Method for improving fruit quality of facility peaches in northern area

Abstract

The invention belongs to the technical field of crop cultivation, and provides a method for improving the fruit quality of facility peaches in northern areas aiming at the current situations that the fruit quality of the facility peaches is poor and the research on improving the quality of the peach fruits is mostly concentrated on the aspect of open-field peaches at present, the method comprises the following steps: S1, crushing sesame oil residues to obtain sesame oil residues; s2, in the fruit swelling period of the protected peaches, applying sesame oil residues into soil of the protected peaches; s3, after the sesame oil residues are applied, irrigating the soil protected with the peaches; s4, in the fruit mature period of the facility peaches, within 7-10 days from fruit harvesting, the environment temperature in the greenhouse is regulated and controlled to be 31-33 DEG C every day, and the environment temperature is accumulated and kept for 3 hours. By applying the sesame oil residues and controlling the temperature before harvesting, the method not only improves the internal quality of the protected peaches, but also increases the variety and content of aroma substances, so that the aroma of the peaches is richer.

Description

Technical Field

[0001] The present invention belongs to the technical field of crop cultivation, and particularly relates to a method for improving the fruit quality of greenhouse peaches in northern regions. Background Art

[0002] Peach trees are one of the main fruit tree species for off-season greenhouse cultivation. Early-maturing, early-ripening, and mid-ripening peach varieties can be used for forcing cultivation in solar greenhouses and plastic greenhouses, while late-ripening and extra-late-ripening varieties can be used for delayed cultivation. In regions with rainy springs in the south, rain shelters can also be built for rain-proof cultivation. The greenhouse cultivation of peach trees in China began in the early 1990s and is currently one of the tree species with the largest cultivation area, the widest range, and the most mature technology. The production of greenhouse peaches in China is mainly concentrated in Shandong, Liaoning, Hebei and other places, and is also cultivated in other northern provinces and central provinces. The cultivation mode is mainly forcing cultivation in solar greenhouses, supplemented by forcing cultivation in plastic greenhouses and delayed cultivation in solar greenhouses. The cultivated varieties are mainly early-maturing and early-ripening nectarines, flat peaches and ordinary peaches, supplemented by mid-ripening and extra-late-ripening varieties.

[0003] Although greenhouse cultivation has achieved the off-season listing of peach fruits, filled the gap in the early spring fruit market, and increased the income of fruit farmers, the fruit quality is always inferior to that of open-field peaches, and there are problems such as "tasteless and lacking peach fragrance". Fruit farmers pursue benefits and only pay attention to the appearance quality of greenhouse peaches while ignoring the internal quality. With the improvement of people's living standards and consumption capabilities, the high-end fresh peaches in the market are in short supply. Therefore, improving the internal quality of greenhouse peaches has become an urgent problem to be solved in greenhouse peach production.

[0004] At present, the appearance quality of greenhouse peach fruits such as fruit size and color, and the internal quality such as sugar-acid ratio and aroma are the main factors determining the market value of greenhouse peach fruits. Currently, most of the research on improving peach fruit quality focuses on open-field peaches, and there are few experimental reports on improving the quality of greenhouse peaches. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for improving the fruit quality of greenhouse peaches.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is:

[0007] A method for improving the fruit quality of greenhouse peaches in northern regions, comprising the following steps:

[0008] S1. Crush the sesame oil residue to obtain sesame oil dregs;

[0009] S2. During the fruit expansion period of greenhouse peaches, apply the sesame oil dregs to the soil of greenhouse peaches;

[0010] S3. After applying the sesame oil residue, irrigate the soil of the protected peach trees. Stop irrigation after the soil becomes moist. During the daily management of the protected peach trees, irrigate again according to the soil conditions.

[0011] S4. During the fruit ripening period of the protected peach trees, within 7 - 10 days before fruit harvest, adjust the environmental temperature in the greenhouse to 31 - 33°C every day and maintain it for 3 hours cumulatively.

[0012] Preferably, in step S2, the application rate of the sesame oil residue is 250 - 750 g / plant.

[0013] Preferably, the application rate of the sesame oil residue is 250 g / plant.

[0014] Preferably, in step S2, the application method of the sesame oil residue is strip - ditch application, and the application depth of the sesame oil residue is 10 cm.

