Method for improving quality of Korla bergamot pears

Abstract

The invention relates to two methods for improving the quality of Korla bergamot pears, and belongs to the technical field of fruit tree planting, the first method is to spray a polypeptide EGAK solution on branches of the Korla bergamot pears in a fruit swelling period every year. The second method comprises the following steps: spraying a mixed solution of polypeptide EGAK and 5-ALA on branches of the Korla pear in a fruit swelling period every year. The invention simultaneously provides two solutions for improving the quality of the Korla pear, wherein the first solution is a 50-500ppm polypeptide EGAK solution; the second solution is a mixed solution of polypeptide EGAK and 5-ALA, and the final concentration of the mixed solution is 50-500 ppm. The method disclosed by the invention is simple and low in cost, can effectively improve the quality of the Korla pear fruits, reduce the acidity and increase the content of vitamin C, and has very high economic value.

Description

Technical Field

[0001] The invention belongs to the technical field of fruit tree planting, and particularly relates to a method for improving the quality of Korla fragrant pear. Background Art

[0002] Korla pear belongs to the Xinjiang pear system of the genus Pyrus in the Rosaceae family. It is one of the fruit crops with important economic value in Xinjiang. Its pleasant flavor and rich nutrients make it popular in the market. The rich and unique aroma and crisp taste are the main characteristics of Korla pear. Among them, sugar, acid and aroma together constitute its overall flavor, and hardness, stone cells and other qualities together constitute its overall taste. Both are important factors in the fresh consumption and processing of fruits. In addition, there are "male pears" (permanent calyx fruits) and "female pears" (decalyx fruits) in Korla pear fruits. Most studies believe that decalyx fruits have better quality and strong aroma, and have strong market competitiveness. However, there are few studies on the volatile metabolites of Korla pear. According to the previous research of our research group on the volatile metabolites of Korla pear, it was found that exogenous spraying of 5-aminolevulinic acid (5-ALA) has a certain effect on the quality of Korla pear.

[0003] Pentaaminolevulinic acid (5-ALA) is a highly effective plant growth regulator and an important biosynthetic precursor of tetrapyrrole compounds, and is widely used in the field of horticulture. Studies have shown that the application of 5-ALA has the effect of improving fruit quality and yield. For example, exogenous 5-ALA increased the content of soluble solids, soluble sugars, titratable acid, vitamin C and soluble protein in the fruit of 'Fengshui' pear, and increased the weight of single fruit. Spraying 5-ALA on the fruit surface or rhizosphere irrigation of 5-ALA significantly promoted fruit coloring, nutritional quality and flavor quality, and promoted the ripening of tomato fruit. In addition, 5-ALA can also increase the aroma content of the fruit. Studies have found that 5-ALA treatment can increase the ethyl acetate content of the fruit and produce geranyl acetone, thereby making the grape aroma richer. Exogenous application of 5-ALA significantly increased the content of volatile compounds in tomato fruit, producing carotenoid derivatives 6-methyl-5-hepten-2-one, geranylacetone, b-ionone and ionone, which impart flavor and aroma to tomato fruit. These results suggest that 5-ALA has the potential to promote the increase of volatile compounds in fruit.

[0004] Peptides are short-chain molecules composed of multiple amino acids connected by peptide bonds. They are the basic units of proteins and independently participate in many important functions in organisms. Peptides can improve the quality of crops and increase the nutritional value of crops. By optimizing the growth process of plants, peptides can enable crops to accumulate more nutrients during growth, thereby improving the overall quality of crops. However, not all peptides have a promoting effect on crop fruits.

[0005] The research team found that exogenous spraying of 5-ALA does have a certain promoting effect on the quality of Korla pear, but the effect is not very good. Therefore, in order to further improve the quality of Korla pear, the inventors further studied and improved the cultivation technology of Korla pear to provide valuable theoretical basis for its application in the agricultural field. Summary of the invention

[0006] In order to improve the quality, taste and related physical and chemical indicators of Korla fragrant pear, the present invention provides two methods for increasing the quality of Korla fragrant pear based on previous research, which are as follows.

