Calcium chloride spraying method for improving flavor quality of aronia fruit
By spraying a 0.3% calcium chloride solution on European plum trees at different growth stages, the metabolism of volatile organic compounds was regulated, solving the problem that calcium chloride was difficult to improve the aroma quality of European plum fruits in existing technologies. This achieved the optimization of fruit aroma and quality improvement, meeting the requirements of green cultivation and resource conservation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- INNER MONGOLIA AGRICULTURAL UNIVERSITY
- Filing Date
- 2026-04-17
- Publication Date
- 2026-06-09
AI Technical Summary
In the current technology, the combination of concentration and frequency of calcium chloride application on European plum fruit has not been standardized, making it difficult to effectively improve the aroma quality of the fruit, especially to inhibit the accumulation of unpleasant odor substances, which affects consumer experience and market acceptance.
During the coloring and swelling stage, hardening stage, and full ripening stage of the European plum fruit tree, spray the entire tree with a 0.3% calcium chloride solution. Use an electric sprayer to operate on a sunny morning. Determine the spraying time and method to regulate the metabolism of volatile organic compounds, promote the accumulation of characteristic fruit aroma substances, and inhibit the production of unpleasant odor substances.
It significantly improves the aroma quality of European plum fruit by regulating the metabolism of volatile organic compounds, increasing characteristic fruit and floral aroma substances, reducing unpleasant odors, improving fruit quality, and reducing agricultural pollution, which meets the requirements of green cultivation and resource conservation.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of fruit tree cultivation technology, specifically relating to a method for spraying calcium chloride to improve the flavor and quality of European plum fruit. Background Technology
[0002] The aroma of European plum (Cerasus humilis) fruit, as a crucial component of its flavor quality, directly influences consumers' sensory experience and market acceptance, and can also exert positive physiological and psychological effects on consumers through its pleasant scent. However, the overall aroma characteristics of the fruit are not determined by a single compound, but rather by a complex system composed of various volatile organic compounds (VOCs), including terpenes, esters, alcohols, aldehydes, and acids. Terpenes, esters, and some aldehydes typically impart pleasant floral and fruity aromas to the fruit; alcohols often exhibit grassy notes; and acids, heterocyclic compounds, and nitrogen- and sulfur-containing compounds are often accompanied by unpleasant odors such as sourness, astringency, fishiness, and bitterness. Therefore, the key to improving the aroma quality of the fruit lies not only in increasing the total amount of volatile substances, but also in optimizing the aroma composition, i.e., "removing the grassy smell and enhancing the aroma" while suppressing unpleasant odor components.
[0003] Calcium is an essential mineral element for plant growth and development, playing a crucial role in regulating plant metabolism, participating in signal transduction, maintaining cell wall strength, and protecting cell membrane structure. Calcium is not only an important nutritional quality of fruit but also significantly influences its quality. Calcium chloride is widely used in fruit cultivation to supplement calcium, enhancing fruit firmness, extending storage life, and mitigating physiological disorders. As a vital component of plant cell walls and cell membranes, calcium ions participate in signal transduction and stress response. They can alter the accumulation of flavor compounds such as organic acids and tannins in fruit by regulating cell wall structure, stabilizing membrane systems, and influencing the activity of enzymes related to organic acid metabolism. Current research on the application of calcium chloride focuses primarily on increasing fruit calcium content, enhancing storage tolerance, or preventing calcium deficiency-related physiological disorders. However, a standardized technical solution for the application concentration and frequency of calcium chloride in *Prunus cerasifera* fruit, aimed at "increasing aroma-related substances, reducing acidity and astringency, and optimizing flavor composition," has not yet been publicly available. Therefore, developing a safe, efficient, easy-to-operate calcium chloride spraying method that can significantly improve the flavor and quality of European plum fruit is of great significance for enhancing the commercial characteristics and industrial added value of European plum. Summary of the Invention
[0004] To address the above problems, this invention provides a method for improving the flavor quality of Prunus cerasifera fruit, comprising the following steps:
[0005] (1) Select European plum trees with uniform tree vigor and no alternate bearing or pests and diseases as the treatment objects;
[0006] (2) Apply calcium chloride solution to the leaves at S1, S2 and S3 respectively; S1 is the coloring and swelling period; S2 is the hard ripening period; S3 is the full ripening period.