[0015] Preferably, in step S3, the irrigation method is spraying or drip irrigation.

[0016] Preferably, in step S3, when the soil is in a moist state, the water content of the soil is 40% - 60%.

[0017] Preferably, in step S4, adjust the environmental temperature in the greenhouse to 31 - 33°C every day by controlling the opening sizes of the top air vents and waist air vents of the greenhouse film and maintain it for 3 hours cumulatively.

[0018] Preferably, in step S4, when the environmental temperature in the greenhouse is higher than 33°C, open the top air vent to avoid the environmental temperature in the greenhouse being too high.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] By applying the sesame oil residue and controlling the temperature before harvest, the present invention not only improves the internal quality of the protected peach fruits, but also reduces the acid volatile substances in the fruits, increases the types and contents of aroma substances, making the aroma of the protected peach fruits more intense. Description of the Drawings

[0021] Figure 1 It is a flowchart of the method for improving the fruit quality of protected peach trees in the northern region provided by the embodiment of the present invention;

[0022] Figure 2 It is a graph showing the measurement results of the relationship between the greenhouse temperature and the net photosynthetic rate of Taohongyu in the northern greenhouse;

[0023] Figure 3 It is a graph showing the measurement results of the relationship between the greenhouse temperature and the net photosynthetic rate of Taohongyu in the southern greenhouse;

[0024] Figure 4This is the result of measuring the relationship between greenhouse temperature and net photosynthetic rate of North Greenhouse Zhongyou No. 13;

[0025] Figure 5 This is the result of measuring the relationship between greenhouse temperature and net photosynthetic rate of No. 13 oil in the southern greenhouse; DETAILED DESCRIPTION

[0026] The following will be combined with Examples 1-3 of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Example 1

[0028] The sesame oil residue in the embodiment of the present invention is a cake-shaped or block-shaped sesame oil residue produced in the sesame oil production process, which is commercially available.

[0029] like Figure 1 As shown, the embodiment of the present invention provides a method for improving the quality of greenhouse peach fruits in northern China, which specifically includes the following steps:

[0030] S1. Crush the cake-shaped or block-shaped sesame oil residue to obtain sesame oil residue; the sesame oil residue in the embodiment of the present invention is a byproduct of producing sesame oil by water substitution method using sesame as raw material, containing organic substances such as protein, amino acid, fat and trace elements. The reason why the present invention selects sesame oil residue instead of other plant residues, such as peanut residue, rapeseed residue and sesame residue, is that the present invention cannot obtain the experimental effect of improving the quality of facility peach fruit obtained by applying sesame oil residue in the present invention after applying peanut residue, rapeseed residue and sesame residue. The effects of applying peanut residue, rapeseed residue and sesame residue on the main quality indicators of facility peach are shown in Table 1 below.

[0031] Table 1 Effects of different application rates of peanut residue, rapeseed residue and sesame residue on the main quality indicators of greenhouse peaches

[0032]

[0033]

[0034] As can be seen from the results in Table 1, the application of peanut residue, rapeseed residue, and sesame residue had no significant effect on the single fruit weight, vertical and horizontal diameters of greenhouse peaches. And the soluble solid content only increased significantly compared with the control when the application amount of peanut residue was 1250 g / plant and 1500 g / plant, indicating that the application of rapeseed residue and sesame residue had no significant effect on the soluble solid content in greenhouse peach fruits. The titratable acid content showed no obvious change trend with the increase of fertilization amount, and it decreased significantly compared with the control when the application amount of rapeseed residue was 500, 750, 1500 g / plant, the application amount of sesame residue was 500 g / plant, and the application amount of peanut residue was 750, 1250 g / plant. Only when the application amount of sesame residue was 1000 g / plant and the application amount of peanut residue was 1000, 1500 g / plant, it could increase significantly compared with the control group. Through the above results, it shows that the application of peanut residue, rapeseed residue, and sesame residue has no obvious and stable effect on improving the fruit quality of greenhouse peaches. Therefore, in this invention, sesame oil residue is selected to study the influence on the internal quality and fruit aroma of greenhouse peach fruits.

