CN106721915A - A kind of dry technique of snap frozen - Google Patents

Abstract

The present invention relates to a kind of dry technique of snap frozen, using first time pre-freeze → freezing microtome section → second pre-freeze → first time lyophilization → second dry technique, in the case where ensureing that material vulnerable component is not damaged, effectively shorten the diffusion path of vapor, reach the dry purpose of snap frozen.

Description

A kind of dry technique of snap frozen

Technical field

Method the present invention relates to food, health products dried food and nuts are prepared into compressing tablet, belongs to food and health products process technology Field.

Background technology

Food does Tibetan by sloughing the Free water in raw material, suppresses growth of microorganism.Drying equipment can be with according to continuity It is divided into intermittently drying and continuous drying；It is divided into convection current, conduction and energy field action according to material heat-supplying mode；Technological development is divided Be four generations, the first generation is box-type drying, the second generation is spraying and roller drying, temperature generally more than 120 DEG C, quality loss Greatly；The third generation is freeze-drying and critical permeating and dewatering, and product quality high cost is high；Forth generation is low-consumption high-quality technology, Including microwave, infrared, heat pump, RF（radio frequency）、RW（refractance window）, these techniques are Western medicine The technology of factory's exploitation, it is adaptable to liquid and slurry.

Pseudo-ginseng is convenient, it is necessary to dried process for storage and transport, and notoginseng drying mode common at present mainly has three kinds, Dry, dry and freeze.Dry pseudo-ginseng：The pseudo-ginseng dried with natural sunshine, is most traditional drying means, is also to use Obtain drying mode at most.Pseudo-ginseng quality after drying is very rigid, and ordinary consumer is difficult to be crushed, it is necessary to be beaten to pharmacy Powder.The moisture for drying pseudo-ginseng is general within 20%, and total saponin content is about 7% or so.

Drying pseudo-ginseng：Because drying can make the nutrition leak of pseudo-ginseng huge, the people for knowing the business is all without the pseudo-ginseng for buying drying.But For businessman, this method is most time saving, because this drying is very easy, it is only necessary to buy a simple drying Machine just can be with, it is not necessary to waits that it's clearing up, it is not required that big threshing ground, so still have some businessmans to adopt dries three in this way Seven.The moisture for drying pseudo-ginseng is higher, and total saposins loss is also larger, and medical value is not high.

Lyophilized pseudo-ginseng：The high-tech means in notoginseng drying field was just applied in recent years, used the low-temperature frozen of 40 degrees below zero It is dry, while allowing pseudo-ginseng to keep original nutrition, at utmost save drug effect, it is also easy to beat powder, it is easy to eat.Lyophilized pseudo-ginseng Moisture is only 3% or so, and total saponin content is 11%, is highest in three kinds of drying modes.Additionally, being different from other two kinds Simple drying mode, freezes pseudo-ginseng due to producing cuspidated technical equipment threshold, so the enterprise of lyophilized pseudo-ginseng can be produced, The large enterprises in industry are substantially, product there are enough guarantees in quality, effect, service.Lyophilized pseudo-ginseng, has become three Seven first-chop synonyms.Same vacuum freezedrying Chinese caterpillar fungus, is very cold empty lyophilized dry with international advanced ultralow temperature Technology, under vacuum, the moisture content in Chinese caterpillar fungus is directly distilled out, forms the porous framework of similar Sponge Porosity, volume Size is almost unchanged, intactly remains the cordycepic acid of Cordyceps sinensis（Mannitol）, adenosine, amino acid and trace element, effectively Composition retention is more than 98%.

Vacuum freeze drying has 7 big advantages:

1. freeze-drying is carried out at low temperature, therefore can be denatured for many thermal sensitivity or the material that inactivates is particularly suitable, The protein such as such as Cordyceps sinensis polysaccharide, microorganism will not be denatured or lose biologos using freeze-drying.Therefore, freeze dry It is dry to be widely used in medical industry, food industry, scientific research and other departments at present.

2. when drying at low temperature, some volatile ingredients loss very little in material is adapted to some chemical products, medicine And food drying.

3. in freeze-drying process, the growth of microorganism and the effect of enzyme cannot be carried out, therefore can keep original proterties.

4. it is dehydrated thoroughly, dried product is lightweight, small volume, and floor space is few during storage, convenient transportation, due to freezing In the state of be dried, therefore volume is almost unchanged, maintains original structure.The vegetables of various freeze-dryings through briquetting, Weight saving is notable.Because volume reduces, correspondingly packing charges also much less.

