Method for improving storage quality of rapeseeds

Abstract

The invention discloses a method for improving storage quality of rapeseeds, and belongs to the technical field of seed storage. The cold plasma technology is adopted to treat the rapeseeds, during the storage period, reduction of the germination rate, the germination potential and the catalase activity can be delayed, meanwhile, increase of the conductivity of the rapeseeds during the storage period can be delayed, the peroxide value and the acid value of crude fat can be reduced, and no negative influence is generated on the oil content of the rapeseeds; the sowing quality and the grease quality of the rapeseeds stored under a normal-temperature or high-temperature condition can be effectively improved. The method does not need large storage equipment, is low in cost, simple, convenient and effective, and provides a new direction for a rapeseed storage technology.

Description

Technical Field

[0001] The invention belongs to the technical field of seed storage, and in particular relates to a method for improving the storage quality of rapeseed. Background Art

[0002] Rapeseed is the seed of the cruciferous plant rapeseed, and is one of the main sources of vegetable oil and plant protein. The Yangtze River Basin is the main rapeseed production area in my country, but rapeseed in this area needs to experience high humidity and hot weather after harvest and during storage. Since rapeseed particles are small, the gaps between seeds are small during storage, which makes it difficult to dissipate heat. In addition, the seeds have strong respiration, and the heat accumulation generated by respiratory metabolism is not easy to diffuse, which is not conducive to ventilation and moisture permeability storage, especially in hot and humid weather. It is easy to cause fever and mildew, thus affecting the storage quality of rapeseed. In addition, rapeseed has a high oil content. During storage, the fat in rapeseed can be hydrolyzed by lipase to produce free fatty acids, which leads to an increase in the acidity of rapeseed and hydrolysis and rancidity. High temperature and high humidity conditions can accelerate the rancidity process, ultimately leading to a decrease in the oil content of rapeseed.

[0003] Compared with other grains and oil seeds, rapeseed has poor stability during storage due to its characteristics of being easy to mold, strong in moisture absorption, and easy to heat and become rancid. The storage methods currently used are low-temperature storage and controlled atmosphere storage. However, the construction investment and operation costs of low-temperature cold storage are high, which is not conducive to long-term storage. Controlled atmosphere storage may cause abnormal seed metabolism and damage tissues. Moreover, the one-time investment in controlled atmosphere storage is high. Since different seeds require different gas conditions and temperature conditions, different warehouses need to be built according to different seeds. Therefore, it is urgent to explore a simple and low-cost method for storing rapeseed. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a method for improving the storage quality of rapeseed, which can effectively alleviate the decline in the storage quality of rapeseed under normal temperature or high temperature conditions, and the method is simple and low-cost.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for improving the storage quality of rapeseed, which comprises the following steps:

[0007] The rapeseed is treated with cold plasma and then sealed and stored after the treatment. The conditions of the cold plasma treatment are as follows: the discharge medium is helium or argon, the treatment power is 80-200W, and the treatment time is 12-18s.

[0008] Preferably, the storage quality includes sowing quality and oil quality of rapeseed during storage.

[0009] Preferably, the sowing quality indicators include germination rate, germination potential, electrical conductivity and catalase activity.

[0010] Preferably, the oil quality indicators include fat content, oil peroxide value and oil acid value.

[0011] Preferably, when the discharge medium is helium, the processing power is 80-120W; when the discharge medium is argon, the processing power is 100-200W.

[0012] Preferably, when the discharge medium is helium, the processing power is 120W; when the discharge medium is argon, the processing power is 200W.

[0013] Preferably, the cold plasma treatment time is 15 s.

[0014] Preferably, the output frequency of the radio frequency power supply for the cold plasma treatment is 10 to 20 MHz.

[0015] Preferably, the temperature of the sealed storage is 20-40°C.

[0016] Preferably, the airtight storage period is 4-12 months.

[0017] Beneficial effects of the present invention:

[0018] The present invention uses cold plasma technology to treat rapeseed, which can delay the phenomenon of the decrease in germination rate, germination potential and catalase activity during storage, and can also delay the increase in conductivity of rapeseed during storage, which can effectively improve the sowing quality of rapeseed stored at normal or high temperature conditions. At the same time, the method of the present invention can reduce the crude fat peroxide value and acid value of rapeseed, and will not have a negative impact on the oil content of rapeseed, which can effectively improve the oil quality of rapeseed stored at normal or high temperature conditions. The method of the present invention does not require large-scale storage equipment, is low in cost, and is simple and effective, providing a new direction for rapeseed storage technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The changes of rapeseed germination rate in different treatment groups during storage at 25℃;

[0020] Figure 2 The changes of rapeseed germination rate in different treatment groups during storage at 35℃;

[0021] Figure 3 The changes of rapeseed germination potential in different treatment groups during storage at 25℃;

[0022] Figure 4 The changes of rapeseed germination potential in different treatment groups during storage at 35℃;

[0023] Figure 5 The changes of electrical conductivity of rapeseed in different treatment groups during storage at 25℃;

[0024] Figure 6 The changes of electrical conductivity of rapeseed in different treatment groups during storage at 35℃;

[0025] Figure 7 The changes of catalase activity in rapeseed in different treatment groups during storage at 25℃;