[0007] Furthermore, during the coloring and swelling period, spray the entire plant with a CaCl2 solution of 0.3% at two times, with an interval of 10 days.
[0008] Furthermore, spray once during the hard ripening stage, using an electric sprayer to spray the entire plant.
[0009] Furthermore, spray the entire plant of the European plum on a sunny morning between 8:00 and 10:00.
[0010] The present invention has the following beneficial effects:
[0011] 1. The method of this invention regulates the aroma metabolism of Prunus armeniaca fruit by spraying the entire plant with a 0.3% (w / v) calcium chloride solution. Compared with the water control, Prunus armeniaca fruit treated with this method showed a significant increase in the accumulation of characteristic aroma compounds. At full ripeness, the calcium chloride solution treatment enhanced the accumulation of volatile metabolites such as ethyl trans-4-decenoate, 2,6,6-trimethyl-1-cyclohexene-1-carboxaldehyde, and 2-ethylhexyl salicylate, which control the aroma of the fruit and flowers.
[0012] 2. The method of this invention significantly improves the aroma quality of *Prunus armeniaca* fruit by spraying the entire plant with a 0.3% (w / v) calcium chloride solution. Compared with the water control, treatment with 0.3% (w / v) calcium chloride solution at full ripeness reduced the accumulation of unpleasant odors caused by volatile metabolites such as 5-ethyl-2-methylthiazole, 4-methyl-1-hexanol, and N,N-dimethylacetamide. This invention provides a new technical means for improving the aroma quality of *Prunus armeniaca* fruit and provides a reference for subsequent research on the effects of calcium chloride on fruit quality.
[0013] 3. The method of this invention focuses on inhibiting the synthesis and metabolism of unpleasant odor substances. This strategy avoids the energy consumption and metabolic burden that may result from excessive stimulation of secondary metabolism, making it a more energy-efficient and effective way to regulate aroma quality.
[0014] 4. This invention improves fruit quality through nutritional regulation (calcium supplementation), which is a green cultivation technology. It can partially replace the use of chemical regulators or preservatives, reduce agricultural non-point source pollution, and is conducive to the sustainable development of orchard ecosystems.
[0015] 5. The method of this invention has a clear application time, is simple to operate, and is easy to master. It can be directly integrated into existing field management practices without increasing labor and material costs. Calcium chloride is widely available and inexpensive, and the spraying operation requires little water, which aligns with the development direction of water-saving and resource-conserving agriculture. Simultaneously, it achieves efficient utilization of limited land resources by improving fruit quality and marketability. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 In the figure, A is the OPLS-DA scatter plot of metabolomics data from samples treated with calcium chloride solution (Ca) and the water control (CK). The horizontal axis represents principal component 1 (89.8% explanatory power), and the vertical axis represents principal component 2 (6.19% explanatory power). Different colors and symbols represent different treatment groups (CK-1 is the water control group; Ca is the calcium chloride treatment group). B is the displacement test plot, where red dots represent R... 2 Y (the model's explanatory power for categorical variables), the blue triangle represents Q. 2 (Model predictive ability), with the horizontal axis representing similarity. The original model's R-value... 2 Y=0.999, Q 2 =0.99, all significantly higher than all permuted models, and Q 2 A negative intercept on the regression line indicates that the OPLS-DA model is not overfitting and its discriminative ability is reliable. C represents the permutation test frequency histogram, and the horizontal axis represents the R-squared value of the permuted model. 2 X, R 2 Y and Q 2 The vertical axis represents the value, and the vertical axis represents the frequency of occurrence of the corresponding value. The R-squared value of the original model is... 2 Y=0.999, Q 2 =0.99, all significantly higher than all permuted models (p<0.005, 200 permutations). D is a histogram of model fitting parameters, where R0.99 2 X = 0.898 represents the model's explanatory power for the metabolomics independent variables, R0 2 Y=0.971 represents the model's explanatory power for the grouped dependent variable, Q 2 =0.959 indicates the model's predictive power.
[0018] Figure 2 A heatmap showing the differences in aroma components in Prunus cerasifera fruit treated with calcium chloride solution. Detailed Implementation
[0019] Various exemplary embodiments of the present invention are now described in detail. Unless otherwise specified, the methods used in the embodiments are conventional methods, and the reagents used are commercially available reagents or reagents prepared using conventional methods. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, characteristics, and embodiments of the present invention.
[0020] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.
[0021] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.
[0022] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.
[0023] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.
