CN101658275B - Instant asparagus and preparation method thereof - Google Patents

Abstract

The invention belongs to the field of food processing, in particular instant asparagus and a preparation method thereof. The instant asparagus takes asparagus or asparagus spent materials as raw materials, and is prepared by procedures such as inspection and acceptance, washing, peeling, grading, precooking, hardening, seasoning, sugar soaking, baking and the like. The invention has simple technology, and better recovers and utilizes crude asparagus and malformed asparagus. The prepared product is easy to be stored for a long term, and has favorable flavor and taste.

Description

A kind of instant asparagus and preparation method thereof

(1) technical field

The invention belongs to food processing field, particularly a kind of instant asparagus and preparation method thereof.

(2) background technology

Along with improving constantly of people's living standard, radical change has taken place in people's health-nutrition consciousness, have enough being satisfied with, drunk under the topic of cuisines, nutrition dietary has become national life quality whether feature for the health affected problem to country, nutrition simultaneously also is familiar with by the consumer to people's health effect, government and consumer are to green health, the needs of nutritional health food have reached urgent and strong stage, how will occupy the live drink of main status of people, food on traditional basis, the drink that becomes not only nourishing healthy but also have certain function, food is extremely urgent.

Asparagus is a herbaceos perennial, claims that its asparagus is because of tender stem and the bamboo shoots of mainly edible tender stem as reed, and asparagus is with its unique delicious local flavor, and higher nutritive value, medical value are subjected to human liking deeply, become the high-grade health-care vegetable of international popular; But asparagus is seasonal strong, be difficult to storage, at present, asparagus produces based on canned food, how these high trophism vegetables of asparagus being made dark leisure food, instant food, instant food popular to people, is the problem of putting for many years in production research department.

In the middle of the canned asparagus spear production process, have a large amount of thick bamboo shoot (diameter is more than 2.0 centimetres), lopsided bamboo shoot are sorted out, how with this part prepared using, also be that pendulum continues the problem that solves in factory.

(3) summary of the invention

The present invention is in order to remedy the deficiencies in the prior art, provides a kind of and be of high nutritive value, rationally utilize instant asparagus of the convenient leisure that the asparagus leftover bits and pieces makes and preparation method thereof.

The present invention is achieved through the following technical solutions:

A kind of instant asparagus, it is characterized in that: with asparagus or asparagus leftover bits and pieces is raw material, through select materials, cleaning, classification, cut, give boil, harden after, be immersed in the baste of forming by Radix Glycyrrhizae, dried orange peel, lemon, vitamin C, malic acid and water after the seasoning, again through soak sugar, baking is made.

The preparation method of this instant asparagus comprises the steps:

(1) selection of asparagus, examination;

(2) pre-treatment of asparagus: after asparagus flushing, peeling, classification, cutting, in the pH value is 3～4 water, give boil after, it is softening to put into the water cooling, adds the colour protecting liquid of being made up of vitamin C and citric acid then and soaks, and at last asparagus is pulled out rinsing, is dried and the classification inspection;

(3) sclerosis rinsing: pull out after placing the hardening bath formed by pure water, calcium chloride and gelatin to harden the asparagus, put into the filtered water rinsing;

(4) seasoning is flooded: asparagus is positioned in the baste of being made up of Radix Glycyrrhizae, dried orange peel, lemon, vitamin C, malic acid and water and pulls airing out behind the dipping;

(5) soak sugar: asparagus is placed by white granulated sugar, vitamin C, citric acid.Carry out in the liquid glucose that Hydros and water are formed after sugar salts down, placing pH again is that 2.5～3 liquid glucose soaks candy system, soaks twice, pulls draining sugar liquid out;

(6) baking: the asparagus of draining sugar liquid is toasted the back moisture regain.

Its concrete steps are as follows:

(1) selection of asparagus, examination

Direct purchase bamboo shoot farming raw material, or with can processing factory sort out be not suitable for the tinning head etc. the bamboo shoot section after outer bamboo shoot and the whole bamboo shoot cutting, acquisition criteria is thick bamboo shoot and lopsided bamboo shoot, slightly bamboo shoot be diameter greater than 2.0 centimetres, 16 centimetres of length.1～5 ℃ of freezer of will putting into that can not at once process stores, and the storage time can not surpass 24 hours, if need to place 1～2 day, then must put into 1～2 ℃ freezer storage, and note taking moist keeping measures.

