CN112753750A - High-voltage electric field low-temperature plasma cold sterilization method for instant dry fruit food - Google Patents
High-voltage electric field low-temperature plasma cold sterilization method for instant dry fruit food Download PDFInfo
- Publication number
- CN112753750A CN112753750A CN202011633378.7A CN202011633378A CN112753750A CN 112753750 A CN112753750 A CN 112753750A CN 202011633378 A CN202011633378 A CN 202011633378A CN 112753750 A CN112753750 A CN 112753750A
- Authority
- CN
- China
- Prior art keywords
- electric field
- voltage electric
- temperature plasma
- sterilization
- cold sterilization
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000001954 sterilising effect Effects 0.000 title claims abstract description 132
- 238000004659 sterilization and disinfection Methods 0.000 title claims abstract description 131
- 230000005684 electric field Effects 0.000 title claims abstract description 82
- 235000013305 food Nutrition 0.000 title claims abstract description 58
- 235000013399 edible fruits Nutrition 0.000 title claims abstract description 50
- 238000000034 method Methods 0.000 title claims abstract description 40
- 238000004806 packaging method and process Methods 0.000 claims abstract description 32
- 235000011869 dried fruits Nutrition 0.000 claims abstract description 25
- 230000004888 barrier function Effects 0.000 claims abstract description 7
- 235000017784 Mespilus germanica Nutrition 0.000 claims description 17
- 244000182216 Mimusops elengi Species 0.000 claims description 17
- 235000000560 Mimusops elengi Nutrition 0.000 claims description 17
- 235000007837 Vangueria infausta Nutrition 0.000 claims description 17
- 244000241872 Lycium chinense Species 0.000 claims description 14
- 235000015468 Lycium chinense Nutrition 0.000 claims description 14
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 4
- 238000007789 sealing Methods 0.000 claims description 4
- 238000009448 modified atmosphere packaging Methods 0.000 claims description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 2
- 239000001569 carbon dioxide Substances 0.000 claims description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 2
- 239000007789 gas Substances 0.000 claims description 2
- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 claims description 2
- 239000001301 oxygen Substances 0.000 claims description 2
- 229910052760 oxygen Inorganic materials 0.000 claims description 2
- 238000012545 processing Methods 0.000 abstract description 12
- 230000001580 bacterial effect Effects 0.000 abstract description 8
- 244000052616 bacterial pathogen Species 0.000 abstract description 5
- 239000002778 food additive Substances 0.000 abstract description 2
- 235000013373 food additive Nutrition 0.000 abstract description 2
- 210000002381 plasma Anatomy 0.000 description 78
- 241000191967 Staphylococcus aureus Species 0.000 description 13
- 230000000694 effects Effects 0.000 description 13
- 241000894006 Bacteria Species 0.000 description 11
- 238000009832 plasma treatment Methods 0.000 description 10
- 230000004044 response Effects 0.000 description 8
- 238000012360 testing method Methods 0.000 description 8
- 230000008859 change Effects 0.000 description 7
- 230000001953 sensory effect Effects 0.000 description 7
- 240000004808 Saccharomyces cerevisiae Species 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 6
- 230000000813 microbial effect Effects 0.000 description 5
- 244000005700 microbiome Species 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- 230000001276 controlling effect Effects 0.000 description 4
- 238000012258 culturing Methods 0.000 description 4
- 238000007865 diluting Methods 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 235000013372 meat Nutrition 0.000 description 4
- 238000004321 preservation Methods 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 230000001105 regulatory effect Effects 0.000 description 4
- 230000000630 rising effect Effects 0.000 description 4
- 244000241838 Lycium barbarum Species 0.000 description 3
- 235000015459 Lycium barbarum Nutrition 0.000 description 3
- 230000009471 action Effects 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 3
- 238000001514 detection method Methods 0.000 description 3
- 230000003993 interaction Effects 0.000 description 3
- 238000005303 weighing Methods 0.000 description 3
- 244000080767 Areca catechu Species 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 235000009754 Vitis X bourquina Nutrition 0.000 description 2
- 235000012333 Vitis X labruscana Nutrition 0.000 description 2
- 240000006365 Vitis vinifera Species 0.000 description 2
- 235000014787 Vitis vinifera Nutrition 0.000 description 2
- 244000126002 Ziziphus vulgaris Species 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 230000000875 corresponding effect Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000000593 degrading effect Effects 0.000 description 2
- 239000002274 desiccant Substances 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 210000002615 epidermis Anatomy 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000012417 linear regression Methods 0.000 description 2
- 238000005457 optimization Methods 0.000 description 2
- 239000002504 physiological saline solution Substances 0.000 description 2
- 239000003755 preservative agent Substances 0.000 description 2
- 230000002335 preservative effect Effects 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 239000006228 supernatant Substances 0.000 description 2
- 240000008154 Piper betle Species 0.000 description 1
- 235000008180 Piper betle Nutrition 0.000 description 1
- 235000006545 Ziziphus mauritiana Nutrition 0.000 description 1
- 235000008529 Ziziphus vulgaris Nutrition 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000013401 experimental design Methods 0.000 description 1
- 239000000796 flavoring agent Substances 0.000 description 1
- 235000019634 flavors Nutrition 0.000 description 1
- 235000013569 fruit product Nutrition 0.000 description 1
- 235000012055 fruits and vegetables Nutrition 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 239000002932 luster Substances 0.000 description 1
- 239000002086 nanomaterial Substances 0.000 description 1
- 230000001717 pathogenic effect Effects 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 235000013311 vegetables Nutrition 0.000 description 1
- 230000037303 wrinkles Effects 0.000 description 1
Images
Classifications
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23B—PRESERVING, e.g. BY CANNING, MEAT, FISH, EGGS, FRUIT, VEGETABLES, EDIBLE SEEDS; CHEMICAL RIPENING OF FRUIT OR VEGETABLES; THE PRESERVED, RIPENED, OR CANNED PRODUCTS
- A23B7/00—Preservation or chemical ripening of fruit or vegetables
- A23B7/015—Preserving by irradiation or electric treatment without heating effect