[0035] S2. During the fruit swelling period of greenhouse peaches, sesame oil residue is applied into the soil of greenhouse peaches. The application method is strip trenching, and the application depth of sesame oil residue is 10 cm, and the application amount of sesame oil residue is 250 g / plant. The reason for choosing to apply sesame oil residue into the soil during the fruit swelling period of greenhouse peaches is that the development of greenhouse peach fruits shows a double S-shaped curve, and the fruit swelling period is a period when the volume of peach fruits increases rapidly, and a large amount of nutrients are needed during this period. Therefore, by applying sesame oil residue during this period in this invention, it can play a role in improving the fruit quality.

[0036] S3. After the application of sesame oil residue is completed, the soil of greenhouse peaches is irrigated with water by the way of spraying or drip irrigation. Stop irrigation when the soil is in a moist state (the state where the soil is moist without waterlogging), and the water content of the soil is 40%-60% at this time; in the subsequent daily management of greenhouse peaches, irrigate according to the soil conditions. Through the design of spraying or drip irrigation in the embodiments of this invention, it can avoid excessive watering from affecting the fruit quality.

[0037] S4. During the fruit ripening period of greenhouse peaches, within 7-10 days before fruit harvesting, control the opening sizes of the top air vent and waist air vent of the greenhouse film every day to regulate the environmental temperature in the greenhouse to 31-33°C and keep it for 3 hours accumulatively. It is confirmed by the experimental data in this invention that under the conditions of this experiment, the temperature at which the photosynthetic rate of greenhouse peach trees is the highest is 31-33°C. Therefore, through the above control of temperature and time in this invention, it can meet the optimal temperature of the photosynthetic rate and maintain it for a certain period of time; when the environmental temperature in the greenhouse is higher than 33°C, open the top air vent to avoid the environmental temperature in the greenhouse being too high, and at the same time increase the transpiration pull of the tree body. Through this step design in this invention, the photosynthetic efficiency of greenhouse peaches is improved, which is beneficial to the accumulation of photosynthetic products and ultimately plays a role in improving the fruit quality.

[0038] Example 2

[0039] This example provides a method for improving the fruit quality of protected peaches in northern regions. The method provided in this example is the same as that in Example 1, except that in step S2 of this example, the application amount of sesame oil residue is 500 g / plant.

[0040] Example 3

[0041] This example provides a method for improving the fruit quality of protected peaches in northern regions. The method provided in this example is the same as that in Example 1, except that in step S2 of this example, the application amount of sesame oil residue is 750 g / plant.

[0042] I. The following studies the influence of the method for improving the fruit quality of protected peaches in northern regions provided in Examples 1 - 3 of the present invention on the internal quality of protected peach fruits

[0043] 1. Detection conditions

[0044] The soluble solids in protected peach fruits were determined using a hand-held sugar meter, the titratable acid content in protected peach fruits was determined by titration using an automatic potentiometric titrator, the total soluble sugar content of protected peach fruits was determined using the anthrone colorimetric method, and the soluble protein content of protected peach fruits was determined using the Coomassie brilliant blue method.

[0045] The determination of soluble sugars and organic acid components in the flesh of protected peaches was carried out using the external standard method of high performance liquid chromatography (HPLC). The measuring instrument was a Shimadzu liquid chromatograph (LC - 20A). The specific determination method is as follows:

[0046] Weigh 1 g of the homogenized pulp and add it to a 10 mL centrifuge tube. Add 8 mL of ultrapure water, and perform ultrasonic extraction in a water bath at 80 °C for 1 h; after cooling, centrifuge at 8000 r / min for 15 min, and take the supernatant; filter it through a microporous filter membrane (0.22 μm × 25 mm) into a sample bottle for on - machine determination.

[0047] Sugar component determination conditions: The chromatographic column is Supelco apHeraNH 2 250 mm × 4.6 mm 5 μm, the mobile phase V(acetonitrile)∶V(water) = 75∶25, the flow rate is 0.8 mL / min, the injection volume is 10 μL, the column temperature is 30 °C, and the detector is a Shimadzu RID - 10A differential refractometer.

