A method for improving the flavor of olive oil by cultivating olives

Abstract

The application discloses an olive cultivation method for improving the flavor of olive oil and belongs to the technical field of olea europaea planting, and specifically comprises the following steps: S1, applying a compound fertilizer containing a nitrogen fertilizer inhibitor to the root of an olea europaea tree during the flowering period of the olea europaea tree; and S2, respectively spraying high-nitrogen foliar fertilizer containing a brassinolide preparation at 1-2 weeks after the application of the compound fertilizer and during the fruit setting period. The olive cultivation method for improving the flavor of olive oil can improve the content of flavor substances in olive fruits on the basis of ensuring yield, effectively improves the flavor quality of olive oil, and has important significance for promoting the development of the olea europaea industry and improving the market competitiveness of olive oil.

Description

Technical Field

[0001] This invention relates to the field of olive cultivation technology, specifically to a method for cultivating olives to enhance their flavor. Background Technology

[0002] Olive oil possesses a complex and multi-layered flavor system, primarily composed of various flavor compounds, including heterocyclic compounds, aldehydes, terpenes, alcohols, esters, phenols, aliphatic hydrocarbons, fatty acids, ketones, and alkenes. These flavor compounds contribute significantly to the nutritional and medicinal value of olive oil, and are the core reason why it is known as "liquid gold."

[0003] Olive trees in my country are mainly cultivated in arid, semi-mountainous regions with loess soils. The soil is typically heavy clay soil with low organic matter content and poor aeration. Furthermore, concentrated rainfall leads to significant nutrient loss and soil compaction. Therefore, scientific fertilization is crucial for olive cultivation, as the selection and application of fertilizers directly impact yield and flavor quality. Traditional olive cultivation methods primarily rely on root fertilization with high nitrogen content, focusing on increasing fruit yield. However, because olive trees' flowers and leaves are highly sensitive to nitrogen, the nitrogen supply from the roots cannot keep pace with the accumulation of flavor compounds in the fruit. This imbalance easily leads to excessive vegetative growth, limited flavor compound formation in the fruit, and difficulty in achieving high flavor content. Consequently, the produced olive oil fails to meet the demands of the high-end market in terms of flavor complexity and intensity.

[0004] Therefore, how to increase the flavor compound content of olive oil while ensuring fruit yield is of great significance for improving the added value and market competitiveness of the olive oil industry. Summary of the Invention

[0005] Therefore, this invention provides an olive cultivation method to improve the flavor of olive oil. While ensuring yield, it can target the increase of flavor compounds in olives, effectively improving the flavor quality of olive oil.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] An olive cultivation method for enhancing the flavor of olive oil includes the following steps:

[0008] S1. During the flowering period of olive trees, apply compound fertilizer containing nitrogen fertilizer inhibitors to the roots of the plants.

[0009] S2. One to two weeks after applying compound fertilizer and during the fruit setting period, spray high-nitrogen foliar fertilizer containing brassinolide preparations.

[0010] In the above technical solution: the flowering and fruit-setting periods are key fertilization periods in olive cultivation. Compound fertilizers provide comprehensive basic nutrients for the growth of all organs. The addition of nitrogen fertilizer inhibitors allows for the effective slow release of nitrogen from the compound fertilizer at the plant roots, ensuring long-term retention and balanced utilization of nitrogen within the plant. This avoids nutrient imbalance caused by excessive absorption in the short term, laying a stable and lasting nitrogen source foundation for the robust development of subsequent fruit and the accumulation of flavor compounds, rather than simply pursuing tree growth or rapid fruit enlargement. One to two weeks after applying the compound fertilizer and during the fruit-setting period, high-nitrogen foliar fertilizers containing brassinolide formulations promote fruit enlargement and the synthesis of flavor compounds. Brassinolide is a highly efficient plant growth regulator that can extend the growth period of flower buds and fruit, providing a longer "window" for the synthesis and accumulation of flavor compounds. Foliar spraying provides targeted nitrogen supplementation to flowers and leaves in a gentle manner, offering continuous and efficient advantages, ensuring nitrogen supply and nutritional balance during fruit growth. Therefore, spraying high-nitrogen foliar fertilizer during specific growth stages can complement the slow-release nitrogen from the roots, achieving a targeted breakthrough in the flavor and quality of olives. This effectively promotes fruit development and the generation of a large amount of flavor substances, significantly increasing the content of flavor substances in the fruit while ensuring fruit yield.