[0007] A method for improving the quality of Korla fragrant pear, specifically comprising spraying a polypeptide EGAK solution on branches of the Korla fragrant pear during the fruit expansion period of each year.

[0008] Wherein, the spraying concentration of the polypeptide EGAK solution is 50-500 ppm.

[0009] Wherein, the spraying amount of the polypeptide EGAK is 2-20 mL / branch.

[0010] The second method for improving the quality of Korla fragrant pear is to spray a mixed solution of polypeptide EGAK and 5-ALA on the branches of Korla fragrant pear during the fruit expansion period every year.

[0011] Wherein, the spraying concentration of the polypeptide EGAK solution is 50-200 ppm.

[0012] Wherein, the spraying concentration of the 5-ALA solution is 200 ppm.

[0013] Obviously, the polypeptide EGAK is sprayed on the branches of Korla fragrant pear to improve the quality of Korla fragrant pear.

[0014] The invention also provides a solution for improving the quality of Korla fragrant pear, specifically a 50-500 ppm polypeptide EGAK solution.

[0015] The second mixed solution for improving the quality of Korla fragrant pear is specifically a mixed solution of polypeptide EGAK and 5-ALA with a final concentration of 50 to 500 ppm.

[0016] Wherein, the concentration of 5-ALA is 200 ppm.

[0017] Beneficial Effects

[0018] The current research results show that some peptides can improve the quality of crops and increase the nutritional value of crops. By optimizing the growth process of plants, peptides can enable crops to accumulate more nutrients during growth, thereby improving the overall quality of crops. Xiao Lele's master's thesis "The Effect of Peptide Spraying on the Yield and Quality of Fresh Grapes" records that the application of peptides alone and the combination of peptides and zinc can increase the yield and quality of fruits. The combination of peptides and zinc increased the yield of grapes by 10.99% compared with the application of zinc alone, and the soluble sugar content in the fruit increased significantly. The inventor sprayed his polypeptide on Korla pear from 2022 to 2023, but the result was that the purchased polypeptide had no significant effect on the fruit quality of Korla pear. Therefore, the inventor analyzed the acid metabolism pathway of sweet pear and obtained two polypeptides, namely polypeptide EGAK and polypeptide EGKI, and used these two polypeptides for spraying. The results showed that polypeptide EGAK could not increase the soluble sugar content of the fruit, but reduced the soluble sugar content. However, polypeptide EGAK can reduce the quality of Korla pear fruit, reduce acidity, and improve the taste of Korla pear. Spraying it together with 5-ALA can also increase the hardness of Korla pear, and the taste and quality are further improved.

[0019] The inventors found through comparative experiments that the effects of spraying polypeptide EGAK and polypeptide EGKI on the quality of Korla pear fruit are quite different, which may be because polypeptide EGAK directly regulates the acid metabolism and sugar metabolism inside the fruit.

[0020] It can be seen from the results of Examples 1 and 2 that when the polypeptide EGAK is sprayed alone at a concentration of 300-400 ppm, the fruit quality is the best. Of course, 200 and 500 ppm also have a certain effect on the fruit. At the same time, if 200 ppm of 5-ALA is mixed for spraying, only 50-200 ppm of the polypeptide EGAK is needed to achieve the same effect.

[0021] In summary, spraying polypeptide EGAK alone or spraying a mixture of polypeptide EGAK and 5-ALA can reduce the acidity of Korla pear and increase the content of vitamin C, while the effect of using 5-ALA alone is not good. It can be seen that 5-ALA plays a synergistic role and reduces the amount of EGAK used.

[0022] The invention has low cost and few spraying times, is applicable to various pear orchards, and after spraying, the acidity of Korla fragrant pear is significantly reduced, the content of vitamin C is significantly increased, the taste is significantly improved, and the invention has high economic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is the chemical structural formula of polypeptide EGAK.

[0024] Figure 2It is the chemical structural formula of polypeptide EGKI. DETAILED DESCRIPTION

[0025] The present invention is described in detail below with reference to examples. All methods and techniques, unless otherwise specified, are conventional methods and techniques.