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23B—PRESERVING, e.g. BY CANNING, MEAT, FISH, EGGS, FRUIT, VEGETABLES, EDIBLE SEEDS; CHEMICAL RIPENING OF FRUIT OR VEGETABLES; THE PRESERVED, RIPENED, OR CANNED PRODUCTS
- A23B7/00—Preservation or chemical ripening of fruit or vegetables
- A23B7/14—Preserving or ripening with chemicals not covered by groups A23B7/08 or A23B7/10
- A23B7/144—Preserving or ripening with chemicals not covered by groups A23B7/08 or A23B7/10 in the form of gases, e.g. fumigation; Compositions or apparatus therefor
- A23B7/148—Preserving or ripening with chemicals not covered by groups A23B7/08 or A23B7/10 in the form of gases, e.g. fumigation; Compositions or apparatus therefor in a controlled atmosphere, e.g. partial vacuum, comprising only CO2, N2, O2 or H2O
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23V—INDEXING SCHEME RELATING TO FOODS, FOODSTUFFS OR NON-ALCOHOLIC BEVERAGES AND LACTIC OR PROPIONIC ACID BACTERIA USED IN FOODSTUFFS OR FOOD PREPARATION
- A23V2002/00—Food compositions, function of food ingredients or processes for food or foodstuffs
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Wood Science & Technology (AREA)
- Zoology (AREA)
- Food Science & Technology (AREA)
- Polymers & Plastics (AREA)
- Apparatus For Disinfection Or Sterilisation (AREA)
Abstract
The invention provides a high-voltage electric field low-temperature plasma cold sterilization method for instant dried fruit food, which comprises the steps of packaging instant dried fruits, placing the packaged instant dried fruits between two electrode plates of a high-voltage electric field Dielectric Barrier (DBD) low-temperature plasma generator, carrying out intermittent multi-cycle sterilization under the conditions of room temperature and humidity of 50-80% RH, carrying out repeated treatment for 3-5 times with single sterilization treatment time of 30-180 s and interval time of 30-180 s, wherein the voltage intensity is 10-35 kV/cm, and the power density is 5-40 w/cm3The processing frequency range is 50-150 Hz. The method of the invention carries out high-voltage electric field low-temperature plasma cold sterilization treatment after packaging the dry fruit food, adopts short-time-interval-multiple sterilization, effectively avoids secondary pollution, simultaneously reduces the use of food additives, effectively reduces the total number of bacterial colonies and pathogenic bacteria on the surface of the dry fruit food, and prolongs the shelf life.
Description
Technical Field
The invention belongs to the technical field of food sterilization, and particularly relates to a high-voltage electric field low-temperature plasma cold sterilization method for instant dry fruit food.
Background
Red dates (Red jujube) and Chinese wolfberry (Lycium barbarum L) are Chinese-featured dry fruit products, the yield and the market space are huge, and the problem of food safety and quality caused by microbial pollution in the processes of processing, packaging and logistics transportation of dry fruit foods circulating in the market at present is receiving increasing attention. Pathogenic bacteria such as coliform bacteria and mould yeast in the red dates; the pathogenic bacteria in the medlar are mainly staphylococcus aureus, coliform bacteria and mould which are the key points of attention of consumers.
The high-voltage electric field low-temperature plasma technology is an international novel food cold sterilization technology, secondary pollution of food is avoided by cold sterilization after packaging, the sterilization process is efficient and rapid, temperature rise does not exist, the original color, aroma and taste fresh sensory quality of the food can be effectively protected, and the high-voltage electric field low-temperature plasma technology is very suitable for cold sterilization of thermosensitive food. At present, the high-voltage electric field low-temperature plasma cold sterilization technology is mainly applied to fresh meat, fruits and vegetables and has made a certain progress. Patent ZL201410347682.3 discloses a method for sterilizing and refreshing fresh meat by using high-voltage electric field low-temperature plasma in cooperation with nano materials; patent CN201811342997.3 discloses a method for cold sterilization of packed betel nuts by high-voltage electric field low-temperature plasma; the method is characterized in that MAP packaging is carried out on fresh meat, areca nuts and the like, then cold sterilization treatment is carried out on the fresh meat, the areca nuts and the like, and the adjustable high-voltage electric field low-temperature plasma exciting factor is only voltage intensity due to the limitation of sterilization equipment conditions.
The dried fruit and vegetable has wrinkles on the surface and rough and irregular surface, and the high-voltage electric field low-temperature plasma is applied to cold sterilization of packaged instant dried fruit food, so that the sterilization and fresh-keeping effects are limited only by regulating and controlling the voltage intensity.
Disclosure of Invention
The invention aims to provide a high-voltage electric field low-temperature plasma cold sterilization method for instant dry fruit food, which improves the sterilization rate of the dry fruit by improving the voltage intensity, the power density and the working frequency, thereby prolonging the storage period of the dry fruit and effectively avoiding secondary pollution and quality damage.
The technical solution for realizing the purpose of the invention is as follows:
the high-voltage electric field low-temperature plasma cold sterilization method for the instant dry fruit food comprises the following steps:
step 1: packaging and sealing the instant dry fruit food;
step 2: placing packaged instant dry fruit food between two electrodes of a high-voltage electric field dielectric barrier DBD low-temperature plasma generator, wherein the distance between the two electrodes of the high-voltage electric field dielectric barrier low-temperature plasma generator is 2-4 cm;
and step 3: adjusting the working frequency and the voltage intensity of a high-voltage electric field, and carrying out intermittent multi-cycle cold sterilization on packaged instant dried fruit food under the conditions that the room temperature is 15-28 ℃ and the relative humidity is 50-80% RH, wherein the working frequency of the high-voltage electric field is 50-150 Hz, the voltage intensity is 10-35 kV/cm, and the power density is 5-40W/cm3。
Further, according to the high-voltage electric field low-temperature plasma cold sterilization method for the instant dried fruit food, the instant dried fruit food in the step 1 comprises dried red dates, dried medlar and the like.