[0048] Organic acid component determination conditions: The chromatographic column is Phenomenex Luna C18 250 mm × 4.6 mm 5 μm, the mobile phase is V(10 mmol KH 2 PO 4 solution)∶V(methanol) = 97∶3, through KH2 PO 4 The pH of the solution was adjusted to 2.1, the flow rate was 0.8 mL / min, the injection volume was 10 μL, the column temperature was 30 °C, the detector was a Shimadzu SPD-20A ultraviolet detector, and the detection wavelength was 210 nm. The mobile phases prepared for the experiment were all filtered through a 0.45 μm microporous filter membrane, and the test samples were all filtered through a 0.22 μm syringe filter membrane.

[0049] 2. Experimental results

[0050] (1) The most suitable photosynthetic temperature for protected peaches

[0051] Taking two peach varieties, Zhongtaohongyu and Zhongyou No. 13, in the north greenhouse and the south greenhouse in a fruit tree research institute as the test objects, the relationship between temperature and the net photosynthetic rate of peach leaves was measured, and the results are as Figures 2 to 5 shown. As Figures 2 to 5 can be seen, for Zhongtaohongyu, at 31.1 - 31.6 °C, the net photosynthetic rate reached 21.9 - 27.3 μmol·m -2 ·s -1 , and for Zhongyou No. 13, at 32.0 - 32.9 °C, the net photosynthetic rate reached 21.7 - 26.6 μmol·m -2 ·s -1 , and the net photosynthetic rate was 1 - 2 times that of the photosynthetic rate in other temperature ranges. It can be concluded that under the greenhouse test conditions of the present invention, the most suitable photosynthetic temperature for protected peaches is between 31 - 33 degrees. Therefore, during the fruit ripening period of the protected peaches of the present invention, within 7 - 10 days before fruit harvest, by controlling the opening sizes of the top air vents and the waist air vents of the greenhouse film every day, the environmental temperature in the greenhouse is regulated to 31 - 33 °C and maintained for 3 hours, which can improve the photosynthetic efficiency of the protected peaches, is beneficial to the accumulation of photosynthetic products, and ultimately plays a role in improving the fruit quality.

[0052] (2) Influence of different greenhouse environments on fruit quality

[0053] Taking Zhongyou No. 13 and Zhongtaohongyu in a certain greenhouse as the control, the greenhouse environment was normally controlled without temperature increase treatment, while the south greenhouse and the north greenhouse were subjected to temperature increase treatment 9 days before mature harvest, and the greenhouse temperature was controlled at about 32 °C every day and ensured for 3 hours. After fruit harvest, the soluble sugar content in the pulp was measured, and the results are shown in Table 2 below. It can be seen from Table 2 that the total soluble sugar content of Zhongyou No. 13 and Zhongtaohongyu in the south greenhouse and the north greenhouse is higher than that of the same variety in the control group, and the average total sugar content of the same variety in the south greenhouse and the north greenhouse is about 1.6 times that of the same variety in the control group. It shows that the design of increasing the greenhouse temperature adopted in the present invention can improve the sugar content of the fruit.

[0054] Table 2 Comparison of soluble sugar content under different greenhouse environments

[0055]

[0056] (3) Influence of the amount of sesame oil residue on the internal quality indexes of greenhouse peach fruits

[0057] In the present invention, the greenhouse peach fruits without applying sesame oil residue were used as the control group, and the quality of the greenhouse peach fruits obtained by the methods provided in Examples 1-3 of the present invention was compared.

[0058] The detection results of the internal quality of the greenhouse peach fruits obtained in Examples 1-3 of the present invention and the greenhouse peach fruits of the control group are shown in Table 3 below. It can be seen from Table 3 that the treatments in Examples 1-3 increased the contents of soluble solids, soluble sugars and soluble proteins in the greenhouse peach fruits; and the content of soluble solids gradually increased with the increase of the amount of sesame oil residue applied, reaching the maximum of 12.35% when the amount of sesame oil residue applied was 750 g / plant (Example 3), which was significantly different from the control group. The content of titratable acid in the greenhouse peach fruits increased significantly after applying sesame oil residue, reaching the maximum when the amount of sesame oil residue applied was 250 g / plant (Example 1). At the same time, the mass fraction of soluble sugars and the sugar-acid ratio in the greenhouse peach fruits were both the largest when the amount of sesame oil residue applied was 750 g / plant, being 87.37 mg / g and 23.48 respectively. The results in Table 3 show that the application of sesame oil residue in the present invention also significantly increased the content of soluble proteins, which was 1.83-2.13 times that of the control group.

