LU102718B1 - Pre-harvested Fruit microbial inhibition Preservative Agent, Post-harvested Fruit Ethylene Inhibitory Preservative Agent and Combined Application Method Thereof - Google Patents

Abstract

The pre-harvested fruit microbial inhibition preservative agent is a spraying solution including an active ingredient of Na-lauroyl-basic amino acid alkyl ester. An active ingredient of the post-harvested fruit ethylene inhibitory preservative agent is a cyclopropene ethylene receptor competitive inhibitor. The method has the following steps: before fresh fruits are harvested, selecting the fresh fruit with a maturity of 70% to 90% and spraying the pre-harvested fruit microbial inhibition preservative agent; after the fresh fruits are harvested, pre-cooling the fresh fruits, and adopting the post-harvested fruit ethylene inhibitory preservative agent for treatment. The present invention not only enhances the yield and quality of high-quality fruits in pre-harvest production, but also meets requirements of storage and preservation of post-harvested fruits. Further, in the present invention significantly inhibits the occurrence of pathogenic microorganisms or decaying microorganisms, reduces the decay rate and the drop rate of the post-harvested fruits, and delays fruit quality decline.

Description

Description LU102718 Pre-harvested Fruit microbial inhibition Preservative Agent, Post- harvested Fruit Ethylene Inhibitory Preservative Agent and Combined Application Method Thereof

TECHNICAL FIELD The present invention relates to the technical field of fresh fruit preservation, and particularly, to a pre-harvested fruit microbial inhibition preservative agent, a post-harvested fruit ethylene inhibitory preservative agent and a combined application method thereof.

BACKGROUND The global fresh fruits have planting area of5.6523 million hectares and yield of 723 million tons. However, most fruits with high added value are perishable and are prone to being overripe and senescence during storage, resulting in a decline in sensory quality and nutritional value. In order to improve storability, modified atmosphere storage, coating storage, or pesticide soaking treatment are methods commonly used for preservation. The application of the modified atmosphere storage is restricted in production practice because of costs of one-time facility, operation and maintenance. However, preservation and storage of a coating film is limited by cost of additional treatment facility and limited selectable coating agents for widely promotion and application in actual production. Therefore, simple and easy-to-operate treatment by a preservative agent becomes the most widely accepted production practical technology for practitioners and even agricultural product treatment enterprises. However, currently used soaking liquids for fruit preservation are mainly microbial inhibition pesticides, such as carbendazim, thiophanate, LU102718 imazalil, prochloraz, sulfur dioxide, iprodione, and triflumizole. Although the pesticide soaking treatment can effectively alleviate diseases and spoilage caused by microorganisms during storage of fresh fruits, pesticide soaking can cause residuals, and more importantly, involves risks in food safety and human health.

In order to solve a dilemma of safety risks caused by pesticide preservation, traditional antiseptic and microbial inhibition food additives such as paraben and benzoate have been tried as the alternatives of pesticides for preservation. However, unlike non-fresh food matrixes, compounds of traditional food additives are difficult to achieve the desired objectives in terms of safety and long-term effectiveness in the preservation of fresh fruits and vegetables. On the one hand, the traditional food additives that are used as preservative agents for the fresh fruits and vegetables often require repeated applications to maintain the long-term effectiveness. On the other hand, a plurality of food additives have phytotoxicity to the fresh fruits and vegetables when used as the preservative agents, which reduces product quality, especially during repeated applications. In view of this, the traditional antiseptic and microbial inhibition food additives in the storage and preservation of the fresh fruits and vegetables have very limited effects. Currently, the fresh fruits and vegetables usually uses post-harvest treatment for preservation. For example: Chinese patent CN1806573A had discloses bayberry preservation technology, which includes the following steps: (1) pretreating, grading and selecting post-harvested bayberry fruits; (2) spraying and coating the bayberry fruits with a mildew-retarding agent and then packing the bayberry fruits into small boxes, wherein the mildew-retarding agent contains natamycin, sec- LU102718 butylamine, and citric acid; (3) storing the bayberry fruits with a low-temperature film of an initial concentration of 2% of CO2 and an initial concentration of 4% of O2 under modified atmosphere, and adding 1-methylcyclopropene; (4) storing and transporting the bayberry fruits at a temperature of 0°C~2°C after pre-cooling. In addition, the bayberry fruits are mulched under a tree 5 days before harvesting to control the fruits to excessively absorb water in rain before harvest. Pre-harvest pre-treatment is as follows: applying a mixture of calcium phosphate and calcium carbonate of fertilizers before harvest. Although the patent has a plurality of pre-harvest measures, the patent belongs to a category of fertilizer and water management, and preservation technology of the patent still belongs to post-harvest treatment.

