Preservative as well as preparation method and application thereof

Abstract

The invention provides a preservative as well as a preparation method and application thereof, and belongs to the technical field of blueberry preservation. The preservative disclosed by the invention is prepared from 0.03 to 0.06 part of basil essential oil, 0.01 to 0.03 part of citronella essential oil, 0.05 to 0.09 part of purple perilla essential oil, 0.05 to 0.10 part of thymol, 0.01 to 0.05 part of sweet osmanthus essential oil, 0.01 to 0.05 part of origanum vulgare essential oil, 0.02 to 0.04 part of cinnamyl aldehyde, 0.05 to 0.08 part of cysteine and 0.5 to 2.0 parts of ethanol. The preservative disclosed by the invention is used for carrying out preservative and fresh-keeping on blueberries, and can be used for remarkably reducing the rotting rate of the blueberries, delaying the aging of the blueberries and keeping the color and flavor of the blueberries.

Description

Technical Field

[0001] The invention relates to the technical field of blueberry preservation, and in particular to an antiseptic preservative and a preparation method and application thereof. Background Art

[0002] Blueberry fruit belongs to the small berry category. It is fresh and tender, has a unique taste, and is rich in a variety of bioactive substances, such as polyphenols, flavonoids, dietary fiber, ascorbic acid, etc. Anthocyanins (flavonoids) in blueberry fruit have good antioxidant function and can prevent chronic diseases such as cancer, cardiovascular disease, diabetes, and inflammation. In 2020, the cultivated area and output of blueberries in my country have surpassed the United States, ranking first in the world, and becoming a new driving force for the development of the global blueberry industry; but my country's sales output of fresh blueberries ranks third, among which post-harvest quality is a key factor affecting the sales of fresh fruits. Blueberry fruit has a soft texture, a thin skin, and it is easy to cause wounds at the fruit stem during harvesting, which makes the blueberry fruit extremely susceptible to infection and rot by pathogenic fungi after harvesting. Therefore, the development of green, safe, broad-spectrum, and long-lasting biological preservatives has become a better choice.

[0003] Plant essential oils have received extensive attention in antibacterial research due to their significant antibacterial activity and wide antibacterial spectrum, as well as their unique advantages of less side effects and residual toxicity compared to chemical antibacterial agents. They are considered to be important raw materials for the development of natural preservatives. However, essential oils have the characteristics of being volatile, easy to sublimate, unstable, and poorly water-soluble. Specific implementation measures need to be explored for their specific application in various industries and fields. Although the antibacterial effect of essential oils can only work when in contact with microorganisms, many studies have confirmed that the fumigation antibacterial effect of essential oils is stronger than contact antibacterial. At relatively low concentrations, gaseous essential oils can inhibit common decay-causing pathogens, while having minimal impact on the sensory properties and environment of food, and can also save costs. Therefore, the fumigation antibacterial effect of essential oils can be used in the preservation of fruits and vegetables. Traditional antiseptic measures still use chemically synthesized fungicides for treatment, but due to environmental pollution, inducing pathogens to produce drug resistance, and food safety issues, many effective fungicides are restricted for use.

[0004] Therefore, it is of great practical significance to provide a safe and nontoxic preservative for blueberries. Summary of the invention

[0005] The purpose of the present invention is to provide a preservative and a preparation method and application thereof, aiming to solve the technical problems that the antiseptic measures used in the prior art for blueberry preservation and freshness-keeping are highly polluting and unsafe.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a preservative and fresh-keeping agent, comprising the following components:

[0008] Basil essential oil, citronella essential oil, perilla essential oil, thymol, osmanthus essential oil, oregano essential oil, cinnamaldehyde, cysteine ​​and ethanol.

[0009] Further, the dosage of the components is 0.03-0.06 parts of basil essential oil, 0.01-0.03 parts of citronella essential oil, 0.05-0.09 parts of perilla essential oil, 0.05-0.10 parts of thymol, 0.01-0.05 parts of osmanthus essential oil, 0.01-0.05 parts of oregano essential oil, 0.02-0.04 parts of cinnamaldehyde, 0.05-0.08 parts of cysteine ​​and 0.5-2.0 parts of ethanol.