[0011] Furthermore, the mass fractions of each element in the high-nitrogen foliar fertilizer sprayed during the flowering period are as follows: brassinolide preparation 0.2-0.4%, nitrogen fertilizer 0.5-0.7%, phosphorus fertilizer 0.2-0.4%, potassium fertilizer 0.05-0.2%, and micronutrients 0.01-0.02%; the mass fractions of each element in the high-nitrogen foliar fertilizer sprayed during the fruit setting period are as follows: brassinolide preparation 0.1-0.2%, nitrogen fertilizer 0.3-0.4%, phosphorus fertilizer 0.2-0.3%, potassium fertilizer 0.2-0.3%, and micronutrients 0.01-0.02%.

[0012] In the above technical solution, high nitrogen during the flowering period promotes nutrition, laying the foundation for flowering and fruit setting. The role of nitrogen is to maintain vigorous photosynthesis in the leaves, providing sufficient organic nutrients for the development of flower organs and subsequent fruit setting. Phosphorus and potassium are combined to ensure reproductive development and help enhance tree vigor and stress resistance. Brassinolide can effectively regulate the balance of endogenous hormones and alleviate environmental stress. Combined with high nitrogen elements, it can significantly improve pollen viability and pollination success rate, preventing "flowering without fruit". During the fruit setting period, the nitrogen content is reduced from 0.5-0.7% during the flowering period to 0.3-0.4%. The purpose is to ensure the basic needs for fruit enlargement while avoiding excessive nitrogen leading to excessive vegetative growth and competition for nutrients with the fruit. The proportion of potassium fertilizer is significantly increased, which can promote the transport of photosynthetic products to the fruit and accelerate fruit enlargement. The amount of brassinolide is reduced and combined with high nitrogen elements to focus on maintaining plant health, preventing premature aging, and ensuring the appearance and internal quality of the fruit. By combining different formulations of high-nitrogen foliar fertilizers during the flowering and fruit-setting periods, the fertilization principle of "promoting growth in the early stage and ensuring quality in the later stage" is reflected. This approach can effectively increase the content of flavor substances in olive fruits while improving tree health and ensuring yield.

[0013] Furthermore, the foliar fertilizer sprayed during the flowering period also includes 0.1-0.2% borax, which can promote flowering and prolong the flowering period; the foliar fertilizer sprayed during the fruit setting period also includes 0.1-0.2% superphosphate, which can improve the adaptability of the fruit, so as to enlarge the fruit and ensure the quality of the fruit.

[0014] Furthermore, compound fertilizer is a mixture of compound fertilizer and organic fertilizer, with the mass ratio of nitrogen, phosphorus and potassium in the compound fertilizer being 1:1:1.

[0015] In the above technical solution, organic fertilizer is the main component and chemical fertilizer is the auxiliary component, with a comprehensive balance of nitrogen, phosphorus and potassium, which helps to increase the yield of olive fruit.

[0016] Furthermore, the compound fertilizer also includes lime, and the mass ratio of organic fertilizer, compound fertilizer and lime in the compound fertilizer is 100:2-3:0.8-1.2.

[0017] In the above technical solution, organic fertilizer is the main component and chemical fertilizer is the supplement. The nitrogen, phosphorus and potassium are comprehensively balanced. At the same time, it is applied in combination with lime to provide high calcium, loose soil with a slightly alkaline pH, which is conducive to the absorption of nitrogen by olive plants, good disease resistance, and can ensure high and stable yield.

[0018] Furthermore, the nitrogen fertilizer inhibitor is a mixture of dicyandiamide and 3,4-dimethylpyrazole phosphate in a mass ratio of 1:1, and its dosage is 2%-3% of the weight of nitrogen fertilizer in the compound fertilizer.

[0019] In the above technical solutions, the selection of the type and dosage of inhibitors can achieve a longer-lasting effect in inhibiting nitrification, enabling compound fertilizers to achieve stability and effectively improving the nitrogen conversion and utilization rate of the soil.

[0020] Furthermore, root fertilization adopts a ring fertilization method: dig a ring trench 30-50 cm wide and 40-60 cm deep at the outer edge of the tree canopy projection range, first sprinkle a layer of wood ash at the bottom of the ring trench, then mix the compound fertilizer with the soil and fill it in and tamp it down.

[0021] In the above technical solutions, ring fertilization can promote nutrient release, create a healthy environment for the root system, and indirectly improve fruit quality.

