阅读说明：本技术 一种防治皇冠梨果皮冷害褐变的组合物及应用 (Composition for preventing and treating crown pear pericarp cold damage browning and application thereof ) 是由 傅茂润 赵韩栋 陈庆敏 焦文晓 杜雅珉 孙斐 韩聪 杨晓颖 于 2020-12-25 设计创作，主要内容包括：本发明属于果实生理性病害防治技术领域,具体涉及一种聚赖氨酸(ε-PL)、壳寡糖在控制水果鸡爪病中的应用；还涉及利用聚赖氨酸、壳寡糖对水果鸡爪病的控制方法。聚赖氨酸和/或壳寡糖在控制水果鸡爪病中的应用,是本发明所要重点保护的内容。本发明中所述及的水果鸡爪病主要是皇冠梨鸡爪病。本发明还提供了将上述的聚赖氨酸、壳寡糖应用于控制皇冠梨鸡爪病中的具体方法步骤。本发明的有益效果在于：采用本发明的方法对皇冠梨鸡爪病进行防控,贮藏90天后常温5天的货架期,皇冠梨鸡爪病的发病率仅为5%,发病指数仅为2.67%；贮藏180天后常温5天的货架期,皇冠梨鸡爪病的发病率仅为6.7%,发病指数仅为3.67%。能有效的防控皇冠梨鸡爪病。(The invention belongs to the technical field of fruit physiological disease control, and particularly relates to application of polylysine (epsilon-PL) and chitosan oligosaccharide in controlling fruit chicken foot disease; also relates to a method for controlling the fruit chicken foot disease by utilizing polylysine and chitosan oligosaccharide. The application of polylysine and/or chitosan oligosaccharide in controlling the fruit chicken foot disease is the important protection content of the invention. The fruit chicken foot disease mainly refers to the Huangguan pear chicken foot disease. The invention also provides specific method steps for applying the polylysine and the chitosan oligosaccharide to control the crown pear chicken foot disease. The invention has the beneficial effects that: the method disclosed by the invention is used for preventing and controlling the crown pear chicken foot disease, the morbidity of the crown pear chicken foot disease is only 5% and the morbidity index is only 2.67% in the shelf life of 5 days at normal temperature after 90 days of storage; after being stored for 180 days, the incidence rate of the Huangguan pear chicken foot disease is only 6.7 percent and the incidence index is only 3.67 percent in the shelf life of 5 days at normal temperature. Can effectively prevent and control the chicken foot disease of the Huangguan pears.)

1. A composition containing polylysine and chitosan oligosaccharide.

2. The composition of claim 1, wherein the weight ratio of polylysine to chitosan oligosaccharide in the composition is 0.05 to 0.15: 8-12;

preferably, the composition is expressed as a solution prepared from polylysine powder and chitosan oligosaccharide powder; or the composition is expressed by a mixed solution obtained by mixing a polylysine solution and a chitosan oligosaccharide solution;

preferably, in the composition, the mass concentration of the polylysine is (0.05-0.15) g/(0.8-1.2) L, and the mass concentration of the chitosan oligosaccharide is (8-12) g/(0.8-1.2) L;

preferably, the mass concentration of the polylysine is (0.05-0.15) g/L, and the mass concentration of the chitosan oligosaccharide is (8-12) g/L.

3. Use of a composition according to claim 1 for controlling the cold damage browning of crown pear pericarp.

4. The use according to claim 3, wherein polylysine and chitosan oligosaccharide are formulated as a solution for use in controlling crown pear pericarp cold damage browning;

or the polylysine solution and the chitosan oligosaccharide solution are mixed to obtain a mixed solution which is applied to controlling the crown pear peel cold damage browning.

5. The use according to claim 3, wherein the polylysine and the chitosan oligosaccharide are dissolved in water to prepare a solution, and the Huangguan pears are refrigerated after being soaked and/or coated on the surfaces of the Huangguan pears;

or mixing the polylysine solution and the chitosan oligosaccharide solution to obtain a mixed solution, soaking the Huangguan pears, refrigerating/coating the Huangguan pears on the surfaces of the Huangguan pears, and refrigerating the Huangguan pears.