[0010] Furthermore, the ethanol is 75% ethanol.

[0011] The present invention also provides a method for preparing the preservative described in the above technical solution, comprising the following steps:

[0012] Mixing basil essential oil, citronella essential oil, perilla essential oil, thymol, osmanthus essential oil, oregano essential oil and cinnamaldehyde to obtain a first mixture,

[0013] mixing the first mixture with ethanol to obtain an essential oil mother solution;

[0014] Mixing cysteine ​​with water to obtain a cysteine ​​mother solution;

[0015] The essential oil mother liquor, the cysteine ​​mother liquor and the remaining ethanol are mixed to obtain the preservative.

[0016] Furthermore, the mass ratio of the first mixture to ethanol is 1:1.

[0017] Furthermore, the mass ratio of cysteine ​​to water is 1:1.

[0018] Furthermore, the temperature at which the essential oil mother solution and the cysteine ​​mother solution are mixed is 20-25°C.

[0019] The present invention also provides the use of the preservative and fresh-keeping agent described in the above technical solution or the preservative and fresh-keeping agent obtained by the preparation method of the preservative and fresh-keeping agent in preserving blueberries.

[0020] Furthermore, the application method is:

[0021] After picking the blueberries, precool them at 5 to 7°C for 12 to 24 hours to obtain precooled blueberries;

[0022] The pre-cooled blueberries are placed in a closed space, the preservative is atomized at low temperature, and fumigated for 30 to 60 minutes to obtain fumigated blueberries;

[0023] The fumigated blueberries are taken out and stored at low temperature away from light.

[0024] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0025] (1) Basil essential oil is extracted from basil and has good antibacterial effects on Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Rhizopus, yeast, Aspergillus niger, anthracnose and scorch rot bacteria. It can also maintain the quality of blueberry fruits and reduce natural decay after harvesting. Citronella essential oil is generally extracted from dried citronella and has good antibacterial effects, such as inhibiting the growth of Escherichia coli, Aspergillus niger, Staphylococcus aureus, Botrytis cinerea, pedicel rot, Alternaria alternata, anthracnose and Fusarium moniliforme. Osmanthus fragrans is one of the first plants in my country to be approved as both a medicine and food. Its stems and leaves are rich in essential oils, the main component of which is perillaldehyde, which has antibacterial, antioxidant, anti-aging, and vasodilatory effects. Thymol (5-methyl-2-isopropylphenol) is one of the main components of thyme essential oil, which has antioxidant, anti-inflammatory, and antibacterial functions, such as being able to inhibit the growth of Listeria monocytogenes, Escherichia coli, Campylobacter jejuni, Salmonella enterica, Staphylococcus aureus, and Fusarium graminearum. Osmanthus fragrans essential oil is an extract of natural golden osmanthus. It is a product unique to my country. It contains aromatic substances such as ionones, alcohols, linalool oxides, and hexahydroxytaxene. There are few studies on its antibacterial effect. Oregano essential oil is a yellow-red or brown-red essential oil extracted and purified from the roots, stems, and leaves of oregano plants. Its main components are carvacrol and thymol. It has the advantages of broad-spectrum bactericidal, biodegradable, safe and non-toxic. It has a certain inhibitory effect on Staphylococcus aureus, Escherichia coli, Streptomyces sclerotiorum, Aspergillus niger, and Rhizopus stolonifer. Cinnamaldehyde is cinnamon oil. , cinnamon oil, patchouli oil, hyacinth oil and rose oil and other plant essential oils are the main components. They are preservatives that can be used for fresh fruits in the Chinese food additive catalog. They have strong antibacterial effects on bacteria and fungi such as Escherichia coli, Staphylococcus aureus, Salmonella, Listeria monocytogenes, Penicillium, Aspergillus flavus, Aspergillus niger, and anthrax. Cysteine ​​is a recognized safe amino acid and is often used as an anti-browning preservative for fresh-cut fruits and vegetables. Recent studies have found that it can inhibit the occurrence of plum brown rot. Although these ingredients have anti-aging and antibacterial effects, they are rarely used in blueberry preservation. The present invention mixes the above components to obtain a preservative with excellent antiseptic effect on blueberries.

