Preparation method of volatile oil preservative and application of volatile oil preservative in preservation of artemisia selengensis

Abstract

The invention relates to the field of vegetable preservation, and discloses a preparation method of a volatile oil preservative and application of the volatile oil preservative in artemisia selengensis preservation, and the method comprises the following steps: step 1, weighing waste leaves and stems of artemisia selengensis, adding a sodium chloride solution, crushing with a juicer, then transferring into a round-bottom flask, enabling the round-bottom flask to be hermetically connected with a volatile oil steam distillation device to extract artemisia selengensis volatile oil, receiving volatile oil by using a centrifugal tube, and transferring the upper layer artemisia selengensis volatile oil by using a pipette; and step 2, weighing a hydrophilic emulsifier sucrose ester and chitosan powder, slowly adding the hydrophilic emulsifier sucrose ester and chitosan powder into the acetic acid solution, stirring while adding to avoid agglomeration, stirring at room temperature until the hydrophilic emulsifier sucrose ester and chitosan powder are completely dissolved to form a transparent or slightly milky white solution, adding the extracted artemisia selengensis volatile oil and glycerol, stirring in a sealed manner at room temperature, and degassing to obtain the artemisia selengensis volatile oil preservative. According to the method, a closed loop of waste recycling, preservative and homologous vegetable preservation can be realized, and the shelf life of artemisia selengensis is prolonged; meanwhile, the artemisia selengensis volatile oil has a certain compensation effect on the loss of the flavor of the clean artemisia selengensis.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of vegetable preservation, in particular to a preparation method of volatile oil preservative and application in preservation of parsnip, the prepared volatile oil preservative is suitable for preservation of parsnip net vegetables. BACKGROUND

[0002] The parsnip is rich in nutrition, but the edible part is only the fresh and tender stem of the whole parsnip, after removing the old stems and leaves of the parsnip net vegetables, the mechanical damage will cause the wound respiration of the parsnip tissue, leading to the strengthening of the respiration intensity, the dissolution of the nutrients at the damage site, and the accelerated corruption and deterioration of the parsnip net vegetables due to the microbial contamination. In the storage process, the special fragrance of the parsnip is also easy to lose, thereby affecting the edible quality of the parsnip net vegetables. The discarded old stems and leaves of the parsnip will cause environmental pollution, the discarded old stems and leaves of the parsnip contain a large amount of useful substances, the parsnip is rich in flavonoids, polyphenols and other active ingredients, can remove various free radicals, has good antioxidant activity, and has good bacteriostatic effect on escherichia coli, yeast and staphylococcus aureus, and can be considered as one of the components of the preservative.

[0003] At present, the preservation methods of vegetables include low-temperature cold storage preservation, air conditioning preservation, chemical preservative preservation and the like, the first two methods need equipment and have large investment, the chemical preservative preservation has low cost and is easy to operate, but with the improvement of people's living standards, the natural preservative is more easily accepted by people due to high safety, environmental protection, no pollution and multiple functions. SUMMARY

[0004] In view of the problems of high preservation cost, low safety, low utilization rate of waste and single effect of the preservative in the prior art, the present application aims to provide a preparation method of volatile oil preservative prepared from parsnip waste at low cost and high safety, realize the closed loop of "waste resourceization, preservative and preservation of homologous vegetables", and prolong the shelf life of parsnip.

[0005] Another object of the present application is to provide the application of the parsnip volatile oil preservative prepared by the preparation method of the volatile oil preservative in the preservation of parsnip, which can prolong the storage period of parsnip net vegetables, and the parsnip volatile oil has the fragrance of parsnip, which can compensate for the loss of flavor of parsnip net vegetables, thereby forming a closed loop of parsnip resource utilization.

[0006] In order to further achieve the above object, the present application adopts the following technical scheme:

[0007] A preparation method of volatile oil preservative, comprising the following steps:

[0008] Step 1, extraction of parsnip volatile oil:

[0009] Weigh 100g of waste leaves and stems of Artemisia argyi, add 1000-1500mL of 20% sodium chloride solution, crush with a juicer, and then transfer to a 2000ml round-bottom flask. Seal the flask with the steam distillation apparatus for volatile oils and extract the volatile oils of Artemisia argyi according to the Chinese Pharmacopoeia (2020 edition, Part IV). Collect the volatile oils with a centrifuge tube and transfer the upper layer of volatile oils with a pipette.