In addition, Chinese patent CN101965861A had disclosed a treatment method for prolonging a freshness lifetime of sand pears. The picked sand pears are pre-cooled, placed in a closed room and fumigated with 1-MCP, then treated with Os once, and finally stored with a microporous film preservation bag at room temperature or at a temperature of 3~5°C. This method is a post- harvest preservation treatment method, and but it is difficult to grasp a treatment concentration of Os and hence easily cause damage to fruits.

Further, Chinese Patent CN106259874A had disclosed a preservative agent for grapes, including the following raw materials: a clove extract, calcium chloride, vitamin C, potassium sorbate, a chitosan citric acid solution. Grapes are soaked in a preservation liquid for 3~6 min after picking. The grapes are taken out, drained, and pre-cooled to a temperature of 0~4°C within 12 h, and packed in a PE bag to keep the grapes fresh. This post-harvest preservation treatment method is complicated in procedures and easily causes grape LU102718 particles to fall off, and the grapes have the preservation effect that is still not good.

Another Chinese patent CN104126654A had disclosed a method for preserving blueberries, including the following steps: (1) soaking fresh blueberries in a starch paste and then washing the fresh blueberries with clear water; (2) putting the treated blueberries in an preservative agent solution (an extract solution for tangerine peel and Eupatorium adenophorum), then drying the surface of blueberries, and putting the blueberries into a perforated air- permeable plastic box; (3) wrapping the plastic box containing blueberries in step (2) with a preservative film; (4) storing the wrapped blueberries in step (3) at a temperature of 2-10°C for refrigeration. The patent uses comprehensive treatments of starch cleaning, preservation liquid treatment, preservation film covering and refrigeration to prolong the freshness lifetime of the blueberries. The method uses a series of post-harvest treatments to keep blueberries fresh with complicated operating procedures and cannot change original picking and storage quality of the blueberries.

In summary, it is very significant to develop a safe and green preservative agent that can effectively prevent and inhibit pathogenic fungi and spoilage microorganisms, resist over-ripening and senescence, and improve the quality of fruits before harvest and extend a storage period after harvest to replace pesticides banned within two weeks before harvest, replace the post-harvest soaking of a pesticide microbial inhibition agent with potential safety hazards, increase a proportion of high-quality fruits and storage quality of harvested fruits and vegetables, hence delay the senescence of fruits after harvest, and thus LU102718 extend a shelf life of storage.

SUMMARY The technical problem to be solved by the present invention is to provide a fruit preservative agent with better fresh-keeping effect and safety to a human body and a combined application method thereof based on the current state of the prior art.

In order to achieve the forgoing objectives, the present invention provides the following solutions: The present invention provides a pre-harvested fruit microbial inhibition preservative agent, including a spraying solution whose active ingredient is Na- lauroyl-basic amino acid alkyl ester. The Na-lauroyl-basic amino acid alkyl ester has a chemical name in the following: R1 3-R2-2-dodecanamidopropanoate Where Rı is an alkyl group with carbons in a number of 2 to 4, and Ra is one of guanidine propyl, amine butyl, and imidazole methyl. R1 and Ra have chemical names in the following: R1=CH2CH3 CH2CH2CH3 CH2CH2CH2CH3 R2= 1. Amino (ethylamino) methaniminium

2. Propan-1-aminium

3. 4-methyl-1H-imidazol-3-ium

Further, the Rı is ethyl, and the Ra is guanidine propyl, that is, the Na- LU102718 lauroyl-basic amino acid alkyl ester is LAE, and a spraying solution of the Na- lauroyl-basic amino acid alkyl ester is a LAE spraying solution. Because guanidine propyl and carbethoxy included in the LAE are stronger hydrophilic, the LAE has better solubility and a better preservation effect.

Further, a Na-lauroyl-basic amino acid alkyl ester spraying solution has a concentration of 0.05-5.0 g/L, preferably 0.1-1.0 g/L. If a spraying concentration is too low, an effective dose cannot be reached, which affects a preservation effect. If the spraying concentration is too high, the fresh fruits and vegetables are affected by phytotoxicity because of the excessively high cationic surfactant concentration.

The present invention also provides a method for preparing a pre- harvested fruit microbial inhibition preservative agent, including the following steps: (a) dissolving a weighed Na-lauroyl-basic amino acid alkyl ester powder in a low-polarity solvent to obtain a mother liquid A; (b) mixing the mother liquid A with water to obtain a Na-lauroyl-basic amino acid alkyl ester spraying solution or the mother liquor A, and mixing another compounded preservative agent with water to obtain a compounded spraying solution. Another preservative agent is a conventional fruit preservative agent, such as anatase nano-TiO2, that is, the Na-lauroyl-basic amino acid alkyl ester powder of the present invention can be used alone as an preservative agent, or can be used preservative after being compounded with other kinds of preservative agents.