(2) pre-treatment of asparagus

Pre-treatment comprises: flushing, again select classification, peeling classification, cut, give boil, classification, inspection.

A. flushing

The FCL flushing of raw material elder generation is washed bamboo shoot machine pressure flush with vibration then, carries out disinfection with the thimerosal that contains effective chlorine when manually cleaning.

B. select classification

In transportation and cleaning process, level and damage phenomenon easily take place to mix, so should select meticulously after the flushing.Tender stem that at first will fall short of specifications and damage stem are chosen superseded, are divided into some levels by tender stem length, thickness, white green pool and breed standard then, and the tender tips of bamboo shoot are in a direction code cartonning.

C. remove the peel classification

Because tender basal part of stem epidermis is aging, when therefore processing whole piece peeling asparagus, raw material base portion epidermis should be removed, skinner length is no less than 2/3rds of tender stem length overall, because will float the bad peeling of back raw material deliquescing, peeling should be carried out before blanching.Machine barking thickness should replenish artificial peeling in 0.6 millimeter to the incorrect asparagus of shape.Manual peeling is no more than 1 millimeter, requires peeling totally, evenly, not to be with corner angle, keeps being bordering on original circularity, and is not blocked up, removes crude fibre layer, breach and variable color part.

Owing to easily have silt particle between the asparagus scale, when therefore processing the whole piece canned asparagus spear, scale should be removed, availablely manually divest, also available descaler is removed with water under high pressure.Machinery is scaled, the work efficiency height, and tender stem is done further flushing when scaling, raw material is more cleaned.

D. cutting

With the tender stem of the asparagus after selected according to different requirements by hand or mechanical means raw material is cut into corresponding length.The certain neat cleaning of cutting period face can not be cut sth. askew, not the magnetic tape trailer tip.The whole piece asparagus generally has 120 millimeters, specifications such as bamboo shoot section 20-40 millimeter.

E. give and boiling

Give and boil and claim to complete and blanching.Giving the purpose of boiling is to make tender stem tissue soft, and enzyme is lost activity, and also can remove attached to the microorganism on the tender stem, removes cement and bitter taste in the tender stem, gets rid of the gas of organization internal, and Wan tender stem can become straight by giving boiling slightly.

Give the water that boils usefulness and be advisable (total hardness 170ppm is following), can not use hard water or be alkaline water with soft water.When the pH value 6.1 of water was above, variable color will take place in asparagus, when the basicity of water is too big, can adds an amount of 0.1% citric acid and adjust pH value, was controlled at pH value 3.6～3.8 and was advisable.Give 79～85 ℃ of temperature to boil water, 2～3 minutes time, water temperature and time should determine that specifically give when boiling, the tender tips of bamboo shoot upwards according to the thickness and the tender degree of raw material, base portion is downward, to put into water near base portion 2/3rds earlier and boil 1～2 minute, and then the tender tips of bamboo shoot partly be put into water boil about 1 minute, in order to avoid the tender tips of bamboo shoot are well-done, scale is loose, influences quality.

In giving saucepan, give and boil 2～3 minutes under the bamboo shoot section similarity condition with basket.

Give that boil must appropriateness, give and boil longly, tender stem is too soft mashed, and easily loses fragrance.Give and boil not thoroughly, then do not reach softening purpose.Judge to give and boil whether appropriate method has two kinds:

A kind of is that the base portion level of will give the stem that underdoes pinches, if its head can crooked 90 °, proves to give and boils appropriateness; Another kind method is at the cooling stage that gives after boiling, and tender stem slowly sinks, and expression is given and boiled appropriateness, and the expression of tender stem come-up is given and boiled not thoroughly, and the then expression of sinking is rapidly given and being boiled excessively.

Give and to put into flowing cold water rapidly after boiling and be cooled to below 36 ℃, make it softening, put into colour protecting liquid then, be vitamin C 0.1%～0.15%, citric acid 0.03%～0.035% (percentage of asparagus weight), pull rinsing out and dry moisture after about 15～30 minutes, with removal part bitter substance, but water floats the fragrance that overlong time can reduce product.

