Summary of the invention
The object of this invention is to provide whole fruit of a kind of hawthorn freeze-drying and preparation method thereof.
The method of preparing the whole fruit of hawthorn freeze-drying provided by the invention, comprises the steps: haw raw material to carry out successively pre-freeze, lyophilization and parsing-desiccation, obtains the whole fruit of described hawthorn freeze-drying.
In the described pre-freeze step of said method, temperature is-26~-35 ℃, preferably-32 ℃; Time is 1-1.5 hour, preferably 1.5 hours; The time of being down to pre-freeze step temperature by room temperature is 1.5-2 hour, preferably 1.5 hours.
In described lyophilization step, condenser temperature is not higher than-35 ℃, and vacuum is 25-50Pa, and temperature of heating plate is 10-15 ℃, and be 3-4 hour drying time.
This step is that hawthorn is whole if really most important step in vacuum freecing-dry process.Lyophilization is also vacuum freeze drying, and equipment therefor is vacuum freeze drier, by refrigeration system, vacuum system, heating system, electrical instrumentation composition of the control system.Its principle is: first material is frozen into below eutectic temperature, make moisture become solid-state ice, then, under higher vacuum, ice is directly distilled as steam, use again water vapour coagulator in vacuum system by water vapor condensation, thereby obtain the method for dried product.Dry run is the process that the states of matter of water changes and shifts.The basic principle of vacuum freeze drying is exactly the mechanism of mass-and heat-transfer under low-temp low-pressure.
At sublimation stage, material need to absorb heat (every gram of ice is sublimed into the heat that steam approximately absorbs 2.8 kJ (kilojoule)s completely), if pass to the heat at distillation interface, equal from the required heat of distillation interface effusion steam, the temperature and pressure at the interface that distils all reaches balance, and distillation is normally carried out.If the shortage of heat of supplying with, the distillation of ice has seized the heat of hawthorn self and the temperature reduction at the interface that makes to distil, and this can cause the reduction of rate of sublimation, will extend whole drying time, and productivity ratio declines.If the steam of overflowing is less than the steam of distillation, unnecessary steam is gathered in distillation interface and makes increased pressure, and sublimation temperature improves, and finally causes goods fusing, makes whole lyophilization failure.
In described parsing-desiccation step, temperature of charge is 20-30 ℃, and vacuum is 25-50Pa, and temperature of heating plate is 25-35 ℃, and condenser temperature is not higher than-35 ℃, and be 3-4 hour drying time.
The described method of preparing the whole fruit of hawthorn freeze-drying, also comprised the steps: before described pre-freeze step, by described haw raw material carry out impurity elimination, clean, stoning and draining.
The described method of preparing the whole fruit of hawthorn freeze-drying, also comprised the steps: before described pre-freeze step, by described haw raw material sabot;
Or, described drain step after, before pre-freeze step, by described haw raw material sabot;
In described sabot step, sabot weight is 3~4.5kg/m
2.
The product for preparing according to the method described above the whole fruit of hawthorn freeze-drying and contain the whole fruit of described hawthorn freeze-drying, also belongs to protection scope of the present invention.Wherein, is the water content of the whole fruit of described hawthorn freeze-drying higher than 4(3 or 4?) %.
The method of preparing the whole fruit of hawthorn freeze-drying provided by the invention, is that raw material is directly carried out to quick-frozen, vacuum drying, without natural air drying and heated-air drying, has farthest kept nutrition and the local flavor of raw material.In process, do not use any additive, and avoided high temperature dehydration to cause the dry and cracked phenomenon of outward appearance shrinkage.Compare with the product such as traditional drying haw flakes, the whole fruit of this hawthorn freeze-drying can retain and concentrate the multiple nutrients composition in fresh sample preferably, as sugar part, vitamin, cellulose and mineral matter etc.As, total sugar content is that 31.3%, Vc content is 142.8mg/100g, and total acid content is 12.3%, and protein content is 3.46%, and general flavone content is 0.23%.Its water content is not generally higher than 4%, and the water activity of dry products is lower, is unfavorable for growth of microorganism breeding, can preserve for a long time.In addition, adopt the whole fruit of hawthorn of vacuum freeze drying through high temperature dehydration, to process in process, can not produce any contraction, product appearance is full, and pucker-free phenomenon has retained the shape of hawthorn fresh fruit, has good exterior quality.In dry run, hawthorn scatters and disappears because of organization internal water sublimed, causes in raw cell or iuntercellular forms uniform alveolate texture, makes product have good crisp brittleness.The quality of this even porous also makes product be easy to water suction, has good rehydration.The alveolate texture that after freeze-drying, hawthorn produces, also makes hawthorn more easily grind.