[0026] (2) The blueberry preservative provided by the present invention is used to treat the fruit, which can better maintain the color and flavor of the fruit and reduce its decay rate. After 35 days of low-temperature storage, the decay rate is only 3%; in addition, the preservative treatment also inhibits the respiration rate and ethylene release of the blueberry fruit; the blueberry preservative provided by the present invention is used to preserve blueberries, which has the advantages of easy operation, low cost and significant effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a comparison diagram of the appearance differences between the control group and the treatment group of the test of the present invention;

[0028] Figure 2 This is a comparison chart of the weight loss rates of the test control group and the treatment group of the present invention;

[0029] Figure 3 This is a comparison chart of reducing sugar content between the test control group and the treatment group of the present invention;

[0030] Figure 4 This is a comparison chart of the respiratory rates of the test control group and the treatment group of the present invention;

[0031] Figure 5 This is a comparison chart of ethylene release between the control group and the treatment group of the present invention. DETAILED DESCRIPTION

[0032] The present invention provides a preservative and fresh-keeping agent, comprising the following components:

[0033] Basil essential oil, citronella essential oil, perilla essential oil, thymol, osmanthus essential oil, oregano essential oil, cinnamaldehyde, cysteine ​​and ethanol.

[0034] In the present invention, the dosage of the components is preferably 0.03-0.06 parts of basil essential oil, 0.01-0.03 parts of citronella essential oil, 0.05-0.09 parts of perilla essential oil, 0.05-0.10 parts of thymol, 0.01-0.05 parts of osmanthus essential oil, 0.01-0.05 parts of oregano essential oil, 0.02-0.04 parts of cinnamaldehyde, 0.05-0.08 parts of cysteine ​​and 0.5-2 .0 part of ethanol; more preferably 0.03-0.05 part of basil essential oil, 0.01-0.02 part of citronella essential oil, 0.05-0.07 part of perilla essential oil, 0.05-0.08 part of thymol, 0.01-0.03 part of osmanthus essential oil, 0.01-0.03 part of oregano essential oil, 0.02-0.03 part of cinnamaldehyde, 0.05-0.06 part of cysteine ​​and 0.5-1.5 parts of ethanol

[0035] In the present invention, the ethanol is preferably 75% ethanol.

[0036] The present invention also provides a method for preparing the preservative described in the above technical solution, comprising the following steps:

[0037] Mixing basil essential oil, citronella essential oil, perilla essential oil, thymol, osmanthus essential oil, oregano essential oil and cinnamaldehyde to obtain a first mixture,

[0038] mixing the first mixture with ethanol to obtain an essential oil mother solution;

[0039] Mixing cysteine ​​with water to obtain a cysteine ​​mother solution;

[0040] The essential oil mother liquor, the cysteine ​​mother liquor and the remaining ethanol are mixed to obtain the preservative.

[0041] In the present invention, the mass ratio of the first mixture to ethanol is preferably 1:1.

[0042] In the present invention, the mass ratio of cysteine ​​to water is preferably 1:1.

[0043] In the present invention, the temperature at which the essential oil mother solution and the cysteine ​​mother solution are mixed is preferably 20-25°C, more preferably 20-23°C.

[0044] The present invention also provides the use of the preservative and fresh-keeping agent described in the above technical solution or the preservative and fresh-keeping agent obtained by the preparation method of the preservative and fresh-keeping agent in preserving blueberries.

[0045] In the present invention, the method of application is preferably:

[0046] After picking the blueberries, precool them at 5 to 7°C for 12 to 24 hours to obtain precooled blueberries;

[0047] The pre-cooled blueberries are placed in a closed space, the preservative is atomized at low temperature, and fumigated for 30 to 60 minutes to obtain fumigated blueberries;

[0048] The fumigated blueberries are taken out and stored at low temperature away from light.