6. The use according to claim 3, wherein the polylysine and the chitosan oligosaccharide are present in a mass ratio of: 0.05-0.15: 8-12;

preferably, the dosage mass ratio of the polylysine to the chitosan oligosaccharide is 0.1: 10.

7. the application method of polylysine and chitosan oligosaccharide in controlling the cool damage browning of the crown pears comprises the following steps:

(1) weighing polylysine powder and chitosan oligosaccharide powder, dissolving in water, and making into solution;

(2) soaking the picked Huangguan pears in the solution in the step (1), keeping for 1-10 min, taking out and draining;

(3) placing the drained crown pears in the step (2) in an environment with the temperature of-1.5-0 ℃ for refrigeration;

or (1) weighing polylysine powder, dissolving in water, and preparing into solution; and weighing chitosan oligosaccharide powder, dissolving the chitosan oligosaccharide powder in water to prepare a solution, and uniformly mixing the two prepared solutions to obtain a mixed solution.

8. An application method of polylysine and chitosan oligosaccharide in controlling the cold damage browning of Huangguan pears is characterized in that (1), 0.05-0.15 g of epsilon-polylysine powder and 8-12 g of chitosan oligosaccharide powder are weighed and dissolved in 1L of water to prepare a solution;

preferably, (1) weighing 0.1g of epsilon-polylysine powder and 10g of chitosan oligosaccharide powder, and dissolving in 1L of water to prepare a solution;

preferably, (2) soaking the picked crown pears in the solution in (1), keeping for 1-5 min, taking out and draining;

preferably, in (2), the picked Huangguan pears are soaked in the solution in (1), kept for 2min, taken out and drained.

9. The method of using polylysine and chitosan oligosaccharide in controlling the cold damage browning of Huangguan pears, as claimed in claim 7, comprising the steps of:

(1) weighing 0.1g of epsilon-polylysine powder and 10g of chitosan oligosaccharide powder, dissolving in 1L of water, and preparing into a solution;

(2) soaking picked Huangguan pears in the solution in the step (1), keeping for 2min, taking out and draining;

(3) and (3) refrigerating the drained Huangguan pears in the step (2) in an environment at the temperature of-1.5-0 ℃.

10. The application method of polylysine and chitosan oligosaccharide in controlling the cool damage browning of the crown pears comprises the following steps:

(1) weighing 0.1g of epsilon-polylysine powder, dissolving in 0.5L of water, and preparing into a solution; weighing 10g of chitosan oligosaccharide powder, dissolving in 0.5L of water, and preparing into solution; mixing the solutions prepared in the two steps to obtain a mixed solution;

(2) soaking picked Huangguan pears in the mixed solution in the step (1), keeping for 2min, taking out and draining;

(3) and (3) refrigerating the drained Huangguan pears in the step (2) in an environment at the temperature of-1.5-0 ℃.

Technical Field

The invention belongs to the technical field of fruit physiological disease control, and particularly relates to application of polylysine and chitosan oligosaccharide in controlling cold damage browning of fruits; also relates to a method for controlling the fruit chicken foot disease by utilizing polylysine and chitosan oligosaccharide.

Background

The Huangguan pears are high-quality pear varieties developed in recent years, have the advantages of thin peels, more juice, small stone cells, smooth appearance and the like, are well liked by consumers and have very wide development prospects. However, compared with other white pear varieties, the Huangguan pear is refrigerated at about 0 ℃, particularly when the Huangguan pear is in shelf life, cold damage symptoms are easy to appear on the surface, particularly pericarp browning appears, the Huangguan pear is shaped like chicken feet, commonly known as chicken foot disease (the chicken foot disease is basically a special physiological disease of the Huangguan pear, and green-peel pear varieties such as big fruit crystal, emerald and the like are also discovered occasionally.