[0026] Figure 8 The changes of catalase activity in rapeseed in different treatment groups during storage at 35℃;

[0027] Fig. 9 The effect of helium cold plasma treatment on crude fat content of rapeseed during storage at 25℃;

[0028] Fig.10 The effect of argon cold plasma treatment on crude fat content of rapeseed during storage at 25℃;

[0029] Fig.11 The effect of helium cold plasma treatment on crude fat content of rapeseed during storage at 35℃;

[0030] Fig.12 The effect of argon cold plasma treatment on crude fat content of rapeseed during storage at 35℃;

[0031] Fig.13 The effect of helium cold plasma treatment on the peroxide value of crude fat in rapeseed during storage at 25℃;

[0032] Fig.14 The effect of argon cold plasma treatment on the peroxide value of crude fat in rapeseed during storage at 25℃;

[0033] Fig.15 The effect of helium cold plasma treatment on the crude fat peroxide value of rapeseed during storage at 35℃;

[0034] Fig.16 The effect of argon cold plasma treatment on the peroxide value of crude fat in rapeseed during storage at 35℃.

[0035] Fig.17 The effect of helium cold plasma treatment on crude fatty acid valence of rapeseed during storage at 25℃;

[0036] Fig.18 The effect of argon cold plasma treatment on crude fatty acid valence of rapeseed during storage at 25℃;

[0037] Fig.19The effect of helium cold plasma treatment on crude fatty acid valence of rapeseed during storage at 35℃;

[0038] Fig. 20 Effects of argon cold plasma treatment on crude fatty acid values ​​of rapeseed during storage at 35°C. DETAILED DESCRIPTION

[0039] The present invention provides a method for improving the storage quality of rapeseed, which comprises the following steps:

[0040] The rapeseed is treated with cold plasma and then sealed and stored after the treatment. The conditions of the cold plasma treatment are as follows: the discharge medium is helium or argon, the treatment power is 80-200W, and the treatment time is 12-18s.

[0041] In the present invention, the rapeseed storage quality includes the sowing quality and oil quality during the rapeseed storage period; the sowing quality indicators include germination rate, germination potential, electrical conductivity and catalase activity; the oil quality indicators include fat content, oil peroxide value and oil acid value.

[0042] In the present invention, there is no special limitation on the variety and source of the rapeseed, which can be selected according to actual needs. As an implementation method, the rapeseed can be selected from rapeseed harvested in the current year and dried; the drying method can be selected from conventional drying methods in the field, such as natural drying and artificial mechanical drying; the moisture content of the rapeseed is preferably 5% to 14%, more preferably 6% to 10%, and more preferably 8.4%.

[0043] In the present invention, the equipment for plasma treatment is conventional equipment in the art. When the discharge medium is helium, the processing power is preferably 80-120W, more preferably 100-120W, and more preferably 120W; when the discharge medium is argon, the processing power is preferably 100-200W, more preferably 150-200W, and more preferably 200W. The processing time is preferably 13-16s, and more preferably 15s. The output frequency of the RF power supply for the cold plasma treatment is preferably 10-20MHz, more preferably 12-17MHz, and more preferably 13.56MHz.

[0044] In the present invention, the temperature of the sealed storage is preferably 20-40°C, more preferably 25-35°C, and more preferably 25°C. The present invention does not specifically limit the method of the sealed storage, and the storage method can be conventionally selected according to actual needs. As an implementable embodiment, the sealed storage includes placing the seeds in a paper bag or a cloth bag for sealed storage, or placing them in a container with a cover for sealed storage, etc. The present invention does not specifically limit the storage time, and it can be conventionally selected according to actual needs; the storage time is preferably 4-12 months, more preferably 5-9 months, and more preferably 6 months.

[0045] During the storage of rapeseed, as the storage time increases, the germination rate, germination potential, and catalase activity of the rapeseed decrease, and the conductivity increases; the method of the present invention can delay the phenomenon of the decrease in the germination rate, germination potential, and catalase activity during storage, and at the same time can delay the increase in the conductivity of the rapeseed during storage. During the storage process, as the storage time increases, the crude fat content of the rapeseed decreases, and the crude fat peroxide value and acid value increase; the method of the present invention can reduce the crude fat peroxide value and acid value of the rapeseed, and will not have a negative impact on the oil content of the rapeseed. The present invention provides a simple, low-cost and effective method for improving the storage quality of rapeseed under normal or high temperature conditions.

[0046] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0047] In the following embodiments, unless otherwise specified, all of them are conventional methods.

[0048] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0049] Example 1

[0050] A method for improving the storage quality of rapeseed, comprising the following steps:

[0051] The rapeseed was treated with cold plasma. The conditions of the cold plasma treatment were as follows: the discharge medium was helium, the treatment power was 80W, the treatment time was 18s, and the RF power supply output frequency was 20MHz; after the treatment, it was stored in a constant temperature and sealed state at 40°C for 4 months.

[0052] Example 2

[0053] A method for improving the storage quality of rapeseed, comprising the following steps:

[0054] The rapeseed was treated with cold plasma. The conditions of the cold plasma treatment were as follows: the discharge medium was helium, the treatment power was 120W, the treatment time was 12s, and the RF power supply output frequency was 10MHz; after the treatment, it was stored in a sealed constant temperature at 20°C for 12 months.