[0059] Table 3 Influence of different amounts of sesame oil residue on the internal quality indexes of greenhouse peaches

[0060]

[0061]

[0062] The detection results of the sugar-acid components of the greenhouse peach fruits obtained in Examples 1-3 of the present invention and the greenhouse peach fruits of the control group are shown in Table 4 below. It can be seen from Table 4 that the application of sesame oil residue in the present invention increased the mass fraction of sucrose in the greenhouse peach fruits, reaching the maximum of 1.70 times that of the control group when the amount of sesame oil residue applied was 750 g / plant; the mass fractions of glucose and fructose in the greenhouse peach fruits both increased after applying sesame oil residue, and the mass fraction of glucose reached the maximum of 1.56 times that of the control group when the amount of sesame oil residue applied was 250 g / plant. There were no significant differences in the mass fractions of fructose and sorbitol in the greenhouse peach fruits under each treatment. The mass fractions of malic acid and citric acid in the greenhouse peach fruits showed a trend of increasing-decreasing-reincreasing with the increase of the amount of sesame oil residue applied, reaching the maximum when the amount of sesame oil residue applied was 250 g / plant and the lowest when the amount of sesame oil residue applied was 500 g / plant, and the mass fraction of malic acid was significantly different from that of the control group at these two amounts of sesame oil residue applied.

[0063] Table 4 Effects of different dosages of sesame oil residue on sugar and acid components of protected peaches

[0064]

[0065] (3) Effects of sesame oil residue dosage on mineral element contents in protected peach fruits

[0066] The detection results of the mineral element contents in the protected peach fruits obtained in Examples 1 - 3 of the present invention and those of the control group are shown in Table 5 below. It can be seen from Table 5 that applying sesame oil residue increased the element contents of N, P, K, and Zn in the fruits, and the contents of the three elements N, P, and K increased more significantly compared with the control; especially for the elements P and K, under the three sesame oil residue dosage treatments, the differences in the contents of P and K elements compared with the control reached a significant level (P < 0.05). The contents of P and K elements in the protected peach fruits obtained in Example 1 of the present invention increased by 2.8% and 7.47% respectively compared with the control group. The content of Fe element decreased sharply with the increase of fertilization amount. The contents of Ca and Mg elements in the protected peach fruits obtained in Example 1 of the present invention were higher than those of the control group, and the contents of Ca and Mg elements in the protected peach fruits obtained in Examples 2 and 3 of the present invention were significantly lower than those of the control group. The content of Zn element increased under the three sesame oil residue dosages, and the content in Example 1 of the present invention was the highest, significantly higher than that of the control group by 29.63%. The change in the content of Mn element was not obvious. The above results show that through the treatment of sesame oil residue in the present invention, on the whole, it can increase the mineral element contents in protected peach fruits.

[0067] oil residue can increase the mineral element contents in protected peach fruits as a whole.

[0068] Table 5 Effects of different dosages of sesame oil residue on mineral element contents in protected peach fruits

[0069]

[0070] (4) Effects of sesame oil residue dosage on mineral element contents in the soil

[0071] The detection results of the contents of mineral elements in the soil treated with sesame oil residue in Examples 1-3 of the present invention and the contents of mineral elements in the soil without treatment with sesame oil residue (control group) are shown in Table 6 below. It can be seen from Table 6 that, compared with the control group, the application of sesame oil residue in Examples 1-3 of the present invention significantly increased the contents of elements N, Ca, Mg, Fe, Mn, and Cu in the 0-20 cm soil layer, and significantly reduced the content of P. Moreover, the application of sesame oil residue in Examples 2 and 3 of the present invention significantly reduced the contents of elements P, Zn, and Cu in the 20-40 cm soil layer, and significantly increased the content of element Mn. However, the application of sesame oil residue in Examples 1-3 of the present invention had no obvious effect on the contents of other mineral elements in the 20-40 cm soil layer. The above results show that the application of sesame oil residue in Examples 1-3 of the present invention increased the mineral nutrition in the soil, improved the soil fertility, and thus facilitated the growth of the fruits of greenhouse peaches and helped to improve the internal quality of greenhouse peaches.

