Application of 3-mercaptohexanol in preparation of plant polyphenol oxidase inhibitor or inhibition of plant or plant fruit browning
By using 3-mercaptohexanol as a polyphenol oxidase inhibitor and capturing o-quinone produced by polyphenol oxidase, the problem of browning of fruits and vegetables is solved, a safe and efficient anti-browning effect is achieved, processing costs are reduced and product quality is improved.
Patent Information
- Application Number
- CN202511005036.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-21
- Publication Date
- 2025-09-09
AI Technical Summary
Existing technologies for inhibiting the browning of fruits and vegetables caused by plant polyphenol oxidase have problems such as low efficiency, high cost, possible harmful residues and impact on product quality. In particular, it is difficult to find safe, efficient and economical solutions among physical and chemical methods.
3-Mercaptohexanol is used as a polyphenol oxidase inhibitor. Plants or plant fruits are treated by soaking them, and its active thiol group is used to capture the o-quinone produced by polyphenol oxidase to form a colorless thioether adduct, thereby blocking the browning pathway.
It significantly inhibits the activity of plant polyphenol oxidase, prolongs the shelf life of fruits and vegetables, reduces processing costs, and has no harmful residues. It is suitable for large-scale application and improves food safety and economic benefits.
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Figure CN120604828A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to application of 3-mercaptohexanol in preparing plant polyphenol oxidase inhibitors or inhibiting browning of plants or plant fruits, belonging to the technical field of fruit and vegetable preservation. Background Art
[0002] Polyphenol oxidases (PPOs) are a class of copper-binding metalloproteinases widely distributed in plants, animals, and fungi. Depending on their substrates, they typically include tyrosinases, phenolases, catechol oxidases, catecholases, o-catechol oxidases, and monophenol oxidases. PPOs are encoded by nuclear genes as precursor proteins, which are then transported to plastids via an N-terminal transit peptide and hydrolyzed into active mature peptides via the C-terminal domain. PPOs are primarily located in plastid membranes (such as chloroplasts and amyloplasts), while their substrates, phenolic compounds, are located in the vacuole. Under normal circumstances, PPOs and their substrates, phenolic compounds, are separated by biological membranes. However, tissue damage, such as pathogen infection or animal feeding, disrupts this barrier, allowing phenolic substrates to come into contact with PPOs. In the presence of oxygen, PPOs catalyze the conversion of phenolic compounds into quinones. Quinones then polymerize with each other or react with proteins and amino acids to form black or brown pigments, leading to tissue browning.
[0003] Currently, PPO genes have been cloned in a variety of plants, including potato, tomato, strawberry, eggplant, poplar, wheat, pineapple, and banana. PPO genes often exist in plants as multigene families, with six in potato, seven in tomato, four in pineapple, and two in poplar. PPO gene sequences are highly conserved among higher plants, with particularly high homology among closely related plants. For example, the PPO gene sequences in tomato, potato, and tobacco (Solanaceae) show 76% to 88% similarity, while those in peach, apple, and pear (Rosaceae) exceed 88% homology. Furthermore, the homology in non-homologous plants, such as beans, apples, and grapes, reaches 53.7% to 56.5%.
[0004] Enzymatic browning caused by PPO is a major problem in fruit and vegetable processing. Browning not only affects the product's color but also its sensory and nutritional qualities. In actual production, damage during harvesting, transportation, storage, and processing often leads to browning of fruits and vegetables, resulting in serious economic losses. Consequently, PPO, as the primary enzyme causing browning, has attracted widespread attention, and extensive research has been conducted on its control. Oxidative browning requires at least three conditions: an enzyme, a substrate, and oxygen. Therefore, theoretically, there are three approaches to inhibiting PPO activity: inactivating the enzyme by altering its structure; adding PPO substrate analogs to produce competitive inhibition; and reducing or eliminating O2. Currently, the most commonly used method in production is to inhibit browning by modifying enzyme activity, typically through physical, chemical, and genetic engineering approaches.
[0005] Physical methods include reducing physical damage during processing, adjusting pH, controlling oxygen concentration, and heat inactivation. However, adjusting pH and controlling oxygen concentration require more precise control of conditions during processing, and the effect is general. Heat inactivation not only inactivates the PPO enzyme, but also inactivates other proteins in plant tissues, thereby affecting the nutritional quality and sensory properties of the product. Chemical methods are to treat the product with substances such as sulfites, citric acid, ascorbic acid (Vc), aluminum (boron or zinc) compounds, and L-cysteine, which can effectively inhibit PPO activity; or bleaching the browned product with bleaching powder or fumigating with sulfur dioxide. However, these treatment methods have strong residual toxicity (such as SO2, Cl - 、Al 3+ ), seriously endangering human health, and even changing product properties (such as starch viscosity, etc.), thereby reducing its recycling value. Whether chemical or physical methods, to a certain extent, will more or less affect the quality of the product, including nutritional quality, sensory quality, etc. Therefore, cultivating and selecting plant varieties with strong browning resistance has become the key to solving the problem of oxidative browning during fruit and vegetable processing. However, due to the lack of good antioxidant browning germplasm materials, it is difficult to obtain antioxidant browning crop varieties using traditional hybrid breeding methods; and although using biotechnology to change plant properties has broad application prospects, it has high costs and low consumer acceptance of genetically modified plants. In addition, PPO is a trait controlled by multiple genes, and its specific regulatory network is still unclear. Therefore, using simple and effective chemical methods to prevent browning during product processing is still the preferred method. Therefore, it is of great significance to develop new, safe, efficient and economical anti-browning substances. Summary of the Invention
[0006] The first object of the present invention is to provide the use of 3-mercaptohexanol in the preparation of plant polyphenol oxidase inhibitors, thereby providing a new compound capable of inhibiting polyphenol oxidase.
[0007] The second object of the present invention is to provide the use of 3-mercaptohexanol in inhibiting browning of plants or plant fruits, and to provide a novel, safe and effective compound for preventing browning of plants or plant fruits.
[0008] In order to achieve the above object, the technical solution adopted by the present invention for the application of 3-mercaptohexanol in the preparation of plant polyphenol oxidase inhibitors is:
[0009] Application of 3-mercaptohexanol in the preparation of plant polyphenol oxidase inhibitors.
[0010] The beneficial effect of the above technical solution is that the use of 3-mercaptohexanol in the preparation of plant polyphenol oxidase inhibitors is a groundbreaking invention. Extensive research in the early stages of the present invention revealed that 3-mercaptohexanol has a significant inhibitory effect on plant polyphenol oxidase, with an inhibition rate of up to 69%. The present invention provides a new compound selection for plant-derived polyphenol oxidase inhibitors, laying a foundation for research on plant-derived polyphenol oxidase inhibition.
[0011] As a further improvement, the plants include potato, tobacco, and apple.
[0012] In order to achieve the above object, the technical solution adopted in the application of 3-mercaptohexanol in inhibiting browning of plants or plant fruits in the present invention is:
[0013] Application of 3-mercaptohexanol in inhibiting browning of plants or plant fruits.
[0014] The beneficial effect of the above technical solution is that, through experiments, the present invention demonstrates that, compared to a control group, potato shreds, tobacco pulp, apple slices, or apple pulp treated with 3-mercaptohexanol can maintain good quality for more than four days at 4°C, extending the shelf life and significantly preventing browning, providing a new method for inhibiting browning in plant products. Furthermore, 3-mercaptohexanol is low-cost, suitable for large-scale application, and has no harmful residues, ensuring good food safety.
[0015] As a further improvement, the method includes a step of soaking the sample to be treated in a 3-mercaptohexanol solution.
[0016] The beneficial effect of the above technical solution is that the present invention uses 3-mercaptohexanol to inhibit browning of plants or plant fruits, which is simple and easy to implement. While having significant effects, it can reduce processing costs and reduce product losses, laying a good foundation for reducing food waste, improving product quality, promoting industrial development, and improving social and economic benefits.
[0017] As a further improvement, the plants include potato, tobacco, and apple.
[0018] As a further improvement, the concentration of the 3-mercaptohexanol solution is 25 to 200 μL / L.
[0019] As a further improvement, when the plant is potato, the concentration of the 3-mercaptohexanol solution is 25-100 μL / L.
[0020] As a further improvement, when the plant is tobacco, the concentration of the 3-mercaptohexanol solution is 100-200 μL / L.
[0021] As a further improvement, when the plant is apple, the concentration of the 3-mercaptohexanol solution is 100-150 μL / L.
[0022] Specifically, low concentrations of 3-mercaptohexanol capture and reduce o-quinone, a key browning intermediate produced by polyphenol oxidase (PPO), through its active thiol group, to form a colorless thioether adduct, thereby effectively blocking the browning pathway of quinone polymerization to melanin and inhibiting browning. However, at higher concentrations, 3-mercaptohexanol itself is rapidly and extensively oxidized by oxygen, generating reactive oxygen species (such as hydrogen peroxide). These reactive oxygen species activate or enhance PPO enzyme activity and can directly and non-enzymatically oxidize phenolic substances to produce more quinones, potentially consuming endogenous antioxidants and ultimately significantly accelerating the oxidative browning reaction chain, leading to an exacerbation of browning. Therefore, the effect of 3-mercaptohexanol on browning is concentration-dependent, with an optimal inhibitory concentration window.
[0023] As a further improvement, the soaking treatment is performed at 20-25° C. for more than 20 minutes. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 Comparison of polyphenol oxidase inhibition rates in Example 1 of the present invention (wherein, abcd represent significant differences);
[0025] Figure 2 The changes in potato shreds after treatment with different concentrations of 3-mercaptohexanol solutions in Example 2 of the present invention on the fourth day (wherein A is an appearance comparison chart, B is a L* value change curve chart, and abc represent significant differences);
[0026] Figure 3 The changes in tobacco slurry on the 4th day after being treated with 3-mercaptohexanol solutions of different concentrations in Example 3 of the present invention;
[0027] Figure 4 Observation diagram of apple slices 4 days after treatment with 100 μL / L 3-mercaptohexanol solution in Example 4 of the present invention (wherein A is the CK control group and B is the 3-mercaptohexanol solution treatment group);
[0028] Figure 5 The changes in potato shreds after treatment with 3-mercaptohexanol solutions of different concentrations in Comparative Example 1 of the present invention on the 8th day are shown;
[0029] Figure 6 The changes in potato shreds after treatment with 3-mercaptopropanol solutions of different concentrations in Comparative Example 1 of the present invention on the 8th day are shown;
[0030] Figure 7 This is a comparison of the inhibition of apple browning by different substances in Comparative Example 2 of the present invention (wherein, the ep tubes from left to right are: sterile water, 3-mercapto-1-propanol, 3-mercaptohexanol, 3-mercaptopropionic acid, 3-mercapto-3-methyl-1-butanol, 3-mercapto-2-butanol, 3-mercapto-2-methylpentanol, ethyl 3-mercaptopropionate, anhydrous ethanol, and dimethyl trisulfide treatment group). DETAILED DESCRIPTION
[0031] Potatoes (Solanum tuberosum L.) are an important food crop and processing ingredient, but they are prone to enzymatic browning after slicing. This browning is primarily caused by the presence of phenolic chemicals and polyphenol oxidase in the tuber. Cutting disrupts the structure of the tuber's internal cell membranes, causing the sequestered polyphenols to leak out. These polyphenols come into contact with oxygen, where they are catalyzed by polyphenol oxidase to form a substance called o-quinone. These compounds then polymerize with each other or with proteins and amino acids to form high-molecular-weight complexes, causing the browning of the cut surface. This is primarily due to the disruption of the cell structure, which allows polyphenol oxidase (PPO) to come into contact with phenolic substances. In the presence of oxygen, an oxidation reaction occurs, generating quinones, which then polymerize to form a brown substance. This not only affects the product's appearance but also reduces its nutritional value and significantly shortens its shelf life.
[0032] Currently, common anti-browning methods include: 1. Ascorbic acid treatment: After blanching potato slices at 60°C for 1 minute, soak them in a 0.25% ascorbic acid solution for 2 minutes. This treatment is not long-lasting and is costly. 2. Sulfite treatment: After slicing potatoes, soak them in a 2.0% sulfite solution for 2 minutes. This can cause allergies and leave residue. 3. Citric acid treatment: Adding a small amount of citric acid or acetic acid to clean water can decompose and destroy polyphenol oxidase, but this has limited effectiveness and can affect flavor. 4. Physical methods, such as vacuum packaging and modified atmosphere packaging, require significant equipment investment. Therefore, developing new, safe, efficient, and cost-effective anti-browning technologies is of great significance.
[0033] Based on the current situation, the present invention provides the use of 3-mercaptohexanol in the preparation of a plant polyphenol oxidase inhibitor. Furthermore, the present invention also provides the use of 3-mercaptohexanol in inhibiting browning of plants or plant fruits, specifically comprising the step of soaking a sample to be treated in a 3-mercaptohexanol solution.
[0034] Specifically, 3-mercaptohexanol is pre-dissolved in a small amount of anhydrous ethanol, such as a 5000 μL / L 3-mercaptohexanol solution; then, an appropriate amount of deionized water is added to obtain a 3-mercaptohexanol solution of a target concentration, such as a 50 μL / L, 100 μL / L, 150 μL / L, or 200 μL / L 3-mercaptohexanol solution. Specifically, the solvent of the 3-mercaptohexanol solution is an ethanol-water solution, wherein the volume percentage of ethanol is no greater than 1‰, preferably no greater than 0.5‰.
[0035] The present invention is further described in detail below with reference to specific examples. Unless otherwise specified, the equipment and reagents used in each embodiment, experimental example and comparative example can be obtained from commercial sources.
[0036] Materials used in the following examples of the present invention: potatoes were processed potatoes with a moderate starch content (purchased from Zhengzhou, Henan Province), weighing 200-300 g, free of pests and diseases, mechanical damage, sprouts, and high freshness; fresh tobacco leaves were from the National Tobacco Gene Research Center, Zhengzhou Tobacco Research Institute, 2-3 months old, free of pests and diseases, mechanical damage, and high freshness; 3-mercaptohexanol, purity ≥98%, CAS number 51755-83-0.
[0037] 1. Specific examples of the use of 3-mercaptohexanol in the preparation of plant polyphenol oxidase inhibitors of the present invention:
[0038] The present invention compares the inhibition of polyphenol oxidase by different substances. The results show that the inhibition rate of 3-mercaptohexanol on plant-derived polyphenol oxidase is 69%. The specific implementation operation is as follows:
[0039] Example 1 Comparison of the inhibitory effects of different substances on polyphenol oxidase
[0040] In this example, anhydrous ethanol, 3-mercaptohexanol, 3-mercapto-1-propanol, 3-mercapto-3-methyl-1-butanol, 3-mercapto-2-butanol, 3-mercapto-2-methylpentanol, and ethyl 3-mercaptopropionate were used to treat polyphenol oxidase, respectively, and the inhibition of polyphenol oxidase by different compounds was compared. The specific operation is as follows:
[0041] 1. Preparation of thiol solutions with different concentrations
[0042] 3-Mercaptohexanol, 3-mercapto-1-propanol, 3-mercapto-3-methyl-1-butanol, 3-mercapto-2-butanol, 3-mercapto-2-methylpentanol, and ethyl 3-mercaptopropionate were pre-dissolved in a small amount of anhydrous ethanol (approximately 10 mL) to prepare a 5000 μL / L thiol solution. An appropriate amount of deionized water was then added to obtain different thiol solutions with a concentration of 100 μL / L.
[0043] 2. Obtaining polyphenol oxidase
[0044] Tyrosinase purchased from Sangon (derived from mushrooms, product number T3824) was used as polyphenol oxidase, and its enzyme activity was detected using a polyphenol oxidase activity detection kit.
[0045] 3. Treatment with different concentrations of thiol solution and inhibition rate detection
[0046] Take the same volume of different thiol solutions and anhydrous ethanol, add 50 μL of polyphenol oxidase (concentration of 1.439 mg / mL), incubate at 4°C for 30 min, and then use sterile water as a control to detect the enzyme activity of each group using a polyphenol oxidase activity detection kit. The sterile water treatment group was used as a control to calculate the inhibition rate of each group.
[0047] The results are as follows Figure 1 As shown in the figure, it can be seen that the inhibitory effects of different substances on polyphenol oxidase vary greatly, among which 3-mercaptohexanol has the best inhibitory effect, with a polyphenol oxidase inhibition rate of 69%.
[0048] 2. Specific examples of the use of 3-mercaptohexanol of the present invention in inhibiting browning of plants or plant fruits:
[0049] Potatoes are important food crops and processing raw materials, tobacco is an important economic crop, and apples are widely grown and sold in my country. The present invention selects the three plants as examples to explore the effect of 3-mercaptohexanol in inhibiting browning of plants or plant fruits. The specific implementation operation is as follows:
[0050] Example 2 3-Mercaptohexanol inhibits potato browning
[0051] In this example, potato shreds were treated with 3-mercaptohexanol at different concentrations and observed for four consecutive days. The results of sensory evaluation and colorimetry showed that 3-mercaptohexanol had a good effect in inhibiting potato browning. The specific implementation steps were as follows:
[0052] 1. Preparation of 3-mercaptohexanol solutions of different concentrations
[0053] 3-Mercaptohexanol was pre-dissolved in a small amount of anhydrous ethanol (about 10 mL) to prepare a 5000 μL / L 3-mercaptohexanol solution; then, an appropriate amount of deionized water was added to obtain 3-mercaptohexanol solutions with concentrations of 25 μL / L, 50 μL / L, 75 μL / L, and 100 μL / L, respectively.
[0054] 2. Obtaining shredded potatoes
[0055] The potatoes were pre-cooled at 4°C for 24 h, rinsed with tap water three times to remove surface dirt, peeled, cut into potato shreds with a specification of 2 mm × 2 mm × 50 mm, and rinsed with cold water for 2 min to remove surface starch to obtain potato shreds.
[0056] 3. 3-Mercaptohexanol treatment
[0057] Mix the potato shreds with 3-mercaptohexanol solution of different concentrations prepared in step 1 at a ratio of 1 g:1.5 mL (deionized water was used as a control for mixing with potatoes), soak at 20°C for 20 min, stir once every 5 min during the soaking process, drain for 3 min, and spin dry for 30 s to dry. Pack 250 g per bag in PE ziplock bags and store in a refrigerated store at 4°C.
[0058] 4. Continuous Monitoring
[0059] The status of potato shreds treated with different concentrations of 3-mercaptohexanol was continuously monitored for four days. Deionized water was added to the potato shreds as a control group (CK). The optimal concentration of 3-mercaptohexanol solution was determined through sensory evaluation and colorimetry.
[0060] Note: A colorimeter (NR10QC, 3nh) was used to measure the color difference of fresh-cut potato shreds. The L* value, which represents the brightness (the degree of black and white) of an object in the CIE-Lab system, reflects the degree of browning of the fresh-cut potato shreds by measuring changes in the L* value. The L* value ranges from 0 to 100. L* values closer to 100 indicate a brighter, less browned potato shreds; conversely, L* values closer to 0 indicate a lower brightness, indicating a more severe browning. The colorimeter was calibrated using a standard white plate (L* = 97.06, a* = 0.04, b* = 2.01) before use. The entire bag of potato shreds was spread flat on a table. The L* value was then measured at at least 15 randomly selected points on the surface of the potato shreds using the colorimeter. Three replicates were performed for each treatment and time point.
[0061] 5. Results Analysis
[0062] (1) Sensory indicators:
[0063] Color: Potatoes are naturally pale yellow or creamy white.
[0064] Texture: The potato shreds are firm and tough without any sticking.
[0065] Smell: The shredded potato has the inherent fragrance of potato and no peculiar smell.
[0066] (2) Physical and chemical indicators:
[0067] Color difference value (L*): ≥55.
[0068] Moisture content: 80-85%.
[0069] pH value: 6.0~6.5.
[0070] (3) Microbiological indicators:
[0071] Total colony count: ≤1×10 4 CFU / g.
[0072] Coliform group: ≤100MPN / 100g.
[0073] (4) Visual effect analysis:
[0074] The results are as follows Figure 2 As shown by Figure 2 As shown in Figure A, after 4 days of storage at 4°C, the different concentrations of 3-mercaptohexanol treatment exhibited a distinct color gradient. The control (CK) strips had already significantly browned, exhibiting a distinct gray-brown color. The 25 μL / L treatment reduced the browning slightly, but the effect was not significant. As the treatment concentration increased, the color of the strips gradually lightened. At 50 μL / L, the strips retained a near-original pale yellow color, demonstrating excellent anti-browning efficacy. When the 3-mercaptohexanol concentration was further increased to 75 μL / L, the visual effect was not significantly different from that of the 50 μL / L treatment. The 100 μL / L treatment showed a slight reduction in browning compared to the 25 μL / L treatment, but was inferior to the 50 μL / L and 75 μL / L treatments.
[0075] (5) Instrument detection and analysis:
[0076] The color difference value (L*) test results are as follows Figure 2 As shown by Figure 2 As shown in Figure B, at the end of the 4-day storage period, the control group had the lowest L* value, approximately 46. The low-concentration group (25 μL / L) had an L* value of 51; the medium-concentration group (50-75 μL / L) had an L* value of approximately 55; and the high-concentration group (100 μL / L) had an L* value of 52. Statistical analysis showed significant differences between the different treatment groups (P < 0.05). There was no significant difference between the 50 μL / L and 75 μL / L concentration groups, confirming that 50 μL / L to 75 μL / L was the optimal treatment concentration.
[0077] (6) Comprehensive evaluation
[0078] Based on 4 days of experimental data, the 50μL / L concentration treatment group was determined to be the optimal treatment concentration; the anti-browning effect was significant, the L* value was maintained above 55, it was economical, the effect was stable, there was no obvious attenuation during the 4-day monitoring period, it was highly safe, and met food safety requirements.
[0079] Example 3 3-Mercaptohexanol Inhibits Browning of Tobacco
[0080] In this example, tobacco was treated with 3-mercaptohexanol at different concentrations and observed for four consecutive days. The sensory evaluation results showed that 3-mercaptohexanol had a good effect in inhibiting tobacco browning. The specific implementation steps were as follows:
[0081] 1. Preparation of 3-mercaptohexanol solutions of different concentrations
[0082] 3-Mercaptohexanol was pre-dissolved in a small amount of anhydrous ethanol (about 10 mL) to prepare a 5000 μL / L 3-mercaptohexanol solution; then, an appropriate amount of deionized water was added to obtain 3-mercaptohexanol solutions with concentrations of 50 μL / L, 100 μL / L, 150 μL / L, and 200 μL / L, respectively.
[0083] 2. Tobacco leaf processing
[0084] Freshly picked tobacco leaves were rinsed three times with tap water to remove surface dirt, cut to remove veins, immersed in liquid nitrogen for rapid freezing, and ground into tobacco jelly powder.
[0085] 3. 3-Mercaptohexanol treatment
[0086] The tobacco jelly powder was mixed with 3-mercaptohexanol solution of different concentrations prepared in step 1 at a ratio of 1 g:5 mL, vortexed to mix, and placed at room temperature for observation.
[0087] 4. Continuous Monitoring
[0088] The tobacco slurry treated with different concentrations of 3-mercaptohexanol was continuously monitored for four days. The tobacco slurry treated with deionized water served as the control group (CK). The optimal concentration of 3-mercaptohexanol solution was determined through sensory evaluation and colorimetry.
[0089] 5. Results Analysis
[0090] (1) Sensory indicators:
[0091] Color: The tobacco pulp is light green.
[0092] Odor: Tobacco has no odor and has a light leafy aroma.
[0093] (2) Physical and chemical indicators:
[0094] Color difference value (L*): ≥55.
[0095] Moisture content: 80-85%.
[0096] pH value: 6.0~6.5.
[0097] (3) Microbiological indicators:
[0098] Total colony count: ≤1×10 4 CFU / g.
[0099] Coliform group: ≤100MPN / 100g.
[0100] (4) Visual effect analysis:
[0101] The results are as follows Figure 3 As shown in the figure, after 4 days of room temperature storage, the different concentrations of 3-mercaptohexanol treatment groups showed a clear color gradient. The slurry in the control group (CK) and the 50 μL / L concentration treatment group had already significantly browned, showing a distinct reddish-brown color. As the treatment concentration increased, the slurry color gradually became lighter. When the 3-mercaptohexanol concentration reached 200 μL / L, the slurry still maintained a near-original light green color, demonstrating an excellent anti-browning effect.
[0102] Example 4 3-Mercaptohexanol Inhibits Browning of Apples
[0103] In this example, apple slices were treated with 100 μL / L 3-mercaptohexanol and observed for 4 consecutive days. The sensory evaluation results showed that 3-mercaptohexanol had a good effect in inhibiting apple browning. The specific implementation steps were as follows:
[0104] 1. Preparation of 3-mercaptohexanol solutions of different concentrations
[0105] 3-Mercaptohexanol was pre-dissolved in a small amount of anhydrous ethanol (about 10 mL) to prepare a 5000 μL / L 3-mercaptohexanol solution; then an appropriate amount of deionized water was added to obtain a 3-mercaptohexanol solution with a concentration of 100 μL / L.