[0055] Example 3

[0056] A method for improving the storage quality of rapeseed, comprising the following steps:

[0057] The rapeseed was treated with cold plasma. The conditions of the cold plasma treatment were as follows: the discharge medium was helium, the treatment power was 100 W, the treatment time was 14 s, and the RF power supply output frequency was 15 MHz. After the treatment, the rapeseed was stored in a sealed constant temperature at 28°C for 5 months.

[0058] Example 4

[0059] A method for improving the storage quality of rapeseed, comprising the following steps:

[0060] The rapeseed was treated with cold plasma. The conditions of the cold plasma treatment were as follows: the discharge medium was argon, the treatment power was 100 W, the treatment time was 18 s, and the RF power supply output frequency was 20 MHz. After the treatment, the rapeseed was stored in a sealed constant temperature at 40°C for 4 months.

[0061] Example 5

[0062] A method for improving the storage quality of rapeseed, comprising the following steps:

[0063] The rapeseed was treated with cold plasma. The conditions of the cold plasma treatment were as follows: the discharge medium was argon, the treatment power was 220 W, the treatment time was 12 s, and the RF power supply output frequency was 10 MHz; after the treatment, it was stored in a sealed constant temperature at 20°C for 12 months.

[0064] Example 6

[0065] A method for improving the storage quality of rapeseed, comprising the following steps:

[0066] The rapeseed was treated with cold plasma. The conditions of the cold plasma treatment were as follows: the discharge medium was argon, the treatment power was 150W, the treatment time was 16s, and the RF power supply output frequency was 17MHz. After the treatment, the rapeseed was stored in a sealed constant temperature at 32°C for 9 months.

[0067] Examples 7 to 18

[0068] A method for improving the storage quality of rapeseed, comprising the following steps:

[0069] The rapeseed was treated with cold plasma, and after the treatment, it was sealed in a ziplock bag and stored in a constant temperature box. The conditions of the cold plasma treatment are shown in Table 1:

[0070] Table 1 Cold plasma treatment conditions

[0071]

[0072] Comparative Example 1

[0073] The same rapeseed samples as in Examples 7 to 18 were taken without any treatment, and were directly sealed in a ziplock bag and stored in a constant temperature box at a storage temperature of 25°C.

[0074] Comparative Example 2

[0075] The same rapeseed samples as in Examples 7 to 18 were taken without any treatment, and were directly sealed in a ziplock bag and stored in a constant temperature box at a storage temperature of 35°C.

[0076] Test Example 1

[0077] Newly harvested and dried rapeseed was selected, and the basic information is shown in Table 2:

[0078] Table 2 Basic information of rapeseed samples

[0079] Sample name variety Oil content g / 100g Moisture content g / 100g Harvest Harvest Year Rapeseed Youyan No. 10 39.7 8.40 Renhuai City, Guizhou Province June 2022

[0080] The rapeseed was divided into 14 groups, each group weighing 5 kg. The rapeseed was treated by the methods of Examples 7 to 18 and Comparative Examples 1 to 2, and 100 g of rapeseed samples were randomly taken every 30 days after storage for detection and analysis.

[0081] (1) Germination rate and germination potential

[0082] The germination rate and germination potential were determined according to the method specified in GB / T 5520-2011. Figure 1-4 shown.

[0083] The germination rate is the ratio of the number of germinated seeds to the total number of seeds measured. It is one of the important indicators for measuring seed quality and reflects the ability of seeds to germinate and grow normally under suitable conditions. Figure 1-2 The results show that the germination rate of rapeseed decreases during storage. Figure 1As shown in the figure, at a storage temperature of 25°C, after the rapeseed was treated with helium cold plasma power at 80W, 100W and 120W, the germination rates of rapeseed on the 180th day were 99.50%, 99.50% and 97.50% respectively, and after the rapeseed was treated with argon cold plasma power at 100W, 150W and 200W respectively, the germination rates of rapeseed on the 180th day were 98.50%, 98.25% and 98.50% respectively, and the untreated group was 96.75%. It can be seen that under 25°C conditions, after 180 days of storage, the germination rate of untreated rapeseed decreased from 100% to 96.75%, and the germination rate of rapeseed treated with cold plasma decreased from 100% to about 98.45%. With the extension of time, the difference between the germination rate of untreated rapeseed and the germination rate of rapeseed treated with cold plasma increases.

[0084] like Figure 2 As shown in the figure, at a storage temperature of 35°C, after the rapeseed was treated with helium cold plasma power at 80W, 100W and 120W, the germination rates of rapeseed on the 180th day were 96.75%, 96.50% and 96.00%, respectively; after the rapeseed was treated with argon cold plasma power at 100W, 150W and 200W, the germination rates of rapeseed on the 180th day were 95.00%, 95.25% and 95.75%, respectively, and the untreated group was 90.25%. It can be seen that under 35°C conditions, after 180 days of storage, the germination rate of untreated rapeseed decreased from 100% to 90.25%, which was a greater change than that at 25°C. The germination rate of rapeseed treated with cold plasma decreased from 100% to about 95.88% at 35°C, which was a smaller decrease than that of the untreated group, but the decrease was higher than that of rapeseed stored at 25°C. It can be seen from this that storage temperature has a great influence on the germination rate of rapeseed. Figure 1 , 2 Overall, it can be seen that the germination rate of untreated rapeseed before 120 days is close to that of the treated group, and the germination rate of untreated rapeseed after 120 days is lower than that of rapeseed treated with cold plasma. Cold plasma technology can delay the decline in rapeseed germination rate.