F. classification inspection

By the classification of asparagus large, medium and small, reject variable color, accompany silt, the failure of obvious thick scale is arranged, and bending, deformity, mechanical wound, disease and pest and head opening person are chosen correction separately.

(3) sclerosis rinsing

The asparagus blanching that in addition completes after treatment, its shredded bamboo shoot, the bamboo shoot section is softer that back processing is caused difficulty, is to improve end product quality and sense organ degree, and the rinsing of therefore must hardening is handled, and its process is:

A. the preparation of hardening bath

Hardening bath is that pure water, calcium chloride and gelatin are mixed with 100: 0.2～0.3: 0.3～0.4 weight ratio, and wherein, gelatin will melt with 85 ℃-95 ℃ hot water.

B. sclerosis is flooded

After preparing hardening solution, place hardening bath to harden asparagus, the time is 1-1.5 hour.

C. rinsing

Asparagus is flooded 1-1.5 hour in hardening bath after, pull out then and put into the filtered water rinsing, to remove unnecessary hardening solution, its rinsing time is 1-1.5 hour.

(4) seasoning dipping

For making better suitable consumers in general's taste of instant asparagus product, comply with consumer's hobby, before asparagus carries out sugaring, be to asparagus seasoned dipping, its process is:

A. prepare baste

Baste is that pure water, Radix Glycyrrhizae, dried orange peel, lemon, vitamin C and malic acid are mixed with 100: 2～3: 3～5: 2～3: 0.2～0.3: 1～1.5 weight ratio, boils under 90-95 ℃ then, is concentrated into 80% of original amount.

B. asparagus seasoned dipping

Behind the preparation baste, asparagus placed in the baste flood, dip time is 6～8 hours, pulls out then to be placed on the stainless (steel) wire, drains baste, carries out airing, and the time is 1～2 hour.

(5) soak sugar

Soak sugared process and comprise once salt down process and soak sugared process for twice of sugar.

Because the asparagus water content is higher, and in the stain system process moisture in the asparagus liquid glucose soak ooze ooze out in a large number down, can the dilution sugar concentration, so take repeatedly to steep method for making.

When the water content of asparagus is 17～19%, total sugar content is 55～60%, wherein content of reducing sugar is 35%, account for 60% when above of total sugar content, asparagus just can " sand return " (finished surface or the inner crystallization of sucrose that produces) and " returning sugar " (finished product generation glucose crystallization) phenomenon, product is the best in quality at this moment.When content of reducing sugar is 30%, account for 50% when following of total reducing sugar, drying back finished product will the sand return phenomenon occur in inconsiderate degree ground, and the instant asparagus of sand return can lose the gloss of normal product and damaged easily, has a strong impact on the outward appearance and the quality of finished product; When content of reducing sugar was between 30～40%, though finished product in the not sand return temporarily of system back, still might produce slight sand return phenomenon through storage, its sand return degree will increasing and lower with content of reducing sugar; When content of reducing sugar is too high, meet the high temperature wet season, " returning sugar " phenomenon easily takes place.

This shows that sucrose and reduced sugar ratio are determining the quality of finished product in the instant asparagus, and the main source in sugared source is a liquid glucose in the finished product,, must gives the attention of height so the preparation of liquid glucose is the key problem in technology that asparagus produces.Because it is few that asparagus contains organic acid, should add a certain amount of organic acid in the liquid glucose of boiling asparagus, adjusts its pH value, can control reduced sugar ratio in the liquid glucose like this.Draw through practice, the pH value of liquid glucose is adjusted at 2～2.5 o'clock, and through boiling in 90 minutes, wherein the major part of sucrose was sent out and can be obtained transforming, and product quality can be guaranteed.Because the asparagus water content is higher, for preventing " sand return ", " returning sugar ", so the processing asparagus is adopted repeatedly sugaring method.