[0049] The use of the preservative and fresh-keeping agent of the present invention and the corresponding application method can significantly reduce the decay rate of blueberries and maintain their flavor and color.

[0050] In the present invention, unless otherwise specified, the required raw materials for preparation are all commercially available products well known to those skilled in the art.

[0051] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0052] Example 1

[0053] (1) 0.03 parts of basil essential oil, 0.01 parts of citronella essential oil, 0.05 parts of perilla essential oil, 0.05 parts of thymol, 0.01 parts of osmanthus essential oil, 0.01 parts of oregano essential oil and 0.02 parts of cinnamaldehyde were mixed and stirred evenly;

[0054] (2) mixing the above mixture with 0.18 parts of 75% ethanol and stirring evenly to obtain an essential oil mother liquor;

[0055] (3) Mix 0.05 parts of cysteine ​​with an equal amount of water and stir evenly to obtain a cysteine ​​mother solution;

[0056] (4) The cysteine ​​mother solution, the essential oil mother solution and 0.32 parts of 75% ethanol are mixed at a temperature of 20° C. and stirred to obtain the preservative.

[0057] Example 2

[0058] (1) 0.06 parts of basil essential oil, 0.03 parts of citronella essential oil, 0.09 parts of perilla essential oil, 0.1 parts of thymol, 0.05 parts of osmanthus essential oil, 0.05 parts of oregano essential oil and 0.04 parts of cinnamaldehyde were mixed and stirred evenly;

[0059] (2) mixing the above mixture with 0.33 parts of 75% ethanol and stirring evenly to obtain an essential oil mother liquor;

[0060] (3) Mix 0.08 parts of cysteine ​​with an equal amount of water and stir evenly to obtain a cysteine ​​mother solution;

[0061] (4) The cysteine ​​mother solution, the essential oil mother solution and 0.67 parts of 75% ethanol are mixed at a temperature of 25° C. and stirred to obtain the preservative.

[0062] Example 3

[0063] (1) 0.05 parts of basil essential oil, 0.02 parts of citronella essential oil, 0.07 parts of perilla essential oil, 0.08 parts of thymol, 0.03 parts of osmanthus essential oil, 0.03 parts of oregano essential oil and 0.03 parts of cinnamaldehyde were mixed and stirred evenly;

[0064] (2) mixing the above mixture with 0.31 parts of 75% ethanol and stirring evenly to obtain an essential oil mother liquor;

[0065] (3) Mix 0.05 parts of cysteine ​​with an equal amount of water and stir evenly to obtain a cysteine ​​mother solution;

[0066] (4) The cysteine ​​mother solution, the essential oil mother solution and 1.69 parts of 75% ethanol are mixed at a temperature of 23° C. and stirred to obtain the preservative.

[0067] test

[0068] The blueberries were treated with the preservative obtained in Example 1 as a treatment group; the blueberries without any treatment were used as a control group, and the difference in appearance between the two groups after 35 days of low-temperature storage was observed. The results are as follows: Figure 1 ;based on Figure 1 It can be seen that the fruit stalk and fruit top of the treated group did not shrink, while the fruit stalk of the control group without any treatment had obvious shrinkage, and mold hyphae grew, and the shrinkage of the fruit top was lighter, but still higher than that of the fruit top of the treated group;

[0069] The changes in color during storage of the control group and the experimental group were observed, and the results are shown in Table 1; Based on Table 1, it can be seen that during the entire storage period, the L* values ​​of the fruits in the control group and the treatment group showed a downward trend, and the L* value of the fruits in the control group was relatively low. On the 5th, 10th and 15th days of storage, the a* values ​​of the fruits in the treatment group were 17%, 25% and 11% lower than those in the control group, respectively. As the storage time increased, the ΔE value gradually decreased, while the ΔE value of the fruits in the treatment group decreased more slowly than that in the control group. From day 0 to day 35, the b* values ​​of the fruits in both the control group and the treatment group showed a gradual upward trend, and there was no significant difference between the control group and the treatment group;

[0070] Table 1 Color changes of blueberry fruits in the control group and the treatment group during low temperature storage