The most commercially used method for controlling the browning of the peel of the crown pears at present is a programmed cooling method. The method adopts a method of reducing the temperature by 1 ℃ about every 2 days to gradually reduce the temperature to about minus 1 ℃ (-1.5-0 ℃). The process takes longer time, generally 25-30 days, and the chicken foot disease cannot be completely avoided; in addition, the quality of the fruits is poor in the later storage period and the shelf life, and the problems of red pulp, softening, dark core, bitter taste and the like are easy to occur, so that the selling price is influenced. There are also some studies reporting that the pericarp browning of the Huangguan pears can be inhibited by applying chitosan, calcium chloride, pullulan coating, methyl jasmonate, exogenous ethylene treatment, etc. However, the chitosan has poor water solubility, needs to be dissolved by adding hydrochloric acid or glacial acetic acid, and has complex operation and potential safety hazard; the exogenous ethylene treatment effect is good (the granted patent number CN 102132724A: a method for inhibiting the pericarp browning of Huangguan pears), but a special ethylene storage and release device is needed, and the ethylene slow-release agent has high general concentration, so that the fruit aging is accelerated, the pulp tissue is soft, the juiciness is lost, and the taste is poor; the other treatment effects are not obvious compared with the effect of inhibiting the chicken foot diseases by programmed cooling.

Zzhuirun et al published the influence of salicylic acid and chitooligosaccharide treatment on the black spot resistance of picked apricot fruits, the activity and gene expression of PAL and POD enzymes, and found that salicylic acid and chitooligosaccharide can reduce the incidence of apricot fruits inoculated with Alternaria alternata and inhibit the diameter expansion of disease spots; the research on the fresh-keeping effect of Huangguan pears by the nano SiOx-chitosan composite coating published by von Jiangyue et al is disclosed in the text as follows: the composite film made of chitosan and nano SiOx has a certain inhibiting effect on the Huangguan pear chicken foot disease, but the morbidity index after treatment is still as high as 30%, the loss rate is high, and the commercial requirement cannot be met.

Therefore, improvement is needed for the above control method, and a method for effectively controlling the fruit chicken foot disease, especially the Huangguan pear chicken foot disease is invented.

Disclosure of Invention

In order to solve the technical problems, the invention provides a method for effectively controlling the crown pear chicken foot disease.

The composition to be protected by the invention is a composition simultaneously containing polylysine and chitosan oligosaccharide;

in the composition, the mass ratio of polylysine to chitosan oligosaccharide is 0.05-0.15: 8 to 12.

Preferably, the composition is in the form of a solution prepared from polylysine powder and chitosan oligosaccharide powder; or, the composition is expressed in the form of a mixed solution obtained by mixing a polylysine solution and a chitosan oligosaccharide solution;

preferably, in the composition, the mass concentration of the polylysine is (0.05-0.15) g/(0.8-1.2) L, and the mass concentration of the chitosan oligosaccharide is (8-12) g/(0.8-1.2) L;

preferably, the mass concentration of the polylysine is (0.05-0.15) g/L, and the mass concentration of the chitosan oligosaccharide is (8-12) g/L.

The method provided by the invention is that polylysine and chitosan oligosaccharide are dissolved in water to prepare a composite solution, and then the Huangguan pears are soaked in the solution and are fished out and drained after a period of time. And then directly placing the drained pears in a refrigeration house for refrigeration.

Or mixing the polylysine solution and the chitosan oligosaccharide solution to obtain a mixed solution, soaking the Huangguan pears, refrigerating/coating the Huangguan pears on the surfaces of the Huangguan pears, and refrigerating the Huangguan pears.

The results show that the pears preserved by the method of the invention have low morbidity index and low morbidity rate after 90 days and 180 days of storage.