A. sugar salts down

Asparagus behind the seasoning dipping is weighed, then the mixed sugar liquid of the citric acid of the inner vitamin C that contains the white granulated sugar that accounts for gross weight 35%, 0.10%-0.15% of preparation, 0.03%-0.05%, 0.01 ‰ Hydros.Asparagus and mixed sugar liquid are carried out sugar salt down, sugar salts down and places for one deck asparagus (thickness is less than 3-4 centimetre) covers one deck mixed sugar liquid, will cover asparagus with mixed sugar liquid at last; After sugar cure in 48 hours, liquid glucose is leached.

B. soak candy system

The liquid glucose that leaches is added HFCS and citric acid, it is modulated into pH value 2.5-3, sugar content is 40% liquid glucose, through boiling in 10～20 minutes, to insert in the liquid glucose through the asparagus of sugar cure, boiling 5-8 minute (but should note should constantly stirring gently in the boiling process, be heated evenly to guarantee asparagus), connecting liquid glucose moves in the cylinder together, with asparagus submerge liquid level can, soak and pull out after 24 hours, draining sugar liquid is placed on airing on the stainless (steel) wire.Water evaporates in the cool solarization process, evaporation capacity is about 1/3 of original weight.

The liquid glucose that leaches is added HFCS and citric acid again, it is modulated into pH value 2.5～3, sugar content is 55～60% liquid glucose, after boiling in 10～20 minutes, the asparagus of airing is poured in the liquid glucose, boiling 10～15 minutes, connecting liquid glucose then moves in the cylinder together, with just submerge liquid level can, soak and after 24 hours asparagus pulled out, evenly be placed on draining sugar liquid on the stainless (steel) wire.

(6) baking

The baking of asparagus divides two parts: the baking process of drying room and the process that eases back after the baking.

A. the baking process of drying room

During the asparagus baking, pay special attention to the color and luster variation of asparagus and the variations in temperature of drying room.

1. baking temperature and time

When toasting for the first time, the asparagus behind the draining sugar liquid is put into dish shakeout, send into drying room, toasted under 60～65 ℃ temperature 6～8 hours, treat that the water content of asparagus was reduced at 26～34% o'clock, take out baking tray, the baking second time is carried out in the moisture regain shaping after 12 hours.

For the second time baking temperature is controlled at 55～60 ℃, dries by the fire approximately 4～6 hours, treats that water content reduces to about 20～25%, and product color is little yellow light oyster white, and transparent feel is arranged, and is soft and can go out the room when glutinous.

2. ventilation dewetting

Will note ventilation dewetting in the middle of the baking, the method for ventilation dewetting and time can be decided according to the height of relative humidity in the drying room and the size of extraneous wind-force.Just should carry out ventilation dewetting when relative humidity is higher than 70% in the drying room, very high as indoor humidity, extraneous wind-force hour can all be opened air intake window and hydrofuge tube; , air intake window and aiutage alternately can be opened when big as the higher and extraneous wind-force of indoor humidity.During ventilation dewetting, indicate with instrument.

3. fall to coil

The dish that falls is transposing drip pan position in the bake process of asparagus, stirs asparagus in the dish.The dish that falls carries out when baking end for the first time.

B. the process that eases back after the baking

Baked product is put in indoor, gets damp again 12～24 hours, pick out have stain or blackout etc. can pack behind the substandard product.Product color after easing back is golden yellow, and transparent feel is arranged, and soft and not glutinous, sugariness is moderate, has tangible asparagus delicate fragrance.

Technology of the present invention is simple, has recycled thick bamboo shoot, lopsided bamboo shoot preferably, and the product of production is easy to long preservation, and local flavor, mouthfeel are good.

(4) specific embodiment

Embodiment:

(1) selection of asparagus, examination

Purchase thick bamboo shoot and lopsided bamboo shoot, thick bamboo shoot be diameter greater than 2.0 centimetres, 16 centimetres of length.1～5 ℃ of freezer of will putting into that can not at once process stores, and the storage time can not surpass 24 hours, if need to place 1～2 day, then must put into 1～2 ℃ freezer storage, and note taking moist keeping measures.

(2) pre-treatment of asparagus

Pre-treatment comprises: flushing, again select classification, peeling classification, cut, give boil, classification, inspection.

A. flushing

The FCL flushing of raw material elder generation is washed bamboo shoot machine pressure flush with vibration then, carries out disinfection with the thimerosal that contains effective chlorine 5～10PPM when manually cleaning.

B. select classification

Select meticulously after the flushing, the tender stem that falls short of specifications and damage stem are chosen superseded, be divided into some levels by tender stem length, thickness, white green pool and breed standard again, the tender tips of bamboo shoot are in a direction code cartonning.

C. remove the peel classification

Raw material base portion epidermis is removed, and skinner length is no less than 2/3rds of tender stem length overall, and machine barking thickness should replenish artificial peeling in 0.6 millimeter to the incorrect asparagus of shape.Manual peeling is no more than 1 millimeter, requires peeling totally, evenly, not to be with corner angle, keeps being bordering on original circularity, and is not blocked up, removes crude fibre layer, breach and variable color part.

The scale of asparagus is removed, availablely manually divested, also available descaler is removed with water under high pressure.

D. cutting

With the tender stem of the asparagus after selected according to different requirements by hand or mechanical means raw material is cut into corresponding length.The certain neat cleaning of cutting period face can not be cut sth. askew, not the magnetic tape trailer tip.The whole piece asparagus generally has 120 millimeters, specifications such as bamboo shoot section 20-40 millimeter.

E. give and boiling

Give the water that boils usefulness and be advisable (total hardness 170ppm is following), can add an amount of 0.1% citric acid and adjust pH value, be controlled at pH value 3.6～3.8 and be advisable with soft water.Give 79～85 ℃ of temperature to boil water, 2～3 minutes time, water temperature and time should determine that specifically give when boiling, the tender tips of bamboo shoot upwards according to the thickness and the tender degree of raw material, base portion is downward, to put into water near base portion 2/3rds earlier and boil 1～2 minute, and then the tender tips of bamboo shoot partly be put into water boil about 1 minute, in order to avoid the tender tips of bamboo shoot are well-done, scale is loose, influences quality; In giving saucepan, give and boil 2-3 minute under the bamboo shoot section similarity condition with basket.

Give and to put into flowing cold water rapidly after boiling and be cooled to below 36 ℃, make it softening, put into colour protecting liquid then, promptly vitamin C 0.1%-0.15%, citric acid 0.03%-0.035% (percentage of asparagus weight) pull rinsing out and dry moisture after about 15～30 minutes.

F. classification inspection

By the classification of asparagus large, medium and small, reject variable color, accompany silt, the failure of obvious thick scale is arranged, and bending, deformity, mechanical wound, disease and pest and head opening person are chosen correction separately.

(3) sclerosis rinsing

The preparation of hardening bath: pure water, calcium chloride and gelatin are mixed with 100: 0.2～0.3: 0.3～0.4 weight ratio, and wherein, gelatin will melt with 85 ℃-95 ℃ hot water.

Place hardening bath to harden asparagus, the time is 1-1.5 hour, pulls out then and puts into the filtered water rinsing, and to remove unnecessary hardening solution, its rinsing time is 1-1.5 hour.

(4) seasoning dipping

Preparation baste: pure water, Radix Glycyrrhizae, dried orange peel, lemon, vitamin C and malic acid are mixed with 100: 2～3: 3～5: 2～3: 0.2～0.3: 1～1.5 weight ratio, under 90-95 ℃, boil then, be concentrated into 80% of original amount.

Asparagus placed in the baste flood, dip time is 6～8 hours, pulls out then to be placed on the stainless (steel) wire, drains baste, carries out airing, and the time is 1～2 hour.

(5) soak sugar

Soak sugared process and comprise once salt down process and soak sugared process for twice of sugar.

Asparagus behind the seasoning dipping is weighed, then the mixed sugar liquid of the citric acid of the inner vitamin C that contains the white granulated sugar that accounts for gross weight 35%, 0.10%-0.15% of preparation, 0.03%-0.05%, 0.01 ‰ Hydros.Asparagus and mixed sugar liquid are carried out sugar salt down, sugar salts down and places for one deck asparagus (thickness is less than 3-4 centimetre) covers one deck mixed sugar liquid, will cover asparagus with mixed sugar liquid at last; After sugar cure in 48 hours, liquid glucose is leached.

The liquid glucose that leaches is added HFCS and citric acid, it is modulated into pH value 2.5-3, sugar content is 40% liquid glucose, through boiling in 10～20 minutes, to insert in the liquid glucose through the asparagus of sugar cure, boiling 5-8 minute (but should note should constantly stirring gently in the boiling process, be heated evenly to guarantee asparagus), connecting liquid glucose moves in the cylinder together, with asparagus submerge liquid level can, soak and pull out after 24 hours, draining sugar liquid is placed on airing on the stainless (steel) wire.Water evaporates in the cool solarization process, evaporation capacity is about 1/3 of original weight.

The liquid glucose that leaches is added HFCS and citric acid again, it is modulated into pH value 2.5～3, sugar content is 55～60% liquid glucose, after boiling in 10～20 minutes, the asparagus of airing is poured in the liquid glucose, boiling 10～15 minutes, connecting liquid glucose then moves in the cylinder together, with just submerge liquid level can, soak and after 24 hours asparagus pulled out, evenly be placed on draining sugar liquid on the stainless (steel) wire.

(6) baking

The baking of asparagus at twice.

When toasting for the first time, the asparagus behind the draining sugar liquid is put into dish shakeout, send into drying room, toasted under 60～65 ℃ temperature 6～8 hours, treat that the water content of asparagus was reduced at 26～34% o'clock, take out baking tray, the baking second time is carried out in the moisture regain shaping after 12 hours.In the bake process of asparagus, change the drip pan position when baking finishes, stir asparagus in the dish.

For the second time baking temperature is controlled at 55～60 ℃, dries by the fire approximately 4～6 hours, treats that water content reduces to about 20～25%, and product color is little yellow light oyster white, and transparent feel is arranged, and is soft and can go out the room when glutinous.Baked product is put in indoor, gets damp again 12～24 hours, pick out have stain or blackout etc. can pack behind the substandard product.

Will note ventilation dewetting in the middle of the baking, relative humidity is controlled at and is lower than 70% in the drying room, during ventilation dewetting, indicates with instrument.Ventilation dewetting is 3～4 times, and each time was advisable with about 15 minutes.

(7) packing

Instant asparagus food is health products in the leisure food.The packaging scheme of this product is according to its characteristics combining with green, health care's idea, and convenient, instant principle is packed:

The one, the asparagus of whole piece is cooked single packing, and packs with 10/bag specification.

The 2nd, the asparagus of section shape is packed with the form of sugar.

During packing, the asparagus after easing back is picked once more according to size, shape, color and luster, quality etc., classification, pick out have stain or blackout etc. substandard product.Product after picking is packed in the corresponding packaging bag according to its specification requirement, put into the multifunctional vacuum packing machine then and pack.

The strip list props up instant asparagus and adopts vacuum nitrogen gas bag dress, and its process is for once finishing with the installation of vacuum nitrogen gas bag, and its inflated with nitrogen quantity is 2～3ml for the nitrogen content in each bag.

Claims (10)

1. instant asparagus, it is characterized in that: with asparagus or asparagus leftover bits and pieces is raw material, through select materials, cleaning, classification, cut, give boil, harden after, be immersed in the baste of forming by Radix Glycyrrhizae, dried orange peel, lemon, vitamin C, malic acid and water after the seasoning, again through soak sugar, baking is made; Its concrete steps are:

(1) selection of asparagus, examination;

(2) pre-treatment of asparagus, after asparagus flushing, peeling, classification, cutting, the pH value be in 3～4 the water in give under 79～85 ℃ boil 2～3min after, putting into flowing cold water rapidly is cooled to below 36 ℃, make it softening, add the colour protecting liquid of forming by the citric acid that accounts for asparagus weight 0.1～0.15% vitamin C and 0.03～0.035% then and soak, pull asparagus out rinsing after 15～30 minutes, dry and the classification inspection;

(3) sclerosis rinsing: pull out after placing the hardening bath formed by pure water, calcium chloride and gelatin to harden the asparagus, put into the filtered water rinsing;

(4) seasoning is flooded: asparagus is positioned in the baste of being made up of Radix Glycyrrhizae, dried orange peel, lemon, vitamin C, malic acid and water and pulls airing out behind the dipping;

(5) soak sugar: place the liquid glucose of being made up of white granulated sugar, vitamin C, citric acid, Hydros and water to carry out after sugar salts down asparagus, placing pH again is that 2.5～3 liquid glucose soaks candy system, soaks twice, pulls draining sugar liquid out;

(6) baking: the asparagus of draining sugar liquid is toasted the back moisture regain.

2. the preparation method of instant asparagus according to claim 1 is characterized in that: comprise the steps:

(1) selection of asparagus, examination;

(2) pre-treatment of asparagus, after asparagus flushing, peeling, classification, cutting, the pH value be in 3～4 the water in give under 79～85 ℃ boil 2～3min after, putting into flowing cold water rapidly is cooled to below 36 ℃, make it softening, add the colour protecting liquid of forming by the citric acid that accounts for asparagus weight 0.1～0.15% vitamin C and 0.03～0.035% then and soak, pull asparagus out rinsing after 15～30 minutes, dry and the classification inspection;

(3) sclerosis rinsing: pull out after placing the hardening bath formed by pure water, calcium chloride and gelatin to harden the asparagus, put into the filtered water rinsing;

(4) seasoning is flooded: asparagus is positioned in the baste of being made up of Radix Glycyrrhizae, dried orange peel, lemon, vitamin C, malic acid and water and pulls airing out behind the dipping;

(5) soak sugar: place the liquid glucose of being made up of white granulated sugar, vitamin C, citric acid, Hydros and water to carry out after sugar salts down asparagus, placing pH again is that 2.5～3 liquid glucose soaks candy system, soaks twice, pulls draining sugar liquid out;

(6) baking: the asparagus of draining sugar liquid is toasted the back moisture regain.

3. the preparation method of instant asparagus according to claim 2 is characterized in that: in the step (2), giving the water that boils usefulness, to be controlled at pH by citric acid be 3.6～3.8.

4. according to the preparation method of claim 2 or 3 described instant asparagus, it is characterized in that: in the step (3), in the hardening bath, the weight ratio between pure water, calcium chloride and the gelatin is 100: 0.2～0.3: 0.3～0.4, and 1～1.5 hour post rinse 1～1.5 hour hardens.

5. according to the preparation method of claim 2 or 3 described instant asparagus, it is characterized in that: in the step (4), baste concentrates the back use through boiling, wherein, the weight ratio of pure water, Radix Glycyrrhizae, dried orange peel, lemon, vitamin C, malic acid is 100: 2～3: 3～5: 2～3: 0.2～0.3: 1～1; The dip time of asparagus in baste is 6～8 hours, and airing is 1～2 hour then.

6. according to the preparation method of claim 2 or 3 described instant asparagus, it is characterized in that: in the step (5), the percentage by weight of each material is in the liquid glucose that uses when sugar salts down: white granulated sugar 35%, vitamin C 0.10～0.15%, citric acid 0.03～0.05%, Hydros 0.01 ‰, and the sugar time of salting down is 48 hours; Thereafter soak in the candy system for twice, the sugar content of primary liquid glucose is 40%, boiling 5～8 minutes, and the sugar content of liquid glucose is 55～60% for the second time, boiling 10～15 minutes was all soaked 24 hours after each boiling.

7. according to the preparation method of claim 2 or 3 described instant asparagus, it is characterized in that: in the step (6), described baking at twice, earlier after toasting 6～8 hours under 60～65 ℃, got damp again 12 hours, and toasted 4～6 hours down at 55～60 ℃ then, got damp again 12～24 hours; Should be noted that ventilation dewetting in the bake process.

8. the preparation method of instant asparagus according to claim 3, it is characterized in that: the described water that boils usefulness that gives is the mixed solution of soft water and citric acid.

9. the preparation method of instant asparagus according to claim 4 is characterized in that: the hot water with 85～95 ℃ before described gelatin uses melts.

10. the preparation method of instant asparagus according to claim 6 is characterized in that: soak the liquid glucose that adopts in the candy system for twice before use earlier through 10～20 minutes boiling.