5. rehydration is fast, instant.Because the moisture that dried material contains is directly evaporation in the frozen state, Therefore in drying process, steam does not drive solable matter to shift to surface of material, will not be in surface of material Depositional salts, i.e., in thing Material surface will not form hard thin skin, also in the absence of because center moisture shifts to surface of material when cell or fiber generation are opened Power, will not make because contraction causes deformation after dry materials, therefore easily water suction restores to the original state.Dried material is loose porous, is in It is spongy, dissolve rapid and complete after adding water, original proterties is almost recovered immediately.The pea and corn of freeze-drying are in soup In only need 3 minutes just can aquation again, and air-dried pea and corn then needs 10 minutes.In addition, freeze-drying It is a kind of natural concentration manufacturing process without adding preservative agent and additive again.

6. because drying is carried out under vacuo, oxygen is few, therefore some oxidizable materials are protected.

7. drying can exclude the moisture of more than 95%-99%, and product is preserved without mutagens matter for a long time after enabling to dry.

Existing lyophilized technique is In-situ condensation, distillation, re-dry.In-situ condensation, is first intended to freeze-dried material with suitable cooling Equipment is cooled to 2 DEG C or so, is subsequently placed in about -40 DEG C of (13.33Pa) freeze drying box.Drying box is closed, refrigerant is passed through rapidly (freon, ammonia), freezes material, and protects 2h or longer time, to overcome the surfusion of solution, makes product fully charge, Can be distilled.The distillation of product is carried out under high vacuum, during pressure reduction, it is necessary to keep article in case Freezing state, with anti-spilled container.After pressure is down to a certain degree in case, then open Roots vaccum pump (or diffusion in vacuum Pump), pressure drops to 1.33Pa, and at less than -60 DEG C, ice is to start distillation, and the vapor of distillation forms ice crystal in condenser.For Ensure the distillation of ice, heating system should be opened, shelf is heated, the heat needed for being continuing to supply ice distillation.Re-dry, in distillation In stage, ice largely distils, and now the temperature of product is no more than lowest total of the melting point, in case being produced in product outside stiff block or product Defect in sight, shelf temperature is normally controlled between ± 10 DEG C within this stage.The water that the re-dry stage of product is removed It is divided into and combines moisture, now the water vapor pressure of the surface of solids is in different degrees of reduction, rate of drying is decreased obviously.Ensureing to produce On the premise of quality, in this stage, planted agent properly increases shelf temperature, is beneficial to the evaporation of moisture, usually heats shelf To 30~35 DEG C, practical operation (should write music through the temperature of many experiments drafting, time, vacuum in advance by the freeze-drying curve of product Line) carry out, overlapped with shelf temperature untill reaching drying until products temperature.

Frozen dried food can add water when edible and be soaked, and need to be machined again as medicine, cut into slices or add Work turns into powder, and it is Chinese patent drug to be further prepared into.

The content of the invention

The lyophilized technological process of traditional food is：Fresh food → pretreatment → section → balance → prefreezing → vacuum is cold Lyophilized dry → packaging → finished product [1].The technological process of this technology is：Fresh food → pretreatment → first time precooling → freezing Section → balance → second prefreezing → vacuum freeze drying → packaging → finished product.Freeze-drying is dry with pneumatic conveying drying, spraying Dry other dry technologies of grade are compared, and vacuum freeze investment is big, and energy resource consumption and production cost are higher, so as to limit The further development of the technology.Therefore, this technology realizes energy-saving, reduction production cost while drug quality is ensured, The current topmost problem for facing in vacuum freeze drying field is solved, solution shortens the diffusion road of water vapour using section Footpath.Influence of the material thickness to drying time is larger, and when the thickness of material increases to 10mm from 8mm, drying time increases 26.4%, illustrate to be greatly prolonged with the sublimation drying that thickens of material, therefore, should try one's best and be entered using relatively thin material Row freeze-drying.

It is further noted that in general freezing dry process, the outer layer of plant can constitute an insulating barrier, prevent The evaporation of its internal moisture, that is to say, that plant is that ecto-entad is dehydrated, and is also meaned at moderate temperatures, to be spent more Time come inside dried plant.In fact, general freeze-drying have 80% time be used to remove inside plants most 20% moisture content afterwards, for example, one strawberry commonly takes up 14 to 16 hours for freeze-drying.Therefore, thickness of insulating layer is reduced It is to shorten one of maximally effective technology of freeze-drying.It is exactly the chi for reducing freezing monomer to reduce insulating barrier most simple effective method It is very little.And the integrality of material is also kept while reducing size using machining, it is to avoid nutrition caused by mechanical damage Ingredients from lossing, destruction and shape are damaged, and Zhou Guoyan is confirmed in tradition section, and the amount of ginsenoside R91 is excessively thin with cutting into slices And slowly decline [2].Therefore, this technology maintains the integrality of raw material using first time pre-freeze, and completes in a cold or frozen state Section, flaking, slitting, chopping.

This technology can also shorten second pre-freeze time, it is necessary to first to dry during vacuum freeze drying Medicine carries out pre-freeze, then under vacuum conditions, moisture is directly changed into gas from ice and is dried medicine.In whole distillation rank Section, medicine preferably must be held in frozen state, cannot otherwise obtain the good product of proterties.It is strict in the medicine pre-freeze stage Control pre-freezing temperature（Several years generally lower than the eutectic point of medicine）.If pre-freezing temperature is not low enough, medicine may be without complete Freeze, foaming can be expanded when distillation is vacuumized；If pre-freezing temperature is too low, can not only increase unnecessary energy ezpenditure, and For some biologics, its survival rate after freezing can be reduced.The first time of this technology freezes purpose to keep material complete Whole property, cryogenic temperature need to only be slightly below eutectic point, complete at ambient pressure, even if therefore partial material does not have deep colling not produce yet Expansion foaming phenomena, less low temperature requirement also lowers energy consumption and improves the survival rate for freezing biology.Second mesh of freezing It is identical with normal freeze-drying, now because the freezing size of material significantly reduces, the time needed for freezing reality is also significantly Shorten.

In the drying sublimation stage, material needs to absorb heat（Every gram of ice is sublimed into vapor and about absorbs 2.8 kJ (kilojoule)s completely Heat）.If do not heated to medicine or shortage of heat, can absorb medicine heat in itself when moisture is in distillation and Making the temperature of medicine reduces, and causes the vapour pressure of medicine and reduces, and then causes the reduction of rate of sublimation, and the whole dry time is just Can extend, productivity ratio declines；If heated to medicine many, the rate of sublimation of medicine can no doubt be improved, but counteract medicine After the absorbed heat of distillation, unnecessary heat can make to freeze medicine temperature rising in itself, medicine is likely to occur part Even all fusings, cause the drying shrinkage foaming phenomena of medicine, and whole drying will fail.The temperature of bulk material three-dimensional is passed Guiding path is more long, and the control difficulty of temperature and heat is also very big, and sheet, the temperature homogeneity of strip are substantially better than bulk material, Therefore control distillation endothermic process is also easier in freeze-drying.

Technology controlling and process, in order to obtain good lyophilized medicine, typically when lyophilized should according to the performance of every kind of freeze dryer and The characteristics of medicine, a freeze-drying curve is worked up on the basis of tried, then control machine, make freeze-drying process each stage Temperature change meet the freeze-drying curve of advance formulation.The production process control of vacuum freeze drying needs to be come by means of computer Control production system works according to freeze-drying curve set in advance.Freeze-drying process control such as computer to pseudo-ginseng monoblock can be divided into Two stages：First stage, at a temperature of less than fusing point, moisture is distilled from the material of freezing, there are about 98%~99% Moisture is removed at this moment.Second stage, freezes the drying sublimation stage of medicine, and temperature of charge is about -30 DEG C~-35 DEG C, Absolute pressure is about 4~7 handkerchiefs, about 24 hours time.After the first time pre-freeze of this technology, freezing microtome section technique, distillation is dry The time in dry stage can shorten to original less than 30%.For the second drying stage, temperature of charge is gradually raised to or slightly higher In room temperature, 0.5% can be decreased below through this stage moisture.The lyophilized final drying temperature of pseudo-ginseng monoblock can rise to 40 DEG C, do About 32 hours dry time, after this technology, second stage shortens to 10 hours.Traditional handicraft need to use computer automation Control system, just can guarantee that pseudo-ginseng monoblock is lyophilized and conforms to quality requirements.New technology takes short, and the drying process of pseudo-ginseng root slices can be with It is visually visible, can be using manual observation control.

Bibliography

[1] Zhou Guoyan, Chunxia WANG, Hu Xiaoliang, Zhan Bo, drying means is to pseudo-ginseng root slices active ingredient and the shadow of organoleptic attribute Ring, the 22nd phase P1-5 of volume 32 of Food Science 2011；

[2] Zhou Guoyan, Zhang Jianjun, Sang Yingying, Yin Fengxue, the research of pseudo-ginseng vacuum freeze-drying technique, Chinese patent drug, 2013 November in year, p2525-2528.

Specific embodiment：

Present invention is generally directed to sheet gourmet food, two examples are devised according to most common pseudo-ginseng root slices and pilose antler chopping：

Embodiment 1, notoginseng decoction piece：Pseudo-ginseng quality is main with head size discrimination, and for the ease of distinguishing, high-end pseudo-ginseng is mostly with whole Block and medicine materical crude slice form are sold.Traditional medicine materical crude slice has two kinds of preparation methods, and first is fresh pseudo-ginseng root slices, and machine cut action can cause Notoginsenoside loses；Second is the section of pseudo-ginseng dried food and nuts, and dried food and nuts is too hard, and it is difficult and frangible to cut into slices.The freezing of this technology notoginseng decoction piece is done Drying process flow is：Fresh pseudo-ginseng → high pressure water cleaning → first time precooling → freezing microtome section → balance → second prefreezing → → second drying → packaging → finished product is dried for the first time.Concrete technology is as follows, and fresh pseudo-ginseng entered high pressure and washes mud, drift Wash after complexing detoxification technology efficiently removes the heavy metal and agricultural chemicals hazard residue of fresh pseudo-ginseng, processing and be put into less than -6 DEG C refrigerator-freezers 2 hours of first time precooling are carried out, prevents putrid and deteriorated, pseudo-ginseng is shaped；After deep colling, in the frozen state, using plane Piece machine cuts into slices pseudo-ginseng frozen product, and thickness is about 1mm；Second pre-freezing temperature of freezing microtome section can not be too low, too low to cause soap Glycosides is lost in, it is necessary to control at -25~-30 DEG C, and cooling time is that can once be made annealing treatment in -20 DEG C of completions after the completion of 1h, freezing； Drying time first time influences very big on saponin(e, and the optimum drying time is 3~5h, and drying temperature is in -25 DEG C~room temperature cycles one It is secondary；Maximum temperature being dried for the second time and selecting 40 DEG C, now saponin(e preserves best, and drying time is 5h.

Embodiment 2：

Pilose antler chopping freezes production technology：Fresh pilose antler → first time precooling → freezing chopping → balance → second prefreezing → → second drying → packaging → finished product is dried for the first time.The fresh pilose antler starch sealing that will have just cut off, prevents outside fine and soft blood Ooze, first time precooling：Pilose antler is put into freezing 2h in less than -10 DEG C refrigerator-freezers, prevents putrid and deteriorated, pilose antler is shaped, in case Chopping is used；Freezing chopping, pilose antler chopping will be frozen using ice shaver in -10 DEG C of freezer；Second prefreezing is using freezing Drying machine, vanning amount is occupying 5 m²Drying box shelf is limited, and drying box of freeze dryer temperature first is down into -40 DEG C after start enters , be placed horizontally at material on the shelf of drying box rapidly by case, by the pilose antler silk in the middle of the contact of TEMP meter, closes drying Case.Freeze-drying:Drying box flaggy and products temperature are down to -45 DEG C, are then freezed to condenser, when condenser temperature drop Vavuum pump is opened during to -40 DEG C, lyophilization is carried out, by being interrupted computer heating control flaggy temperature in -30~20 DEG C, 1 circulation Afterwards, contained most of free water in pilose antler can be removed, 12h is about taken.Then dry for second by being interrupted control heating Flaggy cyclic 2~3 times between 0~30 DEG C, by 8~10h, remove in pilose antler remaining free water and are difficult to what is sloughed Constitution water.When products temperature up to 35 DEG C, drying box vacuum up to during 6~7Pa can outlet, obtain lyophilized pilose antler silk.It is whole to add Work process takes around 1d, and percentage of water loss is about 80%.

Claims (4)

1. the feature of this freeze drying process be flow in include：First time pre-freeze, freezing microtome section, second pre-freeze, first time Lyophilization, second drying.

2. in claim 1, the temperature of first time pre-freeze is less than 0 DEG C.

3. in claim 1, freezing microtome section environment is included in normal temperature and less than 0 DEG C.

4. in claim 1, chip formation includes thin slice, sheet, bulk, inclined tab, thread, section shape, strip.