[0072] Table 6 Effects of different dosages of sesame oil residue on the contents of mineral elements in the soil

[0073]

[0074]

[0075] Second, the effects of the method for improving the quality of greenhouse peach fruits provided in Examples 1-3 of the present invention on the aroma of greenhouse peach fruits were studied.

[0076] The present invention used the greenhouse peach fruits without the application of sesame oil residue as the control group, and compared the quality of the greenhouse peach fruits obtained by the method provided in Examples 1-3 of the present invention.

[0077] 1. Determination conditions for volatile aroma components

[0078] The headspace solid-phase microextraction-gas chromatography-mass spectrometry method was used to determine the volatile aroma components in greenhouse peach fruits. The determination method is as follows:

[0079] Weighed 3 g of pulp homogenate into a 20 ml sample bottle, added 10 μL of internal standard tetramethyldecanol (concentration 1.0388 g / L), sealed the sample bottle with a silica gel septum, and sealed it with an aluminum cap. Three parallel samples were prepared for each batch and determined by the headspace solid-phase microextraction-gas chromatography-mass spectrometry method respectively. The determination method is as follows:

[0080] The sample was equilibrated at 50 °C for 30 min, and then the aged extraction head (Supelco PDMS / DVB 65 μm, lot number PK3) was inserted into the headspace extraction vial. Adsorption extraction was carried out at 50 °C for 30 min, and desorption was carried out for 5 min at an inlet temperature of 230 °C. The analytical instrument was an Agilent 7890A-5975C gas chromatography-mass spectrometry (GC-MS) system equipped with a PAL 3 auto-sampler.

[0081] GC conditions: The chromatographic column was a DB-WAX capillary column (30.0 m × 320 μm × 0.25 μm). The carrier gas was helium (He) (99.999%), and the flow rate was 1.0 mL·min -1 , and splitless injection was used. The initial temperature was 40 °C, held for 5 min, and then increased at a rate of 3 °C·min -1 to 80 °C and held for 2 min. Then it was further increased at a rate of 5 °C·min -1 to 150 °C and held for 2 min. Then it was increased at a rate of 10 °C·min -1 to 230 °C and held for 5 min.

[0082] MS conditions: The ion source (EI) voltage was 70 eV, the temperature was 230 °C, the transfer line temperature was 280 °C, the quadrupole temperature was 150 °C, and the mass scan range was 50 - 550 m / z.

[0083] Qualitative and quantitative analysis: The volatile compounds were qualitatively analyzed using the automatic deconvolution system (AMDIS) associated with the GC-MS workstation and the NIST11 mass spectral library, combined with the retention index (RI) values of the n-alkane mixture (C6 - C30, ≥97%). Tetramethyldipentanol was used as an internal standard for quantitative analysis of the volatile compound content.

[0084] 2. Experimental results

[0085] (1) Effects of the amount of sesame oil residue on the aroma types and contents of greenhouse peach fruits

[0086] The results of the aroma types and contents of the greenhouse peach fruits obtained by the fertilization methods provided in Examples 1 - 3 of the present invention and the greenhouse peach fruits of the control group are shown in Table 7 below.

[0087] Table 7 Types and contents of main aroma components in fruits after different treatments with the amount of sesame oil residue

[0088]

[0089]

[0090] "-" indicates not detected;

[0091] As can be seen from the results in Table 7, a total of 40 aroma components were detected in the fruits of the facility peaches in the control group and Examples 1-3 of the present invention. Among them, there were 11 aldehydes, 8 alcohols, 5 esters, 3 lactones, 4 ketones, 6 acids, 2 phenols, and 1 furan. After applying sesame oil residue, not only the types of acid volatile substances were significantly reduced (6 types were detected in the control group, and 2-3 types were detected in Examples 1-3 of the present invention), but also the content of acid volatiles was significantly lower than that of the control. In addition, the types of volatiles in the other categories all increased compared with the control.

[0092] The results of this experiment showed that aldehydes were the aroma type with the largest number and content. Among them, hexanal (1189.49 - 1797.95 μg / kg) and trans-2-hexenal (980.32 - 2021.92 μg / kg) were the two components with the largest content among all volatiles. Except for hexanal, trans-2-hexenal, and nonanal, the contents of the other aldehyde components increased after applying sesame oil residue. Compared with the control group, (E,E)-2,4-nonadienal, trans-2-, cis-6-nonadienal, leaf alcohol, 1-octen-3-ol, nonanol, cis-2-hexen-1-ol, trans-2-nonen-1-ol, methyl palmitate, methyl benzoate, geranylacetone, and 3-octanone were the types of volatiles that increased after treatment with sesame oil residue. Among the components common to the control group and Examples 1-3 of the present invention, the contents of trans-2-octenal, (E,E)-2,4-heptadienal, benzaldehyde, trans-2-nonenal, β-cyclocitral, 2,4-decadienal, n-hexanol, trans-2-hexenol, γ-hexalactone, and β-ionone all increased significantly after applying sesame oil residue. Generally speaking, the treatment with sesame oil residue increased the total content of alcohol and ketone volatiles; the total content of volatiles in the fruits of the facility peaches obtained in Example 1 of the present invention was the highest, and the contents of aldehydes, esters, and ketones ranked first.

[0093] (2) Effects of the dosage of sesame oil residue on the odor activity values OAVs and aroma characteristics of facility peach fruits

[0094] The odor activity values OAV of the detected volatile substances were calculated through the aroma thresholds found in the literature. When the OAV value is greater than 0.1, it indicates that the substance can increase the fruit aroma to a certain extent. When the OAV value is greater than 1, the substance makes a greater contribution to increasing the fruit aroma. The odor activity values OAVs and aroma characteristics of the facility peach fruits obtained by the fertilization method provided in Examples 1-3 of the present invention and the facility peach fruits obtained in the control group were respectively detected, and the detection results are shown in Table 8 below.

[0095] Table 8 Detection results of the odor activity values OAVs and aroma characteristics of the main aromas of facility peach fruits

[0096]

[0097]

[0098]

[0099] As can be seen from Table 8, among aldehydes, hexanal, (E)-2-nonenal, (E)-2-hexenal, nonanal, (E,E)-2,4-decadienal, (E,E)-2,4-heptadienal, and (E)-2-octenal, and among other aroma categories, hexyl acetate, cis-3-hexenyl acetate, γ-decalactone, β-ionone, and 2-pentylfuran are the main contributing substances (OAVs > 1) of the fruit aroma common to both the control group and Examples 1-3 of the present invention; benzaldehyde, (E)-2-hexenol, and (E)-2-hexenyl acetate are aroma substances with OAV values greater than 0.1 common to the control group and Examples 1-3, having cherry, almond, and grass odors respectively, and making a certain contribution to the formation of fruit fragrance. Generally speaking, the OAV values of β-ionone, hexanal, (E)-2-nonenal, (E)-2-hexenal, and hexyl acetate are among the top among all volatile substances and are the main aroma substances of the tested variety.

[0100] (E,E)-2,4-Nonadienal, (E)-2-(Z)-6-nonadienal, and 1-octen-3-ol are the main aroma contributing substances (OAVs > 1) increased after applying sesame oil residue. (E)-2-(Z)-6-nonadienal, as one of the main aroma substances in Examples 1-3 (OAV value 255.34 - 610.12), increases the fresh aroma of the fruit. Geranyl acetone is an aroma substance with an OAV value greater than 0.1 increased after fertilization, and its aroma characteristics show a floral and fruity odor. Compared with the control, the OAV value of β-ionone among the main aroma substances after fertilization increases significantly, with Example 1 being the most significant; among the substances with the second highest aroma contribution rate, the OAV values of (E)-2-nonenal, (E,E)-2,4-decadienal, (E,E)-2,4-heptadienal, (E)-2-octenal, benzaldehyde, β-cyclocitral, (E)-2-hexenol, and n-hexanol all increase, indicating that applying sesame oil residue can increase the aroma of the fruit to a certain extent.

