CN116391752A - Method for preparing dehydrated vegetables by freeze drying - Google Patents
Method for preparing dehydrated vegetables by freeze drying Download PDFInfo
- Publication number
- CN116391752A CN116391752A CN202310407619.3A CN202310407619A CN116391752A CN 116391752 A CN116391752 A CN 116391752A CN 202310407619 A CN202310407619 A CN 202310407619A CN 116391752 A CN116391752 A CN 116391752A
- Authority
- CN
- China
- Prior art keywords
- drying
- wall plate
- water
- vegetables
- channel
- 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
- 235000013311 vegetables Nutrition 0.000 title claims abstract description 107
- 238000004108 freeze drying Methods 0.000 title claims abstract description 36
- 238000000034 method Methods 0.000 title claims abstract description 34
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 46
- 238000001035 drying Methods 0.000 claims abstract description 44
- 239000000463 material Substances 0.000 claims abstract description 24
- 238000007710 freezing Methods 0.000 claims abstract description 20
- 230000008014 freezing Effects 0.000 claims abstract description 18
- 238000000859 sublimation Methods 0.000 claims abstract description 10
- 230000008022 sublimation Effects 0.000 claims abstract description 10
- 239000000428 dust Substances 0.000 claims abstract description 9
- 238000004519 manufacturing process Methods 0.000 claims abstract description 9
- 239000011265 semifinished product Substances 0.000 claims abstract description 8
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims abstract description 5
- 239000013078 crystal Substances 0.000 claims abstract description 5
- 235000013611 frozen food Nutrition 0.000 claims abstract description 5
- 238000002844 melting Methods 0.000 claims abstract description 5
- 230000008018 melting Effects 0.000 claims abstract description 5
- 239000007787 solid Substances 0.000 claims abstract description 5
- 238000002955 isolation Methods 0.000 claims description 16
- 206010033546 Pallor Diseases 0.000 claims description 15
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 claims description 12
- 229910001424 calcium ion Inorganic materials 0.000 claims description 12
- 238000001816 cooling Methods 0.000 claims description 12
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 claims description 9
- DNIAPMSPPWPWGF-UHFFFAOYSA-N Propylene glycol Chemical compound CC(O)CO DNIAPMSPPWPWGF-UHFFFAOYSA-N 0.000 claims description 9
- 238000005406 washing Methods 0.000 claims description 9
- 239000000498 cooling water Substances 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 7
- 238000005520 cutting process Methods 0.000 claims description 6
- 230000005855 radiation Effects 0.000 claims description 6
- 238000003756 stirring Methods 0.000 claims description 5
- 238000007599 discharging Methods 0.000 claims description 4
- 238000004806 packaging method and process Methods 0.000 claims description 4
- 239000002994 raw material Substances 0.000 claims description 4
- 239000007921 spray Substances 0.000 claims description 4
- 239000008399 tap water Substances 0.000 claims description 4
- 235000020679 tap water Nutrition 0.000 claims description 4
- 235000005254 Allium ampeloprasum Nutrition 0.000 claims description 3
- 240000006108 Allium ampeloprasum Species 0.000 claims description 3
- 240000007087 Apium graveolens Species 0.000 claims description 3
- 235000015849 Apium graveolens Dulce Group Nutrition 0.000 claims description 3
- 235000010591 Appio Nutrition 0.000 claims description 3
- 235000008534 Capsicum annuum var annuum Nutrition 0.000 claims description 3
- 240000008384 Capsicum annuum var. annuum Species 0.000 claims description 3
- 240000008415 Lactuca sativa Species 0.000 claims description 3
- 235000003228 Lactuca sativa Nutrition 0.000 claims description 3
- 244000300264 Spinacia oleracea Species 0.000 claims description 3
- 235000009337 Spinacia oleracea Nutrition 0.000 claims description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 3
- 229910052782 aluminium Inorganic materials 0.000 claims description 3
- 238000009835 boiling Methods 0.000 claims description 3
- 230000003749 cleanliness Effects 0.000 claims description 3
- 239000003960 organic solvent Substances 0.000 claims description 3
- 238000005192 partition Methods 0.000 claims description 3
- 229920006395 saturated elastomer Polymers 0.000 claims description 3
- 241000196324 Embryophyta Species 0.000 claims description 2
- 239000007864 aqueous solution Substances 0.000 claims 2
- 239000000243 solution Substances 0.000 claims 1
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 235000015097 nutrients Nutrition 0.000 abstract description 2
- 230000000694 effects Effects 0.000 description 11
- 244000005700 microbiome Species 0.000 description 11