[0024] Example 1: Aroma Characteristics Analysis of Prunus cerasifera Fruit After Treatment with Calcium Chloride Solution
[0025] To investigate the aroma characteristics of Prunus cerasifera fruit after treatment with calcium chloride solution, volatile components of MeJA-treated Prunus cerasifera samples were extracted using the SH-SPME method and analyzed by GC-MS.
[0026] The specific method is as follows:
[0027] I. Experimental Materials
[0028] 1. Determining the spraying time. Based on the growth and development process of the European plum fruit, spraying should be carried out on a sunny morning between 8:00 and 10:00 before the fruit coloring and expansion stage and before the hardening stage. At this time, the temperature and humidity are moderate, which is conducive to the absorption of calcium chloride solution on the surface of leaves and fruits.
[0029] 2. Preparation of calcium chloride solution. Prepare a calcium chloride solution with a final concentration of 0.3% (w / v). Taking 10 L of solution as an example, accurately weigh 30 g of anhydrous calcium chloride, add a small amount of distilled water, stir thoroughly to dissolve, and then bring the volume to 10 L. Prepare and use immediately.
[0030] 3. Spraying the entire plant with calcium chloride solution. Load the prepared calcium chloride solution into an electric sprayer and spray evenly over the entire European plum plant, ensuring small, even water droplets form on the leaves and fruit surface without dripping. During spraying, adjust the nozzle angle to ensure even coverage of the fruit and leaves.
[0031] 4. Harvesting. Harvest the fruit after it has reached full ripeness. Select healthy fruit that is uniform in size, free from pests, diseases, and mechanical damage to ensure the representativeness and accuracy of the experimental results.
[0032] 5. Sample processing. The collected fruits were transported back to the laboratory in ice boxes, washed with distilled water and dried, then divided into 3 equal portions and flash-frozen in liquid nitrogen at -80 ℃ for storage until analysis.
[0033] II. Handling Methods
[0034] 1. HS-SPME Extraction Conditions: Under constant temperature of 60℃, shake for 5 min, insert a 120µm DVB / CWR / PDMS extraction tip into the sample headspace vial, perform headspace extraction for 15 min, followed by resolution at 250℃ for 5 min, and then perform GC-MS separation and identification. Before sampling, the extraction tip was aged at 250℃ for 5 min in a Fiber Conditioning Station. Note: New extraction tips were aged in a Fiber Conditioning Station for 2 h before extraction. Furthermore, an SPME Arrow was used, whose sensitivity is up to 10 times that of traditional SPME fiber tips.
[0035] 2. Chromatographic conditions: DB-5MS capillary column (30m × 0.25mm × 0.25μm, Agilent J & W Scientific, Folsom, CA, USA), carrier gas was high-purity helium (purity not less than 99.999%), constant flow rate was 1.2mL / min, injection port temperature was 250℃, and solvent delay was 3.5min. Temperature program: 40℃ held for 3.5min, increased to 100℃ at 10℃ / min, then increased to 180℃ at 7℃ / min, and finally increased to 280℃ at 25℃ / min, held for 5min.
[0036] 3. Mass spectrometry conditions: Electron impact ion source (EI), ion source temperature 230℃, quadrupole temperature 150℃, mass spectrometer interface temperature 280℃, electron energy 70eV, scanning mode selected ion detection mode (SIM), qualitative and quantitative ion precise scanning (GB23200.8-2016).
[0037] III. Data Analysis
[0038] The GC-MS detection platform of Maiwei Metabolism (Wuhan) Biotechnology Co., Ltd. was used, and the software Analyst 1.6.3 (Chong J, 2018) was employed for qualitative and quantitative mass spectrometry analysis, including baseline filtering, peak identification, integration, retention time correction, peak alignment, and mass spectrometry fragmentation analysis. Unsupervised principal component analysis (PCA) and supervised orthogonal partial least squares discriminant analysis (OPLS-DA) were used to perform multivariate statistical analysis on overall metabolites among groups and metabolites within groups.
[0039] IV. Aroma Characteristic Analysis
[0040] Using the control group as a reference, differentially expressed metabolites were screened using the criteria of VIP≥1, P-value<0.05 and |Log2FC|≥1. During the full ripening period of Prunus cerasifera, calcium chloride solution treatment promoted the accumulation of volatile metabolites with fruity and floral aromas, such as trans-4-decenoic acid ethyl ester, 2,6,6-trimethyl-1-cyclohexene-1-carboxaldehyde and 2-ethylhexyl salicylate, while reducing the accumulation of volatile metabolites with fishy, sour, and pungent odors, such as 5-ethyl-2-methylthiazole, 4-methyl-1-hexanol and N,N-dimethylacetamide.
