Color protection process of rosemary branches

Abstract

The invention relates to the field of food color protection processes, and particularly discloses a color protection process of rosemary branches, which comprises the following steps: S1, picking fresh rosemary, cutting the branches to the required length, cleaning and removing impurities; s2, preparing two parts of color-protecting solutions, boiling one part of the color-protecting solutions, and pre-cooling the other part of the color-protecting solutions to 0-5 DEG C; s3, putting the rosemary branches subjected to impurity removal into a boiled color protection solution, and carrying out blanching treatment for 25-50 seconds; s4, quickly putting the blanched rosemary branches into a pre-cooled color protection solution, soaking and cooling, and refrigerating and storing; s5, the rosemary branches are fished out, drained and then subjected to vacuum packaging. The color protection solution is prepared from the following components in parts by weight: 2 to 4 parts of compound antioxidant, 0.1 to 0.3 part of sodium bicarbonate and 95 to 98 parts of water. The method has the effect of improving the color and luster of the rosemary.

Description

Technical Field

[0001] This application relates to the field of food color protection technology, and more specifically, it relates to a color protection technology for rosemary branches. Background Technology

[0002] In the food production and processing industry, rosemary, as a common spice, is widely used in cooking to enhance the aroma and flavor of food.

[0003] When cooking steak, rosemary imparts a unique flavor when cooked together with the steak. To facilitate home cooking and the catering industry, freezing fresh rosemary sprigs with steak has become an increasingly popular product format. However, rosemary sprigs face a serious problem of quality deterioration during their shelf life.

[0004] Fresh rosemary is bright green. When vacuum-packed with steak and frozen, it is prone to oxidation and browning, causing the leaves to turn from bright green to an unsightly yellowish-brown or even grayish-brown. This seriously affects the appearance of the steak and also affects consumers' desire to buy it. Summary of the Invention

[0005] In order to improve the color of rosemary branches, this application provides a color-protecting process for rosemary branches.

[0006] This application provides a color-protecting process for rosemary branches, employing the following technical solution: A color-protecting process for rosemary branches includes the following steps: S1. After picking fresh rosemary, cut the branches to the required length and wash and remove impurities; S2. Prepare two portions of color-protecting solution. Boil one portion and pre-cool the other portion to 0-5℃. S3. Place the cleaned rosemary branches in the boiled color-protecting solution and blanch for 25-50 seconds. S4. Quickly place the blanched rosemary sprigs into the pre-cooled color-protecting solution, soak and cool, and store in the refrigerator. S5. After draining the rosemary sprigs, vacuum pack them.

[0007] The color-protecting solution comprises the following components in parts by weight: 2-4 parts of compound antioxidant, 0.1-0.3 parts of sodium bicarbonate, and 95-98 parts of water.

[0008] By employing the above-mentioned technical solution, during the blanching process in the boiled color-protecting solution, rosemary stalks can be inactivated by polyphenol oxidase (which causes browning) and lipoxygenase (which causes off-flavors), as well as other enzymes harmful to quality, thus delaying the browning of the rosemary stalks. Immediately after blanching, the stalks are placed in a pre-cooled color-protecting solution, effectively preventing further loss of flavor compounds due to continuous heating. High-temperature blanching accelerates the conversion of chlorophyll to pheophytin, which causes the rosemary stalks to turn olive brown. Rapid cooling stops this conversion process, allowing the rosemary stalks to retain their natural green color. Simultaneously, it tightens and strengthens the cell walls, preventing the stalks from becoming too soft and mushy. The combined effect of the compound antioxidants and sodium bicarbonate further enhances the antioxidant properties of rosemary while preserving its flavor, thereby delaying the enzymatic browning reaction.

[0009] Optionally, the compound antioxidant comprises the following components in parts by weight: 10-20 parts of tea polyphenols, 15-30 parts of rosemary extract, 30-40 parts of sodium isoascorbate, 1-5 parts of disodium EDTA, 5-10 parts of citric acid, and 10-15 parts of phytic acid.

[0010] By employing the above-mentioned technical solution, sodium isoascorbate, tea polyphenols, and rosemary extract serve as the main antioxidants, effectively scavenging free radicals within rosemary and consuming oxygen, thereby preventing enzymatic browning. Disodium EDTA, citric acid, and phytic acid act as chelating agents, binding with metal ions within rosemary, preventing enzymes from functioning properly, and thus delaying enzymatic browning.

[0011] Optionally, the compound antioxidant may further include 1-5 parts by weight of zinc gluconate.

[0012] By adopting the above technical solution, the chlorophyll inside rosemary will be converted into deenzymatic chlorophyll when heated, and the zinc ions in zinc gluconate can replace the magnesium ions in chlorophyll, thereby forming stable zinc-substituted chlorophyll and maintaining the bright green appearance of rosemary branches.

[0013] Optionally, the preparation process of the rosemary extract is as follows: S1. Take fresh rosemary leaves, wash and dry them; S2. Grind to obtain rosemary powder; S3. Place the dried rosemary powder in an extractor, add an extraction solution for extraction, wherein the extraction solution includes any one of ethanol solution and ethyl acetate, the extraction temperature is 80-85℃, and the extraction time is 5h. S4. Filter the solution obtained after extraction; S5. The filtered solution is subjected to vacuum rotary evaporation under a vacuum of 0.08-0.095 MPa to obtain rosemary extract.

[0014] Optionally, the extraction solution is an ethanol solution. By employing the above technical solutions, both ethanol and ethyl acetate are moderately polar organic solvents, and both perform well in extracting substances from rosemary. However, due to its higher polarity, ethanol can effectively dissolve moderately polar antioxidants such as caryopsisic acid and caryopsisol, and also effectively extracts the more polar rosmarinic acid and flavonoid glycosides, resulting in a more comprehensive extraction. Secondly, ethanol solution is a food-grade solvent with lenient residue limits and extremely low toxicity, while ethyl acetate has some toxicity and stricter solvent residue requirements, making it unsuitable for food ingredients directly facing consumers and potentially increasing control costs and safety risks.

[0015] Optionally, the volume concentration of the ethanol solution is in the range of 70-80%.

[0016] By adopting the above technical solution, the ethanol solution in this range is both polar and non-polar, which can penetrate plant cell membranes and dissolve most of the target antioxidants, such as caryopsisic acid, caryopsisol and rosmarinic acid, so that almost all the key antioxidant components in rosemary can be extracted at the same time, thereby ensuring that the final product has a more comprehensive antioxidant spectrum and a higher overall yield.

[0017] Optionally, the precooling temperature in S2 is preferably 0-2℃.

[0018] By adopting the above technical solution, the pre-cooled color-protecting solution in this range can achieve rapid cooling, which can instantly terminate all heat-driven degradation reactions, including chlorophyll decomposition and non-enzymatic browning. This can lock in the best oily green color of rosemary branches after blanching to the greatest extent, resulting in better appearance and texture.

[0019] Optionally, the blanching time in S3 is preferably 30-45 seconds.

[0020] By employing the above technical solution, this treatment time is sufficient to effectively inactivate most key enzymes that lead to quality deterioration, such as polyphenol oxidase, which directly causes enzymatic browning, and peroxidase, which accelerates enzymatic browning. Chlorophyll degrades into olive-brown pheophytin under heat. The shorter the treatment time, the better the chlorophyll is preserved, resulting in a more vibrant and natural green color for the rosemary. Furthermore, since the volatile compounds within rosemary that give the product its unique flavor are heat-sensitive, short-time treatment can minimize the decomposition of these volatile compounds, thus preserving the flavor.

[0021] Optionally, the refrigerated storage time in S4 is 2-3 days.

[0022] By adopting the above technical solution, it is possible to ensure that the effective ingredients in the color-protecting liquid have sufficient time to continuously and slowly penetrate into the internal tissue of the rosemary sprig, and to provide a safe waiting period for the rosemary sprig in a low-temperature environment, ensuring that the reproduction of microorganisms is controlled to a minimum before entering the packaging, thereby improving the preservation effect.

[0023] In summary, this application has the following beneficial effects: 1. In this application, rosemary branches are blanched and rapidly cooled in a color-protecting solution in sequence, thus... While the internal enzymes are inactivated, the flavor and color are preserved to the maximum extent, so that the color, flavor and nutritional components of the product remain stable during the shelf life.

[0024] 2. Introducing a certain amount of zinc gluconate into the compound antioxidant further stabilizes chlorophyll, making the product's color more vibrant green. Detailed Implementation

[0025] The following detailed description of this application is provided in conjunction with the embodiments. It should be noted that: unless otherwise specified, the conditions in the following embodiments are performed under conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following embodiments are all from commercially available sources.

[0026] Preparation Example 1: The preparation process of rosemary extract is as follows: S1. Take rosemary leaves, wash them, and put them in an oven to dry at 45℃ for 3 hours. S2. Grind the dried rosemary leaves to obtain rosemary powder; S3. Place the dried rosemary powder into a Soxhlet extractor, add 70% ethanol solution for extraction, extract at 80℃ for 5 hours; S4. Filter the extracted mixed solution three times. S5. The filtered solution was subjected to vacuum rotary evaporation at a vacuum degree of 0.085 MPa and the water bath temperature was set to 45℃ to obtain rosemary extract.

[0027] Preparation Example 2: S1. Take rosemary leaves, wash them, and put them in an oven to dry at 45℃ for 3 hours. S2. Grind the dried rosemary leaves to obtain rosemary powder; S3. Place the dried rosemary powder into a Soxhlet extractor, add 75% ethanol solution for extraction, and extract at 82℃ for 5 hours. S4. Filter the extracted mixed solution three times. S5. The filtered solution was subjected to vacuum rotary evaporation at a vacuum degree of 0.09 MPa and the water bath temperature was set to 45℃ to obtain rosemary extract.

[0028] Preparation Example 3: The preparation process of rosemary extract is as follows: S1. Take rosemary leaves, wash them, and put them in an oven to dry at 45℃ for 3 hours. S2. Grind the dried rosemary leaves to obtain rosemary powder; S3. Place the dried rosemary powder into a Soxhlet extractor, add 80% ethanol solution for extraction, and extract at 85℃ for 5 hours. S4. Filter the extracted mixed solution three times. S5. The filtered solution was subjected to vacuum rotary evaporation at a vacuum degree of 0.095 MPa and the water bath temperature was set to 45℃ to obtain rosemary extract.

[0029] Preparation Example 4: The difference from Preparation Example 2 is that ethyl acetate was used instead of the 75 vol% ethanol solution.

[0030] Preparation Example 5: The components of the compound antioxidant include: 10 kg of tea polyphenols, 15 kg of rosemary extract obtained in Preparation Example 1, 30 kg of sodium isoascorbate, 1 kg of disodium EDTA, 5 kg of citric acid, and 10 kg of phytic acid.

[0031] Preparation Example 6: The difference from Preparation Example 5 is that the rosemary extract obtained in Preparation Example 2 was used.

[0032] Preparation Example 7: The difference from Preparation Example 5 is that the rosemary extract obtained in Preparation Example 3 was used.

[0033] Preparation Example 8: The difference from Preparation Example 5 is that the rosemary extract obtained in Preparation Example 4 was used.

[0034] Preparation Example 9: The components of the compound antioxidant include: 15 kg of tea polyphenols, 23 kg of rosemary extract obtained in Preparation Example 2, 35 kg of sodium isoascorbate, 3 kg of disodium EDTA, 7 kg of citric acid, and 12 kg of phytic acid.

[0035] Preparation Example 10: The components of the compound antioxidant include: 20 kg of tea polyphenols, 30 kg of rosemary extract obtained in Preparation Example 2, 40 kg of sodium isoascorbate, 5 kg of disodium EDTA, 10 kg of citric acid, and 15 kg of phytic acid.

[0036] Preparation Example 11: The difference from Preparation Example 9 is that an additional 1 kg of zinc gluconate was added.

[0037] Preparation Example 12: The difference from Preparation Example 9 is that an additional 3 kg of zinc gluconate was added.

[0038] Preparation Example 13: The difference from Preparation Example 9 is that an additional 5 kg of zinc gluconate was added.

[0039] Preparation Example 14: The compound antioxidants consist of 60 kg of ascorbic acid and 40 kg of citric acid.

[0040] Preparation Example 15: The preparation process of the color-protecting solution is as follows: Prepare a color-protecting solution at room temperature of 23±2℃. Add 95kg of water to the container and stir at 150r / min. Add 2kg of the compound antioxidant from Preparation Example 5 and stir for 3min. Then add 0.1kg of sodium bicarbonate powder and continue stirring for 3min.

[0041] Preparation Example 16: The preparation process of the color-protecting solution is as follows: Prepare a color-protecting solution at room temperature of 23±2℃. Add 96.5 kg of water to the container and stir at 150 r / min. Add 3 kg of the compound antioxidant from Preparation Example 5 and stir for 3 min. Then add 0.2 kg of sodium bicarbonate powder and continue stirring for 3 min.

[0042] Preparation Example 17: The preparation process of the color-protecting solution is as follows: Prepare a color-protecting solution at room temperature of 23±2℃. Add 98 kg of water to the container and stir at 150 r / min. Add 4 kg of the compound antioxidant from Preparation Example 5 and stir for 3 min. Then add 0.3 kg of sodium bicarbonate powder and continue stirring for 3 min.

[0043] Preparation Example 18: The difference from Preparation Example 16 is that the compound antioxidant of Preparation Example 6 is used.

[0044] Preparation Example 19: The difference from Preparation Example 16 is that the compound antioxidant of Preparation Example 7 was used.

[0045] Preparation Example 20: The difference from Preparation Example 16 is that the compound antioxidant of Preparation Example 8 is used.

[0046] Preparation Example 21: The difference from Preparation Example 16 is that the compound antioxidant of Preparation Example 9 was used.

[0047] Preparation Example 22: The difference from Preparation Example 16 is that the compound antioxidant of Preparation Example 10 is used.

[0048] Preparation Example 23: The difference from Preparation Example 16 is that the compound antioxidant of Preparation Example 11 is used.

[0049] Preparation Example 24: The difference from Preparation Example 16 is that the compound antioxidant of Preparation Example 12 is used.

[0050] Preparation Example 25: The difference from Preparation Example 16 is that the compound antioxidant of Preparation Example 13 was used.

[0051] Preparation Example 26: The difference from Preparation Example 16 is that the compound antioxidant of Preparation Example 14 is used.

[0052] Example 1: The following is a color-protecting technique for rosemary branches: S1. After picking fresh rosemary, cut it to 12cm and wash it to remove impurities; S2. Take 400g of the color-protecting solution prepared in Preparation Example 15, divide it into two equal portions, boil one portion and pre-cool the other portion to 5°C. S3. Place the cleaned rosemary branches in the boiled color-protecting solution and blanch for 25 seconds. S4. Quickly place the blanched rosemary sprigs into the pre-cooled color-protecting solution, soak and cool, and refrigerate for 2 days. S5. Remove the rosemary sprigs, drain, and vacuum pack.

[0053] Example 2: The difference from Example 1 is that the color-protecting solution prepared in Preparation Example 16 was used.

[0054] Example 3: The difference from Example 1 is that the color-protecting solution prepared in Preparation Example 17 was used.

[0055] Example 4: The difference from Example 1 is that the color-protecting solution prepared in Preparation Example 18 was used.

[0056] Example 5: The difference from Example 1 is that the color-protecting solution prepared in Preparation Example 19 was used.

[0057] Example 6: The difference from Example 1 is that the color-protecting solution prepared in Preparation Example 20 was used.

[0058] Example 7: The difference from Example 1 is that the color-protecting solution prepared in Preparation Example 21 was used.

[0059] Example 8: The difference from Example 1 is that the color-protecting solution prepared in Preparation Example 22 was used.

[0060] Example 9: The difference from Example 1 is that the color-protecting solution prepared in Preparation Example 23 was used.

[0061] Example 10: The difference from Example 1 is that the color-protecting solution prepared in Preparation Example 24 was used.

[0062] Example 11: The difference from Example 1 is that the color-protecting solution prepared in Preparation Example 25 was used.

[0063] Example 12: The difference from Example 10 is that the blanching time is set to 30 seconds.

[0064] Example 13: The difference from Example 10 is that the blanching time is set to 37 seconds.

[0065] Example 14: The difference from Example 10 is that the blanching time is set to 45 seconds.

[0066] Example 15: The difference from Example 10 is that the blanching time is set to 50 seconds.

[0067] Example 16: The difference from Example 13 is that the pre-cooling temperature is set to 2°C.

[0068] Example 17: The difference from Example 13 is that the pre-cooling temperature is set to 0°C.

[0069] Example 18: The difference from Example 17 is that the refrigerated storage time is 3 days.

[0070] Comparative Example 1: The difference from Example 13 is that the color-protecting solution obtained in Preparation Example 26 was used.

[0071] Comparative Example 2: The difference from Example 13 is that the color-protecting solution is replaced with water.

[0072] Comparative Example 3: The difference from Example 13 is that the blanching time is set to 20 seconds.

[0073] Comparative Example 4: The difference from Example 13 is that the color-protecting solution is pre-cooled to 10°C.

[0074] Comparative Example 5: The difference from Example 13 is that the blanching time is set to 60 seconds.

[0075] Comparative Example 6: The difference from Example 13 is that the refrigerated storage time is set to 1 day.

[0076] Comparative Example 7: The difference from Example 13 is that the refrigerated storage time is set to 5 days.

[0077] Testing and inspection: The appearance of the rosemary branches in Examples 1-18 and Comparative Examples 1-7 of this application was inspected, and a color development test was performed on the cross-section. The appearance of the rosemary branches changed color over time as follows: green-yellow-green-yellow-brown-black.

[0078] The testing environment was 23℃±2℃; the testing reagents were 10g / L guaiacol solution and 15g / L hydrogen peroxide solution, wherein the hydrogen peroxide was freshly prepared before the test.

[0079] The detection process for the colorimetric test is as follows: S1. Sampling: Take rosemary branches directly from Examples 1-18 and Comparative Examples 1-7. S2. Mix equal amounts of 10 g / L guaiacol solution and 15 g / L hydrogen peroxide solution, and immerse the cut surface of rosemary branch in the mixed reagent. S3. Wait 90 seconds and observe whether the cut surface or solution turns reddish-brown.

[0080] The detection principle of the colorimetric test is as follows: Rosemary contains various enzymes, such as peroxidase, polyphenol oxidase, and lipoxygenase. Among them, peroxidase, due to its strongest heat resistance, is usually used as an indicator of whether blanching is sufficient.

[0081] Peroxidase catalyzes the decomposition of hydrogen peroxide, forming a highly reactive primary oxidation intermediate. This intermediate reacts with certain colorless hydrogen donors to produce colored products, resulting in a reddish-brown color on the cross-section of rosemary branches. Therefore, observing the color change of the rosemary branch cross-section can determine whether the enzyme is still active.

[0082] The aging test process is as follows: Rosemary branches from Examples 1-18 and Comparative Examples 1-7 were placed in a dark environment with an ambient temperature of 25°C, and their appearance was observed for 10 consecutive days.

[0083] The results of the two experiments are shown in Table 1.

[0084] Table 1. Record of color reaction and appearance changes of rosemary twigs within 10 days The following is a detailed explanation based on the data provided in Table 1: 1. Comparing the test data of Examples 9-11 and Example 4, it can be seen that the rosemary branches with added zinc gluconate can maintain their green color for a longer period of time and have a better appearance. This is because the zinc gluconate reacts with chlorophyll to form zinc-substituted chlorophyll, preventing the conversion of chlorophyll to pheophytin. In Examples 9-11, it is shown that as the amount of zinc gluconate gradually increases, the color-protecting effect of the rosemary branches first strengthens and then weakens. This is because as the concentration of zinc ions increases, the free metal ions catalyze the oxidation of chlorophyll and polyphenols, making the color darker.

[0085] 2. By comparing the monitoring data of Examples 2 and 4-6, it can be concluded that the rosemary extract obtained by ethanol solution extraction can provide better color protection effect.

[0086] 3. Comparison of the test data from Examples 10, 12-15, Comparative Example 3, and Comparative Example 5 shows that the color of rosemary branches gradually turns yellow with increasing blanching time. This is mainly because, with increasing blanching time, the chlorophyll in the rosemary branches gradually transforms into yellowish-brown pheophytin, resulting in an unhealthy yellow color in the branches and leaves. In Comparative Example 3, the cut surface of the rosemary branch showed a reddish-brown color in the colorimetric reaction, indicating that the blanching time was too short, resulting in some enzymes not being completely inactivated. Combined with subsequent aging tests, it can be seen that both excessively long and short blanching times will shorten the storage time of rosemary branches.

[0087] 4. By comparing the test data of Examples 13, 16, 17 and Comparative Example 4, it can be found that as the temperature of the color-protecting solution in the pre-cooling treatment increases, the rosemary branches turn yellow faster. This means that the pre-cooling temperature is too high, which makes the cooling rate of the rosemary branches after blanching too slow. The residual heat from blanching provides the temperature conditions for the conversion of chlorophyll inside the rosemary branches, accelerating the conversion of chlorophyll to pheophytin.

[0088] 5. Compared with Comparative Example 1, Example 1 showed a significantly faster color change in the aging experiment. Although ascorbic acid has strong antioxidant properties, it has poor heat resistance and is easily decomposed by heat during blanching. Even if some ascorbic acid enters the rosemary branch during subsequent cold storage, it still cannot form good antioxidant conditions.

[0089] 6. Compared with Example 13, the rosemary branches of Comparative Example 2 changed color significantly to yellowish-brown after blanching. The cross-section of the rosemary branches was reddish-brown in the color development reaction. This indicates that blanching in boiling water alone cannot completely remove the enzymes inside the rosemary branches within a certain period of time. Subsequent aging tests also showed that Comparative Example 2 could not be preserved for a long time.

[0090] 7. Based on the data from Examples 17, 18, Comparative Example 6, and Comparative Example 7, it can be concluded that the refrigeration storage time should not be too long or too short. If the refrigeration storage time is too short, the rosemary branches will not be able to fully absorb the color-protecting solution. If it is too long, the water-soluble pigments in the rosemary branches and leaves will dissolve into the color-protecting solution, causing the color of the branches and leaves to lighten, resulting in the fading of green and the appearance of yellow.

[0091] In summary, setting the temperature of the pre-cooled color-protecting solution to 0-5℃ and the blanching time to 30-45 seconds can ensure the enzyme inactivation effect while giving the rosemary branches a better appearance and texture. To further enhance the color performance, zinc gluconate can be added to the color-protecting solution to delay the conversion of chlorophyll to pheophytin.

[0092] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A color-protecting process for rosemary branches, characterized in that, Includes the following steps: S1. After picking fresh rosemary, cut the branches to the required length and wash and remove impurities; S2. Prepare two portions of color-protecting solution. Boil one portion and pre-cool the other portion to 0-5℃. S3. Place the cleaned rosemary branches in the boiled color-protecting solution and blanch for 25-50 seconds. S4. Quickly place the blanched rosemary sprigs into the pre-cooled color-protecting solution, soak and cool, and store in the refrigerator. S5. After draining the rosemary sprigs, vacuum pack them. The color-protecting solution comprises the following components in parts by weight: 2-4 parts of compound antioxidant, 0.1-0.3 parts of sodium bicarbonate, and 95-98 parts of water.

2. The color-protecting process for rosemary branches according to claim 1, characterized in that: The compound antioxidant comprises the following components in parts by weight: 10-20 parts tea polyphenols, 15-30 parts rosemary extract, 30-40 parts sodium isoascorbate, 1-5 parts disodium EDTA, 5-10 parts citric acid, and 10-15 parts phytic acid.

3. The color-protecting process for rosemary branches according to claim 2, characterized in that: The compound antioxidant also includes 1-5 parts of zinc gluconate by weight.

4. The color-protecting process for rosemary branches according to claim 2, characterized in that: The preparation process of the rosemary extract is as follows: S1. Take fresh rosemary leaves, wash and dry them; S2. Grind to obtain rosemary powder; S3. Place the dried rosemary powder in an extractor, add an extraction solution for extraction, wherein the extraction solution includes any one of ethanol solution and ethyl acetate, the extraction temperature is 80-85℃, and the extraction time is 5h. S4. Filter the solution obtained after extraction; S5. The filtered solution is subjected to vacuum rotary evaporation under a vacuum of 0.085-0.095 MPa to obtain rosemary extract.

5. The color-protecting process for rosemary branches according to claim 4, characterized in that: The extraction solution is an ethanol solution.

6. The color-protecting process for rosemary branches according to claim 5, characterized in that: The volume concentration of the ethanol solution is in the range of 70-80%.

7. The color-protecting process for rosemary branches according to claim 1, characterized in that: The precooling temperature in S2 is preferably 0-2℃.

8. The color-protecting process for rosemary branches according to claim 1, characterized in that: The blanching time in S3 is preferably 30-45 seconds.

9. The color-protecting process for rosemary branches according to claim 1, characterized in that: The refrigerated storage time in S4 is 2-3 days.

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