[0106] 2. Obtaining fresh-cut apple slices
[0107] Select fresh apples without mechanical damage, of the same maturity, and of the same shape and size. Precool them at 4℃ for 12 hours. Take them out before the test and wash the surface with ultrapure water. Use a sterilized knife to quickly peel and core them, and cut them into small pieces of uniform size and consistent weight.
[0108] 3. 3-Mercaptohexanol treatment
[0109] Mix the apple slices with 100 μL / L 3-mercaptohexanol solution prepared in step 1 at a ratio of 1 g:1.5 mL (for control, use deionized water and apple slices), soak at 20°C for 20 min, stir once every 5 min during the soaking process, drain for 3 min, and spin dry for 30 s to dry. Pack 12 slices per package in PE self-sealing bags and store in a refrigerated store at 4°C.
[0110] 4. Continuous Monitoring
[0111] The status of apple slices treated with 100 μL / L 3-mercaptohexanol solution was continuously monitored for 4 days. The apple slices treated with deionized water served as the control group (CK).
[0112] 5. Results Analysis
[0113] Sensory indicators:
[0114] Color: Fresh-cut apple slices are a natural light yellow.
[0115] Texture: The apple slices are firm and moist, with no sticking between slices.
[0116] Smell: Apple slices have their inherent fragrance and no peculiar smell.
[0117] The results are as follows Figure 4 As shown in the figure, after 4 days of storage at 4°C, the 3-mercaptohexanol-treated group still maintained the original color of the apples. The control group (CK) had already significantly browned, showing a distinct reddish-brown color. 3-Mercaptohexanol treatment showed an excellent anti-browning effect on fresh-cut apple slices.
[0118] 3. Comparative Examples
[0119] Comparative Example 1 Comparison of the long-term inhibition of potato by 3-mercaptohexanol and 3-mercaptopropanol
[0120] In this comparative example, potato shreds were treated with different concentrations of 3-mercaptohexanol and 3-mercaptopropanol, respectively, and the results were observed for 8 consecutive days to compare the long-term inhibitory effects of 3-mercaptohexanol and 3-mercaptopropanol on potato browning. The specific implementation procedures are as follows:
[0121] 1. Preparation of 3-mercaptohexanol and 3-mercaptopropanol solutions with different concentrations
[0122] 3-Mercaptohexanol and 3-mercaptopropanol were pre-dissolved in a small amount of anhydrous ethanol (about 10 mL) to prepare 5000 μL / L 3-mercaptohexanol and 3-mercaptopropanol solutions; then, an appropriate amount of deionized water was added to obtain 3-mercaptohexanol and 3-mercaptopropanol solutions with concentrations of 25 μL / L, 50 μL / L, 75 μL / L, and 100 μL / L, respectively.
[0123] 2. Obtaining shredded potatoes
[0124] The potatoes were pre-cooled at 4°C for 24 h, rinsed with tap water three times to remove surface dirt, peeled, cut into potato shreds with a specification of 2 mm × 2 mm × 50 mm, and rinsed with cold water for 2 min to remove surface starch to obtain potato shreds.
[0125] 3. 3-Mercaptohexanol treatment
[0126] Mix the potato shreds with 3-mercaptohexanol solution and 3-mercaptopropanol solution of different concentrations prepared in step 1 at a ratio of 1 g:1.5 mL, soak at 20°C for 20 min, stir once every 5 min during the soaking process, drain for 3 min, and spin dry for 30 s to dry. Pack 250 g per bag in PE ziplock bags and store in a refrigerated store at 4°C.
[0127] 4. Continuous Monitoring
[0128] The status of potato shreds treated with different concentrations of 3-mercaptohexanol and 3-mercaptopropanol was continuously monitored for 8 days. The potato shreds treated with deionized water served as the control group (CK). Sensory evaluation confirmed the long-term inhibitory effect of 3-mercaptohexanol and 3-mercaptopropanol on potato growth.
[0129] 5. Results Analysis
[0130] The results are as follows Figure 5 and Figure 6 As shown in the figure, after 8 days of storage at 4°C, the groups treated with different concentrations of 3-mercaptohexanol showed obvious color gradients, while the groups treated with different concentrations of 3-mercaptopropanol had significantly browned and showed obvious reddish-brown color, indicating that 3-mercaptohexanol has a better inhibitory effect on browning and lasts longer.
[0131] Comparative Example 2 Comparison of different substances in inhibiting apple browning
[0132] This comparative example uses different substances to treat apple pulp and compares the inhibitory effects of different substances on apple browning. The specific implementation operations are as follows:
[0133] In this example, 3-mercapto-1-propanol, 3-mercaptohexanol, 3-mercaptopropionic acid, 3-mercapto-3-methyl-1-butanol, 3-mercapto-2-butanol, 3-mercapto-2-methylpentanol, ethyl 3-mercaptopropionate, anhydrous ethanol, and dimethyl trisulfide were used to treat apple pulp respectively to compare the inhibition of browning of apple pulp by different compounds. The specific operation is as follows:
[0134] 1. Preparation of thiol solutions with different concentrations
[0135] 3-Mercapto-1-propanol, 3-mercaptohexanol, 3-mercaptopropionic acid, 3-mercapto-3-methyl-1-butanol, 3-mercapto-2-butanol, 3-mercapto-2-methylpentanol, ethyl 3-mercaptopropionate, and dimethyl trisulfide were pre-dissolved in a small amount of anhydrous ethanol (about 10 mL) to prepare a 5000 μL / L solution.
[0136] 2. Obtaining apple pulp
[0137] Fresh apples without pests or mechanical injuries are used, washed, peeled and cut into small pieces of uniform size, quickly frozen with liquid nitrogen and then ground into powder to obtain apple jelly powder.
[0138] 3. Treatment of different compound solutions
[0139] The apple jelly powder was mixed with different compound solutions prepared in step 1 at a final concentration of 50 μL / L, vortexed to mix, and placed at room temperature for observation.
[0140] 4. Continuous Monitoring
[0141] The apple pulp treated with different compound solutions was continuously monitored for 16 hours. Deionized water was added to the apple pulp as a control (CK). Sensory evaluation was performed to determine the inhibitory effects of the different compounds on apple browning.
[0142] The results are as follows Figure 7 As shown in the figure, it can be seen that at the same treatment concentration, 3-mercaptohexanol and 3-mercaptopropionic acid have the best inhibitory effect on the browning of apple pulp, and the pulp maintains its original light yellow color; the 3-mercapto-1-propanol solution treatment group shows slight browning; the other treatment groups have significant browning; this shows that 3-mercaptohexanol and 3-mercaptopropionic acid have a good anti-browning effect on apple pulp.
[0143] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. Application of 3-mercaptohexanol in the preparation of plant polyphenol oxidase inhibitors.
2. The use of 3-mercaptohexanol according to claim 1 in the preparation of plant polyphenol oxidase inhibitors, characterized in that: The plants include potatoes, tobacco, and apples.
3. Application of 3-mercaptohexanol in inhibiting browning of plants or plant fruits.
4. The use of 3-mercaptohexanol according to claim 3 in inhibiting browning of plants or plant fruits, characterized in that: The method comprises the steps of soaking the sample to be treated in a 3-mercaptohexanol solution.
5. Use of 3-mercaptohexanol according to claim 3 or 4 in inhibiting browning of plants or plant fruits, characterized in that: The plants include potatoes, tobacco, and apples.
6. The use of 3-mercaptohexanol according to claim 5 in inhibiting browning of plants or plant fruits, characterized in that: The concentration of the 3-mercaptohexanol solution is 25-200 μL / L.
7. The use of 3-mercaptohexanol according to claim 6 in inhibiting browning of plants or plant fruits, characterized in that: When the plant is potato, the concentration of the 3-mercaptohexanol solution is 25-100 μL / L.
8. The use of 3-mercaptohexanol according to claim 6 in inhibiting browning of plants or plant fruits, characterized in that: When the plant is tobacco, the concentration of the 3-mercaptohexanol solution is 100-200 μL / L.
9. The use of 3-mercaptohexanol according to claim 6 in inhibiting browning of plants or plant fruits, characterized in that: When the plant is apple, the concentration of the 3-mercaptohexanol solution is 100-150 μL / L.
10. The use of 3-mercaptohexanol in inhibiting browning of plants or plant fruits according to claim 5, characterized in that: The soaking treatment is performed at 20-25° C. for more than 20 minutes.