CN1849921A - Method for making microwave vaccum frozen and dried lemon piece - Google Patents

Abstract

The present invention relates to a production method of microwave vacuum freeze-dried lemon slices. Said method includes the following steps: (1), sorting lemon fruit; (2), storing lemon fruit under the condition of constant temperature; (3), utilizing ozone to degrade pesticide residue on the lemon fruit and make sterilization; (4), cutting head and tail of lemon fruit, cleaning the lemon fruit by using ozone water and sterilizing; (5), slicing; (6), freezing sliced lemon; (7), prefreeze-drying; (8), microwave vacuum-drying; and (9), sealing and packaging so as to obtain the invented product.

Description

The manufacture method of microwave vaccum frozen and dried lemon piece

Technical field:

The present invention is relevant with the manufacture method of dry lemon tablet, and is special relevant with the manufacture method of microwave vaccum frozen and dried lemon piece.

Background technology:

The dry lemon tablet of Xiao Shouing is to adopt hot baking method to produce in the market, and of poor quality inside and outside existing, residues of pesticides exceed standard, and harmful health can not be carried out problems such as large-scale industrial production.

Summary of the invention:

The objective of the invention is in order to overcome above deficiency, a kind of low consumption, efficient, free from environmental pollution is provided, produce to large-scale industrialization high-quality, meet domestic and international food security, sanitary standard, can be used for steeping health protection tea, put into the dish seasoning and increase aquatic foods, shape, look, aquatic foods, perfume (or spice) are all good, can preferably keep the manufacture method of the microwave vaccum frozen and dried lemon piece of lemon biologically active and nutrition.

The object of the present invention is achieved like this:

The manufacture method of microwave vaccum frozen and dried lemon piece of the present invention, this method comprises the steps:

1), lemon is really carried out classification and pick up choosing;

2), under 10 ℃～13.5 ℃ temperature, lemon is really carried out storage at a constant temperature;

3), 3ppm～5ppm concentration ozone repeatedly really carries out chemical residual degradation, sterilization to lemon, and each time is at least 30min;

4), cut lemon fruit end to end after Ozone Water clean, sterilize;

5), lemon is really carried out the section of directed transverse diameter machinery, slice thickness 4-4.5mm;

6), carry out freezingly to the lemon after the section, cryogenic temperature is lower than-30 ℃;

7), the precooling drying, precooling drying time is 10～12 hours, vacuum 2.4Pa～2.6pa makes lemon section moisture be lower than 30%;

8), micro-wave vacuum is carried out in the section of the dried lemon of precooling, temperature is 40 ℃～48 ℃, and vacuum 2.4pa～2.6pa is lower than 8% to moisture content;

9), under the gnotobasis,, in carton, after the packing, carry out protection against the tide envelope box with damp-proof membrane again through high-barrier composite material mechanical seal inner packing.

Above-mentioned classification is picked up and is selected operation to select transverse diameter φ 50mm～φ 65mm lemon fruit for use.

Manufacture method of the present invention has following advantage:

A, lemon fresh fruit are after picking up choosing, and the size of section is uniformity relatively, thereby guarantee that shape of product is more even, are convenient to metering.

B, store and high concentration ozone degrading pesticide residues repeatedly more than 3 milligrams, can prolong campaign more than three months by the constant temperature freezer.If without the inventive method, just be through with the seasonal campaign of lemon in five months of the February last ten-days period in September to next year.Particularly lemon is by after the sterilization and degrading pesticide residues operation of high-concentrated ozone, solved the agricultural residual problem that exceeds standard, make product be tending towards internationalization, and residues of pesticides to exceed standard be the gateway of a country that the most of agricultural product of China are refused, can not realize one of most significant problems that exports.

C, must not carry out to lemon freeze-drying sheet that look is protected in special high temperature blanching and chemical agent protects look, because if through high temperature more than 70 ℃, will lose a lot of lemon aldehydes volatile aromas and biological activity, more can not come fixation with steam, because the minimum temperature of saturated vapor, can cause the slaking variation of lemon fruit all more than 100 ℃.The present invention is that overall process is finished in the low temperature below 45 ℃, thereby does not destroy the natural colour of product, and the color and luster of product is close to consistent with the fresh fruit color and luster.Shelf life extension is more than five months.

