Use of furan compounds or compositions for inhibiting discoloration of fruits and vegetables

Abstract

The application provides applications of furan compounds or compositions in inhibiting discoloration of fruits and vegetables, belongs to the technical field of storage and preservation of agricultural products, and specifically relates to applications of furan compounds or compositions of furan compounds in preservation of fruits and vegetables, applications of furan compounds or compositions of furan compounds in inhibiting discoloration of fruits and vegetables, a fruit and vegetable preservative and a fruit and vegetable color protection agent. The inventors first find that furan compounds have certain effects in inhibiting enzymatic browning of fruits and vegetables, and can be used for preservation of fruits and vegetables and color protection of fruits and vegetables.

Description

Technical Field

[0001] This invention belongs to the field of agricultural product storage and preservation technology, specifically relating to the application of furan compounds or compositions in inhibiting the discoloration of fruits and vegetables. Background Technology

[0002] Fresh-cut fruits and vegetables refer to products that have undergone selection, washing, peeling, disinfection, cutting, and refrigeration, and are ready to eat directly or after appropriate processing. With rising living standards and a faster pace of life, the demand for fresh-cut fruits and vegetables has increased, showing a promising market prospect. However, fresh-cut fruits and vegetables face many problems, including easy water loss, susceptibility to enzymatic browning, reduced nutritional value, and microbial spoilage. The most significant problem is enzymatic browning. For example, potatoes, lettuce, eggplant, iceberg lettuce, apples, pears, peaches, and bananas are prone to enzymatic browning after cutting.

[0003] Enzymatic browning refers to the process by which phenolic substances in fruits and vegetables are oxidized by polyphenol oxidase to form quinones, which then polymerize to form melanin. Enzymatic browning not only affects the color, flavor, and texture of fruits and vegetables, causing quality deterioration, but also shortens their shelf life and leads to nutrient loss, resulting in significant waste and economic losses for the fruit and vegetable industry. Therefore, inhibiting enzymatic browning in fruits and vegetables is of great importance.

[0004] To control enzymatic browning, only one of the substrate, enzyme, or oxygen needs to be controlled. The most common method is to soak fruits and vegetables in a browning inhibitor. For example, a preservation method for fresh-cut lotus root (publication number: CN114568489A) discloses a method using a combination of citric acid and sodium bisulfite to inhibit browning. However, due to safety concerns, sulfites have been banned by the FDA for use on fruits and vegetables, so their safety remains to be further discussed. An effective preservation method for fresh-cut potatoes (publication number: CN115380948A) discloses a compound color-protecting and crisp-preserving agent containing ascorbic acid, citric acid, calcium chloride, and sodium isoascorbate. This agent can effectively inhibit microbial growth, extend the shelf life of fresh-cut potatoes, and achieve the purpose of color protection and crisp preservation. However, the complex process of compounding multiple components makes it difficult to apply widely. A novel application of thioacetic acid esters for inhibiting discoloration in fruits and vegetables (Publication No.: CN109548863A) discloses a method for color-protecting fruits and vegetables using thioacetic acid esters. While the method significantly inhibits discoloration, the taste is unacceptable at higher concentrations. Therefore, although many methods exist for inhibiting browning, most are not ideal. Some effective methods have safety concerns, while others are not very effective. Still others are effective, but their taste is a significant problem, hindering large-scale application.

[0005] Therefore, it is essential to find a color-protecting agent that is safe to use, easy to operate, effective, and has little odor.

[0006] Furan compounds are widely used in the pharmaceutical, food, and chemical industries and have high application value. In existing technologies, furan compounds are used to enhance flavor and aroma in food, but their ability to inhibit enzymatic browning in fruits and vegetables has not been reported. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides the application of furan compounds or compositions for inhibiting discoloration of fruits and vegetables.

[0008] In their research on discovering new components that inhibit polyphenol oxidase (PPO) activity and their inhibitory mechanisms, the inventors, through molecular docking and structural analysis, discovered for the first time that furan rings can interact with PPO; furthermore, the inventors found that furan compounds have a certain effect on inhibiting enzymatic browning in fruits and vegetables.

[0009] The technical solution of the present invention is as follows:

[0010] Furan compounds or combinations of furan compounds are used for the preservation of fruits and vegetables.

[0011] Applications of furan compounds or combinations of furan compounds for inhibiting discoloration of fruits and vegetables.

[0012] According to a preferred embodiment of the present invention, the application of furan compounds or compositions of furan compounds in inhibiting enzymatic browning of fruits and vegetables.

[0013] According to a preferred embodiment of the present invention, the furan compound includes one of furanone, chicorylone, soy sauce ketone, 2-pentylfuran, and ethyl trigonelline; the composition of the furan compound includes two or more of furanone, chicorylone, soy sauce ketone, 2-pentylfuran, and ethyl trigonelline.

[0014] More preferably, the furan compound is furanone, chicorylone, or soy sauce ketone, and the concentration used for soaking or spraying is 0.01 g / L or higher.

[0015] More preferably, the concentrations of the furanone, chicorylone, and soy sauce ketone solutions used for soaking are 0.45 g / L or more, 0.08 g / L or more, and 0.45 g / L or more, respectively; and the concentrations of the furanone, chicorylone, and soy sauce ketone solutions used for spraying are all 0.8 g / L or more.

[0016] More preferably, the concentrations of furanone, chicorylone, and soy sauce ketone solutions used for soaking are 0.45-1.5 g / L, 0.08-1.5 g / L, and 0.45-1.5 g / L, respectively; and the concentrations of furanone, chicorylone, and soy sauce ketone solutions used for spraying are all 0.8-2.5 g / L.

[0017] According to a preferred embodiment of the present invention, the fruit and vegetable morphology includes complete individual fruits and vegetables, fruit and vegetable tissues, and fruit and vegetable sap.

[0018] More preferably, the fruit and vegetable tissue includes fruit and vegetable slices, fruit and vegetable shreds, and fruit and vegetable chunks.

[0019] According to a preferred embodiment of the present invention, the fruits and vegetables are potatoes, lettuce, eggplant, iceberg lettuce, apples, bananas, peaches, and pears.

[0020] A fruit and vegetable preservative, the active ingredient of which includes furan compounds or a composition of furan compounds.

[0021] According to a preferred embodiment of the present invention, the furan compound includes one of furanone, chicorylone, soy sauce ketone, 2-pentylfuran, and ethyl trigonelline; the composition of the furan compound includes two or more of furanone, chicorylone, soy sauce ketone, 2-pentylfuran, and ethyl trigonelline.

[0022] A color-protecting agent for fruits and vegetables, the active ingredients of which include furan compounds or a composition of furan compounds.

[0023] According to a preferred embodiment of the present invention, the furan compound includes one of furanone, chicorylone, soy sauce ketone, 2-pentylfuran, and ethyl trigonelline; the composition of the furan compound includes two or more of furanone, chicorylone, soy sauce ketone, 2-pentylfuran, and ethyl trigonelline.

[0024] A method for inhibiting enzymatic browning in fruits and vegetables includes the following steps:

[0025] Soaking, spraying, or coating whole fruits and vegetables or fruit and vegetable tissues with furan compounds or combinations thereof;

[0026] Alternatively, furan compounds or combinations of furan compounds can be directly added to fruit and vegetable pulp or fruit and vegetable powder.

[0027] According to a preferred embodiment of the present invention, in the method, a furan compound or a composition of furan compounds is dissolved in anhydrous ethanol to obtain a mother liquor; the mother liquor is then dissolved in water, mixed, and used.

[0028] According to a preferred embodiment of the present invention, the furan compound includes one of furanone, chicorylone, soy sauce ketone, 2-pentylfuran, and ethyl trigonelline; the composition of the furan compound includes two or more of furanone, chicorylone, soy sauce ketone, 2-pentylfuran, and ethyl trigonelline.

[0029] According to a preferred embodiment of the present invention, the furan compound is furanone, chicorylone, or soy sauce ketone, and the concentration used for soaking or spraying is 0.01 g / L or higher.

[0030] More preferably, the concentrations of the furanone, chicorylone, and soy sauce ketone solutions used for soaking are ≥0.45 g / L, ≥0.08 g / L, and ≥0.45 g / L, respectively; and the concentrations of the furanone, chicorylone, and soy sauce ketone solutions used for spraying are all ≥0.8 g / L.

[0031] More preferably, the concentrations of furanone, chicorylone, and soy sauce ketone solutions used for soaking are 0.45-1.5 g / L, 0.08-1.5 g / L, and 0.45-1.5 g / L, respectively; and the concentrations of furanone, chicorylone, and soy sauce ketone solutions used for spraying are all 0.8-2.5 g / L.

[0032] According to a preferred embodiment of the present invention, the soaking time of the furan compound in the soaking process is 1 second to 50 minutes.

[0033] More preferably, the soaking time of the furan compound is 3-15 minutes.

[0034] According to a preferred embodiment of the present invention, the soaking temperature during the soaking process is 0-50°C.

[0035] More preferably, the soaking temperature is 2-4℃.

[0036] Furanone, also known as 4-hydroxy-2,5-dimethyl-3(2H)furanone, is a flavor enhancer that imparts fruity and caramel aromas. It is naturally found in fruits such as pineapple, mango, and strawberry. It has a low concentration threshold, with a significant flavor-enhancing effect at 0.04 ppb, and is therefore widely used as a flavor enhancer in the food industry.

[0037] Chicorylone, also known as 4-hydroxy-5-methyl-3(2H)-furanone, is a flavoring agent with aromas of bread, caramel, fruit, and jam. It is widely found in natural forms in strawberries, pineapples, and beef broth, and while its aroma intensity is slightly weaker than that of furanone, it is now widely used in the food industry and is recognized as a safe food flavoring by the Food Flavor Manufacturers Association (FEMA).

[0038] Soy sauce ketone, also known as 5-ethyl-4-hydroxy-2-methyl-3(2H)-furanone, has a rich, natural sweet and fruity aroma, along with hints of caramel and toasted bread. It is naturally found in soy sauce, hence its name. Its aroma intensity is stronger than that of furanone, and it is used as a flavor enhancer.

[0039] The beneficial effects of the present invention include at least the following:

[0040] 1. This invention is the first to discover that furan rings can interact with PPO; furthermore, the inventors have discovered that furan compounds have a certain effect on inhibiting enzymatic browning of fruits and vegetables.

[0041] 2. This invention can effectively inhibit enzymatic browning of fruits and vegetables, improve the quality of fresh-cut fruits and vegetables, and extend shelf life.

[0042] 3. Furan compounds are safe to obtain and are already widely used as food additives in the food industry.

[0043] 4. Furan compounds have mature production processes and low costs, so they will not increase costs too much.

[0044] 5. Furan compounds are effective in inhibiting enzymatic browning in fruits and vegetables. The method is simple and can be applied on a large scale and produced in factories. Attached Figure Description

[0045] Figure 1 The effect of different concentrations of furanone solution on browning of potato slurry is shown in the figure.

[0046] Figure 2 Browning degree of potato slurry treated with furanone solution.

[0047] Figure 3 The effect of different concentrations of chicorylone solution on browning of potato slurry is shown in the figure.

[0048] Figure 4 The effect of different concentrations of soy sauce ketone solution on browning of potato slurry is shown in the figure.

[0049] Figure 5 The effect of chicorylone treatment on browning of fresh-cut potato shreds is shown in the figure.

[0050] Figure 6 Visual browning of fresh-cut potato shreds treated with chicorylone.

[0051] Figure 7 Overall sensory evaluation of fresh-cut potato shreds treated with chicorylone.

[0052] Figure 8 The effect of furanone and chicorylone treatments on fresh-cut apples is shown in the figure.

[0053] Figure 9 L* values ​​for fresh-cut apples treated with furanone and chicorylone.

[0054] Figure 10 The effect of furanone and chicorylone treatments on fresh-cut peaches is shown in the figure.

[0055] Figure 11 The L* value of fresh-cut peaches after treatment with furanone and chicorylone.

[0056] Figure 12 The effect of chicorylone treatment on fresh-cut pears is shown in the figure.

[0057] Figure 13The effect of chicorylone treatment on fresh-cut eggplant is shown in the figure.

[0058] Figure 14 The L* value is for fresh-cut eggplant treated with chicorylone.

[0059] Figure 15 The L* value represents the value of fresh-cut lettuce treated with chicorylone.

[0060] Figure 16 The image shows the effect of chicorylone treatment on fresh-cut bananas.

[0061] Figure 17 The effect of different concentrations of 2-ethylfuran solution on browning of potato slurry is shown in the figure.

[0062] Figure 18 The effect of furanone and its composition on browning of fresh-cut potato shreds is shown in the figure. Detailed Implementation

[0063] To more clearly illustrate the technical solution of the present invention, a complete and detailed description of the technical solution of the present invention will be provided below in conjunction with specific embodiments. Obviously, the embodiments described below are merely a part of the present invention, used to better describe the present invention, and not all of the embodiments. Embodiments obtained by those skilled in the art without creative effort are all within the scope of protection of the present invention.

[0064] Methods for representing the implementation effect: The implementation effect of the present invention is represented by measuring color difference, absorbance, visual browning degree, and overall sensory evaluation using instruments.

[0065] Color values ​​were measured using a Minolta Co., Osaka, CR-400 colorimeter (Japan). The color difference values ​​for the calibration standard white board were L* = 97.06, a* = 0.04, and b* = 2.01. Where L* represents brightness, ranging from 0 to 100, where 0 represents pure black and 100 represents pure white; a* represents red-green, ranging from -128 to +127, where -128 represents green and +127 represents red; and b* represents yellow-blue, ranging from -128 to +127, where -128 represents blue and +127 represents yellow.

[0066] The absorbance values ​​were measured using a Beijing Purkinje TU-1810 UV-Vis spectrophotometer at 410 nm. The higher the absorbance value, the more severe the browning.

[0067] Visual browning is assessed using internationally accepted scoring standards, with a score of 1-5: 1 = No color change; 2 = Slight color change, color change area < 5%; 3 = Significant color change, color change area 5-20%; 4 = Relatively severe color change, color change area 20-50%; 5 = Severe color change, color change area > 50%. A level 3 color change indicates the product has lost its commercial value.

[0068] Overall sensory evaluation is conducted on a 9-1 scale, where 9 = excellent (no defects), 7 = good (minor defects), 5 = average (moderate defects), 3 = poor (major defects), and 1 = unusable. A score below 6 indicates the product has lost its value.

[0069] Furan compounds are generally insoluble in water. Therefore, in the experiment, the furan compounds were first dissolved in anhydrous ethanol to prepare a mother liquor, which was then dissolved in water and diluted to obtain solutions of different concentrations. The volume of anhydrous ethanol used for dissolution accounted for 0.1% of the final solution volume. Since high concentrations of ethanol can inhibit browning to some extent, a 0.1% ethanol solution was used as a control to eliminate interference from ethanol in the experiment.

[0070] Example 1

[0071] Furanone inhibits enzymatic browning of potato slurry.

[0072] Chop the potatoes, freeze them with liquid nitrogen, grind them into potato flour, and store them at -80℃. Weigh out 9 portions of 1g potato flour and add 2ml of water, 0.1% ethanol solution (control), 0.001g / L, 0.005g / L, 0.01g / L, 0.05g / L, 0.1g / L, 0.5g / L, and 1g / L furanone solution respectively. Vortex to mix well and let stand for observation.

[0073] like Figure 1 As shown, at 0.5 h, potato flour treated with water, control, and furanone solutions (0.001 g / L, 0.005 g / L, and 0.01 g / L) had already undergone moderate browning. Potato flour treated with 0.05 g / L and 0.1 g / L furanone solutions showed slightly less browning, while potato flour treated with 0.5 g / L and 1 g / L furanone solutions did not show browning. After 2 h, potato flour treated with 0.5 g / L and 1 g / L furanone solutions still had not shown browning, while the control and other treatment groups had all shown severe browning.

[0074] Example 2

[0075] Determination of the browning degree of furanone-inhibited potato slurry

[0076] Weigh 45 portions of 1g potato starch and divide them into three groups of 15 portions each. Add 2ml of water to the control group and add 2ml of 0.5g / L and 1g / L furanone solution to the treatment group respectively. Vortex mix and place at room temperature for 0h, 0.5h, 1h, 2h and 4h respectively. Centrifuge at 10000r / min for 10min at 4℃ and then measure the absorbance at 410nm.

[0077] like Figure 2 As shown, the absorbance value of the control increased after browning occurred at 0.5 h, and gradually increased with time. In contrast, the absorbance values ​​of the 0.5 g / L and 1 g / L furanone solutions remained almost unchanged with time.

[0078] Example 3

[0079] Chicorylone inhibits browning in potato slurry.

[0080] As in Example 1, weigh out 9 portions of 1g potato jelly powder, add 2ml of deionized water, 0.1% ethanol solution (control), 0.001g / L, 0.005g / L, 0.01g / L, 0.05g / L, 0.1g / L, 0.5g / L, and 1g / L chicorylone solution respectively, vortex to mix, and let stand for observation.

[0081] like Figure 3 As shown, after 0.5 hours, potato flour treated with water, control, and 0.001 g / L chicorylone solution showed moderate browning, while potato flour treated with 0.005 g / L and 0.01 g / L chicorylone solutions showed slight browning. Potato flour treated with 0.05 g / L, 0.1 g / L, 0.5 g / L, and 1 g / L chicorylone solutions did not show any browning. Because chicorylone solution is a pale yellow solution, the color of different concentrations of chicorylone solution was not entirely consistent due to the color of the solution. After 1 hour, potato flour treated with water, control, and 0.001 g / L chicorylone solution showed severe browning, while potato flour treated with 0.005 g / L and 0.01 g / L chicorylone solutions also showed slight browning. Potato flour treated with 0.05 g / L, 0.1 g / L, 0.5 g / L, and 1 g / L chicorylone solutions still did not show any browning. Two hours later, potato flour treated with water, control, 0.001 g / L, 0.005 g / L, and 0.01 g / L chicorylone solutions all showed severe browning. Potato flour treated with 0.05 g / L chicorylone solution also showed slight browning. However, potato flour treated with 0.1 g / L, 0.5 g / L, and 1 g / L chicorylone solutions did not show any browning.

[0082] Example 4

[0083] Soy sauce ketones inhibit browning of potato slurry.

[0084] The furanone solution of the corresponding concentration in Example 1 was replaced with soy sauce ketone, and other operations were the same as in Example 1.

[0085] like Figure 4 As shown, after 0.5 hours, potato flour treated with water, control, 0.001 g / L, 0.005 g / L, and 0.01 g / L soy sauce ketone solutions showed moderate browning, while potato flour treated with 0.05 g / L, 0.1 g / L, 0.5 g / L, and 1 g / L soy sauce ketone solutions did not show browning. After 1 hour, potato flour treated with water, control, 0.001 g / L, 0.005 g / L, and 0.01 g / L soy sauce ketone solutions showed more severe browning, with 0.05 g / L... Potato flour treated with 0.1 g / L soy sauce ketone solution showed slight browning, while potato flour treated with 0.5 g / L and 1 g / L soy sauce ketone solution did not show browning. After 2 hours, potato flour treated with water, control, 0.001 g / L, 0.005 g / L, and 0.01 g / L soy sauce ketone solution showed severe browning, potato flour treated with 0.05 g / L and 0.1 g / L soy sauce ketone solution showed moderate browning, and potato flour treated with 0.5 g / L and 1 g / L soy sauce ketone solution did not show browning.

[0086] Example 5

[0087] Chicorylone inhibits browning in fresh-cut potato shreds

[0088] Remove pre-cooled potatoes from the cold storage and select a number of potatoes that are uniform in size and shape, and free from pests, diseases, mechanical damage, sprouts, and green discoloration. Wash the selected potatoes thoroughly with pre-cooled water, soak them in a 0.2 g / L sodium hypochlorite disinfectant solution for 5 minutes, peel them, shred them using a grater, disinfect them with a 0.05 g / L sodium hypochlorite solution, spin dry, and then soak them separately in pre-cooled water, a 0.1% ethanol solution, and a 0.5 g / L chicorylone solution for 10 minutes each. Spin dry, pack them into polyethylene bags, fold the bag openings, and place them in a 2-4℃ cold storage for observation.

[0089] like Figure 5 As shown, 12 hours after treatment (referred to as day 0), both control groups (water and control) had browned. The potato shreds treated with 0.5 g / L chicorylone did not brown. On days 2 and 4, the water and control groups had severe browning, while the potato shreds treated with 0.5 g / L chicorylone still did not brown. On days 6 and 8, the potatoes treated with 0.5 g / L chicorylone showed slight browning, did not lose water, and maintained good quality. On day 10, the potato shreds treated with 0.5 g / L chicorylone showed slight browning.

[0090] Freshly cut potato shreds were scored according to a visual browning rating scale: 1 = no browning, 2 = slight browning, 3 = moderate browning, 4 = moderate to severe browning, and 5 = severe browning. The scoring results are as follows: Figure 6 As shown in the figure, the two control groups showed moderate browning on day 0 and severe browning on day 2, while the potato shreds treated with 0.5 g / L chicorylone showed slight browning from day 6, but the overall score was still below 2 points, i.e., slight browning.

[0091] Freshly cut potato shreds were scored according to the overall sensory evaluation scoring criteria: 9 = Excellent (no defects), 7 = Good (minor defects), 5 = Average (moderate defects), 3 = Poor (significant defects), and 1 = Very Poor. An overall sensory quality score <6 indicates a loss of product value. Figure 7 As shown, water and control showed browning on day 0, scoring less than 6 points and losing commercial value. Potato shreds treated with 0.5 g / L chicorylone showed slight browning on day 6, but still had commercial value on day 10, extending shelf life by 10 days.

[0092] Example 6

[0093] Furanone and chicorylone inhibit browning of fresh-cut apple slices.

[0094] Remove pre-cooled Yantai Fuji apples from the cold storage, selecting those that are uniform in size and shape, free from pests, diseases, and mechanical damage. Wash the selected apples with pre-cooled water, then soak them in a 0.2 g / L sodium hypochlorite disinfectant solution for 5 minutes, and wipe off the surface moisture. Use a segmenter to cut the apples into 12 segments, then disinfect them with a 0.05 g / L sodium hypochlorite solution and shake off the excess water. Mix well and randomly divide into three portions, soaking them in water, a 0.5 g / L furanone solution, and a 0.5 g / L chicorylone solution, respectively, for 15 minutes each. Remove and shake off the excess water, pack them into polyethylene bags, fold the bag openings, and place them in a 2-4℃ cold storage for observation.

[0095] On day 0 (6 hours after treatment), the water-soaked apple slices had already turned brown, while the apple slices soaked in 0.5 g / L furanone and chicorylone had not yet turned brown; on day 1 after treatment, the water-soaked apple slices showed moderate browning, while the apple slices soaked in furanone and chicorylone had not yet turned brown; Figure 8 As shown, on the fourth day after treatment, the apple slices soaked in water had turned severely brown, while the apple slices treated with furanone and chicorylone had not yet turned brown and had high commercial value.

[0096] By measuring its color difference, such as Figure 9As shown, it is easy to see that on day 0 (6 hours after treatment), the L* value of apple slices soaked in water was already significantly lower than that of apple slices soaked in furanone and chicorylone. The L* value decreased significantly on day 1, and then decreased slowly thereafter. In contrast, the L* values ​​of apple slices soaked in furanone and chicorylone remained at a higher level, decreasing more slowly. Furthermore, apple slices soaked in chicorylone showed better color protection, resulting in a brighter color and a higher L* value. Both furanone and chicorylone treatments can extend the shelf life of potato shreds by more than 6 days.

[0097] Example 7

[0098] Furanone and chicorylone inhibit browning of fresh-cut peach slices.

[0099] Remove pre-cooled peaches from the cold storage, selecting those with uniform ripeness, no mechanical damage, no pests or diseases, and consistent size and shape. Wash the selected peaches thoroughly with pre-cooled water to remove surface fuzz and dirt, then disinfect them in a 0.2 g / L sodium hypochlorite solution for 5 minutes, and wipe them dry. Cut the peaches into evenly sized slices, disinfect them in a 0.05 g / L sodium hypochlorite solution, and shake off excess water. Mix well and randomly divide into three portions. Soak each portion in water, a 0.5 g / L furanone solution, and a 0.5 g / L chicorylone solution, respectively, for 15 minutes. Remove, shake off excess water, pack into polyethylene bags, fold the bag opening, and store in a 2-4℃ cold storage for observation.

[0100] On day 0 (6 hours after treatment), the peach slices soaked in water showed slight browning, while those soaked in furanone and chicorylone showed no browning. On day 2 after treatment, the peach slices soaked in water showed moderate browning, while those soaked in furanone and chicorylone still showed no browning. Figure 10 As shown, on the fourth day after treatment, the peaches soaked in water showed significant browning, with the peach slices turning yellow and some even showing signs of rotting. The peach slices soaked in furanone and chicorylone, however, remained fresh, showed no browning, and still possessed high commercial value. The chicorylone-soaked peach slices were greener and whiter than those soaked in furanone, appearing fresher.

[0101] The color difference was measured, and the results are as follows: Figure 11 As shown. On day 0 (6 hours after treatment), the water control group had already shown slight browning, and its L* value was significantly lower than that of the other two treatment groups. As time increased, the L* values ​​of all groups decreased slowly, while the water group showed severe browning on day 4, and its L* value dropped sharply. The furanone and chicorylone treatment groups maintained higher L* values, but the L* value of the furanone group was slightly lower than that of the chicorylone group.

[0102] Example 8

[0103] Chicorylone inhibits browning in fresh-cut pear slices.

[0104] Remove pre-cooled pears from the cold storage, selecting those without browning, uniform ripeness, mechanical damage, disease or pests, and of uniform size and shape. Wash the pears thoroughly with pre-cooled water, then immerse them in a 0.5 g / L sodium hypochlorite solution for 5 minutes to disinfect, and wipe off surface moisture. Use a slicer to cut the pears into 12 segments. After cutting, disinfect them again with a 0.05 g / L sodium hypochlorite solution and shake off excess water. Mix well and divide into two portions; immerse one half in water and the other half in a 0.5 g / L chicorylone solution for 15 minutes. Remove, shake off excess water, pack into polyethylene bags, fold the bag opening, and place in a 2-4℃ cold storage for observation.

[0105] On day 0 (6 hours after treatment), the water control group showed slight browning, with brown spots appearing on the pear slices, and some pear slices showing a distinct brown center. The pear slices soaked in chicorylone showed no browning. On day 2 after treatment, the water control group showed moderate browning, with more brown spots on the pear slices, and the centers of the pear slices generally turning brown. The chicorylone-treated pear slices still showed no browning. Figure 12 As shown, on the 4th day after treatment, the brown spots on the pear slices in the water control group almost covered the entire cut surface, while the chicorylone group showed slight browning, with a few brown spots appearing on individual pear slices, but the overall color was still bright and had high commercial value.

[0106] Example 9

[0107] Chicorylone inhibits browning in fresh-cut eggplant slices

[0108] Remove pre-cooled eggplants from the cold storage, selecting those with uniform ripeness, no mechanical damage, no pests or diseases, and of similar size and shape. Clean the eggplants thoroughly with pre-cooled water, then immerse them in a 0.5g / L sodium hypochlorite solution for 5 minutes to disinfect, and wipe off the surface moisture. Peel the eggplants using a grater, cut them into slices approximately 1cm long, and then disinfect them again with a 0.05g / L sodium hypochlorite solution, pressing them below the water surface during disinfection, and shake off the excess water. Mix well, then immerse half of the eggplant slices in water and the other half in a 0.5g / L chicorylone solution for 15 minutes, ensuring the slices remain submerged to fully preserve color. Remove and shake off excess water, pack them into polyethylene bags, fold the bag opening, and place them in a 2-4℃ cold storage for observation.

[0109] Photos were taken on day 0 (0 hours after treatment). Eggplants in the water control group had already begun to brown, with a duller color and brown edges, while eggplants in the chicorylone group were bright in color and had not yet browned. On day 1 after treatment, the water-soaked eggplants showed obvious browning, with a large amount of brown appearing at the edges, and significant browning around the seeds; the chicorylone-treated eggplants remained bright in color and had not yet browned. Figure 13As shown, on the 6th day after treatment, the eggplants soaked in water showed severe browning, with increased brown spots on the edges, severe browning around the seeds, and the seeds becoming sunken. The area around the eggplants changed from green to brown. The chicorylone group did not show browning, and the area around the seeds and the eggplants was bright in color with no brown spots, indicating extremely high commercial value.

[0110] Figure 14 The figure shows the L* value of eggplant. As can be seen from the graph, on day 0 (i.e., 0h after treatment), the eggplant in the water control group had already turned brown, and its L* value was significantly lower than that in the chicorylone group. Furthermore, the L* value decreased significantly with increasing time. In contrast, the eggplant in the chicorylone group showed almost no browning, and its L* value remained almost unchanged with increasing time, maintaining a relatively high level.

[0111] Example 10

[0112] Chicorylone inhibits browning in fresh-cut lettuce.

[0113] Remove pre-cooled lettuce from the cold storage, selecting those without mechanical damage, pests, or diseases, and of uniform size and shape. Cut off the lettuce leaves, leaving only the root. Wash the root thoroughly with pre-cooled water, then immerse it in a 0.5g / L sodium hypochlorite solution for 5 minutes to disinfect. Drain. Peel the lettuce using a grater, leaving only the green inner part, and slice it into 6-8mm pieces. Disinfect the slices with a 0.05g / L sodium hypochlorite solution and shake off excess water. Mix well, then immerse half of the lettuce slices in water and the other half in a 0.5g / L chicorylone solution for 15 minutes. Drain and shake off excess water, then pack the lettuce into polyethylene bags, fold the opening, and store in a 2-4℃ cold storage for observation.

[0114] On the second day after treatment, the water-soaked lettuce slices showed slight browning, with the center beginning to turn yellow. The lettuce slices soaked in chicorylone showed no browning and maintained good quality. On the fourth day after treatment, the water-soaked lettuce slices had severely browned and begun to turn reddish; the chicorylone-treated lettuce slices began to brown, with some slices showing reddish-brown spots. On the eighth day after treatment, the water-soaked lettuce slices showed severe browning; the browning of the chicorylone-treated lettuce slices intensified, the color deepened, and some slices showed reddish-brown centers.

[0115] Figure 15 The L* value of lettuce slices changed. On day 0 (0h after treatment), there was no obvious visual difference, but the L* value of water-soaked lettuce slices was lower than that of chicoryl-soaked lettuce slices, and the L* value showed a decreasing trend with increasing time; the L* value of chicoryl-soaked lettuce slices was always higher than that of water-soaked lettuce slices. On day 6, the L* values ​​of both the control and treatment decreased significantly.

[0116] Example 11

[0117] Chicorylone inhibits browning in fresh-cut bananas.

[0118] Remove the pre-cooled bananas from the cold storage, selecting those that are uniformly ripe, free from mechanical damage, pests, and diseases, and of similar size and shape. Peel the bananas and slice them into pieces about 1cm thick. Mix the slices together, then immerse half of the bananas in water and the other half in a 0.5g / L chicoryl ketone solution for 15 minutes. Drain and shake off excess water, then pack the bananas into polyethylene bags, fold the bag opening, and store them in a 2-4℃ cold storage for observation.

[0119] like Figure 16 As shown, on day 0 (0 hours after treatment), the banana slices soaked in water had turned brown and lost their commercial value, while the banana slices soaked in chicorylone remained fresh and had commercial value. On day 1 after treatment, the bananas soaked in water had completely turned black, and the banana slices soaked in chicorylone had also turned brown, with a color close to that of 1 hour after soaking in water.

[0120] Example 12

[0121] Chicoryne inhibits browning in head lettuce.

[0122] Remove pre-cooled head lettuce from the cold storage, selecting those free from mechanical damage, pests, and diseases, and of uniform size and shape. Remove the outer skin of the head lettuce, wash the surface thoroughly with pre-cooled water, then immerse it in a 0.5 g / L sodium hypochlorite solution for 5 minutes to disinfect. Cut off the top half, leaving the bottom half with the root, and immerse it in the same solution for 5 minutes. Drain. Soak half of the lettuce in water and the other half in a 0.5 g / L chicorylone solution for 15 minutes. Remove, shake dry, pack into polyethylene bags, fold the bag opening, and store in a 2-4℃ cold storage for observation.

[0123] On the fourth day after treatment, the water-soaked head lettuce had already turned brown, with the roots turning reddish-brown and brown spots appearing on many parts of the white leaves; while the head lettuce soaked in chicorylone still had white leaves and had not turned brown, although reddish-brown spots appeared on the edges of the roots. On the sixth day after treatment, the water-soaked head lettuce had completely turned brown, with many parts of the white leaves turning brown and showing signs of rotting in some areas; the head lettuce soaked in chicorylone still maintained a good condition, with bright white leaves and no browning, and had high commercial value.

[0124] Example 13

[0125] Spraying furanone inhibits browning in potatoes.

[0126] Remove pre-cooled potatoes from the cold storage and select a number that are uniform in size and shape, and free from pests, diseases, mechanical damage, sprouting, and greening. Wash the selected potatoes thoroughly with pre-cooled water, soak them in a 0.2 g / L sodium hypochlorite disinfectant solution for 5 minutes, peel them, spray the surface of the potatoes with water and a 2 g / L furanone solution, and then place the potatoes at room temperature for observation.

[0127] Six hours later (recorded as day 0), potatoes sprayed with water showed moderate browning, while potatoes sprayed with furanone showed no browning. After day 3, potatoes sprayed with water showed severe browning, while potatoes sprayed with furanone showed milder browning. After day 6, potatoes sprayed with furanone showed moderate browning.

[0128] Example 14

[0129] 2-Pentylfuran inhibits browning of potato slurry.

[0130] The furanone solution of the corresponding concentration in Example 1 was replaced with 2-pentylfuran, and other operations were the same as in Example 1.

[0131] After 30 minutes, potato flour treated with water, control, and 0.001 g / L, 0.005 g / L, 0.01 g / L, 0.05 g / L, and 0.1 g / L 2-pentylfuran solutions all showed moderate browning, while potato flour treated with 0.5 g / L and 1 g / L 2-pentylfuran solutions did not show browning. After 1 hour, potato flour treated with 0.5 g / L and 1 g / L 2-pentylfuran solutions showed slight browning. After 2 hours, both the control and potato flour treated with 2-pentylfuran solutions showed severe browning.

[0132] Example 15

[0133] Ethyl trigonelline inhibits browning of potato slurry.

[0134] The furanone solution of the corresponding concentration in Example 1 was replaced with ethyl cucurbitacin, and other operations were the same as in Example 1.

[0135] After 30 minutes, potato flour treated with water, control, 0.001 g / L, 0.005 g / L, 0.01 g / L, 0.05 g / L, 0.1 g / L, and 0.5 g / L ethyl cucurbitacin solutions all showed moderate browning. The potato flour treated with 0.1 g / L ethyl cucurbitacin solution showed less browning than the other concentrations, but it had still browned.

[0136] Example 16

[0137] 2-Ethylfuran inhibits browning of potato slurry.

[0138] The furanone solution of the corresponding concentration in Example 1 was replaced with 2-ethylfuran, and other operations were the same as in Example 1.

[0139] like Figure 17 As shown, after 30 minutes, potato flour treated with water, control, and 2-ethylfuran all underwent browning, while 2-ethylfuran had no significant effect on inhibiting browning.

[0140] Example 17

[0141] Treatment with a mixture of furanone, chicorylone, and soy sauce ketone inhibits browning of fresh-cut potato shreds.

[0142] Remove pre-cooled potatoes from the cold storage. Select potatoes that are uniform in size and shape, and free from pests, diseases, mechanical damage, sprouting, and greening. Wash the selected potatoes thoroughly with pre-cooled water, soak them in a 0.2g / L sodium hypochlorite disinfectant solution for 5 minutes, peel them, shred them using a grater, disinfect them with a 0.05g / L sodium hypochlorite solution, and spin dry. Soak them separately in pre-cooled water, a 0.6g / L furanone solution, a 0.6g / L chicorylone solution, a 0.3g / L furanone + 0.3g / L chicorylone mixed solution, and a 0.2g / L furanone + 0.2g / L chicorylone + 0.2ml / L soy sauce ketone mixed solution for 10 minutes each. Spin dry, pack them into polyethylene bags, fold the bag openings, and place them in a 2-4℃ cold storage for observation.

[0143] like Figure 18 As shown, potato shreds soaked in water showed browning after half a day, while potato shreds soaked in 0.6 g / L furanone solution, 0.6 g / L chicorylone solution, a mixed solution of 0.3 g / L furanone + 0.3 g / L chicorylone, and a mixed solution of 0.2 g / L furanone + 0.2 g / L chicorylone + 0.2 ml / L soy sauce ketone showed no browning after 10 days, all extending shelf life by more than 10 days. Mixing different types of solutions to the same concentration did not significantly weaken or enhance the browning inhibition effect.

[0144] This invention is the first to discover that furan rings can interact with PPO. Furthermore, the inventors have found that furan compounds have a certain effect on inhibiting enzymatic browning in fruits and vegetables. One or more mixtures of furanone, chicorylone, soy sauce ketone, 2-pentylfuran, and ethyl trigonelline, when used for color protection treatment of fruits and vegetables, can inhibit browning of various intact fruits and vegetables, fruit and vegetable tissues, and their pulps, thereby improving the quality of fruits and vegetables and extending their shelf life. The method for inhibiting fruit and vegetable discoloration provided by this invention is simple to operate, has a significant effect on inhibiting browning, and the furan compounds are safe to obtain, low in cost, and suitable for industrial production and large-scale application.

Claims

1. Application of furan compounds or compositions of furan compounds in the preservation of fruits and vegetables; The furan compounds include one of furanone and chicorylone; the composition of furan compounds includes two or more of furanone, chicorylone, and soy sauce ketone; the fruits and vegetables are potatoes, iceberg lettuce, and peaches; Alternatively, the furan compound may be soy sauce ketone, and the fruit or vegetable may be potato; In the aforementioned applications, when soaking or spraying, the concentration of the furan compound or a composition of furan compounds used is 0.01 g / L or higher.

2. Applications of furan compounds or compositions of furan compounds for inhibiting discoloration of fruits and vegetables; The furan compounds include one of furanone, chicorylone, and soy sauce ketone; the composition of furan compounds includes two or more of furanone, chicorylone, and soy sauce ketone. The fruit and vegetable in question is a potato; In the aforementioned applications, when soaking or spraying, the concentration of the furan compound or a composition of furan compounds used is 0.01 g / L or higher.

3. The application as described in claim 2, characterized in that, Application of furan compounds or compositions of furan compounds in inhibiting enzymatic browning of fruits and vegetables.

4. The application as described in claim 1 or 2, characterized in that, In the aforementioned applications, the concentrations of furanone, chicorylone, and soy sauce ketone solutions used for soaking are above 0.45 g / L, above 0.08 g / L, and above 0.45 g / L, respectively; the concentrations of furanone, chicorylone, and soy sauce ketone solutions used for spraying are all above 0.8 g / L.

5. The application as described in claim 4, characterized in that, The concentrations of furanone, chicorylone, and soy sauce ketone solutions used for soaking were 0.45-1.5 g / L, 0.08-1.5 g / L, and 0.45-1.5 g / L, respectively; the concentrations of furanone, chicorylone, and soy sauce ketone solutions used for spraying were all 0.8-2.5 g / L.

6. The application as described in claim 1 or 2, characterized in that, The described fruit and vegetable morphology includes complete individual fruits and vegetables, fruit and vegetable tissues, and fruit and vegetable sap.

7. The application as described in claim 6, characterized in that, The fruit and vegetable tissues mentioned include fruit and vegetable slices, fruit and vegetable shreds, and fruit and vegetable chunks.

8. A fruit and vegetable preservative, characterized in that, The active ingredients include furan compounds or combinations of furan compounds; The furan compounds include one of furanone and chicorylone; the composition of furan compounds includes two or more of furanone, chicorylone, and soy sauce ketone; the fruits and vegetables are potatoes, iceberg lettuce, and peaches; Alternatively, the furan compound may be soy sauce ketone, and the fruit or vegetable may be potato; When soaking or spraying, the concentration of furan compounds or compositions of furan compounds used is 0.01 g / L or higher.

9. A color-protecting agent for fruits and vegetables, characterized in that, The active ingredients include furan compounds or combinations of furan compounds; The furan compounds include one of furanone, chicorylone, and soy sauce ketone; the composition of furan compounds includes two or more of furanone, chicorylone, and soy sauce ketone. The fruit and vegetable in question is a potato; When soaking or spraying, the concentration of furan compounds or compositions of furan compounds used is 0.01 g / L or higher.

10. A method for inhibiting enzymatic browning in fruits and vegetables, characterized in that, Includes the following steps: Soaking or spraying whole fruits and vegetables or fruit and vegetable tissues with furan compounds or combinations of furan compounds; Alternatively, furan compounds or combinations of furan compounds can be directly added to fruit and vegetable pulp or fruit and vegetable powder; The furan compounds include one of furanone, chicorylone, and soy sauce ketone; the composition of furan compounds includes two or more of furanone, chicorylone, and soy sauce ketone. The fruit and vegetable in question is a potato; In the aforementioned applications, when soaking or spraying, the concentration of the furan compound or a composition of furan compounds used is 0.01 g / L or higher; The concentration of furan compounds or furan compound compositions used when directly adding them to fruit and vegetable pulp or fruit and vegetable powder is 0.5 g / L or higher.

11. The method as described in claim 10, characterized in that, In the method, a furan compound or a composition of furan compounds is dissolved in anhydrous ethanol to obtain a mother liquor; the mother liquor is then dissolved in water, mixed, and used.

12. The method as described in claim 10, characterized in that, The concentrations of furanone, chicorylone, and soy sauce ketone solutions used for soaking were above 0.45 g / L, above 0.08 g / L, and above 0.45 g / L, respectively; the concentrations of furanone, chicorylone, and soy sauce ketone solutions used for spraying were all above 0.8 g / L.

13. The method as described in claim 12, characterized in that, The concentrations of furanone, chicorylone, and soy sauce ketone solutions used for soaking were 0.45-1.5 g / L, 0.08-1.5 g / L, and 0.45-1.5 g / L, respectively; the concentrations of furanone, chicorylone, and soy sauce ketone solutions used for spraying were all 0.8-2.5 g / L.

14. The method as described in claim 10, characterized in that, The soaking time for furan compounds in the soaking process is 1 second to 50 minutes.

15. The method as described in claim 14, characterized in that, The soaking time for the furan compounds is 3-15 minutes.

16. The method as described in claim 10, characterized in that, The soaking temperature during the soaking process is 0-50℃.

17. The method as described in claim 16, characterized in that, The soaking temperature is 2-4℃.

Images