Further, the high-voltage electric field low-temperature plasma cold sterilization method for the instant dry fruit food comprises the step 1 of packaging in boxes and bags, wherein the packages are filled with mixed gas of oxygen, nitrogen and carbon dioxide for modified atmosphere packaging or directly air-packaged by filling air.
Further, in the method for cold sterilization of the instant dried fruit food by the high-voltage electric field low-temperature plasma, in the step 3 of intermittent multiple-cycle cold sterilization, the treatment time of single cold sterilization is 30-180 s, the interval time is 30-180 s, and the cycle sterilization frequency is 3-5.
Further, the high-voltage electric field low-temperature plasma cold sterilization method for the instant dried fruit food provided by the invention has the following cold sterilization conditions of the instant dried red dates: the working frequency is 50-150 Hz, the voltage intensity is 10-20 kV/cm, and the power density is 10-40 w/cm3。
Further, the high-voltage electric field low-temperature plasma cold sterilization method for the instant dried fruit food provided by the invention has the following cold sterilization conditions of the instant dried medlar fruit: the working frequency is 50-150 Hz, the voltage intensity is 10-20 kV/cm, and the power density is 5-20 w/cm3。
The high-voltage electric field low-temperature plasma cold sterilization device for the instant dry fruit food based on the method comprises a high-voltage electric field frequency and voltage regulator, a high-voltage electric field generator and a plasma generator which are sequentially connected.
Further, the high-voltage electric field low-temperature plasma cold sterilization device for the instant dry fruit food comprises a frequency converter, a variable transformer, two inductors, two transformers and a plasma generator, wherein the input end of the frequency converter is connected with a medium-voltage input, the medium-voltage input is AC220V or AC380V, and the transformer converts 50Hz alternating current into 0-200 Hz alternating pulse voltage; the output end of the transformer is connected with the input end of the variable transformer through a first inductor, and the first inductor filters harmonic high-frequency components in the alternating-current pulse voltage; the output end of the variable transformer is connected with the first transformer and the second transformer through a second inductor, the second inductor is a DBD negative resistance offset inductor and is matched with a DBD discharge capacitor, and the variable transformer regulates the alternating current pulse voltage to a required voltage value and outputs the alternating current pulse voltage to the first transformer and the second transformer; the output ends of the first transformer and the second transformer are connected with the plasma generator, and the first transformer and the second transformer boost the voltage to the required ultrahigh voltage and output the voltage to the plasma generator.
Compared with the prior art, the invention adopting the technical scheme has the following technical effects:
1. the high-voltage electric field low-temperature plasma cold sterilization method for the instant dried fruit food can effectively reduce the total number of bacterial colonies and pathogenic bacteria on the surface of the dried fruit food and prolong the shelf life.
2. The high-voltage electric field low-temperature plasma cold sterilization method for the instant dry fruit food can be used for carrying out high-voltage electric field low-temperature plasma cold sterilization treatment on the packaged dry fruit food, can effectively avoid secondary pollution and simultaneously reduce the use of food additives
3. The high-voltage electric field low-temperature plasma cold sterilization method for the instant dry fruit food adopts a short-time-interval-multiple sterilization mode under the normal temperature and pressure conditions, the surfaces of the packaging box (bag) and the dry fruit are not obviously heated after the high-voltage electric field low-temperature plasma treatment, and the flavor quality influence caused by the temperature rise is avoided.
Drawings
Fig. 1 is a schematic structural diagram of the high-voltage electric field low-temperature plasma cold sterilization device for the instant dry fruit food.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.
The high-voltage electric field low-temperature plasma cold sterilization method for the instant dry fruit food comprises the following steps:
step 1: packaging and sealing the instant dry fruit food;
step 2: placing packaged instant dry fruit food between two electrodes of a high-voltage electric field dielectric barrier DBD low-temperature plasma generator, wherein the distance between the two electrodes of the high-voltage electric field dielectric barrier low-temperature plasma generator is 2-4 cm;
and step 3: adjusting the working frequency and the voltage intensity of a high-voltage electric field, and carrying out intermittent multi-cycle cold sterilization on packaged instant dried fruit food under the conditions that the room temperature is 15-28 ℃ and the relative humidity is 50-80% RH, wherein the working frequency of the high-voltage electric field is 50-150 Hz, the voltage intensity is 10-35 kV/cm, and the power density is 5-40W/cm3。
The high-voltage electric field low-temperature plasma cold sterilization method for the instant dry fruit food disclosed by the invention realizes the regulation and control function of the frequency modulation of the high-voltage electric field on the basis of regulating and controlling the voltage intensity of the high-voltage electric field through the core technical breakthrough of the high-voltage electric field low-temperature plasma cold sterilization equipment, and the state of the low-temperature plasma is regulated and controlled by further regulating and controlling the frequency modulation and the power density of the high-voltage electric field, so that the cold sterilization efficiency of the high-voltage electric field low-temperature plasma is effectively improved.
Example 1
The embodiment discloses a method for cold sterilization of dried red dates by high-voltage electric field low-temperature plasma under the conditions of different voltage intensities (power densities), which comprises the following steps:
1) sample pretreatment: bulk red dates purchased from a supermarket are placed in a dark and humid place (the temperature is 27 ℃, the humidity is 80% RH) and taken out after being placed for 4 days, the total number of bacterial colonies is about 3.15Log/g, a certain weight (40g +/-1 g) is weighed in a packaging box (the packaging box is 17cm multiplied by 12cm multiplied by 3.6cm), and the packaging box is directly sealed after being filled with air.