[0085] Germination potential refers to the test of the germination speed and uniformity of seeds. The larger the value, the stronger the germination potential. When the germination rate is the same, seeds with high germination potential indicate that the seeds have strong vitality, the germination rate is high when sown on the site, and the seedlings emerge normally after sowing. Figure 3-4 It can be seen that the germination potential of untreated rapeseed is more obviously reduced than that of treated rapeseed. Figure 3As shown in the figure, at 25℃, the germination potential of untreated rapeseed decreased significantly after 30 days. During storage for 30-60 days, the germination potential of rapeseed treated with cold plasma decreased from 99.79% to about 97.00%, and that of untreated rapeseed decreased from 99.50% to below 90%; at 180 days, the germination potential of untreated rapeseed was 49.50%, which decreased to below 50%, while the germination potential of rapeseed treated with helium cold plasma power of 80W, 100W and 120W was 90.00%, 88.75% and 96.00% respectively, and the germination potential of rapeseed treated with argon cold plasma power of 100W, 150W and 200W was 92.00%, 89.00% and 90.75% respectively. The germination potential of treated rapeseed was above 90%, with a difference of more than 40 percentage points.

[0086] like Figure 4 As shown in the figure, the germination potential of rapeseed stored at 35℃ changes more than that of rapeseed stored at 25℃. The germination potential of rapeseed is basically the same under different treatment methods before 30 days, but the germination potential of untreated rapeseed decreases more than that of rapeseed treated with cold plasma technology after 30 days. At 180 days, the germination potential of untreated rapeseed is 38.25%. After the rapeseed is treated with helium cold plasma power of 80W, 100W and 120W, the germination potential is 49.00%, 47.75% and 40.25%, respectively. After the rapeseed is treated with argon cold plasma power of 100W, 150W and 200W, the germination potential is 83.75%, 61.00% and 72.00%, respectively. During storage for 0-180 days, the germination potential of untreated rapeseed decreased from 100% to 38.25%, the germination potential of the helium-based group decreased from 100% to about 45.66%, and the germination potential of the argon-based group decreased from 100% to about 72.25%.

[0087] Depend on Figure 1-4 It can be seen that as the storage time increases, the germination rate and germination potential of rapeseed decrease. This is because as the storage time continues to increase, the aging of rapeseed continues to intensify, and the damage to rapeseed in many aspects such as physiology, biochemistry and genetics continues to intensify, so its germination time continues to increase. Under the same conditions, the germination rate and germination potential of rapeseed treated with cold plasma technology are higher than those of the untreated group. Treatment with cold plasma technology can delay the decline in germination potential of rapeseed during storage.

[0088] (2) Conductivity

[0089] The conductivity determination method is as follows: select 50 rapeseed seeds of uniform size and full grains, repeat each sample 4 times, and require that the weight difference between parallel samples should not exceed 0.1g. Rinse the test sample with distilled water 3 times and place it in a wide-mouth bottle filled with 250mL distilled water. Place it at 25℃ for 24 hours and measure its conductivity value. The results are as follows Figure 5-6 shown.

[0090] Rapeseed will continue to age during storage. As the storage time increases, the integrity of the seed cell membrane will be damaged, resulting in increased permeability. The self-repair ability of the cells will continue to weaken during the aging process, and the amount of intracellular substances exuded will increase, thereby increasing the conductivity of the soaking solution and reducing the vitality of the seeds. Measuring the conductivity of the soaking solution can reflect the degree of aging and decay of the seeds to a certain extent. The change in conductivity during storage can reflect the changes in the physiological quality of rapeseed. The lower the conductivity, the higher the vitality, so it can be used as a measure of the vitality of rapeseed grains.

[0091] Depend on Figure 5-6 The results show that the conductivity of rapeseed stored at different temperatures during storage increases with time. Figure 5 As shown in the figure, at a storage temperature of 25°C, after the rapeseed was treated with helium cold plasma power at 80W, 100W and 120W, the electrical conductivity at the 180th day was 481.88μS / cm, 465.69μS / cm and 498.13μS / cm, respectively; after the rapeseed was treated with argon cold plasma power at 100W, 150W and 200W, the germination rate of rapeseed at the 180th day was 493.32μS / cm, 472.79μS / cm and 482.41μS / cm, respectively, and the untreated group was 652.62μS / cm. Figure 6 As shown, at a storage temperature of 35°C, after the rapeseed was treated with helium cold plasma powers of 80 W, 100 W and 120 W, respectively, the electrical conductivity at the 180th day was 527.01 μS / cm, 566.32 μS / cm and 517.15 μS / cm, respectively; after the rapeseed was treated with argon cold plasma powers of 100 W, 150 W and 200 W, respectively, the germination rate of the rapeseed at the 180th day was 543.69 μS / cm, 533.98 μS / cm and 513.69 μS / cm, respectively, while that of the untreated group was 801.32 μS / cm. At the same storage temperature, the conductivity of untreated rapeseed is always higher than that of rapeseed treated with cold plasma. At 25°C, the change in conductivity of rapeseed treated with different methods during the storage period of 60 days to 180 days is smaller than that of rapeseed stored at 35°C, which indicates that temperature has a great influence on conductivity, and cold plasma technology can delay the increase in conductivity.