Further, the low-polarity solvent is one of ethanol, glycerin, and propylene LU102718 glycol.

The present invention provides a post-harvested fruit ethylene inhibitory preservative agent, of which active ingredient is a cyclopropene ethylene receptor competitive inhibitor. Cyclopropene has a content of active ingredients of 0.5 wt% to 5 wt%.

Further, the cyclopropene ethylene receptor competitive inhibitor includes 1-methylcyclopropene (1-MCP) or 1-methyl-3-(2-methylcyclopropane)-1- cyclopropene (1 -MMCPCP).

Further, for fruits aiming at preserving kernels, the cyclopropene ethylene receptor competitive inhibitor is 1-methylcyclopropene (1-MCP); for fruits aiming at preserving stalks, stems, and pedicles, the cyclopropene ethylene receptor competitive inhibitor is 1-methyl-3-(2-methylcyclopropane)-1- cyclopropene (1-MMCPCP).

Further, the active ingredient is enclosed and solidified by a water-soluble polysaccharide matrix. The water-soluble polysaccharide matrix includes but is not limited to a-cyclodextrin and O-cyclodextrin.

Further, the active ingredients are mixed with an plant essential oil with an microbial inhibition activity after being separately enclosed, and the plant essential oil includes but is not limited to an oregano essential oil, an orange essential oil, a laurel essential oil, a walnut essential oil and the like.

The present invention still provides a method for preparing a pre-harvested fruit microbial inhibition preservative agent and a post-harvested fruit ethylene inhibitory preservative agent, including the following steps: before a fresh fruit is harvested, selecting fresh fruits with a maturity of 70% to 90% and spraying the pre-harvested fruit microbial inhibition preservative agent; after the fresh LU102718 fruit is harvested, pre-cooling the fresh fruits, and treating the fresh fruits with the post-harvested fruit ethylene inhibitory preservative agent.

Further, the time period from 8 to 12 o'clock in the morning on a sunny day is selected to harvest the fresh fruits. Before harvesting the fresh fruits, the pre- harvested fruit microbial inhibition preservative agent is prepared for the first time; the pre-harvested fruit microbial inhibition preservative agent is sprayed, and then the fruits are harvested; pre-cooling treatment is performed after harvest, and the fresh fruits are treated with the post-harvested fruit ethylene inhibitory preservative agent.

Further, the pre-harvested fruit microbial inhibition preservative agent is sprayed within 24 hours after the pre-harvested fruit microbial inhibition preservative agent is completely prepared. The fruits are harvested after two hours after completely spraying the pre-harvested fruit microbial inhibition preservative agent. The post-harvested fruit ethylene inhibitory preservative agent is treated after at least two hours after the pre-cooling is completed.

Further, the post-harvested fruit ethylene inhibitory preservative agent includes the following treatment steps: When the fruits that need to be kept fresh are a respiratory jump type, the post-harvested fruit ethylene inhibitory preservative agent is put in a container, water is added for airtight fumigation treatment. 0.3-1g of the post-harvested fruit ethylene inhibitory preservative agent is added for every 10-50 kg of fruits. Airtight fumigation treatment is performed for 6~24 h; or the fruits are putin a pre-cold room. An open container is put in the pre-cold room. The post- harvested fruit ethylene inhibitory preservative agent is put in the open container. The post-harvested fruit ethylene inhibitory preservative agent has LU102718 an adding amount of 0.5-2g/m°. After water is added to the open container, the pre-cooling room is closed and fruits are treated for 10-30 h.

When the fruits that need to be kept fresh are a non-respiratory jump type, the pre-cooling is performed. The fruits and the post-harvested fruit ethylene inhibitory preservative agent are put together in a sealed bag, and 0.3-1g of the post-harvested fruit ethylene inhibitory preservative agent is added for every 10-50 kg of the fruits, and sealed.

The present invention discloses the following technical effects:

1. The present invention performs pre-harvest treatment with a spraying solution of Na-lauroyl-basic amino acid alkyl ester. Na-lauroyl-basic amino acid alkyl ester is a kind of food preservative agent with high safety and a high microbial inhibition activity. The main microbial inhibition mechanism of the food preservative agent is that an amphiphilic compound is inserted into a phospholipid bilayer of a microorganism cell membrane as positive ions, reducing integrity of the cell membrane, increasing membrane permeability, and hence causing the leakage of intracellular substances to kill bacteria. Further, the preservative agent can be quickly degraded in a human body, and intermediate metabolites and final products thereof are natural endogenous products, which are safe for the human body. However, studies have found that Na-lauroyl-basic amino acid alkyl ester as a soaked post-harvested preservative agent causes phytotoxicity to fresh fruits and accelerates the occurrence of fruit softening and rot if the preservative agent is not handled properly. The present invention uses pre-harvest spraying means, avoiding this problem and achieving a good preservation effect.

2. Pre-harvest and post-harvest treatments are performed at the same LU102718 time, which not only improves proportion and quality of high-quality pre- harvested fruits, but also meets requirements of post-harvested fruit storage and preservation, significantly inhibiting pathogenic microorganisms or decaying microorganisms, and reducing or decreasing a fruit decay rate and a fruit drop rate after harvest, delaying decline of fruit quality. Further, the preservation effect is significantly better than conventional post-harvest preservation treatment technology.

3. In the present invention, the cyclopropene ethylene inhibitor is used after harvest, and is used in cooperation with the Na-lauroyl-basic amino acid alkyl ester before harvest. In addition, an inclusion-curing type cyclopropene preservative agent is used in different ways to adapt to the fruits of the respiratory jump type and the non-respiratory jump type respectively. A cyclopropene ethylene inhibitor mainly acts on an ethylene receptor irreversibly, thereby blocking normal binding with ethylene, controlling the decrease in hardness of the fruits, and delaying senescence of the fruits, while Na-lauroyl-basic amino acid alkyl esters mainly acts as an microbial inhibition effect, and inhibits rot caused by microorganism diseases. Both have a synergistic effect on improving hardness and disease resistance of the fruits, which can further reduce a decay rate and improve a preservation effect.

DESCRIPTION OF THE INVENTION Various exemplary embodiments of the present invention are described in detail. The detailed description should not be considered as a limitation to the present invention, but should be understood as a more detailed description of certain aspects, characteristics, and embodiments of the present invention.

It should be understood that the terms described in the present invention LU102718 are only used to describe specific embodiments and are not used to limit the present invention. In addition, a numerical range in the present invention should be understood that each intermediate value between the upper limit and the lower limit of the range is also specifically disclosed. Each smaller range between any stated value or an intermediate value within the stated range and any other stated value or an intermediate value within the stated range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by the person skilled in the art to which the present invention belongs. Although the present invention only describes preferred methods and materials, any method and material similar or equivalent to those described herein can also be used in the practice or test of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe methods and/or materials related to the documents. In case of conflict with any incorporated document, the contents of this specification shall prevail.

Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific embodiments of the specification of the present invention, which is obvious to the person skilled in the art. Other embodiments derived from the specification of the present invention will be obvious to the person skilled in the art. The specification and embodiments of the present invention are only exemplary.

As used herein, "including", "comprising", "having", "containing", etc., are LU102718 all open terms, which mean including but not limited to.

Embodiment 1 (a). A LAE (R1 was ethyl, Ra was guanidine propyl) spraying solution with a concentration of 1.5¢g/L was prepared.

(b). Within 24 hours after completion of step (a), 20-year-old greenhouse bayberries with a maturity of 90% whose variety was water chestnut species were selected. The LAE spraying solution prepared in step (a) was sprayed evenly on the surfaces of bayberry fruits in the morning on a sunny day. It was advisable to make the fruit surface moist; (c). Harvest was carried out after at least 3 hours after completion of step (b). The operator wore latex gloves and manually picked the bayberries and temporarily stored the bayberries in a turnover basket.

(d). After pre-cooling was performed for four hours at an environment at a temperature of -2+2°C, 1g/15kg of a use amount of the bayberries, clumped solidified powder of B-cyclodextrin with 3% 1-MCP content, and post-harvested treated bayberries were put together in a plastic bag. A mouth of the bag was folded and the bag was boxed. Then, express delivery of the bayberries were performed for 1 d, 2 d, and 3 d, respectively.

A method for preparing the forgoing 1.5g/LLAE spraying solution was as follows: (a) fully dissolving 15009 of a LAE powder in 10L ethanol to obtain a mother liquid A; (b) adding the mother liquor A to 1000L of water while bubbling. In addition, other formulations that can obtain a 1.5g/LLAE spraying solution were also feasible, and the ethanol in step (a) could also use other low-polar solvents LU102718 such as glycerol and propylene glycol.

A method for preparing 1.5g/L of a LAE spraying solution was similar to that of Embodiment 1, and was not repeated here.

Transportation results are shown in Table 1: Table 1: Quality indexes of bayberries after road transportation The Mildew | Hardnes | Soluble | Titratable | Reducing | Vc (mg / number of| rate s (g) solids acid sugar 100g)

RTE EE Embodiment 15 (eos) ss rase | we | east] TE reflecting a freshness preservation effect in Table 1 are mainly a mildew rate (%) and hardness (g). From Table 1, it can be seen that Embodiment 1 has a lower mildew rate and higher hardness than those of a control group (blank, untreated) during the same number of days.

Embodiment 2 (a). À LAE (R1 was ethyl, Ra was guanidine propyl) spraying solution with a concentration of 0.1g/L was prepared.

(b). Within 24 hours after completion of step (a), a pear with a maturity of 80% whose variety was Cuiguan was selected. The LAE spraying solution prepared in step (a) was sprayed evenly on a surface of the pear in the morning on a sunny day.

(c). Harvest was performed after at least 4 hours after completion of step LU102718 (b). Scissors were used to cut stalks of pear fruits and place the stalks in a turnover basket with a cushion: (d). Within two hours after completion of step (c), the 1-MCP solidified powder (1-MCP content was greater than 3%) enclosed by a-cyclodextrin was moistened and put in a polyethylene bag together with the stacked pears. The preservative agent powder had a usage amount of 19/30kg of pears. Airtight fumigation was performed for 24h. Pre-cooling was performed in a pre-cooling room at a temperature of 2+2°C for 3-4h before implementation of step (d). Then storage was performed in a cool room at a temperature of 0+2°C. A storage test was then performed.

A method for preparing the 0.1g/L LAE spraying solution was similar to that of Embodiment 1, and was not repeated here.

Storage results are shown in Table 2: Table 2: Quality indexes of pears when stored for 60 days © Decay Wrinkle Soft HardnessSoluble Titratable Polyphenol Peroxidase rate rate fruit (9) solids acid oxidase (U/9g) (%) (%) rate g/100g (U/9) Embodiment 0.00 0.00 0.00 218.56 12.5 8.299 4.8977 601.49 Control group4.17 12.50 4.17 174.92 12.2 7.299 9.2593 694.37 aan aan be seen from Table 2 that he pears Teated in Embodiment Zhadno fruits with rot and wrinkled skins and soft fruits after 60 days of storage, and maintained good hardness and flavor. The preservative agent had a good inhibitory effect on polyphenol oxidase and peroxidase activity. On the other hand, a control group (blank, untreated) had rotten and soft fruits, and the wrinkled skin was more obvious. The hardness and flavor were significantly decreased, and the activities of polyphenol oxidase and peroxidase were LU102718 significantly increased.

Embodiment 3 (a) A LAE (R1 was ethyl, Ra was guanidine propyl) spraying solution with a concentration of 0.5g/L was prepared.

(b) Within 24 hours after completion of step (a), grapes with a maturity of 70% whose variety was Yongyou No. 1 were selected. The LAE spraying solution prepared in step (a) was sprayed evenly on surfaces of the grapes in the morning on a sunny day.

(c) Harvest was performed after at least three hours after completion of step (b). Scissors or harvesting machinery were used to harvest bunches of grapes and lie the grapes flat on a box body covered with a cushion. During this time, a stack height of the grapes was controlled to ensure the harvested stacked grapes were well ventilated; (d) Within two hours after completion of step (c), a 1-MMCPCP solidified powder enclosed by B-cyclodextrin (1-MMCPCP content was greater than 3%) was moistened and placed in a polyethylene bag together with the stacked grapes. An preservative agent has a usage amount of 1g/25kg of the grapes. Airtight fumigation was performed for 24h, pre-cooling was performed in a pre- cooling room at a temperature of 0+2°C before implementation of step (d). Then storage was performed in a cold room at a temperature of 0+2 °C.

A storage test was then performed.

The method for preparing the 0.5g/L LAE spraying solution was similar to that of Embodiment 1, and was not repeated here.

Storage results are shown in Table 3:

Table 3: Quality indexes of grapes stored for 50 days LU102718 ~~ Decayrate (%) Fruit dropPolyphenol MalondialdehydeTitratable — rate oxidase (umol/g) acid (%) (U /9) (mg/kg) Embodiment 3 22.0802 18.1142 3.727633 0.150019 4.3769 Control group33.4873 23.951 3.881133 1.46401 41773 sown in Table 3, can be seen Tat The method used in Embodiment 3 had a better control effect on a decay rate and a fruit drop rate (related to preservation of fruit stems) compared with a control group (blank, untreated, direct storage). Polyphenol oxidase had a lower activity, a better browning inhibitory effect and a lower malondialdehyde content. Malondialdehyde indicated a peroxidation degree of a membrane lipid, indicating that grapes suffered from lower oxidative damage. The highest titratable acid content meant that the grape flavor had better retention performance.

Embodiment 4 (a). Selected Na-lauroyl-basic amino acid alkyl ester was Na-lauroyl-lysine propyl ester (LLP) with a concentration of 5.0g/L (R1 was propyl, Ra was amine butyl), and compounded with 1.0g/L of anatase nano-TiOa.

(b). Within 24 hours after completion of step (a), rabbit-eye blueberries with a maturity of 70% was selected. À compound spraying solution prepared in step (a) was sprayed evenly on surfaces of blueberries in the morning of the first day of two consecutive sunny days.

(c). After 20 hours after completion of step (b), water or 0.1% potassium dihydrogen phosphate was sprayed to supplement a large amount of H20 and nutrient supply required by nano-TiO2 because of enhanced photosynthesis. Harvest was performed after 48 h. The operator wore latex gloves and manually picked and placed the blueberries in a box;

(d). Within two hours after completion of step (c), the 1-MCP solidified LU102718 powder (1-MCP content was greater than 3%) enclosed by B-cyclodextrin was moistened and the blueberries that need to keep fresh were put together and enclosed in a polyethylene bag. The preservative agent had a usage amount of 19/25kg of the blueberries. Airtight fumigation was performed for 12 h, and pre-cooling was performed in a pre-cooling room at a temperature of 1+2°C before implementation of step (d). Then storage was performed at a temperature of 1+2°C.

A method for preparing the forgoing compound spraying solution was as follows: (a) fully dissolving a 5kg LLP powder in 20L glycerol to obtain a mother liquid A; (b) adding the mother liquid A and 1kg of an anatase nano-TiO2 powder into 1000L of water while bubbling.

Storage results are shown in Table 4: Table 4: Quality indexes of blueberries when stored for 20 days ~~ Soft HardnessSolubleMoistureReducingTitratablePolyphenolPeroxide — fruit +g solids (%) sugar acid oxidase (U/g) decay 0/1009 (U/g) rate (%) 9/1009 Embodiment 11.73 203.66 14.02 82.05 11.65 6.21 18.49 765.65 Control group53.59 170.18 16.10 82.88 11.14 6.48 39.70 858.41 (blank) Main items showing a preservation effect in Table 4 were as follows: soft fruit + decay rate, hardness, and polyphenol oxidase and peroxidase that reflect a degree of browning. It can be seen from Table 4 that compared with a control group (blank, untreated), Embodiment 4 had the soft fruit + low decay rate, high hardness, low activity of two enzymes related to enzymatic browning, and the LU102718 best preservation effect.

Embodiment 5 (a) A LAE (R1 was ethyl, Ra was guanidine propyl) with a concentration of

0.5g/L and a potassium sorbate compound spraying solution with a concentration of 0.1g/L were prepared.

(b) Within 24 hours after completion of step (a), a Hongyang kiwi fruit with a maturity of 80% was selected, and a compounded spraying solution prepared in step (a) was sprayed evenly on surfaces of the kiwi fruits in the morning on a sunny day; (c) Harvest was performed after at least 3 hours after completion of step (b). The operator wore latex gloves and picked the kiwi fruits from pedicles, and then spread the kiwi fruits in a single layer in a submerged frame with a cushion.

(d) Within 2 hours after completion of step (c), a 1-MCP (1-MCP content was greater than 3%) powder enclosed by fB-cyclodextrin and a solidified powder compounded with a volatile orange essential oil were moistened, and the stacked kiwifruits that need to keep fresh were put together in a polyethylene bag. The preservative agent had a usage amount of 1g/40kg of the kiwi fruits. The kiwi fruits were enclosed for 18 h, and pre-cooling was performed in a pre-cooling room at a temperature of -2+2°C before implementation of step (d). Then storage was performed in a cool room at a temperature of -2+2°C.

A storage test was then performed.

A method for preparing the forgoing compound spraying solution was follows:

(a) fully dissolving 500g of a LAE powder in 10L ethanol to obtain a mother LU102718 liquid A; (b) adding the mother liquid A and 100g of a potassium sorbate powder to 1000L of water while being stirred with an electric stirrer for 2 min.

Storage results are shown in Table 5: Table 5: Quality indexes of kiwi fruits when stored for 60 days “ DecayHardness CrispnessBrightness DPPH Malondialdehyde Polyphenol rate (9) ©) (%) (umol/L) oxidase (%) (U/g) Embodiment 8 62.12 605.05 60.90 0.82 0.60 0.26 Control 20 52.08 404.28 57.75 0.64 0.68 2.36 group (blank) It can be seen from the results in Table 5 that a decay rate of Embodiment was lower than that of a control group (blank, untreated). The hardness and crispness were higher than those of the control group. The browning inhibition represented by a color difference brightness was also better than that of a control group in Embodiment 5. A scavenging rate of a DPPH free radical, which represented an antioxidant capacity of the fruits, was better than that of the control group. A malondialdehyde index of Embodiment 5, which represented a degree of oxidative damage, was lower than that of the control group. A polyphenol oxidase activity index of Embodiment 5, which represented a level of oxidative stress and enzymatic browning, was lower than that of the control group.

Embodiment 6 A difference from Embodiment 3 was that a LAE spraying solution in step (a) had a concentration of 0.2g/L. A material for preservation in step (b) was ten-year-old oranges with a maturity of 80% whose variety was Gongchuan. After pre-cooling was performed in a pre-cooling room at a temperature of 4°C for 8 h before implementation of step (d), a solidified powder (1-MMCPCP LU102718 content was 3.5% and the oranges had an amount of 1g/20kg) enclosed by a- cyclodextrin was put into a polyethylene bag together with pre-harvested treated harvested oranges. A mouth of a bag was folded and storage was performed. A storage test was then performed at a temperature of 0+1°C.

A method for preparing the 0.2g/L LAE spraying solution was similar to that of Embodiment 1, and was not repeated here.

Storage results are shown in Table 6: Table 6: Quality indexes of oranges when stored for 30 days © Decay HardnessSoluble Water loss rate Reducing Titratable rate g solids (%) sugar acid (%) (g/1009) (9/1009) Embodiment 6 3.02 61.48 9.78 1.46 7.56 1.22 Control group10.14 27.4 7.93 2.21 4.98 0.95 (blank) It can be seen from the results in Table 6 that during storage in 30 days, a water loss rate and a decay rate of Embodiment 6 were significantly reduced compared with those of a control group (blank, untreated). Fruits were hard. The content of reducing sugar and titratable acid was maintained, and flavor thereof was maintained. Hardness and the titratable acid of the control group were decreased significantly at a 30-th day.

Embodiment 7: A difference between Embodiment 7 and Embodiment 5 was that a LAE spraying solution in step (a) had a concentration of 0.2g/L. A material for preservation in step (b) was 8-year-old Chinese cherries with a maturity of 80% whose variety was short-stalked cherries. An preservative agent used in step (d) also included a laurel essential oil, and had a usage amount of 1g/25kg of the cherries.

Storage results are shown in Table 7:

Table 7: Quality indexes of cherries when stored for 20 days LU102718 Soft Hardne SolubleMoistu Reduci TitratablMalondialdehy PolyphenoPeroxid fruit +ss(g) solids re ng e acid de | oxidase ase decay (%) sugar (g/kg) (umol/g) (u/g) (u/g) rate (g/100 (%) 9) Embodi 6.44 167.25 10.7 91.35 7.97 6.94 0.0161 20.53 88.57 ment 7 Control 34.99 118.53 9.52 91.74 8.49 5.55 0.0179 55.50 120.95 group (blank) It can be seen from Table 7 that after 20 days of storage, soft fruits + decay rate of cherries of Embodiment 3 was significantly lower than those of a control group and was lower than those during implementation of the method. In addition, the cherries of Embodiment 3 were harder. An enzyme activity thereof was lower than that of the control group. Quality thereof was improved, and flavor thereof was maintained unchanged.

Embodiment 8 (a) Selected Na-lauroyl-basic amino acid alkyl ester was Na-lauroyl- histidine butyl ester (LHB) with a concentration of 5.0g/L (R1 was butyl, Ra was imidazole methyl), and compounded with 1.0g/L potassium sorbate.

(b) Within 24 hours after completion of step (a), Yulu flat peaches with a maturity of 80% were selected, and a compounded spraying solution prepared in step (a) was sprayed evenly on surfaces of fruits before 10:00 AM on a sunny day.

(c) After more than 4 hours after completion of step (b), the operator wore latex gloves to pick the fruits and spread the fruits in a single layer of a shallow frame, and then move the fruits into a pre-cooling room. A 1-MCP solidified powder (1-MCP content was greater than 3%) enclosed by B-cyclodextrin was put into a polyethylene bag after being moistened together with the flat peaches that need to keep fresh. The 1-MCP solidified powder had a usage amount of

1g/15kg of the flat peaches. In addition, after pre-cooling was performed for 8 LU102718 hours, 1-MCP was removed into a storage room at a temperature of 1~5°C A method for preparing the forgoing compound spraying solution was as follows: (a) fully dissolving 5kg of a LHB powder in 20L ethanol to obtain a mother liquid A; (b) adding the mother liquid A and 1kg of a potassium sorbate powder to 1000L of water while bubbling.

Storage results are shown in Table 8: Table 8: Quality indexes of flat peaches stored for 15 days © Decay HardnessSoluble solids Reducing Titratable = Malondialdehyde rate g sugar acid (umol/g) (%) g/100g g/100g Embodiment 41 49 14.8 3.37 3.98 0.002 Control group100 15 13.2 2.66 3.04 0.028 (blank) The items showing the preservation effect in Table 8 are mainly as follows: a decay rate, hardness; soluble solids, a reducing sugar and titratable acid reflecting taste of the flat peaches; and malondialdehyde reflecting a degree of oxidation of a membrane lipid. It can be seen from Table 8 that compared with a control group (blank, untreated), Embodiment 8 could greatly reduce the decay rate, maintain the hardness and taste of the fruits, and reduce oxidative stress on the fruits during storage.

The forgoing embodiments only describe the preferred implementations of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, the person skilled in the art can make variations and improvements to the technical solutions of the present invention, which should fall within the protection scope LU102718 determined by the claims of the present invention.

Claims (10)

CLAIMS LU102718

1. À pre-harvested fruit microbial inhibition preservative agent, comprising a spraying solution whose active ingredient is Na-lauroyl-basic amino acid alkyl ester, wherein the Na-lauroyl-basic amino acid alkyl ester has a chemical name in the following: R1 3-R2-2-dodecanamidopropanoate where R1 is an alkyl group with carbons in a number of 2 to 4, and Ra is one of guanidine propyl, amine butyl, and imidazole methyl.

2. The pre-harvested fruit microbial inhibition preservative agent according to claim 1, wherein the R1 is ethyl and the Ra is guanidine propyl.

3. The pre-harvested fruit microbial inhibition preservative agent according to claim 1, wherein a spraying solution has a concentration of 0.05~5.0g/L.

4. A post-harvested fruit ethylene inhibitory preservative agent, wherein an active ingredient thereof is a cyclopropene ethylene receptor competitive inhibitor, and cyclopropene has a content of the active ingredient of 0.5 wt% to wt%.

5. The post-harvested fruit ethylene inhibitory preservative agent according to claim 4, wherein the cyclopropene ethylene receptor competitive inhibitor comprises 1-methylcyclopropene or 1-methyl-3- (2-methylcyclopropane)-1- cyclopropene.

6. The post-harvested fruit ethylene inhibitory preservative agent according to claim 5, wherein for fruits aiming at preserving kernels, the cyclopropene ethylene receptor competitive inhibitor is 1-methylcyclopropene; for fruits aiming a preserving stalks, stems, and pedicles, the cyclopropene ethylene receptor competitive inhibitor is 1-methyl-3-(2-methylcyclopropane)-1- LU102718 cyclopropene.

7. The post-harvested fruit ethylene inhibitory preservative agent according to claim 4, wherein the active ingredient is enclosed and solidified by a polysaccharide matrix.

8. The post-harvested fruit ethylene inhibitory preservative agent according to claim 7, wherein the active ingredient is mixed with a plant essential oil with an microbial inhibition activity after being separately wrapped.

9. A combined application method of a pre-harvested fruit microbial inhibition preservative agent and a post-harvested fruit ethylene inhibitory preservative agent, comprising the following steps: before fresh fruits are harvested, selecting the fresh fruits with a maturity of 70% to 90% and spraying the pre-harvested fruit microbial inhibition preservative agent according to claim 1; after the fresh fruits are harvested, pre-cooling the fresh fruits, and treating the fresh fruits with the post-harvested fruit ethylene inhibitory preservative agent according to claim 4.

10. The combined application method according to claim 9, wherein the post-harvested fruit ethylene inhibitory preservative agent comprises the following treatment steps: when the fruits that need to keep fresh are a respiratory jump type, after pre-cooling treatment is performed, the post-harvested fruit ethylene inhibitory preservative agent is put in a container, water is added and airtight fumigation treatment is performed, 0.3~1g of the post-harvested fruit ethylene inhibitory preservative agent is added for every 10-50kg of fruits; airtight fumigation treatment is performed for 6~24 h, or the fruits are put in a pre-cold room, an open container is put in the pre-cold room, the post-harvested fruit ethylene LU102718 inhibitory preservative agent is put in the open container; after the fruits are harvested, the ethylene inhibitory preservative agent has an adding amount of

0.5-2g/m°; after water is added to the open container, the pre-cooling room is closed and the fruits are treated for 10-30 h; when the fruits that need to keep fresh are a non-respiratory jump type, the pre-cooling is performed, the fruits and the post-harvested fruit ethylene inhibitory preservative agent are put together in a sealed bag, and 0.3-1g of the post-harvested fruit ethylene inhibitory preservative agent is added for every 10-50 kg of the fruits, and enclosed.