D, can use large-scale deep cooling storehouse and vacuum freeze drier, combine, carry out scale commodity lemon and produce with large-scale microwave vacuum dryer, ozone generator.Fully in conjunction with having brought into play of the mutual supplement with each other's advantages of relevant new and high technology in this field.Vacuum freeze drying is utilized the three-phase characteristics (solid-state, liquid, gaseous state) of water more fully, under the vacuum condition when making it below low temperature-1 ℃, institute's water content in the lemon tablet, by ice (solid-state), directly distilling without liquefaction (aquosity) is that little molecule gaseous state is overflowed, taken away the dehydration of realization product by vacuum, and the minimal loss biological activity.But technical process does not have sterilization functions, and when by the process that is warming up to 0 ℃ below-30 ℃, not only the time long, often all surpass more than 12 hours.And it is still very high to contain moisture in the product, also has more than 20%, must continue also that heat drying promptly contains moisture 5-8% to the aridity standard of product under vacuum condition.Time will reach (is example with the lemon dry plate) more than 24 hours.The dehydration of this work-in-process has not been to finish by distilling directly to be changed to gaseous state (steam) by solid-state (ice).Change that evaporating state finishes into but become gaseous state (steam) by liquid (water) heating.At this after-stage, the effect of the expensive dried machine of vacuum refrigeration just has been reduced to the evaporation of general vacuum drier.

Microwave vacuum dryer is under microwave action, by the intermolecular rubbing action heating of organic object, makes the moisture content steam raising at a lower temperature of institute's water content, thereby the realization product drying.It also has the unique low-temperature sterilization functions.But in the equipment of large-scale practicality, can not solve discharge, the sparking problem of microwave field in vacuum low-temperature environment (being in the dry materials storehouse) always, just not solve energy consumption and safety problem.And disposable microwave drying and heat are dried dry product, and the phenomenon of the distortion of serious contraction is arranged, and influence the product appearance quality.

The present invention can be used in combination two kinds of equipment, and lemon tablet is sloughed most moisture earlier in the vacuum freeze-drying machine, lemon tablet is formalized substantially, when moisture finished through the drying bu sublimation stage one, just change micro-wave vacuum over to, the moisture that makes it to touch the mark and require, and product sterilized.Realize reducing equipment investment, energy-saving and cost-reducing by two-step mutual supplement with each other's advantages, safety, health, continuous industry large-scale production lemon dry plate, every batch of input of energy lemon raw material fruit is more than one ton.

E, must not remove seed to lemon section: the one, the lemon seed contains the unrighted acid of needed by human body, nourishing healthy compositions such as limonin.The 2nd, after seed was removed in the lemon section, it was complete to destroy lemon tablet shape, influences presentation quality.The 3rd, go seed work to carry out by hand, just can not realize industrial-scale production.

F, must not spray in addition the lemon dry plate and to add the lemon oil flavouring,, can preserve fragrance ingredient and other natural biological activity of the former fruit of lemon well because the overall process of the inventive method is low temperature drying and high-barrier packing technique.

G, freeze-drying lemon tablet must carry out box-packed because through the lemon tablet of the freezing gained of vacuum microwave,, rehydration is fine, more fast again than existing commercially available heat oven dry lemon tablet, this advantage but is unfavorable for storing very much.The packing of the inventive method has solved hygienic issues and storage problem, and has satisfied people's once edible (putting into the seasoning of cooking), once drinks the requirement of (putting into cup makes tea).Lemon freeze-drying sheet is frangible, if with finished product pack, so in carrying, access procedure, be easy to into fragment lose commercial value must be box-packed and the listing that can not be packed in bag.

Manufacture method low consumption of the present invention, efficient, free from environmental pollution, provide a kind of high-quality to the consumption market, meet domestic and international food security, sanitary standard, favourable health keeps microwave, the vacuum freeze-drying lemon food-lemon tablet of lemon yellow, bright, fragrant, shape and biologically active and nutrition to greatest extent.It can be used for making tea, smells perfume (or spice), views and admires and drink, and also can add the middle seasoning of cooking and increase aquatic foods.