[0092] A variance analysis was conducted on the changes in rapeseed conductivity under different conditions, and the results are shown in Table 3-4.

[0093] Table 3 Variance analysis of the conductivity of rapeseed at 25℃

[0094]

[0095]

[0096] Note: R 2 =0.289 (adjusted R 2 =0.057)

[0097] Table 4 Variance analysis of the conductivity of rapeseed at 35℃

[0098] Source of Difference Type III Sum of Squares Degrees of Freedom Mean Square F Significance Processing 0.161 1 0.161 0.105 0.035 Processing power 0.738 4 0.185 0.12 0.975 Storage time 639.779 6 106.63 69.433 0.000 error 225.75 147 1.536 Corrected Total 980.75 195

[0099] Note: R 2 =0.985 (adjusted R 2 =0.980)

[0100] It can be seen that at both temperatures, the significance of storage time is less than 0.01, indicating that there is a very significant relationship between storage time and the change in conductivity. The conductivity changes significantly with time, and the higher the temperature, the more significant the change in conductivity. The significance of the treatment methods at 25°C and 35°C is 0.047 and 0.035, which are significantly different, indicating that cold plasma technology can effectively delay the increase in rapeseed conductivity and has a delaying effect on the increase in conductivity caused by temperature. Cold plasma treatment storage can effectively maintain the vitality of rapeseed.

[0101] (3) Catalase activity

[0102] The activity of catalase was determined according to the method of GB / T 5522-2008. Figure 7-8 shown.

[0103] Catalase, also known as catalase (CAT), is mainly present in the peroxisome of cells. It is a conjugated enzyme with porphyrin as a cofactor and contains 4 iron atoms in the molecule. It can catalyze the decomposition of hydrogen peroxide into oxygen and water, and can reduce the oxidative toxicity of hydrogen peroxide to cells. As one of the key enzymes in the biological defense system, CAT plays an important role in maintaining the stability and integrity of cell membranes. It is a protective enzyme that enhances defense and slows down aging. CAT is widely present in plant tissue cells. Catalase in grains can slow down the toxic effect of hydrogen peroxide on grain vitality and slow down the deterioration of grain quality. Therefore, its activity can reflect the vitality of grain seeds.

[0104] Depend on Figure 7-8It can be seen that the catalase activity of rapeseed decreased to varying degrees under different treatment methods and storage temperatures, but the downward trend was closely related to the treatment method. Under 25°C and 35°C conditions, the catalase activity of untreated rapeseed was basically lower than that of rapeseed treated with cold plasma technology. Figure 7 As shown in the figure, at 25°C, the catalase activity of rapeseed treated with cold plasma was significantly different from that of untreated rapeseed. After 180 days of storage, the catalase activity of rapeseed treated with helium cold plasma at 80W, 100W and 120W was 33.17 mg H 2 O 2 / g, 33.10mg H 2 O 2 / g and 35.11mg H 2 O 2 / g, and the catalase activity of rapeseed treated with argon cold plasma at 100W, 150W and 200W was 35.15mg H 2 O 2 / g, 33.83mg H 2 O 2 / g and 33.40mg H 2 O 2 / g, and the untreated group was 26.10 mg H 2 O 2 / g. When stored for 0-180 days at 25°C, the catalase activity of untreated rapeseed increased from 76.94 mg H 2 O 2 / g decreased to 26.10mg H 2 O 2 / g, after being treated with cold plasma technology, the catalase activity increased from 77.00mg H 2 O 2 / g decreased to 34.12mg H 2 O 2 / g or so.

[0105] like Figure 8 As shown in Figure 2, at 35°C, after being stored for 180 days, the catalase activity of rapeseed treated with helium cold plasma at 80 W, 100 W, and 120 W was 31.22 mg H 2 O 2 / g, 30.76mg H 2 O 2 / g and 33.83mg H 2 O 2 / g, and the catalase activity of rapeseed treated with argon cold plasma at 100W, 150W and 200W was 30.72mg H 2 O 2 / g, 30.40mg H 2 O 2 / g and 32.48mg H 2 O 2 / g, and the untreated group was 20.49 mg H 2 O 2 / g. When stored at 35℃ for 0-180d, the catalase activity of untreated rapeseed increased from 76.67mg H 2 O 2 / g decreased to 20.49mg H 2 O 2 / g, after being treated with cold plasma technology, the catalase activity increased from 77.28mg H 2 O 2 / g decreased to 31.57mg H 2 O 2 / g. In summary, storage temperature has a great influence on the activity of catalase in rapeseed. After treatment with cold plasma technology, the decrease of catalase activity can be delayed under the same conditions.

[0106] Variance analysis was performed on the changes of rapeseed catalase under different conditions, and the results are shown in Tables 5-6. It can be seen that at both temperatures, the significance of the treatment method was 0.00, and the treatment method was extremely significantly correlated with the activity of catalase, indicating that cold plasma technology can significantly inhibit the decline of rapeseed catalase activity.

[0107] Table 5 Variance analysis of catalase activity changes in rapeseed at 25℃

[0108] Source of Difference Type III Sum of Squares Degrees of Freedom Mean Square F Significance Processing 128.445 1 128.445 54.454 0.00 Processing power 389.693 4 97.423 41.302 0.00 Storage time 37909.905 6 6318.318 2678.643 0.00 error 231.16 98 2.359 Corrected Total 44205.255 146

[0109] Note: R 2 =0.995 (Adjusted R 2 =0.992)

[0110] Table 6 Variance analysis of catalase activity changes in rapeseed at 35℃

[0111]

[0112]

[0113] Note: R 2 =0.999 (Adjusted R 2 =0.999)

[0114] (4) Correlation analysis between treatment methods and rapeseed germination rate, germination potential, conductivity, and catalase activity during storage

[0115] The correlation analysis of the treatment methods on rapeseed germination rate, germination potential, conductivity and catalase activity during storage was carried out. The results are shown in Table 7.

[0116] Table 7 Correlation between rapeseed physiological parameters and storage factors

[0117]

[0118] Note: **The correlation is extremely significant; *The correlation is significant.

[0119] From the correlation analysis in Table 7, it can be seen that the rapeseed treatment method has a very significant correlation with the catalase activity and conductivity, and the treatment method is significantly correlated with the germination rate and germination potential. This shows that after being treated with cold plasma technology, the rapeseed storage effect is better and the sowing quality of rapeseed storage can be effectively maintained.

[0120] Test Example 2

[0121] The rapeseeds were grouped and processed in the same manner as in Experimental Example 1, and 100 g of rapeseed samples were randomly taken every 30 days after storage for testing and analysis.

[0122] (1) Extraction of lipids from rapeseed

[0123] Weigh 100g of rapeseed and put it into a grinder for intermittent operation. Pass the crushed rapeseed through an 80-mesh sieve and place all of it in a brown reagent bottle with a reagent cap and a reagent plug. Add petroleum ether 3 times the volume of the sample, cover with the reagent plug and the reagent cap, soak in a dark place for about 8 hours, filter with filter paper, put the filtrate into a rotary evaporator, evaporate the petroleum ether, and you can get the rapeseed oil.

[0124] (2) Crude fat content

[0125] The determination was carried out according to the first method of Soxhlet extraction method in GB 5009.6-2016 "National Food Safety Standard Determination of Fat in Food". The results are as follows Figure 9-12 When the storage temperature was 25℃ and 35℃, the variance analysis was conducted on the effect of treatment methods on the crude fat content of rapeseed, and the results are shown in Table 8-9.

[0126] Depend on Fig. 9It can be seen that at a storage temperature of 25°C, after the rapeseed was treated with helium cold plasma powers of 80 W, 100 W and 120 W, respectively, the crude fat content of the rapeseed on the 180th day was (38.7±0.14) g / 100g, (38.5±0.15) g / 100g and (38.6±0.11) g / 100g, respectively, while that of the untreated group was (38.6±0.11) g / 100g.

[0127] Depend on Fig.10 It can be seen that at a storage temperature of 25°C, after the rapeseed was treated with argon cold plasma powers of 100 W, 150 W and 200 W, respectively, the crude fat content of the rapeseed on the 180th day was (38.7±0.12) g / 100g, (38.7±0.13) g / 100g and (38.6±0.15) g / 100g, respectively, while that of the untreated group was (38.6±0.11) g / 100g.

[0128] It can be seen from Table 8 that when the storage temperature is 25°C, the storage time has a very significant effect on the change in crude fat content (P < 0.01).

[0129] Table 8 Analysis of variance of the effects of treatment methods on crude fat content of rapeseed when the storage temperature is 25℃

[0130]

[0131] Depend on Fig.11 It can be seen that at a storage temperature of 35°C, after the rapeseed was treated with helium cold plasma powers of 80 W, 100 W and 120 W, respectively, the crude fat content of the rapeseed on the 180th day was (38.6±0.14) g / 100g, (38.6±0.14) g / 100g and (38.8±0.10) g / 100g, respectively, while that of the untreated group was (38.6±0.18) g / 100g.

[0132] Depend on Fig.12 It can be seen that at a storage temperature of 35°C, after the rapeseed was treated with argon cold plasma powers of 100 W, 150 W and 200 W, respectively, the crude fat content of the rapeseed on the 180th day was (38.6±0.13) g / 100g, (38.6±0.16) g / 100g and (38.7±0.14) g / 100g, respectively, while that of the untreated group was (38.6±0.18) g / 100g.

[0133] As shown in Table 9, when the storage temperature was 35°C, storage time had the greatest effect on the change in oil content (F=77.047), followed by gas (F=10.045) and power (F=2.507). Storage time and gas had extremely significant effects on the change in oil content (P<0.01), and power had a significant effect on the change in crude fat content. AC and BC had significant interactions.