- 239000000047 product Substances 0.000 description 10
- 102000004190 Enzymes Human genes 0.000 description 5
- 108090000790 Enzymes Proteins 0.000 description 5
- 244000052616 bacterial pathogen Species 0.000 description 5
- 238000005536 corrosion prevention Methods 0.000 description 5
- 235000016709 nutrition Nutrition 0.000 description 5
- 238000004321 preservation Methods 0.000 description 5
- 239000002932 luster Substances 0.000 description 3
- 230000007246 mechanism Effects 0.000 description 3
- 230000003139 buffering effect Effects 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 239000003205 fragrance Substances 0.000 description 2
- 239000004615 ingredient Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000035764 nutrition Effects 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 230000001953 sensory effect Effects 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 238000009461 vacuum packaging Methods 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 1
- 235000005911 diet Nutrition 0.000 description 1
- 230000000378 dietary effect Effects 0.000 description 1
- 235000013325 dietary fiber Nutrition 0.000 description 1
- 239000000796 flavoring agent Substances 0.000 description 1
- 235000019634 flavors Nutrition 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 238000003306 harvesting Methods 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 235000010755 mineral Nutrition 0.000 description 1
- 235000013343 vitamin Nutrition 0.000 description 1
- 229940088594 vitamin Drugs 0.000 description 1
- 229930003231 vitamin Natural products 0.000 description 1
- 239000011782 vitamin Substances 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
- A23B7/02—Dehydrating; Subsequent reconstitution
- A23B7/024—Freeze-drying, i.e. cryodessication or lyophilisation
-
- 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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P60/00—Technologies relating to agriculture, livestock or agroalimentary industries
- Y02P60/80—Food processing, e.g. use of renewable energies or variable speed drives in handling, conveying or stacking
- Y02P60/85—Food storage or conservation, e.g. cooling or drying
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)
- Freezing, Cooling And Drying Of Foods (AREA)
Abstract
The utility model relates to a method for preparing dehydrated vegetables by freeze drying, belonging to the technical field of deep processing in vegetable production. Sublimation drying, namely, under the high vacuum environment, the frozen food material is sublimated into steam directly from ice solids without melting ice by utilizing the ice crystal sublimation principle, and the water in the sample is sublimated directly from ice to achieve the drying purpose under the low-temperature high-vacuum condition by freezing and fixing the vegetables with water in the top wall plate, so that the sample is not deformed due to the action of surface tension in the drying process; after quick freeze drying, ammonia gas or dry air is injected into a drying chamber of the top wall plate to break vacuum, then the material is immediately removed, the material is discharged in a closed environment with the relative humidity of below 50 percent and the temperature of 22-25 ℃ and less dust, and the semi-finished products are selected and packaged in the same environment. The utility model has the following beneficial effects: can keep most of nutrient components in vegetables without damage, and has high quality.
Description
Technical Field
The utility model relates to a method for preparing dehydrated vegetables by freeze drying, belonging to the technical field of deep processing in vegetable production.
Background
Vegetables are essential non-staple foods for people's life, are the main sources of vitamins, dietary fibers, minerals and the like, and play an important role in our reasonable dietary structure. But the fresh vegetables are living organisms and are subjected to vital activities after harvest, so that the nutrients therein are continuously consumed. Meanwhile, vegetables are perishable products, are easy to be infected and spoiled by microorganisms and the like, are difficult to store for a long time at normal temperature, and are difficult to maintain the original quality. In China, the loss rate of the picked vegetables is as high as one. The vegetable production has strong seasonality and territory, and is difficult to plant in all areas in each season. In addition, the added value of the vegetables sold by the fresh vegetables is not large. Therefore, the vegetables need to be processed as necessary to produce a variety of nutritional, healthy, high value-added, and versatile vegetable products.
The dehydrated vegetable is also called as rehydrated vegetable, and is a dried vegetable which is prepared by washing, drying and the like fresh vegetable, removing most of water in the vegetable. The original color and nutrition of the vegetables are basically kept unchanged. Is easy to store and transport, and can effectively regulate the light and vigorous seasons of vegetable production. When eaten, the vegetable can be restored by immersing the vegetable in clear water, and the original color, nutrition and flavor of the vegetable are maintained.
In the production process of dehydrated vegetables, the moisture in the vegetables needs to be removed through a drying device, so that the vegetables become dried vegetables, and the quality of the vegetables is ensured.
The existing vegetable drying device is used for drying by using multi-purpose hot air, heat energy is required to be transmitted from the outside of the vegetable to the inside of the vegetable for heating and drying, so that more heat energy is consumed, drying efficiency is low, meanwhile, freezing treatment is absent, the structure of the vegetable is easy to deform when moisture evaporates, appearance color changes, and vegetable quality is affected.
Patent number is CN202021499728. X's patent application discloses a freeze-drying device is used in dehydrated vegetable production, including support frame, conveying mechanism and quick-cooling box, support frame both ends symmetry is provided with conveying mechanism, support frame upside one end has through bolted connection quick-cooling box, quick-cooling box one side is provided with the sublimate case side by side, sublimate case upside welding has the microwave emission case, the welding of microwave emission case upper end has negative pressure exhaust mechanism. According to the utility model, through the microwave transmitting box, the stirring fan and the microwave generator, the device can directly heat and sublimate moisture in vegetables through microwaves, so that the consumed heat energy is reduced, and the drying efficiency is improved.
Although the above patent can realize the freeze-drying function, the prior art has incomplete consideration and the following disadvantages:
the original luster of the dehydrated vegetable product can not be maintained, the water content of the dehydrated vegetable product is 4% -8%, the dehydrated vegetable product can be restored within 3-10 min generally, the low water content of the dehydrated vegetable enables microorganisms and enzymes to be in a low life activity state, the growth and propagation of microorganisms, particularly pathogenic bacteria, are prevented, and the effects of corrosion prevention and fresh preservation are achieved.
What is needed is a method for preparing dehydrated vegetables by freeze drying, wherein the dehydrated vegetable products can keep the original gloss, the moisture content of the dehydrated vegetables is 4% -8%, the dehydrated vegetables can be restored within 3-10 min generally, the low moisture content of the dehydrated vegetables enables microorganisms and enzymes to be in a low-life activity state, the growth and propagation of microorganisms, particularly pathogenic bacteria, are prevented, and the effects of corrosion prevention and fresh preservation are achieved.
Disclosure of Invention
In order to solve one of the above problems, according to the above shortcomings in the prior art, the present utility model aims to solve the technical problems: the method for preparing the dehydrated vegetables by freeze drying is provided, so that the dehydrated vegetables can be preserved in original gloss, the moisture content of the dehydrated vegetables is 4% -8%, the vegetables can be restored within 3-10 min generally, the low moisture content of the dehydrated vegetables enables microorganisms and enzymes to be in a low-life activity state, the growth and propagation of microorganisms, particularly pathogenic bacteria, are prevented, and the effects of corrosion prevention and fresh preservation are achieved.
The method for preparing dehydrated vegetables by freeze drying is characterized in that,
s1: pretreating before drying, selecting fresh vegetables, slicing or cutting, washing with spray water or tap water to remove dust and silt on the surfaces of the vegetables, washing, blanching, slightly stirring during blanching, fishing out, and rapidly cooling with flowing water;
s2, pre-freezing, and freezing the pretreated raw materials in a freezer;
s3, sublimation drying, namely, under the high vacuum environment, directly sublimating the water of the frozen food materials from ice solids to steam without melting ice by utilizing the ice crystal sublimation principle, freezing and fixing the water-containing vegetables in the top wall plate, and directly sublimating the water in the sample from ice under the low-temperature high-vacuum condition to achieve the aim of drying, wherein the water is not influenced by surface tension in the drying process, and the sample is not deformed;
s4, drying, namely after quick freeze-drying, injecting ammonia gas or dry air into a drying chamber of the top wall plate to break vacuum, immediately removing the materials, discharging the materials in a closed environment with less dust and relative humidity below 50 percent and temperature of 22-25 ℃, and sorting and packaging semi-finished products in the same environment.
Preferably, the closed environment is a dust-free workshop, and the lyophilized materials have huge surface area and very strong hygroscopicity, so that the operations of the procedures are required to be completed in a drier environment.
Preferably, the blanching step adopts boiling water to rinse the green vegetables after cleaning and cutting at a short time and high temperature; the green vegetables are cooled for a short time by using a cooling water solution containing calcium ions, and remain green.
Preferably, the temperature of the hot water in the step 1 is 95+/-5 ℃, and the short-time high-temperature blanching time is 10-60 seconds.
Preferably, the temperature of the cooling water solution containing calcium ions in the cooling water solution containing calcium ions is 5+/-5 ℃, the concentration of the calcium ions is 1-5 per mill, and the cooling time is 20-30 seconds.
Preferably, the vegetable is at least one of Shanghai green, spinach, lettuce, green pepper, celery and leek.
Preferably, the cleanliness of the dust-free workshop is over ten thousand grades.
Preferably, the shorter the distance between the freezer quick-freezing warehouse and the freeze-drying box door is, the better the distance is, and the channel is a special channel and is only used as a logistics channel, but not used as a people flow channel, and the end of the freeze-drying box door is separated from other parts and equipment of the top wall plate so as to reduce the pollution of environment to semi-finished products.
Preferably, the top wall plate is an intermittent top wall plate which is formed by a drying box body, a heating system, a vacuum system, a refrigerating system and a control system, wherein the drying box body is in two main forms of a cylinder and a square, the cylinder is easy to manufacture, and the square space utilization rate is high; most of heating systems adopt radiation heat transfer, the radiation plate is made of anode electroplated aluminum, the heat transfer medium comprises heat transfer oil, saturated water and secondary steam, and organic solvents such as propylene glycol, glycerol and the like, and the heat source is high-pressure water steam.
Preferably, the passageway between freezer quick-freeze storehouse and the freeze-drying chamber door includes top wall board and the bottom wall board that is parallel to each other with the top wall board, side wall board A and the side wall board B that is parallel to each other with side wall board A, top wall board, bottom wall board, side wall board A and side wall board B splice and enclose into the main passageway, be provided with vertical baffle in this main passageway, divide into the pedestrian passageway of commodity circulation passageway with vertical baffle, the front end of pedestrian passageway is pedestrian entry, the rear end is pedestrian export, be provided with respectively on pedestrian entry and the pedestrian export can open and close isolation door A, isolation door B, isolation door A, isolation door B is normally closed state, isolation door A, isolation door B keeps apart out the buffering and purifies the room, the both ends of commodity circulation passageway are connected to quick-freeze storehouse and operation district respectively, the operation district is connected to the freeze-drying chamber door, the material is packed into the drying chamber in the operation district to the operator, the operator is from the pedestrian passageway gets into, the material is transferred from the commodity circulation passageway by the operator.
Compared with the prior art, the utility model has the following beneficial effects:
the method for preparing dehydrated vegetables by freeze drying can keep most of nutritional ingredients in vegetables from being destroyed, and has the advantages of high quality, good sensory quality, plump appearance, crisp and slightly tough and strong appearance and strong fragrance.