[0022] Furthermore, the application rate of compound fertilizer is as follows: 10-20 kg / tree for trees aged 1-3 years; 30-60 kg / tree for trees aged 4-8 years; and 80 kg / tree for trees aged 8 years and above.

[0023] In the above technical solutions, precise fertilization according to tree age can improve the soil, ensure fertilizer efficiency, restore tree vigor, and at the same time reduce nutrient loss and reduce environmental pollution.

[0024] Furthermore, the brassinolide formulation is obtained by combining brassinolide and carboxylated zeolite powder.

[0025] In the above technical solution, zeolite has a stable neutral pH and abundant porous structure, which can effectively load brassinolide, achieving long-term sustained release of brassinolide and solving the pain points of brassinolide being easily metabolized and requiring multiple sprays. At the same time, carboxylated zeolite powder has abundant carboxyl groups and good compatibility and binding properties, which can bond with the hydroxyl groups in brassinolide and combine with lipids in the waxy layer of flower and fruit epidermis. This allows the brassinolide preparation to not only be released slowly, but also to be "intelligently released" during the flowering period and fruit growth, achieving targeted release of brassinolide preparation to flowers and fruits. While extending the window period for flavor substance synthesis, it effectively solves the problem of nitrogen competition and nutrient imbalance between flowers and leaves, ensuring that flower and fruit development is promoted during the olive flowering and fruit setting periods, and effectively increasing the flavor substance content of the fruit.

[0026] Furthermore, the preparation method of brassinolide formulations includes the following steps:

[0027] A1. Add zeolite powder to an aqueous solution of fatty acid methyl ester sulfonate, heat to 60-70 ℃, stir at a constant temperature, add citric acid, heat to 90-95 ℃, stir at a constant temperature, cool to room temperature, filter and dry to obtain carboxylated zeolite powder.

[0028] A2. Mix the brassinolide aqueous solution with carboxylated zeolite powder evenly to obtain a mixture. Filter and dry the mixture to obtain a brassinolide preparation. The brassinolide preparation has a brassinolide loading of 1.5-2.5% based on the weight of the zeolite powder.

[0029] In the above technical solution, fatty acid methyl ester sulfonate is an anionic surfactant that can effectively clean impurities on the surface of zeolite powder, ensuring the unobstructed flow of its pores. At the same time, it can introduce potential reaction sites on the zeolite surface, allowing the zeolite powder to interact with citric acid and obtain abundant carboxyl groups. Citric acid has high permeability and wetting properties, enabling it to penetrate deep into the pores of zeolite and form stable coordination bonds with metal ions in the zeolite framework. This allows citric acid molecules to be firmly adsorbed by the internal and external bonding of zeolite powder, resulting in uniformly distributed carboxyl groups. This effectively enhances the surface polarity and binding capacity of the zeolite powder carrier, thereby significantly improving the loading, uniformity, and stability of brassinolide.

[0030] The technical solution of the present invention achieves the following beneficial technical effects:

[0031] 1. The core technology of this invention lies in combining traditional fertilization strategies that guarantee yield with nitrogen regulation mechanisms that enhance flavor and quality. Through a synergistic regulation strategy of root-based slow-release nitrogen and foliar targeted nitrogen supplementation, targeted interventions are applied to different parts (roots and leaves), achieving dual optimization of yield and flavor in olive cultivation and resolving the contradiction between high yield and quality. Specifically, during the flowering period, compound fertilizers containing nitrogen inhibitors are applied to the roots to ensure nutrient supply while controlling excessive nitrogen absorption and accumulation. After applying high-nitrogen fertilizer and during fruit setting, high-nitrogen foliar fertilizers containing brassinolide are sprayed, using plant growth regulators to direct nutrient flow to the fruit and activate the biosynthetic pathways of flavor compounds, effectively increasing the content of flavor compounds in olive oil.

[0032] 2. The slow-release effect of nitrogen fertilizer inhibitors in the soil, combined with the intelligent release characteristics of brassinolide preparations in floral and leaf tissues, constructs a complete nitrogen management system from soil to plant, and from root system to fruit. By using carboxylated zeolite powder as a carrier for the loading and targeted release of brassinolide, plant growth regulators can precisely act on the key stages of flower bud differentiation and fruit development, significantly extending the physiological window period for flavor compound synthesis. After carboxylation treatment, the carboxyl groups on the surface of zeolite form stable hydrogen bonds and coordination interactions with brassinolide molecules, while simultaneously exhibiting affinity binding with lipids in the waxy layer of the flower epidermis. This dual-action mechanism allows brassinolide preparations to preferentially adhere to the flower surface after spraying, gradually releasing active ingredients as flowering progresses and fruit develops. This avoids the drawback of conventional brassinolide preparations requiring multiple sprays due to rapid metabolism, resulting in a significant increase in the flavor compound content of olive fruit.

[0033] 3. The cultivation method provided by this invention has significant ecological adaptability. Specifically designed for the soil characteristics of loess-type semi-mountainous arid regions in my country, the addition of lime to the compound fertilizer effectively regulates soil pH and improves the permeability and water and fertilizer retention capacity of heavy clay soils. The rational ratio of organic fertilizer and compound fertilizer balances the needs of soil fertility improvement and nutrient supply. The adoption of ring fertilization technology concentrates fertilizer in the dense root layer, improving nutrient utilization efficiency and reducing the risk of soil and water pollution. The age-based fertilization scheme meets the nutritional needs of olive trees at different growth stages while avoiding resource waste and environmental burden caused by excessive fertilization. (See attached figures for details.)

[0034] Figure 1 Comparative images of olive oil samples from Example 1 and Comparative Example 1 of this invention;

[0035] Figure 2 GC-IMS three-dimensional spectra of flavor components in olive oil samples of Example 1 and Comparative Example 1 of this invention;

[0036] Figure 3 GC-IMS Detection Example 1: List of Main Flavor Components of Olive Oil Sample Detailed Implementation

[0037] Example 1

[0038] An olive cultivation method for enhancing the flavor of olive oil includes the following steps:

[0039] S1. During the flowering period of olive trees (7 years old), a ring fertilization method is adopted. 50 kg of compound fertilizer containing nitrogen fertilizer inhibitor is applied to the roots of the plant. The ring fertilization process is as follows: Dig a ring trench 40 cm wide and 50 cm deep at the outer edge of the tree canopy projection area. First, sprinkle a layer of wood ash at the bottom of the ring trench, then mix the compound fertilizer with the soil and fill it in and tamp it down. The compound fertilizer is a mixture of the following components: 1000 kg of farmyard manure, 25 kg of compound fertilizer, 10 kg of lime and 3 kg of nitrogen fertilizer inhibitor. The mass fraction of nitrogen, phosphorus and potassium in the compound fertilizer is 15%, and the nitrogen fertilizer inhibitor is a mixture of 1.5 kg of dicyandiamide and 1.5 kg of 3,4-dimethylpyrazole phosphate.

[0040] S2. Ten days after applying compound fertilizer, spray with high-nitrogen foliar fertilizer one containing brassinolide (0.3 kg brassinolide, 0.6 kg urea, 0.3 kg potassium dihydrogen phosphate, 0.1 kg potassium sulfate, 0.015 kg trace elements, 0.15 kg borax and 98.535 kg aqueous emulsion), spraying until evenly moistened without dripping. During the fruit setting period, spray with high-nitrogen foliar fertilizer two containing brassinolide (0.15 kg brassinolide, 0.35 kg urea, 0.25 kg potassium dihydrogen phosphate, 0.25 kg potassium sulfate, 0.015 kg trace elements, 0.15 kg superphosphate and 98.835 kg aqueous emulsion), spraying until evenly moistened without dripping.

[0041] The preparation method of brassinolide formulations includes the following steps:

[0042] A1. Add 1 kg of zeolite powder (particle size 5-20 micrometers) to 10 kg of 1% fatty acid methyl ester sulfonate aqueous solution, heat to 65 ℃, stir at constant temperature for 0.5 h, then add citric acid, heat to 90 ℃, stir at constant temperature for 4 h, cool to room temperature, filter and dry to obtain carboxylated zeolite powder.

[0043] A2. Mix the brassinolide aqueous solution with carboxylated zeolite powder evenly to obtain a mixture. Filter and dry the mixture to obtain a brassinolide preparation, wherein the brassinolide loading is 20 g.

[0044] Example 2

[0045] The only difference between this embodiment and Example 1 is that carboxylated zeolite powder was not added in the preparation method of the brassinolide formulation; that is, the brassinolide formulation was replaced with the same amount of brassinolide, as detailed below:

[0046] An olive cultivation method for enhancing the flavor of olive oil includes the following steps:

[0047] S1. During the flowering period of olive trees (7 years old), a ring fertilization method is adopted. 50 kg of compound fertilizer containing nitrogen fertilizer inhibitor is applied to the roots of the plant. The ring fertilization process is as follows: Dig a ring trench 40 cm wide and 50 cm deep at the outer edge of the tree canopy projection area. First, sprinkle a layer of wood ash at the bottom of the ring trench, then mix the compound fertilizer with the soil and fill it in and tamp it down. The compound fertilizer is a mixture of the following components: 1000 kg of farmyard manure, 25 kg of compound fertilizer, 10 kg of lime and 3 kg of nitrogen fertilizer inhibitor. The mass fraction of nitrogen, phosphorus and potassium in the compound fertilizer is 15%, and the nitrogen fertilizer inhibitor is a mixture of 1.5 kg of dicyandiamide and 1.5 kg of 3,4-dimethylpyrazole phosphate.

[0048] S2. Ten days after applying the compound fertilizer, spray with high-nitrogen foliar fertilizer one containing brassinolide (5.88g brassinolide, 0.6 kg urea, 0.3 kg potassium dihydrogen phosphate, 0.1 kg potassium sulfate, 0.015 kg trace elements, 0.15 kg borax and 98.535 kg aqueous emulsion), spraying until evenly moistened without dripping. During the fruit setting period, spray with high-nitrogen foliar fertilizer two containing brassinolide (2.94g brassinolide, 0.35 kg urea, 0.25 kg potassium dihydrogen phosphate, 0.25 kg potassium sulfate, 0.015 kg trace elements, 0.15 kg superphosphate and 98.835 kg aqueous emulsion), spraying until evenly moistened without dripping.

[0049] Example 3

[0050] The only difference between this embodiment and Example 1 is that in the preparation method of the brassinolide formulation, the zeolite is not carboxylated; that is, the carboxylated zeolite powder is replaced with ordinary zeolite powder, as detailed below:

[0051] An olive cultivation method for enhancing the flavor of olive oil includes the following steps:

[0052] S1. During the flowering period of olive trees (7 years old), a ring fertilization method is adopted. 50 kg of compound fertilizer containing nitrogen fertilizer inhibitor is applied to the roots of the plant. The ring fertilization process is as follows: Dig a ring trench 40 cm wide and 50 cm deep at the outer edge of the tree canopy projection area. First, sprinkle a layer of wood ash at the bottom of the ring trench, then mix the compound fertilizer with the soil and fill it in and tamp it down. The compound fertilizer is a mixture of the following components: 1000 kg of farmyard manure, 25 kg of compound fertilizer, 10 kg of lime and 3 kg of nitrogen fertilizer inhibitor. The mass fraction of nitrogen, phosphorus and potassium in the compound fertilizer is 15%, and the nitrogen fertilizer inhibitor is a mixture of 1.5 kg of dicyandiamide and 1.5 kg of 3,4-dimethylpyrazole phosphate.

[0053] S2. Ten days after applying compound fertilizer, spray with high-nitrogen foliar fertilizer one containing brassinolide (0.3 kg brassinolide, 0.6 kg urea, 0.3 kg potassium dihydrogen phosphate, 0.1 kg potassium sulfate, 0.015 kg trace elements, 0.15 kg borax and 98.535 kg aqueous emulsion), spraying until evenly moistened without dripping. During the fruit setting period, spray with high-nitrogen foliar fertilizer two containing brassinolide (0.15 kg brassinolide, 0.35 kg urea, 0.25 kg potassium dihydrogen phosphate, 0.25 kg potassium sulfate, 0.015 kg trace elements, 0.15 kg superphosphate and 98.835 kg aqueous emulsion), spraying until evenly moistened without dripping.

[0054] The preparation method of brassinolide preparation includes the following steps: mixing brassinolide aqueous solution with 1 kg of zeolite powder to obtain a mixture, filtering and drying the mixture to obtain brassinolide preparation, wherein the loading of brassinolide is 20 g.

[0055] Comparative Example 1

[0056] The only difference between this comparative example and Example 1 is that no high-nitrogen foliar fertilizer containing brassinolide was sprayed 10 days after the application of the compound fertilizer and during the fruit setting period. Specifically:

[0057] An olive cultivation method to enhance the flavor of olive oil includes the following steps: During the flowering period of olive trees (7 years old), 50 kg of compound fertilizer containing nitrogen fertilizer inhibitor is applied to the roots of the plant using a ring fertilization method. The ring fertilization process is as follows: Dig a ring trench 40 cm wide and 50 cm deep at the outer edge of the tree canopy projection area. First, sprinkle a layer of wood ash at the bottom of the ring trench, then mix the compound fertilizer with the soil and fill and compact it. The compound fertilizer is a mixture of the following components: 1000 kg of farmyard manure, 25 kg of compound fertilizer, 10 kg of lime, and 3 kg of nitrogen fertilizer inhibitor. The mass fraction of nitrogen, phosphorus, and potassium in the compound fertilizer is 15%, and the nitrogen fertilizer inhibitor is a mixture of 1.5 kg of dicyandiamide and 1.5 kg of 3,4-dimethylpyrazole phosphate.

[0058] Comparative Example 2

[0059] The only difference between this comparative example and Example 1 is that, 10 days after applying the compound fertilizer, a high-nitrogen foliar fertilizer containing brassinolide was not sprayed, as detailed below:

[0060] An olive cultivation method for enhancing the flavor of olive oil includes the following steps:

[0061] S1. During the flowering period of olive trees (7 years old), a ring fertilization method is adopted. 50 kg of compound fertilizer containing nitrogen fertilizer inhibitor is applied to the roots of the plant. The ring fertilization process is as follows: Dig a ring trench 40 cm wide and 50 cm deep at the outer edge of the tree canopy projection area. First, sprinkle a layer of wood ash at the bottom of the ring trench, then mix the compound fertilizer with the soil and fill it in and tamp it down. The compound fertilizer is a mixture of the following components: 1000 kg of farmyard manure, 25 kg of compound fertilizer, 10 kg of lime and 3 kg of nitrogen fertilizer inhibitor. The mass fraction of nitrogen, phosphorus and potassium in the compound fertilizer is 15%, and the nitrogen fertilizer inhibitor is a mixture of 1.5 kg of dicyandiamide and 1.5 kg of 3,4-dimethylpyrazole phosphate.

[0062] S2. During the fruit setting period, spray with a high-nitrogen foliar fertilizer containing brassinolide (0.15 kg brassinolide, 0.35 kg urea, 0.25 kg potassium dihydrogen phosphate, 0.25 kg potassium sulfate, 0.015 kg trace elements, 0.15 kg superphosphate and 98.835 kg aqueous emulsion), spraying until evenly moistened without dripping.

[0063] The preparation method of brassinolide formulations includes the following steps:

[0064] A1. Add 1 kg of zeolite powder (particle size 5-20 micrometers) to 10 kg of 1% fatty acid methyl ester sulfonate aqueous solution, heat to 65 ℃, stir at constant temperature for 0.5 h, then add citric acid, heat to 90 ℃, stir at constant temperature for 4 h, cool to room temperature, filter and dry to obtain carboxylated zeolite powder.

[0065] A2. Mix the brassinolide aqueous solution with carboxylated zeolite powder evenly to obtain a mixture. Filter and dry the mixture to obtain a brassinolide preparation, wherein the brassinolide loading is 20 g.

[0066] Comparative Example 3

[0067] The only difference between this comparative example and Example 1 is that, during the fruit-setting period, a high-nitrogen foliar fertilizer containing brassinolide was not sprayed, as detailed below:

[0068] An olive cultivation method for enhancing the flavor of olive oil includes the following steps:

[0069] S1. During the flowering period of olive trees (7 years old), a ring fertilization method is adopted. 50 kg of compound fertilizer containing nitrogen fertilizer inhibitor is applied to the roots of the plant. The ring fertilization process is as follows: Dig a ring trench 40 cm wide and 50 cm deep at the outer edge of the tree canopy projection area. First, sprinkle a layer of wood ash at the bottom of the ring trench, then mix the compound fertilizer with the soil and fill it in and tamp it down. The compound fertilizer is a mixture of the following components: 1000 kg of farmyard manure, 25 kg of compound fertilizer, 10 kg of lime and 3 kg of nitrogen fertilizer inhibitor. The mass fraction of nitrogen, phosphorus and potassium in the compound fertilizer is 15%, and the nitrogen fertilizer inhibitor is a mixture of 1.5 kg of dicyandiamide and 1.5 kg of 3,4-dimethylpyrazole phosphate.

[0070] S2. Ten days after applying the compound fertilizer, spray with a high-nitrogen foliar fertilizer containing brassinolide (0.3 kg of brassinolide, 0.6 kg of urea, 0.3 kg of potassium dihydrogen phosphate, 0.1 kg of potassium sulfate, 0.015 kg of trace elements, 0.15 kg of borax and 98.535 kg of aqueous emulsion), spraying until evenly moistened without dripping.

[0071] The preparation method of brassinolide formulations includes the following steps:

[0072] A1. Add 1 kg of zeolite powder (particle size 5-20 micrometers) to 10 kg of 1% fatty acid methyl ester sulfonate aqueous solution, heat to 65 ℃, stir at constant temperature for 0.5 h, then add citric acid, heat to 90 ℃, stir at constant temperature for 4 h, cool to room temperature, filter and dry to obtain carboxylated zeolite powder.

[0073] A2. Mix the brassinolide aqueous solution with carboxylated zeolite powder evenly to obtain a mixture. Filter and dry the mixture to obtain a brassinolide preparation, wherein the brassinolide loading is 20 g.

[0074] Proof of effectiveness

[0075] I. Information and parameters related to gas chromatography-ion mobility spectrometry (GC-IMS) detection technology

[0076] 1. Detection Instruments and Equipment: FlavorSpec® gas phase ion mobility spectrometer, GAS (Germany, Dortmund); CTC-PAL 3 static headspace autosampler, CTC Analytics AG (Switzerland, Zwingen); VOCal data processing software (0.4.10), GAS (Germany, Dortmund);

[0077] 2. Test reagents and materials:

[0078] n-Kelvin: 2-Butanone, 2-Pentanone, 2-Hexanone, 2-Hepanone, 2-Octanone and 2-Nonanone (all analytical grade), Aladdin Company; 99.999% nitrogen; 20 mL headspace vials, Shandong Haineng Scientific Instruments Co., Ltd.; MXT-5 capillary column (15m × 0.53 mm, 1.0 μm), Restek Inc., USA.

[0079] 3. Test methods:

[0080] 3.1 Sample preparation method

[0081] Weigh 1 g of olive oil and place it in a 20 mL headspace vial. Incubate at 80 °C for 15 min and then inject the sample. Measure each sample in triplicate.

[0082] 3.2 Headspace injection conditions

[0083] Incubation temperature: 80 ℃; Incubation time: 15 min; Injection volume: 500 µL; Splitless injection; Incubation speed: 500 r / min; Injection needle temperature: 85 ℃.

[0084] 3.3 GC Conditions

[0085] Column temperature: 40 ℃; Carrier gas: High-purity nitrogen (purity ≥ 99.999%); Programmed pressure: Initial flow rate 2.0 mL / min, held for 2 min, linearly increased to 10.0 mL / min within 8 min, linearly increased to 100.0 mL / min within 10 min, and linearly increased to 150.0 mL / min within 5 min. Chromatographic run time: 25 min; Injector temperature: 80 ℃.

[0086] 3.4 IMS Conditions

[0087] Ionization source: tritium source (3H); migration tube length: 53 mm; electric field strength: 500 V / cm; migration tube temperature: 45 ℃; drift gas: high-purity nitrogen (purity ≥ 99.999%); flow rate: 75.0 mL / min; positive ion mode.

[0088] II. Detection of average yield per plant and flavor compound content

[0089] Using olive trees planted at the base as the research object, the tested variety was Ezhi 8. The olive trees were divided into 6 groups of 10 trees each, and treated according to the methods described in Examples 1-3 and Comparative Examples 1-3, while maintaining consistent management levels. During the "color-changing period" when the olive fruit turns from green to purple, fresh, normally growing fruits without disease spots or defects were selected from the upper part of the olive tree canopy in four directions (east, south, west, and north) as samples. The fruit yield per tree was also recorded, and the average yield per tree was calculated. The samples obtained in Examples 1-3 and Comparative Examples 1-3 were ground into a pulp, stirred, centrifuged, allowed to settle, and collected to obtain olive oil samples. GC-MS was used to determine the total content of flavor compounds (heterocyclic compounds, aldehydes, terpenes, alcohols, esters, phenols, aliphatic hydrocarbons, fatty acids, ketones, and alkenes) in each group of olive oil samples. The specific test results are shown in Table 1.

[0090] Table 1

[0091]

[0092] As can be seen from Examples 1-3 and Comparative Examples 1-3, and in conjunction with the data in Table 1, after treating olive trees using the olive cultivation method for improving olive oil flavor described in Examples 1-3, the average yield per tree reached over 27.9 kg, and the flavor substance content reached over 173.6 mg / kg (maximum 185.3 mg / kg). Compared with the comparative examples, it has a higher yield per tree and flavor substance content, indicating that the olive cultivation method for improving olive oil flavor provided by the present invention can increase the yield of olive fruits and significantly increase the flavor substance content of olive oil after cultivation.

[0093] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. A method for cultivating olives to enhance the flavor of olive oil, characterized in that, Includes the following steps: S1. During the flowering period of olive trees, apply compound fertilizer containing nitrogen fertilizer inhibitors to the roots of the plants. S2. One to two weeks after applying compound fertilizer and during the fruit setting period, spray high-nitrogen foliar fertilizer containing brassinolide preparations.

2. The olive cultivation method for improving olive oil flavor according to claim 1, characterized in that, The mass fractions of each element in high-nitrogen foliar fertilizer sprayed during the flowering period are as follows: brassinolide preparation 0.2-0.4%, nitrogen fertilizer 0.5-0.7%, phosphorus fertilizer 0.2-0.4%, potassium fertilizer 0.05-0.2%, and micronutrients 0.01-0.02%. The mass fractions of each element in high-nitrogen foliar fertilizer sprayed during the fruit-setting period are as follows: brassinolide preparation 0.1-0.2%, nitrogen fertilizer 0.3-0.4%, phosphorus fertilizer 0.2-0.3%, potassium fertilizer 0.2-0.3%, and micronutrients 0.01-0.02%.

3. The olive cultivation method for improving olive oil flavor according to claim 2, characterized in that, Foliar fertilizers sprayed during the flowering period also include 0.1-0.2% borax by mass; foliar fertilizers sprayed during the fruit setting period also include 0.1-0.2% superphosphate by mass.

4. The olive cultivation method for improving olive oil flavor according to claim 1, characterized in that, Compound fertilizer is a mixture of compound fertilizer and organic fertilizer, with the mass ratio of nitrogen, phosphorus and potassium in the compound fertilizer being 1:1:

1.

5. The olive cultivation method for improving olive oil flavor according to claim 4, characterized in that, Compound fertilizer also includes lime, and the mass ratio of organic fertilizer, compound fertilizer and lime in compound fertilizer is 100:2-3:0.8-1.

2.

6. The olive cultivation method for improving olive oil flavor according to claim 5, characterized in that, The nitrogen fertilizer inhibitor is a mixture of dicyandiamide and 3,4-dimethylpyrazole phosphate in a 1:1 mass ratio, and its dosage is 2%-3% of the weight of nitrogen fertilizer in the compound fertilizer.

7. The olive cultivation method for improving olive oil flavor according to claim 1, characterized in that, For root fertilization, use a ring fertilization method: dig a ring trench 30-50 cm wide and 40-60 cm deep at the outer edge of the tree canopy projection area. First, sprinkle a layer of wood ash at the bottom of the ring trench, then mix the compound fertilizer with the soil and fill it in and tamp it down.

8. The olive cultivation method for improving olive oil flavor according to claim 5, characterized in that, The application rates of compound fertilizer are as follows: 10-20 kg / tree for trees aged 1-3 years; 30-60 kg / tree for trees aged 4-8 years; and 80 kg / tree for trees aged 8 years and older.

9. The olive cultivation method for improving olive oil flavor according to claim 1, characterized in that, The brassinolide preparation is obtained by combining brassinolide and carboxylated zeolite powder.

10. The olive cultivation method for improving the flavor of olive oil according to any one of claims 1-9, characterized in that, The preparation method of brassinolide formulations includes the following steps: A1. Add zeolite powder to an aqueous solution of fatty acid methyl ester sulfonate, heat to 60-70 ℃, stir at a constant temperature, add citric acid, heat to 90-95 ℃, stir at a constant temperature, cool to room temperature, filter and dry to obtain carboxylated zeolite powder. A2. Mix the brassinolide aqueous solution with carboxylated zeolite powder evenly to obtain a mixture. Filter and dry the mixture to obtain a brassinolide preparation. The brassinolide preparation has a brassinolide loading of 1.5-2.5% based on the weight of the zeolite powder.

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