[0041] Table 1. Volatile metabolites that accumulate and are upregulated after treatment of Prunus armeniaca fruit with calcium chloride solution.
[0042]
[0043] Table 2. Volatile metabolites that accumulate and are downregulated after treatment of Prunus armeniaca fruit with calcium chloride solution.
[0044]
[0045] Table 2 (Continued) - Decreased volatile metabolites in Prunus cerasifera fruit after treatment with calcium chloride solution
[0046]
[0047] Example 2: Aroma Component Difference Analysis
[0048] To assess the impact of calcium chloride solution treatment on plant metabolomics, orthogonal partial least squares discriminant analysis (OPLS-DA) was used to compare samples from the calcium chloride solution treatment group and the water control group. Figure 1 As shown in the OPLS-DA score plot, the calcium chloride solution treatment group and the control group exhibited significant separation in their metabolic profiles, indicating that calcium chloride solution treatment significantly altered the metabolic composition of the plants. Simultaneously, some separation also existed between samples at different time points within the calcium chloride solution group, suggesting that the metabolic response has temporal dynamics. The model evaluation parameter is R0. 2 Y=0.999, Q 2 =0.99, indicating that the model has a good fit and strong predictive ability. Further robustness of the model was verified through a permutation test (200 random permutations), and the results showed that the R-value of the original model was... 2 Y and Q 2 The values were all significantly higher than those of the random permutation model, confirming that the model did not overfit and that the grouping was statistically significant. Calcium chloride solution treatment induced significant and reproducible changes in the metabolic profile of plants, and these changes varied at different treatment time points, indicating its potential application value in regulating plant metabolism.
[0049] To further analyze the contribution of different aroma components to fruits treated with calcium chloride solution, based on the data analysis structure of this embodiment, volatile differential metabolites of Prunus armeniaca at full ripeness were screened using the criteria of VIP≥1, P-value<0.05, and |Log2FC|≥1. Specifically, 51 differential aroma substances were screened at full ripeness, including 23 esters, 4 heterocyclic compounds, 5 ketones, 1 terpene, 5 acids, 2 aldehydes, 1 ether, 9 alcohols, and 1 amine. Figure 2 As can be seen from Tables 1 and 2, compared with the CK group, the content of 11 volatile metabolites increased and the content of 40 volatile metabolites decreased.
[0050] Treatment with calcium chloride solution can induce significant and reproducible changes in the aroma metabolism profile of Prunus cerasifera fruit, and this regulatory effect precisely matches the key developmental stages of aroma substance synthesis. Spraying calcium chloride during the critical aroma metabolism regulation stage from the pre-coloring and expansion stage to the firm-ripe stage of Prunus cerasifera fruit can precisely optimize aroma components at full ripeness by regulating the fruit's aroma metabolism pathways. On the one hand, it significantly upregulates the synthesis and accumulation of characteristic fruit and floral aroma substances such as esters, terpenes, and aldehydes; on the other hand, it inhibits the accumulation of undesirable components such as acids, alcohols, and heterocyclic compounds that produce sour, astringent, fishy, and pungent odors. Ultimately, this optimizes the flavor of Prunus cerasifera fruit, thereby significantly improving its aroma quality and flavor characteristics.
[0051] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.
Claims
1. A method for improving the flavor quality of European plum fruit, characterized in that, Includes the following steps: (1) Select European plum trees with uniform tree vigor and no alternate bearing or pests and diseases as the treatment objects; (2) Apply calcium chloride solution to the leaves at S1, S2 and S3 respectively; S1 is the coloring and swelling period; S2 is the hard ripening period; S3 is the full ripening period.
2. The method according to claim 1, characterized in that, Spray the entire plant with a CaCl2 solution of 0.3% at the end of the coloring and swelling period, twice during the coloring and swelling period, with an interval of 10 days.
3. The method according to claim 1, characterized in that, Apply once during the hard-ripe stage, using an electric sprayer to spray the entire plant.
4. The method according to claim 1, characterized in that, Spray the entire plant of the European plum on a sunny morning between 8:00 and 10:00.