According to the method for preparing the dehydrated vegetables by freeze drying, the original luster of the dehydrated vegetable products can be maintained, the water content of the dehydrated vegetables is 4% -8%, the dehydrated vegetables can be restored within 3-10 min generally, the low water content of the dehydrated vegetables enables microorganisms and enzymes to be in a low-life activity state, the growth and propagation of microorganisms, particularly pathogenic bacteria, are prevented, and the effects of corrosion prevention and freshness preservation are achieved.
The method for preparing dehydrated vegetables by freeze drying can preserve the dehydrated vegetables for a long time for 2 to 3 years after sealing or vacuum packaging the products in low-temperature storage.
According to the method for preparing dehydrated vegetables by freeze drying, the people stream and logistics channel modules which enter and exit the clean room in a dry mode belong to separate modularized units, and when the method is used, the people stream and logistics channel modules which enter and exit the clean room only need to be carried to the positions where the people stream and logistics channel modules need to be used, so that the method is convenient to use.
Drawings
In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. Like elements or portions are generally identified by like reference numerals throughout the several figures. In the drawings, elements or portions thereof are not necessarily drawn to scale.
FIG. 1 is a block diagram of a channel between a freezer quick freezer and a freeze door of the present utility model;
in the figure: 1. top wall panel 2, bottom wall panel 3, side wall panel A4, side wall panel B5, vertical partition 6, isolation door A7, isolation door B8, and the operating area.
Detailed Description
The utility model is further described below with reference to the accompanying drawings:
the present utility model is further illustrated by the following examples, which are not intended to be limiting, but any modifications, equivalents, improvements, etc. within the spirit and principles of the present utility model are intended to be included within the scope of the present utility model.
Examples
As shown in fig. 1, the method for preparing dehydrated vegetables by freeze-drying,
s1: pretreating before drying, selecting fresh vegetables, slicing or cutting, washing with spray water or tap water to remove dust and silt on the surfaces of the vegetables, washing, blanching, slightly stirring during blanching, fishing out, and rapidly cooling with flowing water;
s2, pre-freezing, and freezing the pretreated raw materials in a freezer;
s3, sublimation drying, namely, under the high vacuum environment, directly sublimating the water of the frozen food materials from ice solids to steam without melting ice by utilizing the ice crystal sublimation principle, freezing and fixing the water-containing vegetables in the top wall plate, and directly sublimating the water in the sample from ice under the low-temperature high-vacuum condition to achieve the aim of drying, wherein the water is not influenced by surface tension in the drying process, and the sample is not deformed;
s4, drying, namely after quick freeze-drying, injecting ammonia gas or dry air into a drying chamber of the top wall plate to break vacuum, immediately removing the materials, discharging the materials in a closed environment with less dust and relative humidity below 50 percent and temperature of 22-25 ℃, and sorting and packaging semi-finished products in the same environment.
Examples
As shown in fig. 1, the method for preparing dehydrated vegetables by freeze-drying,
s1: pretreating before drying, selecting fresh vegetables, slicing or cutting, washing with spray water or tap water to remove dust and silt on the surfaces of the vegetables, washing, blanching, slightly stirring during blanching, fishing out, and rapidly cooling with flowing water;
s2, pre-freezing, and freezing the pretreated raw materials in a freezer;
s3, sublimation drying, namely, under the high vacuum environment, directly sublimating the water of the frozen food materials from ice solids to steam without melting ice by utilizing the ice crystal sublimation principle, freezing and fixing the water-containing vegetables in the top wall plate, and directly sublimating the water in the sample from ice under the low-temperature high-vacuum condition to achieve the aim of drying, wherein the water is not influenced by surface tension in the drying process, and the sample is not deformed;
s4, drying, namely after quick freeze-drying, injecting ammonia gas or dry air into a drying chamber of the top wall plate to break vacuum, immediately removing the materials, discharging the materials in a closed environment with less dust and relative humidity below 50 percent and temperature of 22-25 ℃, and sorting and packaging semi-finished products in the same environment.
Furthermore, the closed environment is a dust-free workshop, and the lyophilized materials have huge surface area and very strong hygroscopicity, so that the operations of the procedures are required to be completed in a drier environment.
Further, the blanching step adopts boiling water to rinse the green vegetables after cleaning and cutting at a short time and high temperature; the green vegetables are cooled for a short time by using a cooling water solution containing calcium ions, and remain green.
Further, the temperature of the hot water in the step 1 is 95+/-5 ℃, and the short-time high-temperature blanching time is 10-60 seconds.
Further, the temperature of the cooling water solution containing calcium ions in the cooling water solution containing calcium ions is 5+/-5 ℃, the concentration of the calcium ions is 1-5 per mill, and the cooling time is 20-30 seconds.
Further, the vegetable is at least one of Shanghai green, spinach, lettuce, green pepper, celery and leek.
Further, the cleanliness of the dust-free workshop is over ten thousand grades.
Further, the shorter the distance between the quick freezing warehouse and the freeze-drying box door is, the better the distance is, and the channel is a special channel and is only used as a logistics channel, but not used as a people flow channel, and the end of the freeze-drying box door is separated from other parts and equipment of the top wall plate so as to reduce the pollution of environment to semi-finished products.
Further, the top wall plate is an intermittent top wall plate which is formed by a drying box body, a heating system, a vacuum system, a refrigerating system and a control system, wherein the drying box body is in two main forms of a cylinder and a square, the cylinder is easy to manufacture, and the square space utilization rate is high; most of heating systems adopt radiation heat transfer, the radiation plate is made of anode electroplated aluminum, the heat transfer medium comprises heat transfer oil, saturated water and secondary steam, and organic solvents such as propylene glycol, glycerol and the like, and the heat source is high-pressure water steam.
Further, the passageway between freezer quick-freeze storehouse and the freeze-drying chamber door includes roof board 1 and the bottom wall board 2 that is parallel to each other with roof board 1, side wall board A3 and the side wall board B4 that is parallel to each other with side wall board A3, roof board 1, bottom wall board 2, side wall board A3 and side wall board B4 splice and enclose into the main passageway, be provided with vertical baffle 5 in this main passageway, divide into the pedestrian passageway of commodity circulation passageway with vertical baffle 5, pedestrian passageway's front end is pedestrian entry, the rear end is pedestrian export, be provided with the isolation door A6 that can open and close on pedestrian entry and the pedestrian export respectively, isolation door A6, isolation door B7 is normally closed state, isolation door A6, isolation door B7 keeps apart buffering and purifies the room, the both ends of commodity circulation passageway are connected to quick-freeze storehouse and operation district 8 respectively, the operator loads the material into the drying chamber in operation district 8, operator is from the pedestrian passageway gets into, the material is transferred from the commodity circulation passageway by the operator.
The method for preparing dehydrated vegetables by freeze drying can keep most of nutritional ingredients in vegetables from being destroyed, and has the advantages of high quality, good sensory quality, plump appearance, crisp and slightly tough and strong appearance and strong fragrance.
According to the method for preparing the dehydrated vegetables by freeze drying, the original luster of the dehydrated vegetable products can be maintained, the water content of the dehydrated vegetables is 4% -8%, the dehydrated vegetables can be restored within 3-10 min generally, the low water content of the dehydrated vegetables enables microorganisms and enzymes to be in a low-life activity state, the growth and propagation of microorganisms, particularly pathogenic bacteria, are prevented, and the effects of corrosion prevention and freshness preservation are achieved.
The method for preparing dehydrated vegetables by freeze drying can preserve the dehydrated vegetables for a long time for 2 to 3 years after sealing or vacuum packaging the products in low-temperature storage.
According to the method for preparing dehydrated vegetables by freeze drying, the people stream and logistics channel modules which enter and exit the clean room in a dry mode belong to separate modularized units, and when the method is used, the people stream and logistics channel modules which enter and exit the clean room only need to be carried to the positions where the people stream and logistics channel modules need to be used, so that the method is convenient to use.
The foregoing has shown and described the basic principles, main features and advantages of the present utility model. It will be understood by those skilled in the art that the present utility model is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present utility model, and various changes and modifications may be made without departing from the spirit and scope of the utility model, which is defined in the appended claims. The scope of the utility model is defined by the appended claims and equivalents thereof.
The present utility model is not described in detail in the present application, and is well known to those skilled in the art.
Claims (10)
1. A method for preparing dehydrated vegetables by freeze drying, characterized in that:
s1: pretreating before drying, selecting fresh vegetables, slicing or cutting, washing with spray water or tap water to remove dust and silt on the surfaces of the vegetables, washing, blanching, slightly stirring during blanching, fishing out, and rapidly cooling with flowing water;
s2, pre-freezing, and freezing the pretreated raw materials in a freezer;
s3, sublimation drying, namely, under the high vacuum environment, directly sublimating the water of the frozen food materials from ice solids to steam without melting ice by utilizing the ice crystal sublimation principle, freezing and fixing the water-containing vegetables in the top wall plate, and directly sublimating the water in the sample from ice under the low-temperature high-vacuum condition to achieve the aim of drying, wherein the water is not influenced by surface tension in the drying process, and the sample is not deformed;
s4, drying, namely after quick freeze-drying, injecting ammonia gas or dry air into a drying chamber of the top wall plate to break vacuum, immediately removing the materials, discharging the materials in a closed environment with less dust and relative humidity below 50 percent and temperature of 22-25 ℃, and sorting and packaging semi-finished products in the same environment.
2. The method of preparing dehydrated vegetables according to claim 1, wherein the closed environment is a dust-free plant, and the freeze-dried material has a large surface area and a very strong hygroscopicity, so that the operations of these processes are required to be performed in a relatively dry environment.
3. The method for preparing dehydrated vegetables according to claim 2, wherein the blanching step is a short-time high-temperature blanching of the green vegetables washed and cut with boiling water; the green vegetables are cooled for a short time by using a cooling water solution containing calcium ions, and remain green.
4. A method for preparing dehydrated vegetables according to claim 3, wherein the hot water in the step (1) has a temperature of 95±5 ℃ and a short-time high-temperature blanching time of 10 to 60 seconds.
5. The method for preparing dehydrated vegetables according to claim 4, wherein the cooling aqueous solution containing calcium ions in the cooling aqueous solution containing calcium ions has a temperature of 5 ° ± 5 ℃ and a calcium ion concentration of 1-5%o, and the cooling time is 20-30 seconds.
6. The method for preparing dehydrated vegetables according to claim 5, wherein the vegetables are at least one of Shanghai green, spinach, lettuce, green pepper, celery and leek.
7. The method for preparing dehydrated vegetables according to claim 6, wherein the cleanliness of the dust-free workshop is ten thousand or more.
8. The method for preparing dehydrated vegetables according to claim 7, wherein the shorter the distance between the freezer quick-freezing warehouse and the freeze-drying box door is, the better the distance is, and the channel is a special channel, which is only used as a logistics channel, and not used as a people stream channel, and the freeze-drying box door end is separated from other parts and equipment of the top wall plate, so as to reduce the pollution of environment to semi-finished products.
9. The method for preparing dehydrated vegetables according to claim 8, wherein the top wall plate is an intermittent top wall plate comprising a drying box body, a heating system, a vacuum system, a refrigerating system and a control system, wherein the drying box body has two main forms of a cylinder and a square, the cylinder is easy to manufacture, and the square space utilization rate is high; most of heating systems adopt radiation heat transfer, the radiation plate is made of anode electroplated aluminum, the heat transfer medium comprises heat transfer oil, saturated water and secondary steam, and organic solvents such as propylene glycol, glycerol and the like, and the heat source is high-pressure water steam.
10. The method for preparing dehydrated vegetables according to claim 9, wherein the channel between the quick freezing warehouse and the freeze-drying box door of the freezing warehouse comprises a top wall plate, a bottom wall plate, a side wall plate A and a side wall plate B which are mutually parallel to the top wall plate, wherein the top wall plate, the bottom wall plate, the side wall plate A and the side wall plate B are spliced and enclosed into a main channel, a vertical partition plate is arranged in the main channel, the vertical partition plate is divided into a pedestrian channel of a logistics channel, the front end of the pedestrian channel is a pedestrian inlet, the rear end of the pedestrian channel is a pedestrian outlet, openable and closable isolation doors A and B are respectively arranged on the pedestrian inlet and the pedestrian outlet, the isolation doors A and B are in a normally closed state, the isolation doors A and B isolate a buffer clean room, two ends of the logistics channel are respectively connected to the quick freezing warehouse and an operation area, the operation area is connected to the freeze-drying box door, an operator loads materials into the drying box in the operation area, the operator enters the self-walking human channel, and the materials are transferred from the logistics channel by the operator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310407619.3A CN116391752A (en) | 2023-04-17 | 2023-04-17 | Method for preparing dehydrated vegetables by freeze drying |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310407619.3A CN116391752A (en) | 2023-04-17 | 2023-04-17 | Method for preparing dehydrated vegetables by freeze drying |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116391752A true CN116391752A (en) | 2023-07-07 |
Family
ID=87012149
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310407619.3A Pending CN116391752A (en) | 2023-04-17 | 2023-04-17 | Method for preparing dehydrated vegetables by freeze drying |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116391752A (en) |
-
2023
- 2023-04-17 CN CN202310407619.3A patent/CN116391752A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Jayaraman et al. | Drying of fruits and vegetables | |
| Alp et al. | The microbiological quality of various foods dried by applying different drying methods: a review | |
| Bekele et al. | Going beyond conventional osmotic dehydration for quality advantage and energy savings | |
| CN103609663B (en) | A kind of dry fruits and vegetables method of vacuum refrigeration associating pressure-difference and puffing technology | |
| CN100407946C (en) | Production of sweeled apple crisp by microwave-pressure differential process | |
| US20180168203A1 (en) | Device and method of dehydration of biological products | |
| CN105875804A (en) | Method for improving color of dried day lily product by combining ultrasonic-assisted blanching with cascade drying | |
| CN104026214B (en) | A kind of preparation method of vacuum freeze drying strawberry goods | |
| CN105509416B (en) | A kind of method of the three dry conditioning taro quality of energy integrated combination of hot wind-far infrared-microwave | |
| Clarke | Refractance window TM-“Down under” | |
| CN103891872A (en) | Vacuum freeze drying method of fistular onion stalk | |
| Ergün et al. | The effects of the novel home freezing system on microstructure, color, antioxidant activity, and microbiological properties of strawberries | |
| CN107197927A (en) | The boat-carrying continuous process of the continuous dry-making method of dried of boat-carrying of krill and its peeled shrimp that shells | |
| CN102144663B (en) | Non-thermal processing method of fresh-cut fruits and vegetables | |
| CN1973641B (en) | Technique of prolonging the antistaling period of packed and cooled fresh meat | |
| CN108739986A (en) | A method of freeze-drying prepares dehydration Chinese toon | |
| CN101223933A (en) | Raw candy preserved apricot and producing process and technology thereof | |
| CN102308868A (en) | Cooling method capable of quickly reducing center temperature of postmortem pig carcass | |
| CN116391752A (en) | Method for preparing dehydrated vegetables by freeze drying | |
| JPWO2020149300A1 (en) | Food freezing system and manufacturing method of frozen food | |
| Sehrawat et al. | Trends in drying of fruits and vegetables | |
| CN110301510A (en) | A kind of combined drying method improving macaque peach crisp expansion rate | |
| CN103689765B (en) | The cooling system that continous way feedstuff mildew becomes | |
| RU2518957C2 (en) | Method for preservation of organic single-piece products and preserved organic single-piece products manufacture method | |
| EP0671884B1 (en) | Method of and apparatus for dehydrating biological products and dehydrated biological products |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication |