阅读说明：本技术 一种果实诱导着色剂 (Fruit inducing colorant ) 是由 王长清 郭徐澄 于 2019-10-18 设计创作，主要内容包括：本发明涉及到植物化控领域,具体涉及到一种果实诱导着色剂。一种果实诱导着色剂至少包括芸苔素内酯和/或S-诱抗素、茉莉酸类化合物、润湿剂、增溶剂、草木灰浸泡液等组分,通过组分之间的拮抗和协同作用,缩短了果实的成熟期,使果实外观色泽鲜艳,口感香甜,并延长了果实的耐贮藏性,同时不会引起植物叶片老化、果实过早脱落、植物早衰等现象,从整体上有效地调控了植物的生长机制。(The invention relates to the field of phytochemical control, in particular to a fruit-induced coloring agent. A fruit inducing colouring agent at least contains brassinolide and/or S-abscisic acid, jasmonic acid compound, wetting agent, solubilizer, plant ash soak solution, etc. through the antagonism and synergism between the components, the mature period of the fruit is shortened, the fruit is bright in appearance and luster, fragrant and sweet in taste, the storability of the fruit is prolonged, meanwhile, the phenomena of plant leaf aging, premature fruit falling, premature plant senescence, etc. are not caused, and the growth mechanism of the plant is effectively regulated and controlled as a whole.)

1. The composition is characterized by comprising brassinolide and/or S-abscisic acid and jasmonic acid compounds, wherein the weight ratio of the total sum of the brassinolide and/or the S-abscisic acid to the jasmonic acid compounds is 1 (10-100).

2. A fruit inducing coloring agent, wherein said coloring agent comprises the composition of claim 1, and said composition comprises from 2 to 50 weight percent of said coloring agent.

3. The fruit inducing colorant of claim 2, further comprising a wetting agent.

4. The fruit inducing colorant according to claim 3, wherein the wetting agent is a compound of a sulfonate wetting agent and a polycarboxylate wetting agent, and the weight ratio of the sulfonate wetting agent to the polycarboxylate wetting agent is (3-5): 1.

5. the fruit inducing colorant of claim 4, wherein the sulfonate wetting agent is selected from one or more of lignosulfonate, sodium dodecylbenzenesulfonate, sodium methylenedinaphthalene sulfonate, sodium dibutylnaphthalene sulfonate, castor oil sulfonate, tristyrylphenol polyoxyethylene ether sulfonate, alkylphenol polyoxyethylene ether sulfonate, succinate sulfonate, sodium tetrapropylbenzenesulfonate, sodium diisooctyl succinate sulfonate, sodium p-methoxyfatty amido benzene sulfonate, alkyl glyceryl ether sulfonate; the polycarboxylate wetting agent is selected from one or more of sodium polyacrylate, sodium polymethacrylate, acrylic acid-maleic anhydride copolymer, acrylic acid-itaconic acid copolymer, methacrylic acid-sodium styrene sulfonate copolymer, acrylic acid-maleic anhydride-sodium styrene sulfonate copolymer, acrylic acid-sodium styrene sulfonate-hydroxyethyl methacrylate copolymer, acrylic acid-sodium styrene sulfonate-hydroxypropyl acrylate copolymer, methacrylic acid-itaconic acid-sodium allyl sulfonate and methacrylic acid-styrene-hydroxypropyl acrylate copolymer.

6. The fruit inducing colorant according to claim 5, wherein the colorant further comprises a solubilizing agent.

7. The fruit inducing colorant according to claim 6, wherein the solubilizing agent is β -cyclodextrin.

8. The fruit inducing coloring agent of claim 7, wherein said coloring agent further comprises a plant ash soak solution, and is prepared by the following steps: putting the plant ash raw material into water according to the mass ratio of 1 (3-7), soaking for more than 24 hours, and filtering to remove insoluble substances, wherein the filtrate is the plant ash soak solution.

9. The fruit inducing colorant according to claim 8, wherein the plant ash soak solution is 8-15 wt% of the colorant.

10. A method for using a fruit-inducing coloring agent, comprising the step of mixing the fruit-inducing coloring agent according to any one of claims 2 to 9 with water in a mass ratio of 1: (80-100) and spraying the mixture on the surface of the fruit.

Technical Field

The invention relates to the field of phytochemical control, in particular to a fruit-induced coloring agent.

Background

The fruit color is an important index for evaluating the appearance quality of the fruit and is also a sensory index which is most emphasized by consumers, and the fruit with positive and beautiful appearance and bright color is always popular with the consumers, so the colored fruit has great advantages in the sale process. Fruit color development is influenced by multiple factors such as illumination, temperature, water and the like, and fruit growers usually adopt a chemical regulation method to improve the fruit color in order to improve economic benefit at present, such as spraying plant growth regulators such as naphthylacetic acid, ethephon, abscisic acid and jasmonic acid, and promoting the fruit color by inducing the fruit to mature.

However, the single use of these plant growth regulators has the problems that the unidirectional efficacy is difficult to control, the plant growth mechanism is disturbed, the fruit ripening is accelerated, and simultaneously, the problems of fruit decay, leaf aging, premature plant senescence, insufficient sugar and the like are easily caused, for example, when ethephon is used alone, the fruit ripening is not easy to control, the fruit is easy to soften and rot, and the storage period is short, and in addition, the use of ethephon can accelerate the formation of plant abscission, cause fruit abscission, leaf aging, and even inhibit the growth of plants, and cause premature plant senescence; when the abscisic acid is used alone, although the fruits can be colored faster, the conversion of organic substances in the fruits is slower, so that the fruits have insufficient sugar and are beautiful but not sweet; other plant growth regulators, while having the function of increasing fruit coloring, also reduce the subsequent storability and sugar content, and affect plant growth.

Disclosure of Invention

In order to solve the technical problems, the invention provides a composition in a first aspect, wherein the composition comprises brassinolide and/or S-abscisic acid and a jasmonic acid compound, and the weight ratio of the total sum of the brassinolide and/or the S-abscisic acid to the jasmonic acid compound is 1 (10-100).

In a second aspect, the invention provides a fruit inducing colorant, which comprises the composition, wherein the composition accounts for 2-50 wt% of the colorant.

In a preferred embodiment of the present invention, the colorant further comprises a wetting agent.

As a preferable technical scheme of the invention, the wetting agent is a compound of a sulfonate wetting agent and a polycarboxylate wetting agent, and the weight ratio of the sulfonate wetting agent to the polycarboxylate wetting agent is (3-5): 1.

as a preferable technical solution of the present invention, the sulfonate wetting agent is selected from one or more of lignosulfonate, sodium dodecylbenzene sulfonate, sodium methylene dinaphthalene sulfonate, sodium dibutyl naphthalene sulfonate, castor oil sulfonate, triphenylethyl phenol polyoxyethylene ether sulfonate, alkylphenol polyoxyethylene ether sulfonate, succinate sulfonate, tetrapropylene benzene sulfonate, sodium diisooctyl succinate sulfonate, sodium p-methoxy fatty amido benzene sulfonate, and alkyl glyceryl ether sulfonate; the polycarboxylate wetting agent is selected from one or more of sodium polyacrylate, sodium polymethacrylate, acrylic acid-maleic anhydride copolymer, acrylic acid-itaconic acid copolymer, methacrylic acid-sodium styrene sulfonate copolymer, acrylic acid-maleic anhydride-sodium styrene sulfonate copolymer, acrylic acid-sodium styrene sulfonate-hydroxyethyl methacrylate copolymer, acrylic acid-sodium styrene sulfonate-hydroxypropyl acrylate copolymer, methacrylic acid-itaconic acid-sodium allyl sulfonate and methacrylic acid-styrene-hydroxypropyl acrylate copolymer.

In a preferred embodiment of the present invention, the colorant further comprises a solubilizer.

In a preferred embodiment of the present invention, the solubilizer is β -cyclodextrin.

As a preferable technical scheme of the invention, the colorant also comprises plant ash soak solution, and the preparation method comprises the following steps: putting the plant ash raw material into water according to the mass ratio of 1 (3-7), soaking for more than 24 hours, and filtering to remove insoluble substances, wherein the filtrate is the plant ash soak solution.

As a preferable technical scheme, the plant ash soaking solution accounts for 8-15 wt% of the colorant.

The third aspect of the invention provides a use method of the fruit inducing colorant, wherein the fruit inducing colorant and water are mixed according to the mass ratio of 1: (80-100) and spraying the mixture on the surface of the fruit.

Has the advantages that: the invention provides a fruit inducing colorant, which is compounded by brassinolide and jasmonic acid compounds, wherein the brassinolide and the jasmonic acid compounds balance the synthesis and degradation speeds of chlorophyll through antagonism and synergism, improve the contents of anthocyanin and carotenoid in pericarp, promote the occurrence of cell division and accelerate the speed of cell division, so that the fruit is bright in appearance and luster, the sweetness of the fruit is effectively increased, the quality of the fruit is improved, the mature period of the fruit is shortened, and the phenomena of plant leaf aging, premature senility and the like are avoided. In addition, the special wetting agent, the solubilizer and the plant ash soaking solution are added to perform a synergistic effect with brassinolide and the jasmonic acid compound, so that the stability of the coloring agent is improved, the absorption of the coloring agent by plants is promoted, the sweet-sour ratio of fruits is further increased, the storage stability of the fruits is prolonged, and the problem that premature fruits are easy to soften and rot is effectively solved.

Detailed Description

The disclosure may be understood more readily by reference to the following detailed description of preferred embodiments of the invention and the examples included therein. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.

The terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, as used herein, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted to include the ranges "1 to 4", "1 to 3", "1 to 2 and 4 to 5", "1 to 3 and 5", and the like. When a range of values is described herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range.

In addition, the indefinite articles "a" and "an" preceding an element or component of the invention are not intended to limit the number requirement (i.e., the number of occurrences) of the element or component. Thus, "a" or "an" should be read to include one or at least one, and the singular form of an element or component also includes the plural unless the stated number clearly indicates that the singular form is intended.

In order to solve the technical problems, the first aspect of the invention provides a composition, which comprises brassinolide and/or S-abscisic acid and jasmonic acid compounds, wherein the weight ratio of the total sum of the brassinolide and/or S-abscisic acid to the jasmonic acid compounds is 1: (10-100).

In some embodiments, the composition comprises brassinolide and the S-abscisic acid, jasmonic acid, in a weight ratio of 0.5: 0.5: (20-70); preferably, the weight ratio of the three components is 0.5: 0.5: 50.

in some embodiments, the composition comprises brassinolide and a jasmonate in a weight ratio of 1: (20-70); preferably, the weight ratio of the two is 1: 50.

brassinolide

Brassinolide is also called brassinolide, Yifengsu and Tianfengsu, is a novel sterol plant endogenous hormone, and can promote the nutritional growth and facilitate the fertilization in each stage of the plant growth and development; the artificially synthesized brassinolide has high activity, can be absorbed by leaves, stems and roots of plants, and then is conducted to the acting parts. Brassinolide is a high-efficiency plant growth regulator, and the physiological effects of brassinolide show certain characteristics of auxin, gibberellin and cytokinin, such as: promoting cell division and fruit expansion; delaying leaf aging, keeping green for a long time, enhancing chlorophyll synthesis, improving photosynthesis, and promoting leaf color deepening and greening; breaking apical dominance, promoting lateral bud germination, inducing bud differentiation, increasing branch number and flower number, and improving pollen fertility, thereby increasing yield; preventing flower and fruit dropping, promoting protein synthesis, increasing sugar content, improving crop quality, and improving commodity.

S-abscisic acid

The S-abscisic acid is a key factor for balancing endogenous hormones of plants and metabolism of related growth active substances, has the capability of promoting the plants to absorb water and fertilizer in a balanced manner and coordinating metabolism in vivo, can effectively regulate and control root/crown and vegetative growth and reproductive growth of the plants, and has an important effect on improving the quality and yield of crops.

Jasmonic acid compound

The jasmonic acid compound is a novel plant growth regulating substance widely existing in plants, and has important regulation and control effects on plant growth and development, stress resistance and synthesis of secondary metabolites. Exogenous application can stimulate the expression of defense plant genes, induce the chemical defense of plants, and generate the effect similar to mechanical damage and insect feeding, and the existing research shows that jasmonic acid compounds can induce the biosynthesis of ethylene and ester substances in fruits, improve the contents of anthocyanin and beta-carotene, promote the degradation of chlorophyll, and improve the color of fruits.

In some embodiments, the jasmonate compound is selected from one or more of jasmonic acid, methyl jasmonate, and propyl dihydrojasmonate; preferably, the jasmonate compound is methyl jasmonate.

The brassinolide has double functions of promoting plant cell division and cell elongation, and can improve the chlorophyll content of leaves, enhance photosynthesis and increase the accumulation of photosynthetic assimilation products; the jasmonic acid compounds can accelerate cell division, promote the degradation of chlorophyll and promote the biosynthesis of ethylene and ester substances in fruits. The two are compounded for use to generate antagonism, on one hand, the synthesis and degradation rates of chlorophyll in the fruit ripening process are balanced, the contents of anthocyanin and carotenoid are improved, the fruit color is bright, on the other hand, the conversion of organic substances in the fruit and the change speed of the apparent color of the fruit are synchronized, the full conversion of the organic substances in the fruit is ensured, and the fruit taste is good. In addition, the two components can promote the occurrence of cell division and accelerate the speed of cell division through synergistic action, so that the fruit can be mature in a shorter time, the senescence and decomposition of cells can be inhibited to a certain extent, and the premature shedding of the fruit and the leaf senescence can be effectively prevented.

The compounding ratio of the brassinolide and the jasmonic acid compounds determines the equilibrium state generated by antagonism of the brassinolide and the jasmonic acid compounds and the optimal effect generated by synergism, directly influences the growth mechanism of the plant, and finally influences the fruit quality and the subsequent growth of the plant. If the brassinolide content is too high, although the stem elongation and the leaf flourishing are promoted, the development and the division of root tissues are inhibited, and the nutrient content of fruits is excessively seized, so that the fruit dysplasia and the plant premature senility are caused; if the jasmonates content is too high, premature ripening of the fruit, insufficient sugar, perishable and leaf senescence can occur. The inventor unexpectedly finds that the content of phenylalanine ammonia lyase generated in an experimental system increases with the increase of the content of brassinolide at a certain jasmonic acid compound content, but the increasing speed increases and then slows down, while the activity of ethylene forming enzyme increases with the increase of the content of brassinolide and then decreases, and the trend of the activity is approximately synchronous with the trend of the increasing speed of the content of phenylalanine ammonia lyase, and the inventor conjectures the possible reasons that: the brassinolide and the jasmonic acid compounds have the effects of enhancing the activity of the ethylene forming enzyme and inducing the synthesis of plant ethylene, when the ethylene in the whole system is excessive, other corresponding substances can inhibit the activity of the ethylene forming enzyme in turn, further the generation of the ethylene is inhibited, and the increase of the content of phenylalanine ammonia lyase in the system is correspondingly inhibited. According to the analysis of the experimental result, when the weight ratio of the brassinolide to the jasmonic acid compound in the composition is 1: (10-100), the content and increasing speed of phenylalanine ammonia lyase in the system are moderate, and the phenylalanine ammonia lyase is a key enzyme for synthesizing plant secondary substances (including phenols and flavonoids), so that the fruit coloring inducing effect is good.

The brassinolide of the present invention can be obtained commercially, for example, commercially available brassinolide includes, but is not limited to, the product (CAS No.: 78821-43-9, active ingredient content: 98%) purchased from Shandong chemical science and technology Co., Ltd.; the jasmonate compounds of the present invention are commercially available, and for example, commercially available jasmonates include but are not limited to methyl jasmonate (CAS No: 39924-52-2, content 95%) purchased from Hansa chemical company Limited, Shanghai, under product number M111207.

According to a second aspect of the present invention, there is provided a fruit inducing colourant comprising a composition as described above, wherein the composition comprises from 2 to 50 wt% of the colourant; preferably, the composition comprises 20 wt% of the colorant.

The composition comprises brassinolide and jasmonic acid compounds which belong to exogenous non-nutritive chemical substances, act on specific parts of plants, can promote or inhibit certain specific links in the life process of the plants at a very low concentration, and different chemical substances have antagonism and/or synergism on a certain plant growth mechanism, can generate specific effects on target plants only under specific conditions (including the proportion of effective components in the composition, the concentration in a colorant, external illumination, humidity and the like), and usually the opposite result can be obtained by changing the concentration. In the invention, the brassinolide and the jasmonic acid compound have the effect of promoting the generation of ethylene, and according to experimental research, the inventor determines the preferable weight ratio between the brassinolide and the jasmonic acid compound, but simultaneously, other components in the colorant need to be comprehensively considered to determine the preferable concentration of each component in the colorant, and further determine the use mode and the use amount of the colorant in practical application.

In some embodiments, the colorant further comprises a wetting agent.

In a preferred embodiment, the wetting agent is a compound of a sulfonate wetting agent and a polycarboxylate wetting agent, and the weight ratio of the sulfonate wetting agent to the polycarboxylate wetting agent is (3-5): 1.

preferably, the sulfonate wetting agent is selected from one or more of lignosulfonate, sodium dodecylbenzene sulfonate, sodium methylenedinaphthalene sulfonate, sodium dibutylnaphthalene sulfonate, castor oil sulfonate, tristyrylphenol polyoxyethylene ether sulfonate, alkylphenol polyoxyethylene ether sulfonate, succinate sulfonate, sodium tetrapropylene benzene sulfonate, sodium diisooctyl succinate sulfonate, sodium p-methoxyfatty amido benzene sulfonate and alkyl glyceryl ether sulfonate, and the polycarboxylate is selected from sodium polyacrylate, sodium polymethacrylate, acrylic acid-maleic anhydride copolymer, acrylic acid-itaconic acid copolymer, methacrylic acid-sodium styrene sulfonate copolymer, acrylic acid-maleic anhydride-sodium styrene sulfonate copolymer, acrylic acid-sodium styrene sulfonate-hydroxyethyl methacrylate copolymer, acrylic acid-sodium styrene sulfonate-hydroxypropyl acrylate copolymer, sodium ethylene glycol sulfonate copolymer, sodium ethylene, One or more of methacrylic acid-itaconic acid-sodium allyl sulfonate and methacrylic acid-styrene-hydroxypropyl acrylate copolymerization; more preferably, the sulfonate wetting agent is castor oil sulfonate, the polycarboxylate wetting agent is methacrylic acid-styrene-hydroxypropyl acrylate copolymer, and the weight ratio of the methacrylic acid, the styrene and the hydroxypropyl acrylate monomer in the preparation process is 50: (15-20): (20-25); preferably, the weight ratio of the sulfonate wetting agent to the polycarboxylate wetting agent in the wetting agent is 4: 1.

in a more preferred embodiment, the wetting agent comprises 1 to 3 wt% of the colorant; preferably, the wetting agent comprises 2 wt% of the colorant.

The wetting agent in the invention mainly plays a role in wetting, and improves the dissolving performance of other components in the composition and the preferential absorption of the composition by plants when the composition is prepared into an aqueous solution. The inventor finds that when the wetting agent is a compound of a sulfonate wetting agent and a polycarboxylate wetting agent, the two agents can generate strong synergistic effect at a specific ratio relative to the wetting agent with a single component. Furthermore, the inventors found that when the polycarboxylate-type wetting agent is copolymerized with methacrylic acid-styrene-hydroxypropyl acrylate, and the methacrylic acid-styrene-hydroxypropyl acrylate copolymer synthesized in different proportions is used in the colorant, insoluble substances may occur, or the colorant cannot be well absorbed by plants, and presumably, the three monomer proportions affect the proportion of the hydrophilic and lipophilic parts of the wetting agent when the methacrylic acid-styrene-hydroxypropyl acrylate copolymer is synthesized, if the hydrophilic action of the wetting agent is stronger, the action force of the hydrophobic group is relatively weakened, so that the binding force of the wetting agent and brassinolide and jasmonic acid compounds in the composition is weaker, and the wetting agent cannot play a role in solubilization and absorption promotion, but if the hydrophobic action is stronger, the wetting agent may not be completely dissolved, the inventor finds that when the weight ratio of three monomers of methacrylic acid, styrene and hydroxypropyl acrylate is 50: (15-20): (20-25), the hydrophilic-lipophilic balance value of the methacrylic acid-styrene-hydroxypropyl acrylate copolymerized wetting agent determined by a water counting method is within 14-16, and the methacrylic acid-styrene-hydroxypropyl acrylate copolymerized wetting agent is compounded with a specific sulfonate wetting agent in a specific ratio for use, so that the effect of the wetting agent compound is good.

The castor oil sulfonates described herein may be obtained commercially, for example, commercially available castor oil sulfonates include, but are not limited to, the products available from Schchen Taixin Lanxing technology, Inc. (sulfonation. gtoreq.1.8%); the methacrylic acid-styrene-hydroxypropyl acrylate copolymer can be prepared by a chemical synthesis method, and the preparation method comprises the following steps: adding 80 parts by weight of deionized water, 10 parts by weight of sodium bisulfite and 15-20 parts by weight of styrene into a four-neck flask, heating and stirring, weighing 50 parts by weight of methacrylic acid and 20-25 parts by weight of hydroxypropyl acrylate into a constant-pressure dropping funnel, weighing 6 parts by weight of initiator ammonium persulfate into another constant-pressure dropping funnel, simultaneously dropping methacrylic acid/hydroxypropyl acrylate solution and ammonium persulfate solution when the temperature in the flask rises to 100 ℃, controlling the dropping speed of the solution, carrying out heat preservation reaction for 4 hours, cooling, neutralizing with NaOH aqueous solution to enable the pH to be about 7, putting into an oven, drying to obtain a solid, and measuring the hydrophilic-lipophilic balance value of the obtained wetting agent by adopting a water number method.

In some embodiments, the colorant further comprises a solubilizing agent.

In a preferred embodiment, the solubilizing agent is β -cyclodextrin.

In a more preferred embodiment, the solubilizer comprises 5 to 7 wt% of the colorant; preferably, the solubilizer constitutes 6 wt% of the colorant.

Cyclodextrin

Cyclodextrin, CD (Cyclodextrin) for short, is a general name of a series of cyclic oligosaccharides produced by amylose under the action of cyclodextrin glucosyltransferase produced by bacillus, and is classified into alpha-cyclodextrin, beta-cyclodextrin and gamma-cyclodextrin. The beta-cyclodextrin molecule has a three-dimensional structure in a ring hollow cylinder shape, the opening of the gap and the outside of the gap contain a large amount of hydroxyl, the beta-cyclodextrin molecule is hydrophilic, and the inside of the beta-cyclodextrin molecule is hydrophobic.

In the experimental process of the inventor, the coloring agent is diluted and sprayed on the fruits when the cyclodextrin is not used as the solubilizer, so that the color of the skin becomes bright after a period of time, but the inside of the fruits is not ripe after picking, the outside of the fruits is softened and rotten quickly after the fruits are placed for a period of time after picking, the inside of the fruits is still hard, and the phenomenon of layering is also found when the aqueous solution of the coloring agent which is not used up is used. However, when the colorant is added with beta-cyclodextrin, the aqueous solution of the colorant does not generate layering phenomenon after being placed for a long time, and the obtained fruit is not only bright but also has sweet taste. The present inventors speculate that the possible reason is that beta-cyclodextrin forms an inclusion complex with the active component in the colorant through a hydrophobic bond, the active component in the colorant is trapped in the cyclodextrin cavity, the chance of contact with the external environment is relatively reduced, thereby improving the stability of the colorant aqueous solution, and in addition, the colorant aqueous solution can not act on the exterior of the fruit immediately after being sprayed on the surface of the fruit, but the colorant slowly permeates into the interior of the plant fruit under the action of the wetting agent and the beta-cyclodextrin, active component molecules in the colorant are slowly released along with the prolonging of the exposure time of the colorant aqueous solution in the sunlight air environment and uniformly act on the interior and exterior of the fruit, but not on the surface of the fruit quickly, thereby not only ensuring the bright appearance and color of the fruit, but also ensuring the full conversion of the internal organic substances and the fragrant and sweet taste.

The beta-cyclodextrin of the present invention can be obtained commercially, for example, commercially available beta-cyclodextrin includes, but is not limited to, products purchased from Biotechnology Ltd of Jiangsu Fengyuan (CAS number: 7585-39-9, total sugar: 86.5% or more, and moisture: 12% or less).

In some embodiments, the colorant further comprises a plant ash soak solution, and is prepared by the following method: putting the plant ash raw material into water according to the mass ratio of 1 (3-7), soaking for more than 24 hours, and filtering to remove insoluble substances, wherein the filtrate is the plant ash soak solution.

In a preferred embodiment, the plant ash soaking solution accounts for 8-15 wt% of the colorant; preferably, the plant ash soak solution accounts for 11 wt% of the colorant.

In a more preferred embodiment, the plant ash raw material is selected from one or more of conifer ash, broadleaf ash, shrub ash, wheat straw ash, rice straw ash, cottonseed hull ash, bran hull ash, sunflower straw ash; preferably, the plant ash raw material is conifer ash.

Plant ash

The plant ash is the residue of the burnt plant, so the plant ash contains mineral elements, almost all of which contain potassium element at most, and also contain calcium, magnesium, silicon, sulfur, iron, manganese, copper, zinc and other trace nutrient elements, therefore the plant ash is an inorganic farmyard manure with wide source, low cost, complete nutrients and obvious fertilizer efficiency.

The conifer ash refers to residues of conifer trees after combustion, the conifer trees are trees with slender leaves like needles, most of the trees are trees or shrubs, and the trees comprise, but are not limited to, swertia chinensis, Korean pine, Chinese pine, cedar, white bark pine, Osaka pine, Wuzhen pine, masson pine, Pinus armandii, larch, spruce and fir.

The main component of the plant ash is potassium carbonate which can provide potassium element for plants, potassium ions are used as activators of various enzymes, particularly enzymes in a sugar metabolism pathway, on one hand, the sugar accumulation is promoted, on the other hand, the sugar transportation from leaves and branches to fruits is promoted, the sugar content of the fruits is increased, and the coloring of the fruits is promoted, so that the fruit color can be bright by adding the plant ash soaking solution into a coloring agent, the sugar content is high, and the inventor also finds that the fruits obtained by the method can be stored for a long time without softening and rotting phenomena. The inventor conjectures that the possible reasons are that partial ion components in the plant ash penetrate into the fruit peel to interfere the activity of polygalacturonase therein, or the action of brassinolide increases the content of RNA polymerase inhibiting the polygalacturonase from increasing along with the fruit ripening, thereby inhibiting the conversion of protopectin in the fruit peel to soluble pectin, and possibly that the ion components in the plant ash change the cross-linking structure of protopectin and cellulose in the fruit tissue to ensure that the protopectin and the cellulose are not easily separated in the fruit ripening process, so that the fruit peel is relatively firm after the fruit ripens and has good storage resistance.

In addition, the inventor finds that when other potassium fertilizers are used or different plant ash is used as raw materials to prepare the plant ash soaking solution, the coloring agent is added, the sweetness of the fruit can be improved to a certain degree, the color of the fruit is improved, but the sweet-sour ratio of the fruit is different, and the fruit is different in softening and rotting speed. It is presumed that the possible reasons are that the plant ash not only regulates the change of the structure between the fruit cell tissues and various small molecular substances in the fruit due to the synergistic effect of potassium ions therein, but also the relative content of various ionic components in the plant ash simultaneously affects the change, for example, when the potassium ions are used too much, the plant is inhibited from absorbing other ions, the fruit is not storage-resistant, the potassium ions promote the plant to absorb nitrogen, nitrogen forms protein with more carbohydrates, on one hand, the carbohydrates are the raw materials for forming cell walls, the fruit walls are thinned, the fruit is putrescible, on the other hand, the carbohydrates are the raw materials for synthesizing sugar, and the sugar content in the fruit is reduced.

The third aspect of the invention provides a use method of the fruit inducing colorant, wherein the fruit inducing colorant and water are mixed according to the mass ratio of 1: (80-100) and spraying the mixture on the surface of the fruit, wherein the spraying time is not limited, and the spraying time can be any one or more of the young fruit period, the mature period and the coloring period of the fruit.