[0010] Step 2, Preparation of Artemisia argyi volatile oil preservative:

[0011] Weigh 0.5-1 g of hydrophilic emulsifier sucrose ester and 0.2-2 g of chitosan powder, and slowly add them to 60 mL of 0.5% acetic acid solution while stirring to avoid agglomeration. Stir at room temperature for 1-3 hours until completely dissolved, forming a transparent or slightly milky white solution. Then add 40 mL of Artemisia argyi volatile oil and 0.15-0.6 g of glycerin. Stir in a sealed container at room temperature for 0.5 hours, and then degas for 0.5-1.5 hours to obtain Artemisia argyi volatile oil preservative.

[0012] The application of the volatile oil preservative for Artemisia annua prepared by the aforementioned method in the preservation of Artemisia annua includes: filling the prepared volatile oil preservative for Artemisia annua into a container, soaking freshly purchased cleaned Artemisia annua in the preservative for 5-15 minutes, taking it out and placing it in a cool and ventilated place for 10-15 minutes, and packaging it after the film layer dries.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1. The present invention found that the activities of peroxidase (POD) and polyphenol oxidase (PPO) in cleaned watercress soaked in watercress volatile oil preservative were significantly reduced during storage. This indicates that watercress volatile oil treatment can effectively reduce the browning degree of cleaned watercress, slow down its oxidative stress, and also avoid stress response caused by mechanical damage to a certain extent.

[0015] 2. This invention combines the natural antibacterial and antioxidant properties of Artemisia argyi volatile oil, the film-forming barrier properties of chitosan (antibacterial, water-locking, and oxygen-barrier), and the emulsifying stability of sucrose esters to form a dual preservation effect of "antibacterial + physical barrier," which can achieve synergistic effects of homologous components.

[0016] 3. This invention can solve the problem of resource utilization of waste leaves and stems of Artemisia argyi, and also solve the problem of short shelf life of clean Artemisia argyi. At the same time, the volatile oil of Artemisia argyi has the fragrance of Artemisia argyi, which can compensate for the loss of flavor of clean Artemisia argyi, thus forming a closed-loop utilization of Artemisia argyi resources. Attached Figure Description

[0017] Figure 1This is a schematic diagram showing the change in weight loss rate between treatment with Artemisia argyi volatile oil preservative and treatment with a solution without Artemisia argyi volatile oil in Example 3 of the present invention;

[0018] Figure 2 This is a schematic diagram illustrating the changes in vitamin C content between treatment with Artemisia argyi volatile oil preservative and treatment with a solution without Artemisia argyi volatile oil in Example 3 of the present invention.

[0019] Figure 3 This is a schematic diagram illustrating the changes in chlorophyll content between treatment with Artemisia argyi volatile oil preservative and treatment with a solution without Artemisia argyi volatile oil in Example 3 of the present invention. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0021] A method for preparing a volatile oil preservative includes the following steps:

[0022] 1. Extraction of volatile oil from Artemisia annua: Weigh 100g of waste leaves and stems of Artemisia annua, add 1000-1500mL of 20% sodium chloride solution, crush with a juicer, and then transfer to a 2000ml round-bottom flask. Seal the flask with a steam distillation apparatus (Shanghai Yarong, model RE-52A) for volatile oil extraction. Extract the volatile oil from Artemisia annua according to the Chinese Pharmacopoeia (2020 edition, Part IV). Collect the volatile oil with a centrifuge tube and transfer the upper layer of Artemisia annua volatile oil with a pipette.

[0023] The raw material for this invention is waste leaves and stems of Artemisia annua, with a cost of virtually zero. All reagents used are edible and have high safety.

[0024] 2. Preparation of Artemisia annua volatile oil preservative: Weigh 0.5-1g of hydrophilic emulsifier sucrose ester and 0.2-2g of chitosan powder, and slowly add them to 60mL of 0.5% acetic acid solution while stirring to avoid agglomeration. Stir at room temperature for 1-3 hours until completely dissolved to form a transparent or slightly milky white solution. Then add 40mL of Artemisia annua volatile oil extracted in step 1 and 0.15-0.6g of glycerol. Stir in a sealed container at room temperature for 0.5 hours, and then degas for 0.5-1.5 hours to obtain Artemisia annua volatile oil preservative.

[0025] A small amount of glycerin was added during this process to improve the flexibility of the membrane and reduce coating cracking caused by transpiration of Artemisia annua.