[0134] Table 9 Analysis of variance of the effects of treatment methods on crude fat content of rapeseed when the storage temperature is 35℃

[0135] Sources of variation SS Degrees of Freedom Mean Square F-number P-value Gas (A) 0.326 1 0.326 10.045 0.002 Power(B) 0.325 4 0.081 2.507 0.047 Storage time (C) 15.001 6 2.500 77.047 0.000 AC 0.472 6 0.079 2.426 0.031 BC 1.492 24 0.062 1.916 0.014 error 3.180 98 0.032 total 226034.620 147 Corrected Total 23.083 146

[0136] (3) Crude fat peroxide value

[0137] According to GB 5009.227-2016 "National Food Safety Standard for Determination of Peroxide Value in Food", the first method of titration was used to measure the mass fraction equivalent to iodine. The results are as follows Figure 13-16 When the storage temperature was 25℃ and 35℃, the variance analysis was conducted on the effect of treatment methods on the crude fat peroxide value of rapeseed. The results are shown in Tables 10-11.

[0138] Depend on Fig.13 and 14 It can be seen that at a storage temperature of 25°C, after rapeseed was treated with helium or argon cold plasma, the crude fat peroxide value of rapeseed during storage showed an upward trend with the extension of storage time, and tended to be horizontal in the period from 150d to 180d. After rapeseed was treated with helium or argon cold plasma, the peroxide value of each period during the storage period was lower than that of the untreated group. In the helium treatment, the peroxide value of the 120W treatment group during the storage period was lower than the peroxide value of other power treatments. At 180 days, the peroxide values ​​of rapeseed in the 80W, 100W and 120W treatment groups were (0.048±0.002) g / 100g, (0.047±0.001) g / 100g and (0.045±0.001) g / 100g, respectively, and that of the untreated group was (0.063±0.003) g / 100g. In the argon treatment, the peroxide value of the 200W treatment group during the storage period was lower than that of the other power treatments. At the 180th day, the peroxide values ​​of rapeseed in the treatment groups with processing powers of 100 W, 150 W and 200 W were (0.046±0.002) g / 100g, (0.042±0.001) g / 100g and (0.038±0.001) g / 100g, respectively, and that of the untreated group was (0.063±0.003) g / 100g.

[0139] As shown in Table 10, when the storage temperature is 25°C, the storage time has the greatest impact on the change of peroxide value (F=1170.018), followed by power (F=40.647). The storage time and power have a very significant effect on the change of peroxide value (P<0.01). The BC interaction is significant.

[0140] Table 10 Variance analysis of the effects of treatment methods on crude fat peroxide value of rapeseed when storage temperature is 25℃

[0141] Sources of variation SS Degrees of Freedom Mean Square F-number P-value Gas (A) 0.000 1 0.000 1.018 0.315 Power(B) 0.001 4 0.000 40.647 0.000 Storage time (C) 0.017 6 0.003 825.304 0.000 AC 0.000 6 0.000 0.771 0.595 BC 0.000 24 0.000 2.286 0.002 error 0.000 98 0.000 total 0.192 147 Corrected Total 0.021 146

[0142] Depend on Fig.15 and 16 It can be seen that at a storage temperature of 35°C, the crude fat peroxide value of rapeseed treated with helium or argon cold plasma during storage showed an increasing trend with the extension of storage time. After rapeseed treated with helium or argon cold plasma, the peroxide value of rapeseed at each period during the storage period was lower than that of the untreated group. In the helium treatment, the peroxide value of the 120W treatment group during the storage period was lower than that of the other power treatments. At the 180th day, the peroxide values ​​of rapeseed in the 80W, 100W and 120W treatment groups were (0.055±0.001)g / 100g, (0.054±0.002)g / 100g, and (0.052±0.003)g / 100g, respectively, and that of the untreated group was (0.066±0.001)g / 100g. In the argon treatment, the peroxide value of the 200 W treatment group during the storage period was lower than that of the other power treatments. On the 180th day, the peroxide values ​​of rapeseed in the 100 W, 150 W and 200 W treatment groups were (0.054±0.001) g / 100g, (0.049±0.001) g / 100g, and (0.048±0.001) g / 100g, respectively, while that of the untreated group was (0.066±0.001) g / 100g.

[0143] As shown in Table 11, when the storage temperature is 35°C, the storage time has the greatest impact on the change of peroxide value (F=1170.018), followed by power (F=35.908). The storage time and power have a very significant effect on the change of peroxide value (P<0.01). The BC interaction is significant.

[0144] Table 11 Variance analysis of the effects of treatment methods on crude fat peroxide value of rapeseed when storage temperature is 35℃

[0145] Sources of variation SS Degrees of Freedom Mean Square F-number P-value Gas (A) 0.000 1 0.000 2.759 0.100 Power(B) 0.000 4 0.000 35.908 0.000 Storage time (C) 0.020 6 0.003 1170.018 0.000 AC 0.000 6 0.000 1.070 0.386 BC 0.000 24 0.000 1.881 0.016 error 0.000 98 0.000 total 0.212 147 Corrected Total 0.024 146

[0146] (4) Crude fatty acid value

[0147] The determination was carried out according to the first method of cold solvent indicator titration method in GB 5009.229-2016 "National Food Safety Standard Determination of Acid Value in Food". Figure 17-20 When the storage temperature was 25℃ and 35℃, the variance analysis was conducted on the effect of treatment on the crude fatty acid value of rapeseed, and the results are shown in Table 12-13.