[0071]

[0072]

[0073] The weight loss rate of the fruits in the treatment group and the control group was recorded. Figure 2 shown; based on Figure 2 It can be seen that during the entire storage period, the weight loss rate of the fruits in the treatment group and the control group showed an upward trend. From the 5th to the 35th day, the weight loss rate of the fruits in the treatment group showed a significantly lower trend than that in the control group;

[0074] During the low temperature storage period, the reducing sugar content of the fruits in the treatment group and the control group was measured. Figure 3 shown; based on Figure 3 It can be seen that during the entire storage period, the reducing sugar content of the fruits in the treatment group and the control group showed a gradual downward trend. From the 5th to the 35th day, the decreasing trend of the reducing sugar content of the fruits in the treatment group was significantly lower than that in the control group;

[0075] The respiration rate of the fruits in the treatment group and the control group was measured during the low temperature storage period. Figure 4 shown; based on Figure 4It can be seen that during the entire storage period, the respiration rate of the fruits in the treatment group and the control group showed a slow upward trend, and there was little change on the 25th to 35th day of storage. From the 5th to the 35th day, the respiration rate of the fruits in the treatment group was significantly lower than that in the control group;

[0076] During the low temperature storage period, the ethylene release of the fruits in the treatment group and the control group was measured. Figure 5 shown; based on Figure 5 It can be seen that during the entire storage period, the ethylene release of the fruits in the treatment group and the control group increased slightly on the 0th to 5th day, and then remained basically unchanged during the subsequent storage time. During the 5th to 35th day of storage, the ethylene release of the fruits in the treatment group was significantly lower than that in the control group.

[0077] In summary, the preservative obtained by the present invention has an excellent preservation effect when used for preserving blueberries.

[0078] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A preservative, characterized in that: Includes the following components: Basil essential oil, citronella essential oil, perilla essential oil, thymol, osmanthus essential oil, oregano essential oil, cinnamaldehyde, cysteine ​​and ethanol.

2. The preservative according to claim 1, characterized in that: The components are used in amounts of 0.03-0.06 parts of basil essential oil, 0.01-0.03 parts of citronella essential oil, 0.05-0.09 parts of perilla essential oil, 0.05-0.10 parts of thymol, 0.01-0.05 parts of osmanthus essential oil, 0.01-0.05 parts of oregano essential oil, 0.02-0.04 parts of cinnamaldehyde, 0.05-0.08 parts of cysteine ​​and 0.5-2.0 parts of ethanol.

3. The preservative according to claim 1, characterized in that: The ethanol is 75% ethanol.

4. The method for preparing the preservative according to claims 1 to 3, characterized in that: The following steps are involved: Mixing basil essential oil, citronella essential oil, perilla essential oil, thymol, osmanthus essential oil, oregano essential oil and cinnamaldehyde to obtain a first mixture, Mixing the first mixture with ethanol to obtain an essential oil mother solution; Mixing cysteine ​​with water to obtain a cysteine ​​mother solution; The essential oil mother liquor, the cysteine ​​mother liquor and the remaining ethanol are mixed to obtain the preservative.

5. The method for preparing the preservative according to claim 4, characterized in that: The mass ratio of the first mixture to ethanol is 1:

1.

6. The method for preparing the preservative according to claim 4, characterized in that: The mass ratio of cysteine ​​to water is 1:

1.

7. The method for preparing the preservative according to claim 4, characterized in that: The temperature at which the essential oil mother solution and the cysteine ​​mother solution are mixed is 20-25°C.

8. Use of the preservative according to any one of claims 1 to 3 or the preservative obtained by the preparation method of the preservative according to any one of claims 4 to 7 in preserving blueberries.

9. The use according to claim 8, characterized in that: The method of application is: After picking the blueberries, precool them at 5 to 7°C for 12 to 24 hours to obtain precooled blueberries; The pre-cooled blueberries are placed in a closed space, the preservative is atomized at low temperature, and fumigated for 30 to 60 minutes to obtain fumigated blueberries; The fumigated blueberries are taken out and stored at low temperature away from light.

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