[0101] III. Comprehensive evaluation of the main quality indicators of the protected peach fruits provided in Examples 1-3 of the present invention

[0102] To evaluate the application effects of different dosages of sesame oil residue, the present invention conducted a principal component analysis on the main internal quality indicators of the protected peach fruits in the control group and Examples 1-3. The results are shown in Table 9 below. From the results in Table 9, a total of 3 principal components with eigenvalues greater than 1 were extracted, and their cumulative contribution rate reached 77.779%, which can reflect most of the information in the indicators.

[0103] Table 9 Component matrix, eigenvalue, and cumulative contribution rate of each index of the protected peach fruits in Examples 1-3 of the present invention

[0104] Index Component 1 Component 2 Component 3 Soluble sugar 0.897 -0.131 0.346 Soluble solids 0.523 -0.43 0.368 Soluble protein 0.755 -0.174 -0.287 Titratable acid 0.679 0.651 -0.044 Sugar-acid ratio 0.337 -0.793 0.429 Malic acid 0.116 0.827 0.458 Citric acid -0.145 0.768 0.476 Glucose 0.611 0.574 -0.13 Sucrose 0.777 -0.208 -0.041 Fructose 0.471 0.267 -0.582 Characteristic value 3.456 3.004 1.318 Percentage of variance 34.556 30.041 13.182 Cumulative contribution rate 34.556 64.598 77.779

[0105] The principal component scores, comprehensive scores and ranking results of the protected-cultivation peach fruits provided in Embodiments 1-3 of the present invention are shown in Table 10 below. It can be seen from Table 10 that the comprehensive score of the protected-cultivation peach fruits obtained in Embodiment 1 of the present invention is the highest, that is, when the amount of sesame oil residue is 250 g / plant, the effect of improving fruit quality is the best.

[0106] Table 10 Principal component scores, comprehensive scores and ranking of sesame oil residue treatment

[0107] Group Component 1 Component 2 Component 3 Comprehensive score Rank Control group -2.715 0.038 0.445 -0.868 4 Example 1 0.997 2.456 -0.147 1.063 1 Example 2 0.054 -1.677 -1.050 -0.624 3 Example 3 1.664 -0.817 0.753 0.429 2

[0108] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for improving the quality of greenhouse peach fruits in northern China, characterized in that: The following steps are involved: S1, crushing sesame oil residue to obtain sesame oil residue; S2. During the fruit expansion period of greenhouse peaches, apply the sesame oil residue to the soil of greenhouse peaches; S3, after the application of sesame oil residue is completed, the soil of the facility peach is irrigated, and the irrigation is stopped after the soil is in a moist state. In the daily management of the facility peach, irrigation is carried out again according to the soil conditions; S4. During the peach fruit ripening period, within 7-10 days before fruit harvest, the ambient temperature in the greenhouse should be controlled at 31-33℃ every day and maintained for a cumulative 3 hours.

2. The method for improving the quality of peach fruits grown in northern China according to claim 1, characterized in that: In step S2, the amount of sesame oil residue applied is 250-750 g / plant.

3. The method for improving the quality of peach fruits grown in northern China according to claim 2, characterized in that: The amount of sesame oil residue applied is 250g / plant.

4. The method for improving the quality of greenhouse peach fruits in northern China according to claim 1, characterized in that: In step S2, the sesame oil residue is applied in a strip-shaped groove, and the application depth of the sesame oil residue is 10 cm.

5. The method for improving the quality of greenhouse peach fruits in northern China according to claim 1, characterized in that: In step S3, the irrigation method is spraying or drip irrigation.

6. The method for improving the quality of greenhouse peach fruits in northern China according to claim 1, characterized in that: In step S3, when the soil is in a wet state, the water content of the soil is between 40% and 60%.

7. The method for improving the quality of greenhouse peach fruits in northern China according to claim 1, characterized in that: In step S4, the ambient temperature in the greenhouse is regulated at 31-33°C by controlling the opening sizes of the top vents and waist vents of the greenhouse film every day, and is maintained for a cumulative period of 3 hours.

8. The method for improving the quality of greenhouse peach fruits in northern China according to claim 1, characterized in that: In step S4, when the ambient temperature in the greenhouse is higher than 33°C, the top vent is opened to prevent the ambient temperature in the greenhouse from being too high.

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