[0026] Example 1

[0027] The components of the Artemisia argyi volatile oil extracted in step 1 of the above preparation method were detected by GC-MS. The GC-MS chromatographic conditions were as follows: HP-5MS (30 m × 250 μm × 0.25 μm) capillary column; high-purity nitrogen as carrier gas; injection port temperature 250℃; split injection, injection volume 2 μL, split ratio 10:1; temperature gradient: 40℃ for 1 min, increased to 80℃ at 10℃ / min and held for 1 min, increased to 110℃ at 5℃ / min and held for 1 min, increased to 130℃ at 2℃ / min and held for 2 min, increased to 150℃ at 1℃ / min and held for 1 min, increased to 185℃ at 5℃ / min and held for 1 min, and increased to 230℃ at 30℃ / min and held for 5 min. Mass spectrometry conditions: EI ionization source; ion source temperature 230℃; quadrupole temperature 150℃; power supply voltage 70 eV; scan mass range 30-550 amu; solvent delay 2 min.

[0028] The mass spectra obtained after mass spectrometry scanning of each peak were compared with relevant mass spectrometry data by searching computer spectral libraries to confirm the peaks in terms of base peak, mass-to-nucleus ratio, and relative abundance. The main components were identified as shown in Table 1.

[0029] Table 1. Main components of Artemisia argyi volatile oil

[0030]

[0031]

[0032] As shown in Table 1, the volatile components in Artemisia argyi volatile oil include complex compounds such as alkenes, phenols, fatty acids, alcohols, ketones, and esters. Among them, alkenes, esters, ketones, and alcohols are the main sources of the fresh aroma of Artemisia argyi.

[0033] Example 2

[0034] A method for preparing a volatile oil preservative includes the following steps:

[0035] 1. Extraction of volatile oil from Artemisia annua: Weigh 100g of waste leaves and stems of Artemisia annua, add 1500mL of 20% sodium chloride solution, crush with a juicer, and then transfer to a 2000ml round-bottom flask. Seal the flask with the steam distillation apparatus for volatile oil and extract the volatile oil from Artemisia annua according to the Chinese Pharmacopoeia (2020 edition, Part IV). Collect the volatile oil with a centrifuge tube and transfer the upper layer of Artemisia annua volatile oil with a pipette.

[0036] 2. Preparation of Artemisia annua volatile oil preservative: Weigh 0.8g of hydrophilic emulsifier sucrose ester and 1.2g of chitosan powder, and slowly add them to 60mL of 0.5% acetic acid solution while stirring to avoid agglomeration. Stir at room temperature for 2 hours until completely dissolved to form a transparent or slightly milky white solution. Then add 40mL of Artemisia annua volatile oil extracted in step 1 and 0.5g of glycerol. Stir in a sealed container at room temperature for 0.5 hours, and then degas for 0.5 hours to obtain Artemisia annua volatile oil preservative.

[0037] Example 3

[0038] Freshly purchased Artemisia annua (pure water spinach) was divided into two groups. One group served as the experimental group, which was soaked in the Artemisia annua volatile oil preservative solution prepared in Example 2 for 15 minutes. The other group served as the control group, which was soaked in a solution without Artemisia annua volatile oil (except for the Artemisia annua volatile oil, the other components and concentrations were exactly the same as the experimental group) for 15 minutes. The treated Artemisia annua was placed on plastic trays and left in a cool, ventilated place for 10 minutes. Then, both groups of samples were stored in a constant temperature incubator at 25±1℃ for 7 days. Samples were taken daily to measure the weight loss rate, vitamin C content, and chlorophyll content of the Artemisia annua in different experimental groups.

[0039] Changes in weight loss rate are a crucial indicator of vegetable freshness. When cells contain sufficient water, they maintain turgor pressure, resulting in firm, plump, glossy, and tender vegetables. After harvesting, vegetables continue to undergo vigorous transpiration and respiration during storage, easily losing water. Consequently, vegetables wilt, separate from their outer leaves, and rot, leading to a decline in quality and loss of commercial value. Figure 1 As shown, the weight loss rate of cleaned water chestnut vegetables treated with water chestnut volatile oil preservative was significantly reduced, indicating that the water chestnut volatile oil preservative can reduce the transpiration of cleaned water chestnut vegetables and prevent water loss, thereby better ensuring the quality of cleaned water chestnut vegetables.

[0040] Vegetables contain abundant chlorophyll; however, after harvesting, the chlorophyll content continuously decreases, causing vegetables to wilt and turn yellow, significantly reducing their freshness and affecting food quality, processing performance, and commercial value. For example... Figure 2 As shown, the chlorophyll content of cleaned Artemisia annua vegetables decreased over time during storage, but the chlorophyll content of cleaned Artemisia annua vegetables that were not treated with Artemisia annua volatile oil preservative was significantly lower than that of the treated group.

[0041] Vitamin C is widely found in fruits and vegetables. It plays an antioxidant role in the aging process of fruits and vegetables, helps plants resist drought, ozone, and ultraviolet radiation, and is also an important nutritional indicator for vegetables. Figure 3 As shown, the treatment with Artemisia argyi volatile oil preservative can, to some extent, delay the significant loss of vitamin C.

[0042] Example 4

[0043] Freshly purchased Artemisia annua (pure water spinach) was divided into two groups. One group was soaked in the Artemisia annua volatile oil preservative solution prepared in Example 2 for 15 minutes; the other group was left untreated. The treated Artemisia annua was placed on plastic trays and left in a cool, ventilated place for 10 minutes. Then, both groups of samples were stored in a constant temperature incubator at 25±1℃ for 7 days. Samples were taken daily to measure the PPO and POD activities in different experimental groups of Artemisia annua.

[0044] The untreated group of water chestnut vegetables wilted and turned brown on the 3rd day, and showed obvious signs of rotting on the 5th day; while the water chestnut vegetables soaked in water chestnut volatile oil preservative still looked relatively fresh on the 7th day.

[0045] Table 2. Effects of volatile oil preservatives on the PPO and POD activities of cleaned Artemisia annua vegetables.

[0046]

[0047] Note: Different lowercase letters indicate significant differences, P<0.05.

[0048] PPO is one of the enzymes involved in cellular respiration in fruits and vegetables. It catalyzes the oxidation of phenolic substances into quinones, which further polymerize into brown or black pigments, leading to enzymatic browning in fruits and vegetables, thus adversely affecting their color and flavor. Generally, the likelihood of fruit browning is positively correlated with PPO activity. Table 2 shows that the PPO activity in the untreated group was higher than that in the treated group, indicating that the degree of browning in the untreated Artemisia annua was higher than that in the treated group.

[0049] POD is a key enzyme in plant cells that maintains oxygen metabolism balance. It catalyzes the reaction of hydrogen peroxide and phenolic substances, leading to further dehydration and polymerization, which causes browning in plant tissues. Table 2 shows that the overall POD activity in the treatment group was lower than that in the untreated group. This indicates that the volatile oil preservative for Artemisia argyi can prevent oxidative stress in cleaned Artemisia argyi, thus extending its shelf life.

[0050] The above description is merely a specific embodiment of the present invention, and the scope of protection of the present invention is not limited thereto. Any transformations or substitutions that can be conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing a volatile oil preservative, characterized in that, Includes the following steps: Step 1, Extraction of volatile oil from Artemisia annua: Weigh the waste leaves and stems of Artemisia annua, add sodium chloride solution, crush them with a juicer, and then transfer them to a round-bottom flask. Seal the flask with a steam distillation apparatus for volatile oil extraction. Collect the volatile oil with a centrifuge tube and transfer the upper layer of volatile oil with a pipette. Step 2, Preparation of Artemisia argyi volatile oil preservative: Take hydrophilic emulsifier sucrose ester and chitosan powder, slowly add them to acetic acid solution while stirring to avoid agglomeration, stir at room temperature until completely dissolved to form a transparent or slightly milky white solution, add the Artemisia argyi volatile oil extracted in step 1 and glycerol, stir in a sealed container at room temperature, and then degas to obtain Artemisia argyi volatile oil preservative.

2. The method for preparing the volatile oil preservative according to claim 1, characterized in that, The concentration of the sodium chloride solution is 20%.

3. The method for preparing the volatile oil preservative according to claim 1, characterized in that, The hydrophilic emulsifier sucrose ester is 0.5-1g, the chitosan powder is 0.2-2g, the Artemisia argyi volatile oil is 40 mL, and the glycerol is 0.15-0.6g.

4. The method for preparing the volatile oil preservative according to claim 1, characterized in that, The concentration of the acetic acid solution is 0.5%.

5. The method for preparing the volatile oil preservative according to claim 1, characterized in that, The stirring time at room temperature is 1-3 hours.

6. The method for preparing the volatile oil preservative according to claim 1, characterized in that, The closed stirring time at room temperature is 0.5 hours.

7. The method for preparing the volatile oil preservative according to claim 1, characterized in that, The degassing time is 0.5-1.5 hours.

8. A preservative for Artemisia argyi volatile oil prepared by the preparation method according to any one of claims 1-7.

9. The application of the volatile oil preservative of Artemisia argyi according to claim 8 in the preservation of Artemisia argyi.

10. The application according to claim 9, characterized in that, Put the volatile oil preservative of Artemisia argyi into a container, soak the freshly purchased cleaned Artemisia argyi in the volatile oil preservative for 5-15 minutes, take it out and place it in a cool and ventilated place for 10-15 minutes. After the film is dry, package it.

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