2) And (3) sterilization treatment: placing the packaging box between two electrodes of a high-voltage electric field low-temperature plasma sterilization device, adjusting the distance between the two electrodes to be 3.8cm, and performing plasma cold sterilization treatment under the conditions of room temperature and relative humidity of 50-80% RH; a short-time interval-multiple circulation sterilization mode is adopted, the treatment time is 120s, the interval time is 30s, and the steps are repeated for 3-5 times; the working frequency of the high-voltage electric field low-temperature plasma is 50 Hz; the low-temperature plasma is respectively at different voltage intensities of 13.16, 15, 16.84 and 18.68kv/cm (the corresponding power densities are respectively 11.05, 18.04, 25.96 and 34.53w/cm3) And (5) treating the dried red dates.
3) Under the same conditions, the samples without plasma treatment were control. The total bacterial count is measured according to GB4789.2-2016 (food microbiology test colony count determination), and the brightness value (L) and the red value (a) of the red dates are measured by an automatic color difference meter.
The total number of colonies and the color number before and after the plasma treatment at different power densities are shown in tables 1 and 2 below.
TABLE 1 microbial change table of dried fructus Jujubae (total number of colonies/Log (CFU/g))
| Voltage (kV) | Control group | 50 | 57 | 64 | 71 |
| Voltage intensity (kV/cm) | Control group | 13.16 | 15 | 16.84 | 18.68 |
| Power density (w/cm)3) | Control group | 11.05 | 18.04 | 25.96 | 34.53 |
| Total number of colonies (Log/g) | 3.15±0.21 | 2.82±0.08 | 2.25±0.12 | 2.01±0.08 | 1.79±0.11 |
| a* | 21.06±0.85 | 20.82±1.82 | 21.54±1.23 | 21.22±1.07 | 24.25±1.11 |
| L* | 18.04±1.53 | 20.02±1.45 | 18.21±1.09 | 18.92±0.98 | 20.01±1.54 |
From the above table 1, it is understood that the low temperature plasma treatment has a significant effect of degrading microorganisms on the epidermis of the dried red dates, and it is seen from the table that when the voltage intensity is increased to 13.16kV/cm (the power density is 11.05w/cm3), the total bacterial colony sterilization rate is significantly decreased compared to the control group, and the sterilization rate is also gradually increased as the voltage intensity is further increased. The higher the voltage intensity is, the better the sterilization effect is, but the voltage intensity exceeds 18.68kV/cm (the power density is 34.53 w/cm)3) When the voltage intensity is increased to 18.68kV/cm, the number of colonies on the surface of the dried red dates can be reduced by 1.36 Log. And after the dried red dates are treated by the high-voltage electric field low-temperature plasma, the red value and the brightness value of the surface are not affected, and the sensory quality of the dried red dates can be improved to a certain extent.
Example 2
The embodiment discloses a method for cold sterilization of dried red dates under the conditions of different working frequencies of high-voltage electric field low-temperature plasmas, which comprises the following steps:
1) sample pretreatment: placing bulk red dates bought from a supermarket in a dark and humid place (the temperature is 27 ℃, the humidity is 80% RH) for 4 days, taking out, weighing a certain weight (40g +/-1 g) in a packaging box (the packaging box is 17cm multiplied by 12cm multiplied by 3.6cm) at the moment, and directly sealing and packaging after filling air.
2) And (3) sterilization treatment: placing the packaging box between two electrodes of a high-voltage electric field low-temperature plasma sterilization device, and adjusting the distance between the two electrodes to be 3.8 cm; the voltage intensity of the high-voltage electric field low-temperature plasma is 13.14kV/cm, and the power density is 11.05w/cm3(ii) a Processing the dried red dates by low-temperature plasmas at different working frequencies of 50Hz, 70 Hz, 90Hz, 110Hz and 130 Hz; carrying out plasma cold sterilization treatment at room temperature for 120s at intervals of 30s, repeating the treatment for 3-5 times at a relative humidity of 50-80% RH; adopts a short-time-interval-multiple circulation sterilization mode.
3) Under the same conditions, the samples without plasma treatment were control. The total number of bacteria is measured according to GB4789.2-2016 (determination of total number of colonies for food microbiology test).
The total number of colonies and the color of colonies before and after the treatment under the different operating frequency conditions of the plasma are shown in tables 3 and 4 below.
TABLE 2 microbial change table of dried fructus Jujubae (total number of colonies/Log (CFU/g))
As can be seen from the above table 2, the total number of colonies on the high surface of the dried red dates is firstly remarkably reduced along with the increase of the working frequency of the low-temperature plasma of the high-voltage electric field and then tends to be gentle, which indicates that the higher the working frequency is to a certain extent, the better the sterilization effect on the dried red dates is. When the frequency is higher than 90Hz, the sterilization rate tends to be flat, and the maximum value of the sterilization rate at 110Hz can reduce about 1 Logcfu/g of epidermal microorganisms. The method shows that the working frequency can be increased to improve the sterilization effect of the dried red dates in the actual industrial application, but the working frequency is not necessarily too high. And the rising of the frequency has no obvious influence on the color of the dried red dates, but the rising of the frequency can improve the brightness of the dried red dates to a certain extent and improve the sensory quality of the dried red dates.
Embodiment 3 discloses a curved surface optimization test method for the response of high-voltage electric field low-temperature plasma to the sterilization rate of dried red dates, which comprises the following steps:
1) and (3) sterilization treatment: the packaging box is arranged between two electrodes of the high-voltage electric field low-temperature plasma sterilization device, the distance between the two electrodes is adjusted, and the low-temperature plasma carries out cold sterilization treatment on the dried red dates under the treatment conditions with different response curved surfaces.