The present invention produces product overall process safety, aseptic.Can realize GMP authentication, HACCP authentication, be a suitability for industrialized production project in line with international standards.

The specific embodiment:

The manufacture method of microwave vaccum frozen and dried lemon piece of the present invention is as follows:

1, choosing is picked up in the classification of new lemon fruit, selects transverse diameter  50- 65 fruits for use;

2, send into 10 ℃-13.5C of the constant heat storage storage at a constant temperature behind ozone sterilization.

3, and residues of pesticides are carried out ozone degradation, each 30 minutes time is more than the ozone concentration 3ppm.Thereby reach sterilization 99.9%, and prolongation added the duration more than three months.

4, the lemon fruit behind degrading pesticide residues after cutting end to end, carries out high concentration (more than the 0.8ppm) Ozone Water sterilization and cleans.

5, through the directed section of slicer, directed when the key of directed section is to cut into slices to the lemon fruit.By the orientation section, guarantee the section of full fruit transverse diameter, the decorative pattern of sheet shape is attractive in appearance, the not easily separated disengagement of pulp pericarp.Slice thickness is 4mm to 4.5mm.

6, cut into slices through the special-purpose charging tray of the stainless steel of manually packing into, and in even spreading depth≤50mm, reinstall the PP Pipe Compound jiggering and send into the deep cooling storehouse through guide rail, carry out low-temperature quick-freezing.In 8-12 hour, freeze to below-30 ℃.

7, lemon tablet that fast will be after freezing, the materials jiggering is sent into vacuum freeze drier, carries out the precooling drying, time≤12 hour, vacuum reaches more than the 2.4pa, material temperature rise to 0 ℃, chankings moisture content is reduced to below 30% by 86%.

8, vacuum breaker takes out, and changes dish and sends into microwave vacuum dryer and carry out the microwave sterilization heat drying.Microwave power 30KW.Vacuum reaches 2.4pa to 2.6pa, and chankings moisture content is reduced to≤discharging in 8% o'clock.

9, carry out the mechanical packaging of a unit rapidly 300,000 grades of sterile workshop; Packaging material are high-barrier high density food-grade PEF, polypropylene composite membrane composite material films such as (or) polyethylene aluminium foils, and to guarantee the product health, waterproof, airtight realization height is guaranteed the quality.Lemon tablet unit after packing, during metering is packed in the packing carton, covering glassine paper (pop), and then the outer packing box of packing into, the finished product warehouse-in.

The foregoing description is that foregoing of the present invention is further described, but this should be interpreted as that the scope of the above-mentioned theme of the present invention only limits to the foregoing description.All technology that realizes based on foregoing all belong to scope of the present invention.

Claims (2)

1, the manufacture method of microwave vaccum frozen and dried lemon piece, this method comprises the steps:

1), lemon is really carried out classification and pick up choosing;

2), under 10 ℃～13.5 ℃ temperature, lemon is really carried out storage at a constant temperature;

3), 3ppm～5ppm concentration ozone repeatedly really carries out chemical residual degradation, sterilization to lemon, and each time is at least 30min;

4), cut lemon fruit end to end after Ozone Water clean, sterilize;

5), lemon is really carried out the section of directed transverse diameter machinery, slice thickness 4-4.5mm;

6), carry out freezingly to the lemon after the section, cryogenic temperature is lower than-30 ℃;

7), the precooling drying, precooling drying time is 10～12 hours, vacuum 2.4Pa～2.6pa makes lemon section moisture be lower than 30%;

8), micro-wave vacuum is carried out in the section of the dried lemon of precooling, temperature is 40 ℃～48 ℃, vacuum 2.4pa～2.6pa, is lower than 8% to moisture content;

9), under the gnotobasis,, in carton, after the packing, carry out protection against the tide envelope box with damp-proof membrane again through high-barrier composite material mechanical seal inner packing.

2, the manufacture method of microwave vaccum frozen and dried lemon piece as claimed in claim 1 is characterized in that classification is picked up to select operation to select transverse diameter φ 50mm～φ 65mm lemon fruit for use.