[0148] Depend on Fig.17 and 18 It can be seen that at a storage temperature of 25°C, the crude fatty acid value of rapeseed treated with helium or argon cold plasma during storage showed a trend of first rising, then falling, and finally rising as the storage time prolonged, and a downward trend appeared on the 120th day. After rapeseed was treated with helium or argon cold plasma, the acid value of each period during the storage period was lower than that of the untreated group. In the helium treatment, the acid value of the 120W treatment group during the storage period was lower than that of the other power treatments. At the 180th day, the acid value of rapeseed in the 80W, 100W and 120W treatment groups was (0.56±0.01) mg / g, (0.53±0.03) mg / g, (0.51±0.01) mg / g, respectively, and that of the untreated group was (0.59±0.02) mg / g. In the argon treatment, at the 180th day, the acid value of rapeseed in the treatment groups with treatment powers of 100 W, 150 W and 200 W were (0.52±0.02) mg / g, (0.50±0.01) mg / g, and (0.48±0.01) mg / g, respectively, and that of the untreated group was (0.59±0.02) mg / g.

[0149] It can be seen from Table 12 that when the storage temperature is 25°C, the storage time has the greatest impact on the change of acid value (F=572.373), followed by power (F=28.186). The storage time and power have extremely significant effects on the change of acid value (P<0.01).

[0150] Table 12 Variance analysis of the effects of treatment methods on crude fatty acid values ​​of rapeseed when storage temperature is 25℃

[0151]

[0152]

[0153] Depend on Fig.19 and 20It can be seen that at a storage temperature of 35°C, the crude fatty acid value of rapeseed treated with helium or argon cold plasma during storage showed a trend of first rising, then falling, and finally rising as the storage time prolonged, and a downward trend appeared on the 120th day. After rapeseed was treated with helium or argon cold plasma, the acid value of each period during the storage period was lower than that of the untreated group. In the helium treatment, the acid value of the 120W power treatment group during the storage period was lower than that of the other power treatments. At the 180th day, the acid value of rapeseed in the 80W, 100W and 120W power treatment groups was (0.58±0.01) mg / g, (0.55±0.02) mg / g, (0.52±0.02) mg / g, respectively, and the untreated group was (0.65±0.01) mg / g. In the argon treatment, the acid value of the 200W power treatment group during the storage period was lower than that of the other power treatments. On the 180th day, the acid value of rapeseed in the treatment groups with treatment powers of 100 W, 150 W and 200 W were (0.56±0.01) mg / g, (0.51±0.01) mg / g, and (0.50±0.02) mg / g, respectively, and that of the untreated group was (0.65±0.01) mg / g.

[0154] It can be seen from Table 13 that when the storage temperature is 35°C, the storage time has the greatest impact on the change of acid value (F=613.481), followed by power (F=27.151). The storage time and power have extremely significant effects on the change of acid value (P<0.01).

[0155] Table 13 Variance analysis table of the effect of treatment methods on crude fatty acid value of rapeseed when storage temperature is 35℃

[0156] Sources of variation SS Degrees of Freedom Mean Square F-number P-value Gas (A) 0.000 1 0.000 0.006 0.936 Power(B) 0.040 4 0.010 27.151 0.000 Storage time (C) 1.360 6 0.227 613.481 0.000 AC 0.001 6 0.000 0.337 0.916 BC 0.010 24 0.000 1.090 0.370 error 0.036 98 0.000 total 27.031 147 Corrected Total 1.726 146

[0157] (5) Correlation of treatment methods with rapeseed oil quality during storage

[0158] The correlation between the treatment methods and the rapeseed oil quality during storage was analyzed, and the results are shown in Table 14.

[0159] As shown in Table 14, the fat content of rapeseed is significantly correlated with the storage time. The peroxide value is significantly correlated with the treatment gas, treatment power and storage time. The acid value is significantly correlated with the treatment gas, treatment power and storage time.

[0160] Table 14 Correlation analysis of treatment methods on rapeseed oil quality during storage

[0161]

[0162] Note: ** indicates significant correlation at the 0.01 level (bilateral), and * indicates significant correlation at the 0.05 level (bilateral).

[0163] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for improving the storage quality of rapeseed, characterized in that: The method comprises the following steps: The rapeseed is treated with cold plasma and then sealed and stored after the treatment. The conditions of the cold plasma treatment are as follows: the discharge medium is helium or argon, the treatment power is 80-200W, and the treatment time is 12-18s.

2. The method according to claim 1, characterized in that The storage quality includes sowing quality and oil quality of rapeseed during storage.

3. The method according to claim 2, characterized in that The indices of sowing quality include germination rate, germination potential, electrical conductivity and catalase activity.

4. The method according to claim 2, characterized in that: The indicators of oil quality include fat content, oil peroxide value and oil acid value.

5. The method according to claim 1, characterized in that When the discharge medium is helium, the processing power is 80-120W; when the discharge medium is argon, the processing power is 100-200W.

6. The method according to claim 5, characterized in that When the discharge medium is helium, the processing power is 120W; when the discharge medium is argon, the processing power is 200W.

7. The method according to claim 1, characterized in that The cold plasma treatment time is 15 s.

8. The method according to claim 1, characterized in that The output frequency of the radio frequency power supply for the cold plasma treatment is 10 to 20 MHz.

9. The method according to claim 1, characterized in that: The temperature of the sealed storage is 20-40°C.

10. The method according to claim 1, characterized in that The airtight storage period is 4-12 months.

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