The application of polylysine and chitosan oligosaccharide in controlling the cold damage browning of the Huangguan pears is the range to be protected in the invention;

the polylysine and the chitosan oligosaccharide are applied to the crown pear chicken foot disease in the form of a main solution, namely, the polylysine and the chitosan oligosaccharide are prepared into a solution to soak the crown pears, and then the crown pears are refrigerated;

the dosage and mass ratio of the polylysine to the chitosan oligosaccharide is as follows: 0.05-0.15: 8-12;

preferably, the mass ratio of the polylysine to the chitosan oligosaccharide is 0.1: 10;

the application method of polylysine and chitosan oligosaccharide in controlling the cool damage browning of the crown pears comprises the following steps:

(1) weighing polylysine powder and chitosan oligosaccharide powder, dissolving in water, and preparing into solution;

(2) soaking the picked Huangguan pears in the solution in the step (1), keeping for 1-10 min, taking out and draining;

(3) placing the drained crown pears in the step (2) in an environment with the temperature of-1.5-0 ℃ for refrigeration;

or (1) weighing polylysine powder, dissolving in water, and preparing into solution; and weighing chitosan oligosaccharide powder, dissolving the chitosan oligosaccharide powder in water to prepare a solution, and uniformly mixing the two prepared solutions to obtain a mixed solution.

Preferably, in the step (1), 0.05-0.15 g of epsilon-polylysine powder and 8-12 g of chitosan oligosaccharide powder are weighed and dissolved in 1L of water to prepare a solution;

preferably, (1) weighing 0.1g of epsilon-polylysine powder and 10g of chitosan oligosaccharide powder, and dissolving in 1L of water to prepare a solution;

preferably, (2) soaking the picked crown pears in the solution in (1), keeping for 1-5 min, taking out and draining;

preferably, in (2), the picked Huangguan pears are soaked in the solution in (1), kept for 2min, taken out and drained.

More preferably, the application method of polylysine and chitosan oligosaccharide in controlling the cold damage browning of the Huangguan pears comprises the following steps:

(1) weighing 0.1g of epsilon-polylysine powder and 10g of chitosan oligosaccharide powder, dissolving in 1L of water, and preparing into a solution;

(2) soaking picked Huangguan pears in the solution in the step (1), keeping for 2min, taking out and draining;

(3) and (3) refrigerating the drained Huangguan pears in the step (2) in an environment at the temperature of-1.5-0 ℃.

The application method of polylysine and chitosan oligosaccharide in controlling the cool damage browning of the crown pears comprises the following steps:

(1) weighing 0.1g of epsilon-polylysine powder, dissolving in 0.5L of water, and preparing into a solution; weighing 10g of chitosan oligosaccharide powder, dissolving in 0.5L of water, and preparing into solution; mixing the solutions prepared in the two steps to obtain a mixed solution;

(2) soaking picked Huangguan pears in the mixed solution in the step (1), keeping for 2min, taking out and draining;

(3) and (3) refrigerating the drained Huangguan pears in the step (2) in an environment at the temperature of-1.5-0 ℃.

The invention adopts two main raw materials for preventing and treating the crown pear chicken foot disease: polylysine and chitosan oligosaccharide; the two raw materials have the following characteristics:

polylysine is a homotypic monomer polymer containing 25-30 lysine residues, is called epsilon-polylysine (epsilon-PL), has good bactericidal capacity and thermal stability, is a biological preservative with excellent preservative performance and huge commercial potential, and is widely used for the fresh-keeping and the preservation of instant rice, wet-cooked noodles, cooked vegetables, marine products, sauces, soy sauce, fish slices and biscuits. Meanwhile, the epsilon-polylysine is used in combination with other natural bacteriostatic agents, so that the obvious synergistic effect is achieved, and the bacteriostatic ability of the bacteriostatic agent can be improved.

Chitosan oligosaccharide, also called chitosan oligosaccharide, chitosan oligosaccharide and chitosan oligosaccharide, is an oligosaccharide product with the polymerization degree of 2-20, the molecular weight of which is less than or equal to 3200Da, which is obtained by degrading chitosan by a special biological enzyme technology (also reported by using chemical degradation and microwave degradation technologies), and is a low molecular weight product with better water solubility, large functional effect and high biological activity. It has several unique functions of high solubility, complete water solubility, easy absorption and utilization by organism, etc. and its action is 14 times that of chitosan.

The invention has the beneficial effects that:

compared with the method in the background art, the method provided by the invention is used for preventing and controlling the crown pear chicken foot disease, the morbidity of the crown pear chicken foot disease is only 5% and the morbidity index is only 2.67% in the shelf life of the crown pear chicken foot disease which is stored for 90 days and is at normal temperature for 5 days; after being stored for 180 days, the incidence rate of the Huangguan pear chicken foot disease is only 6.7 percent and the incidence index is only 3.67 percent in the shelf life of 5 days at normal temperature. The result shows that the mixed solution prepared from the epsilon-polylysine and the chitosan oligosaccharide can effectively prevent and control the Huangguan pear chicken foot disease.

Drawings

FIG. 1 is a photograph of a comparative example, which was stored for 180 days on a shelf at room temperature for 5 days;

FIG. 2 is a photograph showing shelf life 5 days at room temperature after cryopreservation for 180 days after treatment with 20mg/L of epsilon-polylysine;

FIG. 3 is a photograph showing shelf life 5 days at room temperature after cryopreservation for 180 days after treatment with 100mg/L of epsilon-polylysine;

FIG. 4 is a photograph showing shelf life 5 days at room temperature after cryopreservation for 180 days after treatment with 200mg/L of epsilon-polylysine;

FIG. 5 is a photograph showing shelf life 5 days at room temperature after cryopreservation for 180 days by treating with 1% COS;

FIG. 6 is a photograph showing shelf life 5 days at room temperature after cryopreservation for 180 days by treating with 2% COS;

FIG. 7 is a photograph showing shelf life 5 days at room temperature after being treated with 100mg/L of ε -polylysine and 1% COS and stored at low temperature for 180 d;

FIG. 8 is a photograph showing shelf life 5 days at room temperature after 100mg/L of ε -polylysine + 2% COS treatment and cryopreservation for 180 d.

Detailed Description

The present invention will now be further described with reference to specific embodiments in order to enable those skilled in the art to better understand the present invention.

Example 1

Preparing a solution:

(1) epsilon-polylysine (epsilon-PL): a commercially available product is prepared by weighing 20, 100mg and 200mg epsilon-PL powder by taking water as a solvent, and respectively preparing solutions with the concentrations of 20mg/L, 100mg/L and 200 mg/L;

(2) chitooligosaccharide (COS): weighing 10g of chitosan oligosaccharide powder of a commercially available product, dissolving in 1L of water, and preparing into a solution with the concentration of 1%;

weighing 20g of chitosan oligosaccharide powder, dissolving in 1L of water, and preparing into 2% solution;

(3) epsilon-polylysine + chitosan oligosaccharide (epsilon-PL) combination: respectively weighing 100mg of epsilon-PL powder and 10g of chitosan oligosaccharide powder, dissolving in 1L of water, and preparing into a composite solution of 100mg/L of epsilon-PL and 1% of COS;

100mg of epsilon-PL powder and 20g of chitosan oligosaccharide powder are respectively weighed and dissolved in 1L of water to prepare a composite solution of 100mg/L of epsilon-PL and 2% of COS.

Treating the Huangguan pear fruit:

the Huangguan pears are collected from Xinji city of Hebei province in 7-month middle ten days, 120 fruits are used for each group, and the Huangguan pears are fished out and drained after being soaked for 2min at normal temperature; soaking the control in clear water for 2 min; all samples (treatment group and control group) were directly put into a freezer for refrigeration at-1.5-0 ℃.

Fruit peel morbidity and morbidity index statistics:

120 fruits are adopted as samples for each treatment, and the occurrence of browning of the peel of the crown pears is observed.

The incidence of diseases is as follows: indicating fruits with brown peels, wherein the incidence rate is the number of the fruits per the total number of the fruits (120) multiplied by 100%;

incidence index: used to measure the degree of fruit morbidity. The incidence of the pericarp is divided into 5 grades, wherein 0 grade is no incidence, I grade is incidence area smaller than 25%, II grade is incidence area larger than 25% and smaller than 50%, III grade is incidence area larger than 50% and smaller than 75%, and IV grade is incidence area larger than 75%.

TABLE 1 Effect of polylysine and Chitosan oligosaccharide treatment on pericarp browning of crown Pear

Note: the different letters in each column represent significant differences (P < 0.05).

As can be seen from the above Table 1 and the accompanying figures 1-8, the crown pears in the CK group have high morbidity and morbidity index after being stored for 90 days and 180 days; from the appearance of the Huangguan pears, the surfaces of the Huangguan pears show speckles like rust, namely chicken feet diseases; the result shows that untreated Huangguan pears are directly refrigerated, the chicken foot disease is serious, and obviously, the chicken foot disease is induced by low-temperature storage;

the treatment group with the epsilon-PL of 20mg/L in the attached figure 2 has better results than the control group in the attached figure 1, but a considerable part of the surfaces of the Huangguan pears have chicken foot diseases; this shows that 20mg/L of epsilon-PL can reduce the chicken foot disease of the Huangguan pears to a certain extent, but the effect is limited;

the treatment group of 1% COS in the attached figure 3 is remarkably superior to CK, and is slightly stronger than the treatment group of epsilon-PL 20mg/L, and the lesion area of the chicken foot disease is smaller than that of the treatment group of epsilon-PL 20mg/L, but the control of the chicken foot disease of the Huangguan pears is not ideal as a whole;

the result of the treatment group with 2% COS in the attached figure 4 is better than that of the treatment group with 1% COS, and only a small amount of chicken foot disease stripes are visible on the surface of the Huangguan pears, which shows that after the dosage of COS is increased, the control effect on the chicken foot disease is stronger, but the chicken foot disease cannot be completely controlled;

in the attached figure 5, the result of the epsilon-PL 100mg/L treatment group is better than that of the epsilon-PL 20mg/L treatment group, and only a small amount of cockscomb disease stripes are visible on the surface of the Huangguan pears, but even after the dosage of the Huangguan pears is increased, the control effect is not obvious, and the complete control of the cockscomb disease cannot be realized;

FIG. 6 shows the result of the ε -PL 200mg/L treatment group, which still has the appearance that a portion of the Huangguan pears have the chicken foot spots on their surface, but the color depth of the spots is slightly lighter than that of the ε -PL 100mg/L treatment group, which indicates that even if the ε -PL is increased based on the ε -PL 100mg/L treatment group, the effect is still small, and it can be easily inferred that even if the ε -PL is increased based on the ε -PL 100mg/L treatment group, the effect is still limited;

in the attached figures 7 and 8, the processing groups of epsilon-PL 100mg/L + 1% COS and epsilon-PL 100mg/L + 2% COS are respectively shown, from the results, the surfaces of the two groups of the Huangguan pears are almost free from chicken foot disease stripes, which shows that the epsilon-PL and the COS are jointly processed to play a role in synergy and have a remarkable role in preventing and treating the chicken foot disease of the Huangguan pears. When used in combination, the effect is superior to either single material treatment.

In the invention, through a large amount of experiments and creative work, the inventor mixes epsilon-PL and COS within a reasonable range, and has a synergistic effect on preventing and treating the Huangguan pear chicken foot disease.

Example 2

The application method of polylysine and chitosan oligosaccharide in controlling the cool damage browning of the crown pears comprises the following steps:

(1) weighing 0.1g of epsilon-polylysine powder, dissolving in 0.5L of water, and preparing into a solution; weighing 10g of chitosan oligosaccharide powder, dissolving in 0.5L of water, and preparing into solution; mixing the solutions prepared in the two steps to obtain a mixed solution;

(2) soaking picked Huangguan pears in the mixed solution in the step (1), keeping for 2min, taking out and draining;

(3) and (3) refrigerating the drained Huangguan pears in the step (2) in an environment at the temperature of-1.5-0 ℃.

The experiment results show that the crown pears in the example 2 have basically the same appearance and form after being stored for 90d and shelf life 5d and stored for 180d and being stored for 5 days at normal temperature, and almost no chicken foot diseases exist on the surfaces of the crown pears in the example 2.