[0026] Among them, 5-ALA (99%) was purchased from Shanghai Yuanye Biotechnology Co., Ltd. (product number S30944, only provided for scientific research experiments). The peptide EGAK was synthesized by sequentially connecting the peptide bonds of glutamic acid, glycine, alanine and lysine, and the peptide EGKI was synthesized by sequentially connecting the peptide bonds of glutamic acid, glycine, lysine and isoleucine. The source of the prepared peptides was QYAOBIO (China Peptides Co., Ltd.).

[0027] Experimental methods

[0028] (1) Single fruit weight, longitudinal and transverse diameter

[0029] Five fruits were randomly selected from each tree from the four directions of southeast, northwest, and northeast. There were 20 fruits per tree and 60 fruits per treatment. They were weighed with a 1 / 10,000 electronic balance and the average value was calculated to obtain the single fruit weight. The vertical and horizontal diameters were measured with a vernier caliper to calculate the average value. Fruit shape index: The fruit shape index is expressed as the ratio of the vertical diameter to the horizontal diameter of the fruit.

[0030] (2) Hardness

[0031] The hardness of each pear was measured using a GY-1 hardness meter. Fifteen fruits were randomly selected from each treatment, with 5 fruits in a group. The hardness of each pear was measured at four positions using a GY-1 hardness meter, and the average value was calculated.

[0032] (3) Soluble solids

[0033] A digital saccharimeter was used for determination. Fifteen fruits were randomly selected from each treatment, with 5 fruits randomly selected as a group. The soluble solids content of each pear was measured at four positions using a digital saccharimeter, and the average value was calculated.

[0034] (4) Stone cell content

[0035] The frozen method was used for determination. The mixed pear pulp was frozen in a -20℃ refrigerator for 24 hours and then blended into juice in a juicer. Water was added and the upper suspended matter was poured out. The upper suspended matter was rinsed at least 4 times. The lower stone cells were collected by filtering with filter paper and then dried in an oven at 70℃ for 3 hours. The dried stone cells were weighed.

[0036] (5) Soluble sugar content

[0037] The anthrone-sulfuric acid colorimetric method was used for determination. Glucose solution was prepared and a standard curve was drawn. The soluble sugar in the pear samples with different treatments was extracted and its absorbance was measured at 630 nm. The amount of sugar in the sample (μg) was obtained through the standard curve. The soluble sugar content in the sample was calculated according to the following formula:

[0038]

[0039] In the formula: C-the amount of glucose in the sample test tube obtained from the standard curve (μg);

[0040] n-dilution factor;

[0041] 1000-conversion factor;

[0042] V t -Total volume of sample extract (mL);

[0043] V s - Volume of sample liquid taken during measurement (mL);

[0044] W-sample fresh weight (g).

[0045] (6) Titratable acid content: Determined by acid-base neutralization titration. Determined by NaOH titration, weigh 5g of ground fruit, wash into a test tube with a small amount of distilled water, place in a boiling water bath for 40min, take out and cool, filter and dilute to 100mL. Pipette 20mL of the test solution into a conical flask, add 2 drops of 1% phenolphthalein, and titrate with 0.05mol / LNaOH standard solution until the light pink color does not fade.

[0046]

[0047] Where: C-NaOH standard solution molar concentration;

[0048] V 1 - Volume of NaOH consumed during titration (mL);

[0049] V 0 - Volume of sample solution aspirated (mL);

[0050] m-sample mass (g);

[0051] K - coefficient for conversion to grams of a certain acid.

[0052] (7) Vitamin C content: Determined by 2,6-dichlorophenol indophenol titration method. The determination result is calculated by 2,6-dichlorophenol indophenol titration method:

[0053]

[0054] Where: V1 - Volume of dye consumed in sample titration (mL);

[0055] V 0 - Volume of dye consumed in blank titration (mL);

[0056] C-amount of ascorbic acid in 1mL (mg);

[0057] V S - Volume of sample solution taken during titration (mL).