2) Under the same conditions, the samples without plasma treatment were control. Detecting the number of the mould and the yeast according to GB4789.15-2016 (national food safety standard food microbiology inspection mould and colony mother count); the number of coliform groups was determined according to GB 4789.3-2016, food safety national Standard food microbiology test coliform group count.
TABLE 3 horizontal table for response surface design factor
The packaging box is placed between two electrodes of the high-voltage electric field low-temperature plasma sterilization device, different batches of experiments are carried out according to the test level designed by software, after the high-voltage electric field low-temperature plasma cold sterilization experiment is finished, the sample is placed at room temperature for 2 hours and then subjected to microorganism detection, and the sterilization rate is used as an index, so that a result table 4 is obtained.
Table 4 response surface experimental design and results table
And utilizing the fitted multiple regression equation to express the interaction of the two factors in the response surface. Table 5 shows that the threshold of the processing voltage decreases with increasing processing time at a fixed processing frequency, but is not significant. When the treatment time was 90s, the treatment voltage threshold was 69.05kV, and the sterilization rate was 94.39%, whereas when the treatment time was increased to 150s, the treatment voltage threshold was decreased to 66.69kV, and the sterilization rate threshold was increased to 99.84%. The values of the two factors in the table are subjected to linear regression analysis, and the linear relation between the two factors can be shown (y ═ and-0.0394x+72.594，R21). The critical value of the sterilization rate increases with the increase of the treatment time, and reaches the maximum when the treatment time is 150 seconds.
TABLE 5 Critical values of the influence of different treatment voltages on the sterilization rate of dried fructus Jujubae at different treatment times
When the treatment time was fixed at 120s, the treatment voltage threshold and the sterilization rate threshold were varied with the variation of the treatment frequency, as detailed in table 6. As can be seen from the table, the effect of the treatment voltage threshold value on the sterilization rate increases as the treatment frequency increases. Linear regression analysis of the two factors in the table for processing voltage threshold and processing frequency (y 0.0825x + 60.443, R)21), the critical value of the sterilization rate increases and then decreases as the treatment frequency increases, and the critical value of the sterilization rate is 98.01% at a maximum when the treatment frequency is about 100 Hz.
TABLE 6 influence of different treatment voltages on critical value of sterilization rate of dried fructus Jujubae under different treatment frequency
As can be seen from the above table 4, the Design-Expert software is used for carrying out multiple regression fitting analysis on the response surface data in the table 4, the working voltage and the working frequency of the low-temperature plasma of the high-voltage electric field have obvious interaction on the sterilization rate of the dried red dates, the working voltage and the working frequency have inflection points on the sterilization rate of the dried red dates, and the influence on the sterilization rate is in the order of magnitude: operating voltage > operating frequency. The optimal sterilization conditions optimized by the response curved surface model are that the working voltage is 65kV, the processing time is 150s and the working frequency is 86Hz, and the sterilization rate of the plasma cold sterilization technology on the total number of colonies of the dried red dates can reach 99.6% under the optimal process conditions, wherein mould yeast and coliform groups are not detected, and the quality such as color and luster and the like has no obvious influence, which is shown in the following table 7.
TABLE 7 pathogenic bacteria and quality change table before and after treatment of optimum conditions for high-voltage electric field and low-temperature plasma cold sterilization
As can be seen from Table 7, before and after plasma treatment, pathogenic coliform bacteria and mold yeast are not detected, the total number of original colonies can be reduced by 2.15 logs, and the red date redness value and brightness value are not significantly changed before and after treatment. The results show that the plasma cold sterilization treatment can obviously reduce the number of colonies on the surface of the dried red dates, and has no obvious influence on the sensory quality of the dried red dates, so that the shelf life of the dried red dates is prolonged.
Example 4
The embodiment discloses a method for cold sterilization of dried Chinese wolfberry fruits under the conditions of different voltage intensities (power densities) of high-voltage electric field low-temperature plasmas, which comprises the following steps:
1) due to different drying methods of the dried medlar fruits on the market, the added preservative, the desiccant and other factors, the colony number difference of the surfaces of the purchased dried medlar fruits is large, and in order to ensure the colony number consistency, the dried medlar fruits are subjected to cold sterilization treatment after being dyed with staphylococcus aureus.
2) Taking out a staphylococcus aureus preservation tube for passage 2 times from-40 ℃, adding the staphylococcus aureus preservation tube into 100ml of broth, culturing for 10h at 37 ℃ at 200r/min, centrifuging the cultured bacterial liquid, removing supernatant, adding physiological saline for cleaning for 2-3 times, adjusting OD value to ensure that the colony count is 107CFU/ml, and then diluting the diluted bacteria liquid and normal saline according to the ratio of 1: 3, diluting in proportion, filling into a spray can, and uniformly spraying on the surface of the dried medlar bought from a net.
3) And (3) placing the contaminated dried medlar fruits in an incubator for culturing for 30min, taking out, weighing 40g +/-1 g of dried medlar fruits in a packaging box, and filling air for packaging.
4) And (3) sterilization treatment: placing the packaging box between two electrodes of a high-voltage electric field low-temperature plasma sterilization device, adjusting the distance between the two electrodes to be 3.8cm, and performing plasma cold sterilization treatment under the conditions of room temperature and relative humidity of 50-80% RH; a short-time interval-multiple circulation sterilization mode is adopted, the treatment time is 120s, the interval time is 30s, and the steps are repeated for 3-5 times; the working frequency of the high-voltage electric field low-temperature plasma is 50 Hz; the low-temperature plasma is used for treating the dried Chinese wolfberry fruits under different voltage intensities of 11.84, 14.47, 17.11 and 19.74kv/cm (corresponding to power densities of 6.85, 15.85, 25.83 and 39.35w/cm3 respectively).
5) Under the same conditions, the samples without plasma treatment were control. The microbial detection refers to GB 4789.10-2016 (food microbiology test for Staphylococcus aureus) for measuring bacteria number, and the automatic color difference meter is used for measuring brightness value (L) and red value (a) of fructus Lycii.
TABLE 8 change table of the amount of Staphylococcus aureus on the surface of the dried fruit of Lycium barbarum (Total number of colonies/Log (CFU/g))
From the above table 8, it is understood that the low temperature plasma treatment has a significant effect of degrading microorganisms in the epidermis of the dried lycium barbarum, and it is seen from the table that when the voltage intensity is increased to 14.47kV/cm (the power density is 15.85w/cm3), the sterilization rate of the staphylococcus aureus number is significantly decreased compared to the control group, and the sterilization rate is also gradually increased as the voltage intensity is further increased. The higher the voltage intensity is, the better the sterilization effect is, but the voltage intensity exceeds 17.11kV/cm (the power density is 25.83 w/cm)3) The sterilization rate became gentle, and it was found from the graph that the voltage intensity increased to 19.74kV/cm (the power density was 39.35 w/cm)3) The number of the golden grape on the surface of the dried medlar can be reduced by 1.11 Log. And after the dried Chinese wolfberry fruits are treated by the high-voltage electric field low-temperature plasma, the red value and the brightness value of the surface are not damaged, and the sensory quality of the dried Chinese date fruits can be improved to a certain extent.
Example 5
The embodiment discloses a method for cold sterilization of dried Chinese wolfberry fruits under the conditions of different working frequencies of high-voltage electric field low-temperature plasmas, which comprises the following steps:
1) due to different drying methods of the dried medlar fruits on the market, the added preservative, the desiccant and other factors, the colony number difference of the surfaces of the purchased dried medlar fruits is large, and in order to ensure the colony number consistency, the dried medlar fruits are subjected to cold sterilization treatment after being dyed with staphylococcus aureus.
2) Taking out a staphylococcus aureus preservation tube for passage 2 times from-40 ℃, adding the staphylococcus aureus preservation tube into 100ml of broth, culturing for 10h at 37 ℃ at 200r/min, centrifuging the cultured bacterial liquid, removing supernatant, adding physiological saline for cleaning for 2-3 times, adjusting OD value to ensure that the colony count is 107CFU/ml, and then diluting the diluted bacteria liquid and normal saline according to the ratio of 1: diluting at a ratio of 3, placing in a spray can, uniformly spraying on the surface of dried fructus Lycii purchased from net, and measuring the bacteria on the surface of fructus Lycii to be 5.31 + -0.32 Log/g.
3) And (3) placing the contaminated dried medlar fruits in an incubator for culturing for 30min, taking out, weighing 40g +/-1 g of dried medlar fruits in a packaging box, and filling air for packaging.
4) And (3) sterilization treatment: placing the packaging box between two electrodes of a high-voltage electric field low-temperature plasma sterilization device, and adjusting the distance between the two electrodes to be 3.8 cm; the voltage intensity of the high-voltage electric field low-temperature plasma is 13.14kV/cm, and the power density is 11.05w/cm3(ii) a Processing the dried red dates by low-temperature plasmas at different working frequencies of 50Hz, 70 Hz, 90Hz, 110Hz and 130 Hz; performing plasma cold sterilization treatment at room temperature and at a relative humidity of 50-80% RH; and (3) repeating the steps for 3-5 times by adopting a short-time-interval-multiple-cycle sterilization mode, wherein the treatment time is 120s, and the interval time is 30 s.
5) Under the same conditions, the samples without plasma treatment were control. The microbial detection refers to GB 4789.10-2016 (food microbiology test, Staphylococcus aureus test) for detecting bacteria.
TABLE 9 quantitative change table of Staphylococcus aureus on dried fructus Lycii surface (Total bacteria/Log (CFU/g))
As can be seen from the above table 9, the golden grape number on the high surface of the dried Chinese wolfberry fruit is firstly remarkably reduced and then slowly increased along with the increase of the working frequency of the low-temperature plasma in the high-voltage electric field, which indicates that the higher the working frequency is to a certain extent, the better the sterilization effect on the dried Chinese wolfberry fruit is, the sterilization rate tends to be gentle when the working frequency exceeds 90Hz, and about 1 Logcfu/g of epidermal microorganisms can be reduced to the maximum at 110 Hz. The method shows that the sterilization effect of the dried Chinese wolfberry can be improved by increasing the working frequency in the actual industrial application, but the working frequency is not necessarily too high. The table shows that the increase of the frequency has no obvious influence on the color of the dried red dates, which indicates that the sensory quality of the dried red dates cannot be damaged by the increase of the high-voltage electric field low-temperature plasma frequency.
Combining the above 5 embodiments, we can get: a single factor test of the dried red dates shows that the sterilization rate of the low-temperature plasma on the dried red dates is firstly obvious along with the increase of working frequency, voltage intensity and action time under a certain condition (p)<0.05) the temperature tends to be flat after rising; the rising of the voltage intensity is in positive correlation with the change of the working frequency critical value (R)21) and is negatively correlated with the variation of the action time threshold value (R)21), the working voltage, the action time and the working frequency have obvious interaction on red date sterilization. The optimal conditions for optimization by the response surface are: the working voltage is 65kV, the processing time is 150s, and the working frequency is 86 Hz. Under the optimal process condition, the total number of colonies on the surface of the dried red dates can be reduced from 3.15 LogCFU/g to 1.05 LogCFU/g, and the original mold, yeast and coliform bacteria are not detected; the red value and the brightness value of the red dates have no obvious change with the untreated group, and the physicochemical quality of the dried red dates cannot be damaged.
The high-voltage electric field low-temperature plasma has a remarkable sterilization effect on the packaged dried Chinese wolfberry fruits. With the increase of the voltage intensity, the colony number on the surface of the dried Chinese wolfberry fruit is gradually gentle after being remarkably increased, and the colony number is lower than that of a control group; the number of bacterial colonies on the surface of the dried Chinese wolfberry can be reduced to a certain extent along with the increase of the working frequency, but the sterilization rate tends to be flat when the frequency is higher than 90 Hz. The working frequency of the high-voltage electric field plasma cold sterilization is an important parameter in the sterilization process of the dried Chinese wolfberry fruits; and within the processing time of 30-180 s, the voltage intensity and the working frequency of the plasma are improved without damaging the quality of the Chinese wolfberry.
When the voltage intensity is increased to 18.68kV/cm, the colony count on the surface of the red dates can be reduced from 3.15 +/-0.21 Log/g to 1.79 +/-0.11 Log/g; when the working frequency is increased to 110Hz, the colony count on the surface of the red dates can be reduced to 2.19 +/-0.12 from 3.15 +/-0.21 Log/g; under the optimal sterilization condition, the total number of colonies on the surface of the dried red date fruits subjected to the plasma cold sterilization treatment can kill 99.6 percent, and coliform groups and mould yeasts are not detected. The voltage intensity of the dried medlar fruits can be reduced by about 1 Log/cfu/g of staphylococcus aureus under the cold sterilization condition with the working frequency of 110Hz of 19.74kV/cm, the high-voltage electric field low-temperature plasma cold sterilization technology can be effectively applied to cold sterilization and fresh keeping of dried fruit food packaging products, and the safety and high quality of the products are obviously improved. In conclusion, the high-voltage electric field low-temperature plasma cold sterilization method has a good sterilization effect on the instant dried fruit food, can well maintain good sensory quality of the product, and is beneficial to prolonging the shelf life of the product.
The foregoing is directed to embodiments of the present invention and, more particularly, to a method and apparatus for controlling a power converter in a power converter, including a power converter, a power.
Claims (6)
1. The high-voltage electric field low-temperature plasma cold sterilization method for the instant dry fruit food is characterized by comprising the following steps of:
step 1: packaging and sealing the instant dry fruit food;
step 2: placing packaged instant dry fruit food between two electrodes of a high-voltage electric field dielectric barrier DBD low-temperature plasma generator, wherein the distance between the two electrodes of the high-voltage electric field dielectric barrier low-temperature plasma generator is 2-4 cm;
and step 3: adjusting the working frequency and the voltage intensity of a high-voltage electric field, and carrying out intermittent multi-cycle cold sterilization on packaged instant dried fruit food under the conditions that the room temperature is 15-28 ℃ and the relative humidity is 50-80% RH, wherein the working frequency of the high-voltage electric field is 50-150 Hz, the voltage intensity is 10-35 kV/cm, and the power density is 5-40W/cm3。
2. The method for cold sterilization of instant dried fruit food by high-voltage electric field low-temperature plasma according to claim 1, wherein the instant dried fruit food in step 1 comprises dried red dates, dried medlar and the like.
3. The method for cold sterilization of instant dried fruit food by high voltage electric field low temperature plasma as claimed in claim 1, wherein the packaging in step 1 comprises box packaging and bag packaging, and the packaging is filled with mixed gas of oxygen, nitrogen and carbon dioxide for modified atmosphere packaging or air-filled direct air packaging.
4. The method for cold sterilization of instant dried fruit food by using high-voltage electric field low-temperature plasma as claimed in claim 1, wherein in the intermittent multiple-cycle cold sterilization in step 3, the single cold sterilization treatment time is 30-180 s, the interval time is 30-180 s, and the cycle sterilization frequency is 3-5 times.
5. The high-voltage electric field low-temperature plasma cold sterilization method for the instant dried fruit food according to claim 1, wherein the cold sterilization conditions of the instant dried red dates are as follows: the working frequency is 50-150 Hz, the voltage intensity is 10-20 kV/cm, and the power density is 10-40 w/cm3。
6. The method for cold sterilization of instant dried fruit food by high-voltage electric field low-temperature plasma according to claim 1, wherein the cold sterilization conditions of the instant dried fruits of Chinese wolfberry are as follows: the working frequency is 50-150 Hz, the voltage intensity is 10-20 kV/cm, and the power density is 5-20 w/cm3。
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011633378.7A CN112753750A (en) | 2020-12-31 | 2020-12-31 | High-voltage electric field low-temperature plasma cold sterilization method for instant dry fruit food |
| AU2021101813A AU2021101813A4 (en) | 2020-12-31 | 2021-04-08 | Method for cold sterilization of dried fruits through non-thermal plsma generated by high-voltage electric field |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011633378.7A CN112753750A (en) | 2020-12-31 | 2020-12-31 | High-voltage electric field low-temperature plasma cold sterilization method for instant dry fruit food |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112753750A true CN112753750A (en) | 2021-05-07 |
Family
ID=75697899
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011633378.7A Pending CN112753750A (en) | 2020-12-31 | 2020-12-31 | High-voltage electric field low-temperature plasma cold sterilization method for instant dry fruit food |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN112753750A (en) |
| AU (1) | AU2021101813A4 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113925083A (en) * | 2021-11-02 | 2022-01-14 | 南京林业大学 | Storing and fresh-keeping method for peeled phyllostachys praecox shoots |
| CN114468200A (en) * | 2022-02-28 | 2022-05-13 | 吉林大学 | Efficient sterilization method for fresh ginseng slices |
| CN114747619A (en) * | 2022-05-18 | 2022-07-15 | 苏州屹润食品科技有限公司 | Low-temperature plasma cold sterilization and mycin degradation method for aspergillus flavus in coarse cereals |
| CN114794219A (en) * | 2022-03-28 | 2022-07-29 | 吉林大学 | Efficient sterilization method for fresh ginger slices |
| CN115736086A (en) * | 2022-11-24 | 2023-03-07 | 南京财经大学 | Method for removing bad flavor of soybean protein powder based on air-conditioning auxiliary low-temperature plasma |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105581219A (en) * | 2015-12-23 | 2016-05-18 | 宁夏大学 | Combined sterilization method for microorganisms on dried Lycium barbarum |
| CN109221373A (en) * | 2018-11-13 | 2019-01-18 | 苏州屹润食品科技有限公司 | A kind of packaging betel nut high voltage electric field low temperature plasma sterilization method |
| CN111165566A (en) * | 2020-01-06 | 2020-05-19 | 四川省农业科学院农产品加工研究所 | High-voltage electric field low-temperature plasma cold sterilization and preservation technical method for low-salt pickled vegetables |
-
2020
- 2020-12-31 CN CN202011633378.7A patent/CN112753750A/en active Pending
-
2021
- 2021-04-08 AU AU2021101813A patent/AU2021101813A4/en not_active Ceased
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105581219A (en) * | 2015-12-23 | 2016-05-18 | 宁夏大学 | Combined sterilization method for microorganisms on dried Lycium barbarum |
| CN109221373A (en) * | 2018-11-13 | 2019-01-18 | 苏州屹润食品科技有限公司 | A kind of packaging betel nut high voltage electric field low temperature plasma sterilization method |
| CN111165566A (en) * | 2020-01-06 | 2020-05-19 | 四川省农业科学院农产品加工研究所 | High-voltage electric field low-temperature plasma cold sterilization and preservation technical method for low-salt pickled vegetables |
Non-Patent Citations (1)
| Title |
|---|
| 曹丽娜等: ""高压电场低温等离子体对槟榔包装产品冷杀菌效能特性的影响"", 《食品与机械》 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113925083A (en) * | 2021-11-02 | 2022-01-14 | 南京林业大学 | Storing and fresh-keeping method for peeled phyllostachys praecox shoots |
| CN114468200A (en) * | 2022-02-28 | 2022-05-13 | 吉林大学 | Efficient sterilization method for fresh ginseng slices |
| CN114794219A (en) * | 2022-03-28 | 2022-07-29 | 吉林大学 | Efficient sterilization method for fresh ginger slices |
| CN114747619A (en) * | 2022-05-18 | 2022-07-15 | 苏州屹润食品科技有限公司 | Low-temperature plasma cold sterilization and mycin degradation method for aspergillus flavus in coarse cereals |
| CN115736086A (en) * | 2022-11-24 | 2023-03-07 | 南京财经大学 | Method for removing bad flavor of soybean protein powder based on air-conditioning auxiliary low-temperature plasma |
Also Published As
| Publication number | Publication date |
|---|---|
| AU2021101813A4 (en) | 2021-06-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112753750A (en) | High-voltage electric field low-temperature plasma cold sterilization method for instant dry fruit food | |
| AU2020103824A4 (en) | Low-Salt Pickle Preservation Method by High-Voltage Electric Field Cold Plasma-Based Sterilization | |
| Jeong et al. | Influence of moisture content on inactivation of Escherichia coli O157: H7 and Salmonella enterica serovar Typhimurium in powdered red and black pepper spices by radio-frequency heating | |
| Qin et al. | Nonthermal inactivation of Saccharomyces cerevisiae in apple juice using pulsed electric fields | |
| CN107156279A (en) | A kind of fresh-keeping of vegetables method and device | |
| Hosseinzadeh Samani et al. | Modeling the simultaneous effects of microwave and ultrasound treatments on sour cherry juice using response surface methodology | |
| CN112219896B (en) | Method for stabilizing volatile odor characteristic substances in rice storage process by aid of low-temperature plasma | |
| Puligundla et al. | Pulsed electric field (PEF) technology for microbial inactivation in low-alcohol red wine | |
| CN109221373A (en) | A kind of packaging betel nut high voltage electric field low temperature plasma sterilization method | |
| KR20170050258A (en) | A food sterilizing apparatus using non-thermal plasma generated by dielectric barrier dischage and sterilizing method using the same | |
| Palanimuthu et al. | Improving cranberry shelf-life using high voltage electric field treatment | |
| CN1011853B (en) | Technology and apparatus for preserving foods fresh by alternately using electric field between parallel plates and corona field | |
| Khadijeh et al. | Effects of in-package pasteurization on preventing spoilage in emulsion vacuum packaged sausages during refrigerated storage | |
| CN110897076A (en) | Method for cleaning and preserving fruits and vegetables based on ultrasonic-assisted plasma activated water | |
| CN219182760U (en) | Low-frequency high-voltage pulse electric field cooperated cold plasma food sterilization equipment | |
| CN104188046A (en) | Sterilization method for kiwi berry juice | |
| Doan et al. | Inactivation of E. coli O157: H7 by Ohmic Heating at Different Frequencies and Temperatures in Buffer and Pomelo Juice. | |
| CN105028598B (en) | A kind of box-packed flavor livestock and poultry product irradiation keeping method | |
| CN109757552A (en) | A kind of plasma-activated lactate buffer solution and its preparation method and application with Efficient antibacterial performance | |
| CN114931200A (en) | Fresh wet noodle plasma active water preparation synergistic medium barrier cold sterilization fresh-keeping method | |
| CN114794219A (en) | Efficient sterilization method for fresh ginger slices | |
| CN115136979A (en) | Low-temperature plasma cold sterilization synergistic modified atmosphere storage and preservation method for kiwi fruits | |
| CN110881517A (en) | Magnetic field sterilizing device | |
| CN114601096A (en) | Liquid fluid sterilization method based on magnetic induction electric field technology | |
| CN113973904A (en) | Fresh strawberry fruit preservation method combining strong pulse light with hot air treatment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |