CN117179044A

CN117179044A - Application of furan compound or composition in inhibiting fruit and vegetable discoloration

Info

Publication number: CN117179044A
Application number: CN202311308686.6A
Authority: CN
Inventors: 王庆国; 常晓涌; 冯岩岩
Original assignee: Shandong Agricultural University
Current assignee: Shandong Agricultural University
Priority date: 2023-10-10
Filing date: 2023-10-10
Publication date: 2023-12-08

Abstract

The invention provides application of furan compounds or a furan compound composition for inhibiting color change of fruits and vegetables, belongs to the technical field of agricultural product storage and preservation, and particularly relates to application of furan compounds or a furan compound composition for preserving fruits and vegetables; application of furan compounds or furan compound composition in inhibiting fruit and vegetable discoloration; and provides a fruit and vegetable preservative and a fruit and vegetable color fixative; the inventor discovers that the furan compound has a certain effect on inhibiting enzymatic browning of fruits and vegetables for the first time, and can be used for fruit and vegetable fresh-keeping and fruit and vegetable color protection.

Description

Application of furan compound or composition in inhibiting fruit and vegetable discoloration

Technical Field

The invention belongs to the technical field of agricultural product storage and preservation, and particularly relates to application of furan compounds or a furan compound composition for inhibiting color change of fruits and vegetables.

Background

The fresh-cut fruits and vegetables are products which can be directly eaten or can be eaten after proper processing through processes of selecting, cleaning, peeling, sterilizing, cutting, refrigerating, preserving and the like. Along with the improvement of living standard and the acceleration of living rhythm, the demands of people for fresh-cut fruits and vegetables are increased, and the fresh-cut fruits and vegetables show good market prospect. However, fresh-cut fruits and vegetables are subject to various problems such as easy water loss, easy enzymatic browning, low nutritive value, microbial spoilage and the like, wherein the most important problem is the enzymatic browning. Cutting of fruits and vegetables such as potatoes, lettuce, eggplants, lettuce rolls, apples, pears, peaches, bananas and the like is prone to enzymatic browning.

The enzymatic browning refers to the process that phenolic substances in fruits and vegetables are oxidized to generate spread spectrum and quinone are polymerized to form melanin under the action of polyphenol oxidase. The enzymatic browning not only can influence the color, flavor and texture of the fruits and vegetables to deteriorate the quality of the fruits and vegetables, but also can shorten the shelf life of the fruits and vegetables, and cause loss of nutrient components, thereby causing a great deal of waste and economic loss for the fruits and vegetables industry. Therefore, how to inhibit enzymatic browning of fruits and vegetables has important significance.

In order to control enzymatic browning, only one of the substrate, enzyme and oxygen needs to be controlled. The most commonly used method is to soak fruits and vegetables with a browning inhibitor, for example, a fresh-keeping method of fresh-cut lotus roots (publication number: CN 114568489A) discloses a method of using citric acid and sodium bisulphite to inhibit browning of fresh-cut lotus roots, and the safety problem of sulfite is forbidden to be used on fruits and vegetables by FDA because the safety problem of sulfite is still further questioned. The utility model discloses a fresh-cut potato fresh-keeping effective method (publication number: CN 115380948A), which discloses a compound color-protecting and crisp-keeping agent, comprising ascorbic acid, citric acid, calcium chloride and sodium erythorbate, which can effectively inhibit the growth of microorganisms, prolong the shelf life of the fresh-cut potato, achieve the purpose of color protection and crisp-keeping, but has complex compound process of various components and is difficult to widely apply. The new application of the thioacetate compound in inhibiting the discoloration of the fruit and vegetable tissues (publication number: CN 109548863A) discloses a method for carrying out color protection treatment on fruits and vegetables by using the thioacetate compound, wherein the effect of inhibiting the discoloration of the fruit and vegetable tissues is remarkable, but the taste is unacceptable when the concentration is higher. Therefore, although there are many methods for inhibiting browning, most of the methods are not ideal, and the effects are good, so that the safety problem exists, the safety effect is poor, and some of the effects are good, but the taste problem is prominent, so that the method is difficult to be applied on a large scale.

Therefore, it is necessary to find a color fixative which is safe in source, simple in operation, good in effect and small in taste.

The furan compounds are widely used in the medicine, food and chemical industries and have high application value. In the prior art, furan compounds play a role in flavoring in foods, but have not been reported in inhibiting enzymatic browning of fruits and vegetables.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides application of furan compounds or compositions for inhibiting the color change of fruits and vegetables.

The inventor finds that the furan ring can interact with the PPO for the first time through molecular docking and analysis of the structure of the new component for inhibiting the activity of the polyphenol oxidase (PPO) and the inhibition mechanism research of the new component; further, the inventor finds that the furan compound plays a certain role in inhibiting enzymatic browning of fruits and vegetables.

The technical scheme of the invention is as follows:

furan compound or furan compound composition is used for fresh-keeping of fruits and vegetables.

Furan compound or furan compound composition is used for inhibiting the application of fruit and vegetable discoloration.

According to the invention, the furan compounds or the furan compound composition are preferably applied to inhibiting enzymatic browning of fruits and vegetables.

According to the invention, preferably, the furan compound comprises one of furanone, chicory ketone, soy sauce ketone, 2-amyl furan and ethyl fenugreek lactone; the furan compound composition comprises two or more of furanone, chicory ketone, soy sauce ketone, 2-amyl furan and ethyl trigonelline.

Further preferably, the furans are furanones, chicory ketones and soy sauce ketones, and the concentration used in soaking or spraying is more than 0.01 g/L.

More preferably, the concentration of furanone, chicory ketone and soy sauce ketone solution used for soaking is above 0.45g/L, above 0.08g/L and above 0.45g/L respectively; the concentration of furanone, cichorione and soy sauce ketone solution used for spraying is above 0.8 g/L.

More preferably, the concentration of furanone, chicory ketone and soy sauce ketone solution used for soaking is respectively 0.45-1.5g/L, 0.08-1.5g/L and 0.45-1.5g/L; the concentration of furanone, cichorione and soy sauce ketone solution used for spraying is 0.8-2.5g/L.

Preferably, the fruit and vegetable morphology according to the invention comprises complete fruit and vegetable individuals, fruit and vegetable tissues and fruit and vegetable pulp.

Further preferably, the fruit and vegetable tissue comprises fruit and vegetable slices, fruit and vegetable shreds and fruit and vegetable blocks.

Preferably, the fruits and vegetables are potatoes, lettuce, eggplant, lettuce, apples, bananas, peaches and pears.

A fruit and vegetable antistaling agent contains furan compounds or furan compound composition as effective component.

A fruit and vegetable color fixative comprises furan compounds or furan compound composition as effective component.

A method for inhibiting enzymatic browning of fruits and vegetables, comprising the steps of:

soaking, spraying and smearing the furan compounds or the furan compound composition into the whole individual fruits and vegetables or the tissues of fruits and vegetables;

or furan compounds or furan compound composition is directly added into fruit and vegetable slurry or fruit and vegetable powder.

According to a preferred embodiment of the present invention, the method comprises dissolving a furan compound or a combination of furan compounds with absolute ethanol to obtain a mother liquor; and dissolving the mother solution into water, and uniformly mixing for use.

According to the invention, the furans are preferably furanones, chicory ketones and soy sauce ketones, and the concentration used in soaking or spraying is above 0.01 g/L.

Further preferably, the concentrations of furanone, chicory ketone and soy sauce ketone solutions used for soaking are respectively above 0.45g/L, above 0.08g/L and above 0.45 g/L; the concentration of furanone, cichorione and soy sauce ketone solution used for spraying is above 0.8 g/L.

According to the invention, the soaking duration of the furans compound in the soaking process is preferably 1s-50min.

Further preferably, the soaking time of the furan compound is 3-15min.

According to the invention, the soaking temperature in the soaking process is preferably 0-50 ℃.

Further preferably, the soaking temperature is 2-4 ℃.

The furanone is also called 4-hydroxy-2, 5-dimethyl-3 (2H) furanone, is a flavor enhancer, presents the flavor of fruits and caramel, has a low concentration threshold value when being naturally present in fruits such as pineapple, mango, strawberry and the like, has obvious flavoring effect reaching 0.04ppb, and is widely used as a flavoring agent in the food industry.

Chicory ketone is also called 4-hydroxy-5-methyl-3 (2H) -furanone, is an essence and spice, and has bread flavor, caramel flavor, fruit flavor, jam flavor and the like. Natural products are widely used in strawberries, pineapples, beef bouillons and the like, have slightly weaker fragrance intensity than furanones, are widely used in the food industry at present, and are safe edible flavors approved by the American society of food flavor manufacturers, FEMA.

Soy sauce ketone is also called 5-ethyl-4-hydroxy-2-methyl-3 (2H) -furanone, which has intense natural sweet and fruity flavor, and also has caramel flavor and the flavor of baked bread. It naturally occurs in soy sauce and is also known as soyaketone. The flavor intensity is stronger than furanone, and is used as flavoring agent.

The beneficial effects of the invention at least comprise the following:

1. the invention discovers that the furan ring can interact with PPO for the first time; further, the inventor finds that the furan compound plays a certain role in inhibiting enzymatic browning of fruits and vegetables.

2. The invention can effectively inhibit enzymatic browning of fruits and vegetables, improve the quality of fresh-cut fruits and vegetables and prolong the shelf life.

3. Furans are safe in source and have been widely used in the food industry as food additives.

4. The furan compounds have mature production technology and lower cost, and do not increase excessive cost.

5. The furan compound has good effect of inhibiting enzymatic browning of fruits and vegetables, and the method is simple, and can be applied on a large scale and produced in a factory.

Drawings

FIG. 1 is a graph showing the effect of furanone solutions of different concentrations on browning of potato pulp.

Figure 2 shows the browning of furanone solution treated potato pulp.

FIG. 3 is a graph showing the effect of various concentrations of chicory ketone solution on browning of potato pulp.

FIG. 4 is a graph showing the effect of soy sauce ketone solutions of different concentrations on browning of potato pulp.

FIG. 5 is a graph showing the effect of chicory ketone treatment on browning of cut potato chips.

Fig. 6 is a graph of visual browning levels for chicory ketone treated freshly cut potato strings.

FIG. 7 is a plot of the overall sensory evaluation of chicory ketone treated freshly cut potato strings.

FIG. 8 is a graph showing the effect of furanone and chicory ketone treatment on freshly cut apples.

Fig. 9 shows the L values of freshly cut apples after furanone and chicory ketone treatment.

FIG. 10 is a graph showing the effect of furanone and chicory ketone treatment on freshly cut peaches.

Fig. 11 shows the L values of fresh cut peaches after furanone and chicory ketone treatment.

FIG. 12 is a graph showing the effect of chicory ketone treatment on fresh cut pears.

FIG. 13 is a graph showing the effect of chicory ketone treatment on freshly cut eggplants.

Fig. 14 shows the L values of fresh cut eggplants after chicorone treatment.

Fig. 15 is the L values of fresh cut lettuce after chicorone treatment.

FIG. 16 is a graph showing the effect of chicory ketone treatment on freshly cut bananas.

FIG. 17 is a graph showing the effect of different concentrations of 2-ethylfuran solution on browning of potato pulp.

FIG. 18 is a graph showing the effect of furanone and combination treatment on browning of cut potato chips.

Detailed Description

In order to more clearly illustrate the technical scheme of the present invention, a complete and detailed description of the technical scheme of the present invention will be provided below in conjunction with specific embodiments. It should be apparent that the embodiments described below are only a part of the present invention to better describe the present invention, but not all embodiments. Embodiments which can be obtained by a person skilled in the art without the inventive effort fall within the scope of protection of the present invention.

The implementation effect expression method comprises the following steps: the effect of the present invention was expressed by measuring color difference, absorbance, visual browning degree, and overall sensory evaluation with an instrument.

Color value was measured using a Minolta Co., japan, osaka, CR-400 color difference meter; standard white board colour difference for calibration was l=97.06, a=0.04, b=2.01. Wherein L represents luminance ranging from 0 to 100,0 represents pure black, and 100 represents pure white; a represents red and green, ranging from-128 to +127, -128 represents green, and +127 represents red; b represents yellow blue, ranging from-128 to +127, wherein-128 represents blue and +127 represents yellow.

Determination of absorbance values was performed using a beijing-general TU-1810 uv-vis spectrophotometer at 410nm, wherein a larger absorbance value indicates more severe browning.

Visual browning degree refers to international common scoring standard, wherein the color scoring standard is 1-5 points, and 1 = no color change; 2 = slight discolouration, discolouration area < 5%; 3=obvious color change, 5-20% of color change area; 4=more serious discoloration, 20-50% of discoloration area; 5=severe discoloration, discoloration area > 50%. And 3, the grade is changed, namely the commodity value is determined to be lost.

Overall sensory evaluation was rated on a scale of 9-1, where 9 = excellent, no defect, 7 = good, slight defect, 5 = general, moderate defect, 3 = poor, major defect, 1 = unusable. And if the score is less than 6, the commodity value is considered to be lost.

The furan compound is generally insoluble in water, so that the furan compound is firstly dissolved in absolute ethyl alcohol to prepare mother liquor, then dissolved in water and diluted to obtain solutions with different concentrations in the experiment. The volume of absolute ethanol used for dissolution was 0.1% of the final solution volume. Since ethanol with a high concentration has a certain browning inhibiting effect, ethanol with a volume concentration of 0.1% was used as a Control in order to eliminate the interference of ethanol on the experiment.

Example 1

Furanones inhibit enzymatic browning of potato pulp

Cutting potato, freezing with liquid nitrogen, grinding into potato powder, and storing at-80deg.C. 9 parts of potato jelly powder with the volume concentration of 0.1 percent is weighed, 2ml of water, 0.001g/L, 0.005g/L, 0.01g/L, 0.05g/L, 0.1g/L, 0.5g/L and 1g/L of furanone solution are respectively added, vortex mixing is carried out, standing and observation are carried out.

As shown in FIG. 1, at 0.5h, the water, control, 0.001g/L, 0.005g/L, 0.01g/L furanone solution treated potato flour had developed a moderate browning, the 0.05g/L, 0.1g/L furanone solution treated potato flour was slightly less browned, and the 0.5g/L, 1g/L furanone solution treated potato flour did not develop browning. After 2 hours, the potato flour treated with the 0.5g/L and 1g/L furanone solutions still had no browning, and the control and other treatment groups had severe browning.

Example 2

Determination of Furanone inhibition of browning of Potato slurry

Weighing 45 parts of 1g of potato jelly powder, dividing into three groups, adding 2ml of water into each group by contrast, treating, respectively adding 2ml of 0.5g/L and 1g/L furanone solution, mixing uniformly by vortex, respectively standing at room temperature for 0h, 0.5h, 1h, 2h and 4h, centrifuging at 10000r/min at 4 ℃ for 10min, and measuring the absorbance at 410 nm.

As shown in fig. 2, the absorbance value increased after the control was browned for 0.5h, and the absorbance value gradually increased with the increase in time. While the absorbance value of the furanone solution of 0.5g/L and 1g/L is hardly changed with the time.

Example 3

Cichorinone inhibits browning of potato pulp

9 parts of 1g potato jelly is weighed as in example 1, 2ml of deionized water, 0.1% ethanol solution (control) in volume concentration, 0.001g/L, 0.005g/L, 0.01g/L, 0.05g/L, 0.1g/L, 0.5g/L and 1g/L chicory ketone solution are respectively added, and the mixture is uniformly vortexed and kept stand for observation.

As shown in FIG. 3, after 0.5h, the water, control, 0.001g/L chicory ketone solution treated potato flour had developed a moderate browning, 0.005g/L, 0.01g/L chicory ketone solution treated potato flour developed a slight browning, and none of the 0.05g/L, 0.1g/L, 0.5g/L, 1g/L chicory ketone solution treated potato flour developed a browning. As the chicory ketone solution is a light yellow solution, the color of the chicory ketone solution with different concentrations is not completely consistent due to the influence of the color of the solution. After 1h, browning of the water, control, 0.001g/L chicory ketone solution treated potato flour had been severe, and slight browning had occurred to the 0.005g/L, 0.01g/L chicory ketone solution treated potato flour, and no browning had occurred to the 0.05g/L, 0.1g/L, 0.5g/L, 1g/L chicory ketone solution treated potato flour. After 2 hours, the browning of the potato powder treated with water, control, 0.001g/L, 0.005g/L and 0.01g/L of the chicory ketone solution was severe, the browning of the potato powder treated with 0.05g/L of the chicory ketone solution was slight, and the browning of the potato powder treated with 0.1g/L, 0.5g/L and 1g/L of the chicory ketone solution was not.

Example 4

Soy sauce ketone for inhibiting browning of potato pulp

The furanone solution of example 1 was changed to soyaketone, and the other operations were the same as in example 1.

As shown in FIG. 4, after 0.5h, the water, control, 0.001g/L, 0.005g/L, 0.01g/L of the soy sauce ketone solution treated potato flour had suffered from moderate browning, and the 0.05g/L, 0.1g/L, 0.5g/L, 1g/L of the soy sauce ketone solution treated potato flour had not suffered from browning; after 1h, the browning of the potato powder treated by the water, the control, the 0.001g/L, the 0.005g/L and the 0.01g/L soy sauce ketone solution is serious, the browning of the potato powder treated by the 0.05g/L and the 0.1g/L soy sauce ketone solution is slight, and the browning of the potato powder treated by the 0.5g/L and the 1g/L soy sauce ketone solution does not occur; after 2 hours, the potato powder treated with water, control, 0.001g/L, 0.005g/L and 0.01g/L of the soy sauce ketone solution was severely browned, the potato powder treated with 0.05g/L and 0.1g/L of the soy sauce ketone solution was moderately browned, and the potato powder treated with 0.5g/L and 1g/L of the soy sauce ketone solution was not browned.

Example 5

Cichorium intybus ketone for inhibiting browning of fresh cut potato chips

And taking out the potatoes pre-cooled in advance from the refrigeration house, and selecting a plurality of potatoes which are uniform in size and shape, have no plant diseases and insect pests on the appearance, are free from mechanical injury, are free from sprouting and are free from greening. Cleaning selected potatoes with pre-chilled water, soaking for 5min with 0.2g/L sodium hypochlorite disinfectant, peeling, shredding with a shredding device, sterilizing with 0.05g/L sodium hypochlorite solution, spin-drying, soaking in pre-chilled water, 0.1% ethanol solution and 0.5g/L chicory ketone solution for 10min, spin-drying water, packaging into polyethylene bags, folding the bag openings, and observing in a refrigerator at 2-4deg.C.

As shown in FIG. 5, after 12 hours of treatment (noted as day 0), both controls, i.e., the water and control group, had been browned, the 0.5g/L chicory ketone treated potato pieces had not been browned, the 2 nd and 4 th day water and control had been severely browned, the 0.5g/L chicory ketone treated potato pieces had not been browned, the 0.5g/L chicory ketone treated potato pieces on days 6 and 8 were slightly browned, were not dehydrated, and still maintained good quality, and the 0.5g/L chicory ketone treated potato pieces on day 10 had been slightly browned.

Cut potato chips were scored according to a scoring criteria for visual browning, 1 = no browning at all, 2 = slight browning, 3 = moderate browning, 4 = moderate severe browning, 5 = severe browning, and the scoring results are shown in fig. 6. The two control groups had a moderate browning on day 0 and had a severe browning on day 2, whereas the 0.5g/L chicory ketone treated potato chips had a slight browning from day 6, but the overall score was still below 2 minutes, i.e. a slight browning.

Cut potato strips were scored according to scoring criteria for overall sensory evaluation, 9=excellent, defect free, 7=good, slightly defective, 5=general, moderately defective, 3=poor, larger defect, 1=very poor. The overall sensory quality score <6 represents the commodity value loss, with the score shown in fig. 7. The clear water and the control have brown stain on the 0 th day, the score is less than 6 minutes, the commodity value is lost, the potato chips treated by 0.5g/L chicory ketone have slight brown stain on the 6 th day, the potato chips still have commodity value on the 10 th day, and the shelf life can be prolonged by 10 days.

Example 6

Furanone and chicory ketone for inhibiting browning of fresh cut apple slices

And taking out the pre-cooled tobacco stage red Fuji from the refrigeration house, and selecting apples which are uniform in size and shape, free of plant diseases and insect pests and free of mechanical injury for standby. Cleaning selected apples with pre-chilled water, soaking in 0.2g/L sodium hypochlorite disinfectant for 5min, and wiping off surface water. Dividing the apples into 12 pieces by using a piece cutter, sterilizing by using a sodium hypochlorite solution with the concentration of 0.05g/L, and drying water. Mixing, randomly dividing into three parts, respectively soaking in water, furanone 0.5g/L and chicory ketone 0.5g/L for 15min, taking out, drying, packaging into polyethylene bag, folding, placing into 2-4deg.C freezer, and observing.

After day 0 (6 h post treatment), the water-soaked apple pieces had been browned, whereas 0.5g/L furanone and chicory ketone-soaked apple pieces had not been browned; on the 1 st day after treatment, the apple slices soaked by water are moderately browned, while the apple slices soaked by furanone and chicory ketone are still not browned; as shown in fig. 8, on the 4 th day after the treatment, the apple slices immersed in water have been severely browned, while the apple slices treated with furanone and chicory ketone have not been browned yet, thus having high commercial value.

By measuring the color differences, as shown in fig. 9, it was not difficult to find that on day 0 (6 h after treatment), the L values of the water-soaked apple slices were significantly lower than those of furanone and chicory ketone-soaked apple slices, and that on day 1, the L values were significantly decreased, followed by a slow decrease. The L values of the apple slices soaked by the furanone and the chicory ketone are always at a higher level, the drop is slower, the color protection effect of the apple slices soaked by the chicory ketone is better, the color is brighter, and the L values are higher. The furanone and chicory ketone treated potato shreds can prolong shelf life by more than 6 days.

Example 7

Furone and chicory ketone for inhibiting browning of fresh cut peach slices

And taking out the peach pre-cooled in advance from the refrigeration house, and selecting the peach with uniform maturity, no mechanical injury, no plant diseases and insect pests and uniform size and shape. Cleaning the selected peach with pre-cooled water, washing off surface hair and dirt, sterilizing in 0.2g/L sodium hypochlorite solution for 5min, and wiping off surface water. Cutting peach into slices with uniform thickness and size, sterilizing in sodium hypochlorite solution of 0.05g/L, and drying. Mixing, randomly dividing into three parts, respectively soaking in water, furanone 0.5g/L and chicory ketone 0.5g/L for 15min, taking out, drying, packaging into polyethylene bag, folding, placing into 2-4deg.C freezer, and observing.

On day 0 (6 h after treatment), the soaked peaches had developed slight browning, whereas the furanones and chicory ketones soaked peaches had not developed browning. On day 2 after treatment, the soaked peach pieces had been moderately browned, while the furanone and chicory ketone soaked peach pieces had not been browned. As shown in fig. 10, on day 4 after the treatment, the soaked peaches were more severely browned, the color of the peaches had been yellow, and even some portions of the peaches were partially rotten. The peach slices soaked by furanone and chicory ketone still remain fresh, have no browning and have high commodity value. Wherein the chicory ketone soaked peach slices are greener and whiter in color and appear fresher than furanone soaked peach slices.

The color difference was measured, and the result is shown in FIG. 11. On day 0 (6 h after treatment), the water control group had developed slight browning, with a significantly lower L value than the other two treatment groups. Over time, the L values of the groups decreased slowly, whereas the clear water group was severely browned on day 4, with the L values decreasing abruptly, the furanone and chicory ketone treated group remained higher, but the furanone group had a slightly lower L value than the chicory ketone group.

Example 8

Cichorium intybus ketone for inhibiting browning of fresh cut pear slices

And taking out the pear which is pre-cooled in advance from the cold storage, and selecting the pear which has no brown stain, consistent maturity, no mechanical injury, no plant diseases and insect pests and uniform size and shape for later use. Cleaning pear with pre-chilled water, soaking in 0.5g/L sodium hypochlorite solution for 5min, and wiping off surface water. Dividing the pears into 12 pieces by using a cutter, sterilizing by using 0.05g/L sodium hypochlorite solution after cutting, and drying water. After mixing, the mixture was divided into two portions, one half was immersed in water and the other half was immersed in 0.5g/L chicory ketone solution for 15min. Taking out, drying, placing into polyethylene bag, folding, placing into 2-4deg.C freezer, and observing.

On day 0 (6 h after treatment), the water control group was slightly browned, brown spots appeared on the pears, a portion of the centers of the pears were visibly brown, and the pears soaked with chicory ketone were not browned yet. On day 2 after treatment, the water control group had developed moderate browning, brown spots on the pears became increased, the center of the pears became generally brown, and the chicrones remained unaffected. As shown in fig. 12, on day 4 after treatment, the brown spots of the water control group pears almost covered the whole cut surface, the chicorone group was slightly brown, a little brown spots appeared on individual pears, but the whole pears were still brighter in color and had high commodity value.

Example 9

Cichorium intybus ketone for inhibiting browning of fresh-cut eggplant slices

And taking out the eggplants which are pre-cooled in advance from the refrigeration house, and selecting the eggplants which have consistent maturity, no mechanical injury, no plant diseases and insect pests and uniform size and shape for later use. Cleaning the surface of eggplant with pre-chilled water, immersing in 0.5g/L sodium hypochlorite solution for disinfection for 5min, and wiping off surface water. Peeling with a silk wiper, cutting into eggplant slices about 1cm, sterilizing with 0.05g/L sodium hypochlorite solution, pressing under water surface during sterilization, and drying. After mixing, half of the mixture is immersed in water, and half of the mixture is immersed in 0.5g/L chicory ketone solution for 15min, and the mixture is immersed below the liquid surface in the immersing process to fully protect the color. Taking out, spin-drying, placing into polyethylene bag, folding, placing into 2-4deg.C freezer, and observing.

On day 0 (0 h after treatment), the eggplants of the water control group had started browning, the color was darker, the edge had brown appearance, and the eggplants of the chicory ketone group were bright in color, and had not yet been browned. On the 1 st day after treatment, the soaked eggplants are obvious in browning, a large amount of brown color appears at the edges, and the browning around the seeds is obvious; the eggplant treated by the chicory ketone is not brown, and the color is bright. As shown in fig. 13, on the 6 th day after the treatment, the soaked eggplant was severely browned, the edge brown spots were increased, the surrounding of the seeds was severely browned, the seeds were sunk, and the surrounding of the eggplant was changed from green to brown; the chicory ketone group still has no brown stain, the color around the seeds and the surrounding eggplants is bright, no brown spots appear, and the chicory ketone group has extremely high commodity value.

Fig. 14 shows the L values of eggplants, and it can be seen from the graph that on day 0 (i.e. 0h after treatment), the eggplants of the water control group had been browned, the L values were significantly lower than the L values of the chicory ketone group, and the L values decreased significantly with time. While eggplants of the chicory ketone group have little browning, the L-value is hardly changed with the increase of time, and still maintained at a higher level.

Example 10

Cichorinone for inhibiting browning of fresh cut lettuce

And taking out the pre-cooled lettuce from the refrigerator, and selecting the lettuce which is free of mechanical injury, plant diseases and insect pests and uniform in size and shape for later use. Cutting off lettuce leaves by a knife, leaving only roots, cleaning the lettuce roots by pre-chilled water, immersing the lettuce roots in 0.5g/L sodium hypochlorite solution for disinfection for 5min, and taking out and draining. Peeling with a silk cleaner, cutting into pieces of lettuce with thickness of 6-8mm, sterilizing with 0.05g/L sodium hypochlorite solution, and drying. After mixing, half of the lettuce slices were immersed in water and half in 0.5g/L chicory ketone solution for 15min. Taking out, spin-drying, placing into polyethylene bag, folding, placing into 2-4deg.C freezer, and observing.

On day 2 after treatment, the water soaked lettuce slices developed slight browning, the central part began to yellow, the chicory ketone soaked lettuce slices did not brown yet, and better quality was maintained. On the 4 th day after treatment, the water soaked lettuce slices are severely browned and begin to reddish; the chicory ketone treated lettuce slices began to brown and some lettuce slices appeared a little reddish brown. On the 8 th day after treatment, the water soaked lettuce slices are severely browned; the browning degree of the lettuce slices treated by the chicory ketone is increased, the color is deepened, and the center of part of the lettuce slices is reddish brown.

Fig. 15 shows the change in L values of lettuce slices. On day 0 (i.e. 0h after treatment), visual differences were not apparent, but the L-value of water-soaked lettuce slices was lower than that of chicory ketone-soaked, and the L-value was decreasing with increasing time; the L-value of chicory ketone soaked lettuce slices is always higher than that of water soaked lettuce slices. On day 6, both control and treatment L values were significantly reduced.

Example 11

Cichorium intybus ketone for inhibiting browning of fresh cut banana

And taking out the bananas pre-cooled in advance from the refrigeration house, and selecting bananas with consistent maturity, no mechanical injury, no plant diseases and insect pests and uniform size and shape for standby. Peeling banana, cutting into banana slices with thickness of about 1cm, mixing, soaking half in water, and soaking half in 0.5g/L chicory ketone solution for 15min. Taking out, spin-drying, placing into polyethylene bag, folding, placing into 2-4deg.C freezer, and observing.

As shown in fig. 16, on day 0 (i.e., 0h after treatment), the water soaked banana chips had been browned, lost commodity value, and the chicory ketone soaked banana chips remained fresh and had commodity value. On day 1 after treatment, the water soaked bananas had been fully blackened, the chicory ketone soaked banana chips had also been browned, and the color was close to that after 1 hour of water soaking.

Example 12

Cichorium intybus ketone for inhibiting browning of lettuce

Taking out the rolled lettuce pre-cooled in advance from the refrigeration house, and selecting the rolled lettuce which is free of mechanical injury, plant diseases and insect pests and uniform in size and shape for standby. Removing the outer skin of lettuce, cleaning the surface with pre-cooled water, soaking in 0.5g/L sodium hypochlorite solution for sterilization for 5min, cutting the upper half part, leaving the lower half part with root, soaking in 0.5g/L sodium hypochlorite solution for sterilization for 5min, taking out, and draining. Half immersed in water and half immersed in 0.5g/L chicory ketone solution for 15min. Taking out, spin-drying, placing into polyethylene bag, folding, placing into 2-4deg.C freezer, and observing.

On the 4 th day after treatment, the water soaked lettuce has brown stain, the root turns into reddish brown, and the white leaves appear brown at a plurality of places; while the lettuce with the cichorium intybus soaked in the cichorium intybus ketone is still white, no browning occurs, and the root edge is in a red brown spot. Day 6 after treatment. The lettuce with the rolled ball soaked in the clear water is completely browned, and the white leaves are brown at a plurality of places and have a local decay trend; the chicory ketone soaked lettuce rolls still keeps a good state, white leaves are still bright, no browning occurs, and the chicory ketone soaked lettuce rolls have high commodity value.

Example 13

Furanone spraying to inhibit browning of potato

And taking out the potatoes pre-cooled in advance from the refrigeration house, and selecting a plurality of potatoes which are uniform in size and shape, have no plant diseases and insect pests on the appearance, are free from mechanical injury, are free from sprouting and are free from greening. Cleaning the selected potatoes with pre-chilled water, soaking for 5min with 0.2g/L sodium hypochlorite disinfectant, peeling, spraying water and 2g/L furanone solution onto the surfaces of the potatoes, and then placing the potatoes at room temperature for observation.

After 6 hours (noted as day 0), the potato with surface sprayed water had been moderately browned and the potato with surface sprayed furanone had not been browned; after day 3, the potato sprayed with water on the surface had been severely browned, and the potato sprayed with furanone on the surface was slightly browned. After day 6, the furanone-sprayed potato was moderately browned.

Example 14

2-pentylfuran to inhibit browning of potato pulp

The procedure was the same as in example 1 except that the furanone solution of example 1 was changed to 2-pentylfuran.

After 30min, the water, control, 0.001g/L, 0.005g/L, 0.01g/L, 0.05g/L, 0.1g/L of 2-pentylfuran solution treated potato flour had all been moderately browned, while the 0.5g/L, 1g/L of 2-pentylfuran solution treated potato flour had no browning; after 1h, the potato powder treated by the 0.5g/L and 1 g/L2-amyl furan solution is slightly brown; serious browning occurred for both the control and 2-pentylfuran solution treated potato flour for 2 h.

Example 15

Ethyl trigonelline inhibits browning of potato pulp

The procedure of example 1 was repeated except that the furanone solution of the corresponding concentration of example 1 was changed to ethyl trigonelline.

After 30min, the potato powder treated by the water, the control, the 0.001g/L, the 0.005g/L, the 0.01g/L, the 0.05g/L, the 0.1g/L and the 0.5g/L ethyl trigonelline solution has the moderate browning, and the browning degree of the potato powder treated by the 0.1g/L ethyl trigonelline solution is lighter than that of other concentrations, but also has the browning.

Example 16

2-ethylfuran inhibits browning of potato pulp

The procedure was the same as in example 1 except that the furanone solution of example 1 was changed to 2-ethylfuran.

As shown in FIG. 17, after 30min, all of the water, control and 2-ethylfuran treated potato flour had developed browning, and 2-ethylfuran had no significant browning inhibiting effect.

Example 17

Mixing furanone, chicory ketone and soy sauce ketone to inhibit browning of fresh cut potato chips

And taking out the potatoes pre-cooled in advance from the refrigeration house, and selecting a plurality of potatoes which are uniform in size and shape, have no plant diseases and insect pests on the appearance, are free from mechanical injury, are free from sprouting and are free from greening. Cleaning selected potatoes with pre-chilled water, soaking for 5min with 0.2g/L sodium hypochlorite disinfectant, peeling, wiping into filaments with a filament wiper, sterilizing with 0.05g/L sodium hypochlorite solution, spin-drying, respectively adding pre-chilled water, 0.6g/L furanone solution, 0.6g/L chicory ketone solution, 0.3g/L furanone+0.3 g/L chicory ketone mixed solution, 0.2g/L furanone+0.2 g/L chicory ketone+0.2 ml/L soy sauce ketone mixed solution, soaking for 10min, spin-drying water, packaging into polyethylene bags, folding the bag openings, and placing into a refrigerator for observation at 2-4 ℃.

As shown in FIG. 18, the potato flakes soaked with water had been browned for half a day, but the potato flakes soaked with the water had not been browned for more than 10 days on day 10, with the furanone solution of 0.6g/L, the chicory ketone solution of 0.6g/L, the furanone+0.3 g/L, the chicory ketone mixture solution of 0.2g/L, the furanone+0.2 g/L, and the soy sauce ketone mixture solution of 0.2 ml/L. After different kinds of solutions are mixed to the same concentration, the browning inhibition effect is not obviously weakened or enhanced.

The invention discovers that the furan ring can interact with PPO for the first time; further, the inventor finds that the furan compound plays a certain role in inhibiting enzymatic browning of fruits and vegetables, and one or a mixture of more than two of furanone, chicory ketone, soy sauce ketone, 2-amyl furan and ethyl trigonelline is used for carrying out color protection treatment on fruits and vegetables, so that the browning of various complete fruits and vegetables, tissues of fruits and vegetables and slurry thereof can be inhibited, the quality of fruits and vegetables is improved, and the shelf life of fruits and vegetables is prolonged. The method for inhibiting the color change of the fruits and vegetables is simple to operate, has obvious browning inhibiting effect, is safe in source of furan compounds, low in cost, can be used for industrial production, and is suitable for large-scale application.

Claims

1. Furan compound or furan compound composition is used for fresh-keeping of fruits and vegetables.

2. Furan compound or furan compound composition is used for inhibiting the application of fruit and vegetable discoloration.

3. The use according to claim 2, wherein the furans or the combination of furans is used to inhibit enzymatic browning of fruits and vegetables.

4. The use according to claim 1 or 2, wherein the furans comprise one of furanones, chicory ketones, soy ketones, 2-amyl furan, ethyl trigonelline; the furan compound composition comprises two or more of furanone, chicory ketone, soy sauce ketone, 2-amyl furan and ethyl trigonelline;

preferably, the furans are furanone, chicory ketone and soy sauce ketone, and the concentration used during soaking or spraying is more than 0.01 g/L;

preferably, the concentration of furanone, chicory ketone and soy sauce ketone solution used for soaking is more than 0.45g/L, more than 0.08g/L and more than 0.45g/L respectively; the concentration of furanone, chicory ketone and soy sauce ketone solution used for spraying is above 0.8 g/L;

preferably, the concentration of furanone, chicory ketone and soy sauce ketone solution used for soaking is respectively 0.45-1.5g/L, 0.08-1.5g/L and 0.45-1.5g/L; the concentration of furanone, cichorione and soy sauce ketone solution used for spraying is 0.8-2.5g/L.

5. The use according to claim 1 or 2, wherein the fruit and vegetable morphology comprises intact fruit and vegetable individuals, fruit and vegetable tissue, fruit and vegetable pulp;

preferably, the fruit and vegetable tissue comprises fruit and vegetable slices, fruit and vegetable shreds and fruit and vegetable blocks;

preferably, the fruits and vegetables are potatoes, lettuce, eggplants, lettuce, apples, bananas, peaches and pears.

6. A fruit and vegetable preservative is characterized in that the effective component comprises furan compounds or a furan compound composition;

preferably, the furan compound comprises one of furanone, chicory ketone, soy sauce ketone, 2-amyl furan and ethyl fenugreek lactone; the furan compound composition comprises two or more of furanone, chicory ketone, soy sauce ketone, 2-amyl furan and ethyl trigonelline.

7. A fruit and vegetable color fixative is characterized in that the effective component comprises furan compounds or a furan compound composition;

8. A method for inhibiting enzymatic browning of fruits and vegetables, comprising the steps of:

or furan compounds or furan compound composition is directly added into fruit and vegetable slurry or fruit and vegetable powder;

preferably, in the method, furan compounds or furan compound combinations are dissolved by absolute ethyl alcohol to prepare mother liquor; and dissolving the mother solution into water, and uniformly mixing for use.

9. The method of claim 8, wherein the furans comprise one of furanones, chicory ketones, soy ketones, 2-amyl furan, ethyl trigonelline; the furan compound composition comprises two or more of furanone, chicory ketone, soy sauce ketone, 2-amyl furan and ethyl trigonelline;

10. The method of claim 8, wherein the furans of the soaking process are soaked for 1s to 50min;

preferably, the soaking time of the furan compound is 3-15min;

preferably, the soaking temperature in the soaking process is 0-50 ℃;

preferably, the soaking temperature is 2-4 ℃.