[0058] The experiment was conducted at the Xiyu Xiangfei Pear production base in Xiaolanggan Village, Awati Township, Korla City. The row spacing was 3m*4m. The trees were 20 years old, vigorous, and uniformly growing. 3 to 5 pear trees were randomly selected for each group, and each tree was sprayed with one treatment. When spraying the test trees, large branches with good sunlight in the southwest, no pests and diseases, uniform growth, and vigorous growth were selected for spraying. The spraying time was selected before 12:00 in the morning on a sunny and windless or breezy day. The standard was that all the sprayed parts were wet and liquid droplets dripped. The spraying amount was 2 to 20 mL / branch according to the different thicknesses of branches.

[0059] The experiment was sprayed twice, once every 15 days. The first spraying was carried out on July 4, 2024 (fruit expansion period), and the second spraying was carried out on July 19, 2024 (fruit expansion period).

[0060] Sample collection: Fruits of test samples were collected on September 12, 2024 (fruit maturity period). Fruits with good lighting conditions outside the crown, a height of 1 to 1.5 m, uniform size, no pests and diseases, and regular fruit shape were collected as test samples for each treatment. A total of 18 fruits were collected as test samples for each treatment. Among them, 9 fruits were used as samples for measuring appearance quality, including longitudinal diameter, transverse diameter, fruit shape index and fruit weight, and 9 fruits were used as samples for measuring internal quality, including hardness and soluble solids.

[0061] Example 1

[0062] This example provides a method for improving the quality of Korla fragrant pear, which includes spraying the polypeptide EGAK alone. The specific experimental method is as follows.

[0063] The concentrations of EGAK were set to 200, 300, 400, and 500 ppm for spraying. The specific experiment is shown in the following table.

[0064] period Group 1 Group 2 Group 3 Group 4 Group 5 July 4th 200 300 400 500 Equivalent clean water (CK) July 15 200 300 400 500 Equivalent clean water (CK)

[0065] The fruit harvest period will begin on September 12, 2024. Taking into account the differences between fruits, 9 fruits were selected for measurement and the average value was taken. The specific fruit shape index, single fruit weight, soluble solids and hardness are shown in the following table.

[0066] Group Fruit shape index (%) Single fruit weight (g) Soluble solids (%) <![CDATA[Hardness (kg / cm 2 )]]> Group 1 1.04±0.02 132.52±2.89 11.12±0.17 5.80±0.11 Group 2 1.06±0.03 136.72±4.57 12.64±0.26 5.93±0.18 Group 3 1.04±0.02 135.22±2.75 12.30±0.29 6.07±0.16 Group 4 1.04±0.02 137.36±4.30 11.34±0.12 5.76±0.18 Group 5 1.03±0.02 120.97±4.96 10.96±0.35 6.41±0.14

[0067] From the table above, we can see that after the treatment with polypeptide EGAK, the weight of single fruit increased, the soluble solid content increased, and the average hardness of the fruit decreased, but the improvement effect was obvious. From the average result, the effect on the fruit shape index was not significant. It can be seen that spraying polypeptide EGAK alone has no obvious effect on the shape and weight of the fruit.

[0068] The specific ratios of soluble sugar, stone cells, Vc, titratable acid and solid acid are shown in the following table.

[0069]

[0070] It can be seen from the above table that after treatment with polypeptide EGAK, the vitamin C content increased significantly, while the titratable acid content decreased, the solid acid ratio increased significantly, the stone cell content did not change significantly, the soluble sugar content decreased, the sweetness did not decrease, and the sourness decreased significantly. It can be seen that spraying polypeptide EGAK can increase the vitamin C content.

[0071] Example 2

[0072] This embodiment provides a method for improving the quality of Korla fragrant pear, and the specific experimental method is as follows.

[0073] The concentrations of 50, 100, 150, and 200 ppm of polypeptide EGAK were set to be mixed with 200 ppm of 5-ALA (5-aminolevulinic acid) for spraying. 200 ppm of 5-ALA was the best spraying concentration obtained in the previous experiments. The specific experiments are shown in the following table.