The specific embodiment
Below in conjunction with specific embodiment, the present invention is further elaborated, but the present invention is not limited to following examples.Described method is conventional method if no special instructions.Described raw material all can obtain from open commercial sources if no special instructions.Described percentage composition, if no special instructions, is quality percentage composition.
Embodiment 1,
Get fresh hawthorn (kind is for prosperous) and, as raw material, measure by the following method the indices of fresh sample haw raw material:
Determination of moisture method: seasoning.Be specially: accurate weighing sample 2-10g, put dryly, cooling and claim to the measuring cup that has lid of constant weight, move in the normal pressure baking oven of 95-105 ℃, uncap after drying 2-4h and take out, add a cover to be placed in drier and weigh after cooling 0.5h.Dry again after one hour and weigh.Repeat this operation, until twice of the front and back 2mg of being no more than of poor quality is, be dried rear constant weight, moisture=(fresh weight (weight before dry)-dry rear constant weight)/fresh weight.
Total reducing sugar assay method: measure total sugar content according to standard GB/T 6194-86 fruit, vegetables total reducing sugar assay method.Instrument and reagent preparation, same GB6194-86.
VC assay method: measure Vit C contents according to the assay method (DNPH method) of total ascorbic acid in standard GB/T 12392-90 fruit, vegetables and goods thereof.
Total acid assay method: measure total acid content according to the assay method of total acid in standard GB/T/T12456-90 food.
Method of protein measurement: according to standard GB/T 8856-88, fruit, victual thick protein assay method are measured protein content.
Determination of Total Flavonoids method: measure general flavone content according to the assay method of standard GB/T/T20574-2006 general flavone content.
Above-mentioned indices testing result is as shown in table 1:
The index determining result of table 1, fresh sample hawthorn
Nutritional labeling |
Fresh sample |
Fresh sample water content (%) |
76.02 |
Total reducing sugar (%) |
7.8 |
Vc(mg/100g) |
1.18 |
Total acid (%) |
3.53 |
Protein (%) |
0.68 |
General flavone (%) |
0.054 |
Be prepared as follows the whole fruit of hawthorn freeze-drying:
Choose fresh haw raw material, take out after inferior, impurity, by Fructus Crataegi cleaning, stoning, drain standby; Fructus Crataegi after draining is carried out to sabot, and sabot weight is 3kg/m
2, lower the temperature gradually after 1.5 hours; Under-26 ℃ of temperature conditions, carry out pre-freeze, then dry storehouse condenser temperature is reduced to below-35 ℃, cool chamber Pressure Drop, to 25Pa, reaches after described temperature and pressure;
Dry storehouse temperature of heating plate is warming up to 10 ℃, then keep after described vacuum and described temperature 3h, keep temperature of charge to carry out parsing-desiccation at 20 ℃, 25 ℃ of temperature of heating plate, dryness storehouse pressure 25Pa, condenser temperature <-35 ℃, keep 3h, discharging after making water content reach below 4%, obtains the whole fruit of hawthorn freeze-drying;
Again the whole fruit classification of hawthorn freeze-drying is adopted to craft or automatic grader, packing adopts nitrogen-filled packaging, obtains the whole fruit of hawthorn freeze-drying provided by the invention.
As follows the whole fruit of gained hawthorn freeze-drying is carried out to Quality Detection:
1, organoleptic detection
Sample is poured in clean ceramic whiteware dish, with the naked eye directly observes color and luster, form and impurity, smell its smell, tastes flavour, and acquired results is as shown in table 2.
Table 2, organoleptic detection result
As seen from table, the whole fruit of gained hawthorn freeze-drying has retained color and the local flavor of fresh hawthorn; In the cell of vacuum freeze-drying hawthorn or iuntercellular expand and form uniform alveolate texture, have good crisp brittleness, can in mouth, melt rapidly after edible, mouthfeel is good.
2, the detection of physical and chemical index
According to preceding method, detect and prepare total sugar content, Vc content, crude fiber content, protein content, the fat content in the whole fruit of gained hawthorn freeze-drying, result shows that the water content of the whole fruit of above-mentioned novel hawthorn freeze-drying is 3.45%, total sugar content is 31.3%, Vc content is 142.8mg/100g, total acid content is 12.3%, protein content is 3.46%, and general flavone content is 0.23%.
Known, the whole fruit of this hawthorn freeze-drying can retain and concentrate the multiple nutrients composition in fresh hawthorn preferably, as sugar, vitamin, cellulose and mineral matter etc.
3, the shelf-life is detected
Preceding method being detected to the whole fruit of hawthorn freeze-drying of preparing after gained packing places after 12 months at normal temperature, detect indices, obtaining its water content is 3.43%, total sugar content is 31.2%, Vc content is 142.6mg/100g, total acid content is 12.2%, and protein content is 3.42%, and general flavone content is 0.22%.
Result shows, the whole fruit of this hawthorn freeze-drying is placed after 12 months at normal temperature, its color and luster, flavour and mouthfeel, shape and just prepare products obtained therefrom and compare and have no significant change;
Embodiment 2, the whole fruit of hawthorn freeze-drying
Get fresh hawthorn (kind is large Venus) as raw material, according to method described in embodiment 1, detect, acquired results is as shown in table 3:
The index determining result of table 3, fresh sample hawthorn
Nutritional labeling |
Fresh sample |
Fresh sample water content (%) |
75.02 |
Total reducing sugar (%) |
7.9 |
Vc(mg/100g) |
1.28 |
Total acid (%) |
3.73 |
Protein (%) |
0.78 |
General flavone (%) |
0.057 |
Be prepared as follows the whole fruit of hawthorn freeze-drying:
Choose fresh haw raw material, take out after inferior, impurity, by Fructus Crataegi cleaning, stoning, drain standby;
Fructus Crataegi after draining is carried out to sabot, and sabot weight is 3.5kg/m
2, lower the temperature gradually after 1.75 hours;
Under-30 ℃ of temperature conditions, carry out pre-freeze, then dry storehouse condenser temperature is reduced to below-35 ℃, cool chamber Pressure Drop, to 35Pa, reaches after described temperature and pressure;
Dry storehouse temperature of heating plate is warming up to 12 ℃, then keep after described vacuum and described temperature 3.5h, keep temperature of charge to carry out parsing-desiccation at 25 ℃, 30 ℃ of temperature of heating plate, dryness storehouse pressure 30Pa, condenser temperature <-35 ℃, keep 3.5h, discharging after making water content reach below 4%, obtains the whole fruit of hawthorn freeze-drying;
Again the whole fruit classification of hawthorn freeze-drying is adopted to craft or automatic grader, packing adopts nitrogen-filled packaging, obtains the whole fruit of hawthorn freeze-drying provided by the invention.
According to same procedure described in embodiment 1, the whole fruit of gained hawthorn freeze-drying is carried out to Quality Detection, wherein, organoleptic detection result is as shown in table 4.
Table 4. organoleptic detection result
As seen from table, the whole fruit of gained hawthorn freeze-drying has retained color and the local flavor of fresh hawthorn; In the cell of vacuum freeze-drying hawthorn or iuntercellular expand and form uniform alveolate texture, have good crisp brittleness, can in mouth, melt rapidly after edible, mouthfeel is good.
According to same procedure described in embodiment 1, the whole fruit of gained hawthorn freeze-drying is carried out to the detection of physical and chemical index, result is: water content is 3.40%, and total sugar content is 33.0%, Vc content is 147.6mg/100g, total acid content is 13.1%, and protein content is 3.32%, and general flavone content is 0.21%.
Known, the whole fruit of this hawthorn freeze-drying can retain and concentrate the multiple nutrients composition in fresh hawthorn preferably, as sugar, vitamin, cellulose and mineral matter etc.
According to same procedure described in embodiment 1, the whole fruit of gained hawthorn freeze-drying is carried out to shelf-life detection, result is: water content is 3.39%, and total sugar content is 33.0%, Vc content is 147.5mg/100g, total acid content is 13.0%, and protein content is 3.31%, and general flavone content is 0.20%.
Result shows, the whole fruit of this hawthorn freeze-drying is placed after 12 months at normal temperature, its color and luster, flavour and mouthfeel, shape and just prepare products obtained therefrom and compare and have no significant change.
Embodiment 3, the whole fruit of hawthorn freeze-drying
Get fresh hawthorn (kind is large Venus) as raw material, according to method described in embodiment 1, detect, acquired results is as shown in table 5:
The index determining result of table 5, fresh sample hawthorn
Nutritional labeling |
Fresh sample |
Fresh sample water content (%) |
74.10 |
Total reducing sugar (%) |
7.5 |
Vc(mg/100g) |
1.15 |
Total acid (%) |
3.50 |
Protein (%) |
0.65 |
General flavone (%) |
0.051 |
Be prepared as follows the whole fruit of hawthorn freeze-drying:
Choose fresh haw raw material, take out after inferior, impurity, by Fructus Crataegi cleaning, stoning, drain standby;
Fructus Crataegi after draining is carried out to sabot, and sabot weight is 4.5kg/m
2, lower the temperature gradually after 2 hours;
Under-35 ℃ of temperature conditions, carry out pre-freeze, then dry storehouse condenser temperature is reduced to below-35 ℃, cool chamber Pressure Drop, to 50Pa, reaches after described temperature and pressure;
Dry storehouse temperature of heating plate is warming up to 15 ℃, then keep after described vacuum and described temperature 4h, keep temperature of charge to carry out parsing-desiccation at 30 ℃, 35 ℃ of temperature of heating plate, dryness storehouse pressure 50Pa, condenser temperature <-35 ℃, keep 4h, discharging after making water content reach below 4%, obtains the whole fruit of hawthorn freeze-drying;
Again the whole fruit classification of hawthorn freeze-drying is adopted to craft or automatic grader, packing adopts nitrogen-filled packaging, obtains the whole fruit of hawthorn freeze-drying provided by the invention.
According to same procedure described in embodiment 1, the whole fruit of gained hawthorn freeze-drying is carried out to Quality Detection, wherein, organoleptic detection result is as shown in table 6.
Table 6, organoleptic detection result
As seen from table, the whole fruit of gained hawthorn freeze-drying has retained color and the local flavor of fresh hawthorn; In the cell of vacuum freeze-drying hawthorn or iuntercellular expand and form uniform alveolate texture, have good crisp brittleness, can in mouth, melt rapidly after edible, mouthfeel is good.
According to same procedure described in embodiment 1, the whole fruit of gained hawthorn freeze-drying is carried out to the detection of physical and chemical index, result is: water content is 3.12%, and total sugar content is 32.9%, Vc content is 145.8mg/100g, total acid content is 12.8%, and protein content is 3.30%, and general flavone content is 0.20%.
Known, the whole fruit of this hawthorn freeze-drying can retain and concentrate the multiple nutrients composition in fresh hawthorn preferably, as sugar, vitamin, cellulose and mineral matter etc.
According to same procedure described in embodiment 1, the whole fruit of gained hawthorn freeze-drying is carried out to shelf-life detection, result is: water content is 3.10%, and total sugar content is 32.8%, Vc content is 145.7mg/100g, total acid content is 12.7%, and protein content is 3.30%, and general flavone content is 0.20%.
Result shows, the whole fruit of this hawthorn freeze-drying is placed after 12 months at normal temperature, its color and luster, flavour and mouthfeel, shape and just prepare products obtained therefrom and compare and have no significant change.