe. ⑥ Observe the growth trend or reading of the colony. The antibacterial zone of each group of natural plant food preservatives was measured and the relevant data are recorded in Table 1.

[0111] Table 1 Inhibition zone test results of different preservatives

[0112]

[0113] As can be seen from Table 1, compared with the control group, the natural plant food preservatives of Examples 1 to 3 showed excellent effects in inhibiting bacteria, molds and yeasts, and the differences between the groups were not large. These results show that the natural plant food preservatives of Examples 1 to 3 have significant antibacterial effects.

[0114] In order to verify the effects of the various components of the preservative, experiments of Comparative Examples 1 to 4 were set up.

[0115] The main difference between the raw material ratio of the natural plant food preservative in Comparative Example 1 and Example 1 is that cinnamon extract is not contained. Compared with Example 1, the bacterial inhibition zone of Comparative Example 1 was reduced by 3.81 mm, the mold inhibition zone was reduced by 5.34 mm, and the yeast inhibition zone was reduced by 4.14 mm. The results show that cinnamon extract plays an important role in antibacterial effect.

[0116] The main difference between the raw material ratio of the natural plant food preservative in Comparative Example 2 and Example 1 is that anise extract is not contained. Compared with Example 1, the bacterial inhibition zone of Comparative Example 2 was reduced by 2.55 mm, the mold inhibition zone was reduced by 3.62 mm, and the yeast inhibition zone was reduced by 2.50 mm. The results show that anise extract affects the antibacterial effect of natural plant food preservatives.

[0117] The main difference between the raw material ratio of the natural plant food preservative in Comparative Example 3 and Example 1 is that vinegar powder is not contained. Compared with the Example 1 group, it was found that the bacterial inhibition zone of the Comparative Example 3 group was reduced by 2.03 mm, the mold inhibition zone was reduced by 2.83 mm, and the yeast inhibition zone was reduced by 3.25 mm. This result shows that vinegar powder affects the antibacterial effect of the natural plant food preservative.

[0118] The main difference between the raw material ratio of the natural plant food preservative in Comparative Example 4 and Example 1 is that chitin is not contained. Compared with the Example 1 group, it was found that the bacterial inhibition zone of the Comparative Example 4 group was reduced by 1.22 mm, the mold inhibition zone was reduced by 1.52 mm, and the yeast inhibition zone was reduced by 0.92 mm. This result shows that chitin has an effect on antibacterial properties.

[0119] Test 2: Anticorrosion test and result analysis

[0120] The seven groups of natural preservatives prepared were applied to pearl powder balls to conduct preservative application tests. The test method is as follows: Figure 2 In the experiment, all samples were stored at room temperature and the mold was observed every day. The following is the comparative data of the application of different preservatives in starch products:

[0121] Table 2 Statistical results of different preservatives used in pearl powder balls

[0122]

[0123] Among them, the sample pictures corresponding to each instance group are as follows Figure 3 and 4 As shown, the examples 1 to 3 correspond to Figure 3 a~c in the figure; compare groups 1 to 4 in turn. Figure 4 a~d in.

[0124] As shown in Table 2, compared with the control group, the natural plant food preservatives of Examples 1 to 3 have excellent anti-corruption effects; at the same time, the differences between the groups are not obvious. The above results show that the natural plant food preservatives of Examples 1 to 3 have significant anti-corruption effects.

[0125] In order to verify the effects of the various components of the additive, the tests of Comparative Examples 1 to 4 were set up:

[0126] The main difference between the raw material ratio of the natural plant food preservative in Comparative Example 1 and Example 1 is that cinnamon extract is not contained. Compared with Example 1, the shelf life of Comparative Example 1 was reduced by 84 days, which indicates that cinnamon extract plays an important role in preservation.

[0127] The main difference between the raw material ratio of the natural plant food preservative in Comparative Example 2 and Example 1 is that anise extract is not contained. Compared with Example 1, the shelf life of Comparative Example 2 was reduced by 55 days, which indicates that anise extract plays a role in preservation.

[0128] The main difference between the raw material ratio of the natural plant food preservative in Comparative Example 3 and Example 1 is that vinegar powder is not included. Compared with Example 1, the shelf life of Comparative Example 3 was reduced by 66 days, which shows that vinegar powder plays a role in preservation.

[0129] The main difference between the raw material ratio of the natural plant food preservative in Comparative Example 4 and Example 1 is that chitosan is not contained. Compared with Example 1, the shelf life of Comparative Example 4 was reduced by 25 days, which indicates that chitosan plays a role in preservation.

[0130] From the above, it can be seen that the natural plant food preservative prepared by the present invention can not only effectively inhibit bacteria, molds and large yeasts, and has excellent antibacterial effect, but also has excellent antiseptic effect. This shows that the natural plant food preservative produced by the present invention has a broader market prospect and is more suitable for promotion.

[0131] The difference between this application and the prior art is that:

[0132] Firstly, the main raw material adopted by the present invention is the natural plant eagle tea which is both a traditional Chinese herbal medicine and a unique tea resource. The natural preservative prepared with the eagle tea as the raw material is safe and healthy; secondly, the raw materials and reagents adopted by the present invention are safe and non-toxic, achieving the pure naturalness and non-toxic side effects of the natural preservative; thirdly, the natural preservative prepared by the present invention not only has strong bactericidal and antibacterial effects, but also has a simple preparation process and low production cost; finally, the natural preservative prepared by the present invention using eagle tea extract, vinegar powder, cinnamon extract, anise extract and chitin as raw materials, compounded and dried can be appropriately adjusted according to different application objects, and has a wide range of applicable objects.

[0133] Finally, it should be noted that although the above embodiments have been described in the specification and drawings of this application, this does not limit the scope of patent protection of this application. All technical solutions generated by replacing or modifying equivalent structures or equivalent processes based on the essential concept of this application using the contents recorded in the specification and drawings of this application, as well as directly or indirectly implementing the technical solutions of the above embodiments in other related technical fields, are included in the scope of patent protection of this application.

Claims

1. A natural preservative, characterized in that: The following raw materials are included in mass percentage: Eagle tea extract 50%~60%, vinegar powder 10%~20%, cinnamon extract 10%~30%, anise extract 2%~15%, and chitin 0.2%~3%.

2. The natural preservative according to claim 1, characterized in that The chitin includes chitosan and / or chitooligosaccharide.

3. A method for preparing a natural preservative, characterized in that: For preparing the natural preservative as claimed in claim 1 or 2, comprising the following steps: Weigh the raw materials according to the following mass percentages: Eagle tea extract 50%~60%, vinegar powder 10%~20%, cinnamon extract 10%~30%, anise extract 2%~15%, and chitosan 0.2%~3%; the error range of the raw material ratio is controlled within 5%; The raw materials are mixed and sieved to obtain a finished natural preservative.

4. The method for preparing the natural preservative according to claim 3, characterized in that: The mixing speed is 300-350 r / min, and the mixing time is 10-20 minutes.

5. The method for preparing the natural preservative according to claim 3, characterized in that: When the mixed raw materials are sieved, the sieve size used is 40 mesh.

6. The method for preparing the natural preservative according to claim 3, characterized in that: The preparation steps of the vinegar powder include: The fermented raw materials are fermented in liquid form to produce concentrated vinegar with a solid content of 60% to 70%; Processing the concentrated vinegar under spray drying conditions to obtain vinegar powder; The processing technology of vinegar powder includes: inlet temperature of 150~170℃, material concentration of 15%~25%, maltodextrin addition of 25%~30%, roxburghii polysaccharide addition of 3%~5%, and feed rate of 5.2mL / min.

7. The method for preparing the natural preservative according to claim 6, characterized in that: The fermentation raw materials include: one or more of glutinous rice, red koji and sesame.

8. The method for preparing the natural preservative according to claim 3, characterized in that: The preparation steps of the eagle tea extract are as follows: Remove impurities from the fresh leaves of Laoying tea, maintain the predetermined thickness, spread them out for a predetermined period of time at 21-28℃, and turn them over at least once during the process; The tea leaves after being spread out to dry are spread out flat and steam-fixed at a predetermined thickness; Rolling is performed using a rolling machine, first at a predetermined speed, then with pressure, and then dried until the moisture content is 10% to produce sun-dried green tea; Mix a certain amount of sun-dried green tea with a certain proportion of water, inoculate a certain proportion of Aspergillus niger spore suspension, seal it, culture it under constant temperature for a period of time, and dry it to obtain fermented eagle tea; The dried fermented eagle tea was ground into powder and sieved, extracted with 55%-75% ethanol for three times, the extracts were combined and centrifuged to obtain the supernatant, concentrated by rotary evaporation to a solid content of 60%-80%, and freeze-dried to obtain the eagle tea extract.

9. The method for preparing the natural preservative according to claim 8, characterized in that: The ethanol extraction comprises: using 55% to 75% ethanol to extract at 25 to 35° C. for 10 to 24 hours; The rotary evaporation is carried out at a temperature of 45-50°C; The temperature of the low-temperature freeze drying is -7 to -10°C, and the time is 25 to 40 minutes.

10. The method for preparing a natural preservative according to claim 8, characterized in that: The preparation method of the Aspergillus niger spore suspension is: Select Aspergillus niger strains from the slant culture medium, inoculate them into potato dextrose agar medium, and culture them at 28°C until Aspergillus niger grows all over the medium; Use an inoculating loop to pick up the activated Aspergillus niger into sterile saline containing sterile glass beads and shake thoroughly; The spore suspension was filtered through sterile cotton wool and the spore concentration was adjusted to 1.0 × 10 7 Pieces / mL.

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