[0074]

[0075] The fruit harvest period will begin on September 12, 2024. Taking into account the differences between fruits, 9 fruits were selected for measurement and the average value was taken. The specific fruit shape index, single fruit weight, soluble solids and hardness are shown in the following table.

[0076] Group Fruit shape index (%) Single fruit weight (g) Soluble solids (%) <![CDATA[Hardness (kg / cm 2 )]]> Group 1 1.04±0.01 132.74±2.79 12.12±0.42 6.68±0.20 Group 2 1.06±0.03 132.30±1.67 12.07±0.19 6.77±0.26 Group 3 1.05±0.02 133.54±2.22 12.14±0.32 6.65±0.09 Group 4 1.06±0.03 133.15±2.31 12.46±0.15 6.97±0.14 Group 5 1.04±0.02 131.44±4.35 11.29±0.43 6.60±0.16 Group 6 1.05±0.02 121.41±1.47 10.94±0.18 6.50±0.15 Group 7 1.04±0.01 131.83±1.16 11.06±0.33 6.13±0.13

[0077] It can be seen from the above table that after spraying polypeptide EGAK and 5-ALA, the weight of single fruit increased, but the increase was not obvious, the soluble solid content increased, and the average hardness of the fruit increased. From the average results, it has little effect on the fruit shape index.

[0078] The specific ratios of soluble sugar, stone cells, Vc, titratable acid and solid acid are shown in the following table.

[0079]

[0080] As can be seen from the table above, after spraying polypeptide EGAK and 5-ALA, the vitamin C content increased significantly, while the titratable acid content decreased, and the solid acid ratio increased significantly. In this way, under the condition that the vitamin C content in the fruit increased, the total titratable acid also decreased, indicating that the acidic components in the fruit decreased. It may be that after mixed spraying, the decomposition of major acid-producing substances such as citric acid and tartaric acid was accelerated, which reduced the acidity of the fruit, while the stone cell content did not change, but the soluble sugar content decreased. From the results of tasting, there was no significant difference in sweetness compared with the CK control group. Analysis showed that the mixed spraying of polypeptide EGAK and 5-ALA mainly accelerated the acid metabolism and sugar metabolism of the fruit. Since the sweetness of Korla pear itself is relatively large, the taste of Korla pear is generally increased.

Claims

1. A method for improving the quality of Korla fragrant pear, characterized in that: The method for improving the quality of Korla fragrant pear is specifically to spray the polypeptide EGAK solution on the branches of Korla fragrant pear during the fruit expansion period of each year.

2. The method for improving the quality of Korla fragrant pear according to claim 1, characterized in that: The spraying concentration of the polypeptide EGAK solution is 50-500 ppm.

3. According to the method for improving the quality of Korla fragrant pear, it is characterized in that: The spraying amount of the polypeptide EGAK is 2-20 mL / branch.

4. A method for improving the quality of Korla fragrant pear, characterized in that: The method for improving the quality of Korla fragrant pear specifically comprises spraying a mixed solution of polypeptide EGAK and 5-ALA on branches of Korla fragrant pear during the fruit expansion period of each year.

5. The method for improving the quality of Korla fragrant pear according to claim 1, characterized in that: The spraying concentration of the polypeptide EGAK solution is 50-200 ppm.

6. The method for improving the quality of Korla fragrant pear according to claim 1, characterized in that: The spraying concentration of the 5-ALA solution is 200 ppm.

7. A use of polypeptide EGAK, characterized in that: The polypeptide EGAK is sprayed on branches of Korla fragrant pear to improve the quality of Korla fragrant pear.

8. A solution for improving the quality of Korla pear, characterized in that: The solution is a 50-500 ppm polypeptide EGAK solution.

9. A mixed solution for improving the quality of Korla fragrant pear, characterized in that: The mixed solution is a mixed solution of polypeptide EGAK and 5-ALA with a final concentration of 50-500 ppm.

10. The mixed solution for improving the quality of Korla fragrant pear according to claim 9, characterized in that: The concentration of 5-ALA is 200 ppm.

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