GB2157939A

GB2157939A - Preparation of dry extracts

Info

Publication number: GB2157939A
Application number: GB08510327A
Authority: GB
Inventors: Jinichi Sato; Toshiro Kurusu; Yasuji Takahama
Original assignee: Sato Foods Industries Co Ltd
Current assignee: Sato Foods Industries Co Ltd
Priority date: 1984-04-27
Filing date: 1985-04-23
Publication date: 1985-11-06
Also published as: DE3515163A1; GB8510327D0; CH663908A5; JPS60227665A; FR2563442A1; JPH0260308B2; KR850007201A

Abstract

Preparation of a granular dried extract of tea leaves, roasted beans, roasted cereals, fruit, vegetable or honey juice comprises preparing a concentrated aqueous solution containing said extract and starch hydrolyzate(s), dissolving carbon dioxide gas therein at a low temperature and under pressure and spray drying the obtained solution in a dry atmosphere to give a product in the form of hollow spheres which exhibit large particle sizes, a small bulk specific gravity and an excellent flowability. A preferred starch hydrolysate comprises an a cyclic dextrin optionally mixed with a cyclic dextrin.

Description

SPECIFICATION Processfor dry granulation of extracts BACKGROUND OF THE INVENTION Field of the Invention: This invention relates to a process for preparing a granular dried extract of four example, tea leaves, roasted beans, roasted cereals, fruits, vegetable or honeyjuice, which comprises spray drying an aqueous solution containing said extract, whereby an extract of poor drying characteristics can be easily dried and the drying and granulation can be simul taneously carried out in an extremely short period, thus very efficiently giving a granular dried extract which exhibits an excellent solubility, flowability and caking resistance without causing deterioration ofthe flavor.

Description of the Prior Art: Instant drinks such as instant black tea, instant coffee, instant barley tea and instantjuices have been conventionally prepared by dry powdering, e.g., spray drying, an aqueous extract solution obtained by extracting each material with water or by squeezing. In spray drying,the hygroscopicity and thermofusing properties characteristic of these extracts would result in poor drying characteristics as well as deterioration of flavor. In addition, the dried powders thus obtained are in theform of dust-size particles of approximately 100ill in diameter,sothatundissolved lumps might be frequently formed when dissolved in waterat use.

These powdery products havefurtherdisadvantages such that the high dusting properties and poor flowabilitythereof make the packing step difficult and thatthey are liable to solidify.

In orderto overcome these disadvantages, it has been attempted to granulate these dust-size particles obtained by spray drying with the use of granulators such as a fluid-bed granulatororan extruding granulator. However, the hygroscopicity and thermofusing properties characteristic ofthese extracts make the granulation step very difficult and the proionged heating during the granulation step would cause a deterioration oftheflavor of the products. Furthermore, the obtained products are in the form of hard granuleswhich are hardlysoluble in water. Thus it is extremelydifficulttoobtain a granular product of an excellentflavor and a high solubility bythese methods.

SUMMARY OF THE INVENTION According to the process ofthe present invention, an extract of poor drying characteristics can be readily dried and the drying and granulation can be simultaneously carried out in an extremely short period, thus very efficiently giving an instant product of said extract which exhibits excellent properties including high solubility, flowability and caking resistance without causing deterioration ofthe flavor.

The process ofthe present invention comprises dissolving an appropriate amount of carbon dioxide gas in a thick aqueous solution of an extract containing appropriate starch hydrolyzate(s) in an appropriate amount under pressure and/or at a low temperature, introducing the obtained mixture into a spray equipped with a pressure nozzle and spraying it therefrom into a drying chamberto dry.

DETAILED DESCRIPTION OF THE INVENTION The aqueous extract solutions used in the present invention may be roughly classified into those of tea leaves, those of roasted beans, those of roasted cereals,fruitjuices, veseta ble juices and honey juices.

Examples ofthe aqueous extract solutions of tea leaves are tea drinks such as green tea, toasted tea, oolong tea and black tea, aqueous extracts of herbs such as Chinese matrimony vine, cranesbill, hydrangea, bamboo leaves and persimmon leaves and concentrates thereof.

Examples of the aqueous extract solutions of roasted beans are those obtained by extracting roasted beanssuch as coffee or cacao beans under atmospheric or elevated pressure and concentrates thereof.

Examples of the aqueous extract solutions of roasted cereals are those obtained by extracting roasted cereals such as barley, rye, adlay, unpolished rice or rice bran in the presence off enzyme(s) such as amylase under atmospheric or elevated pressure and concentrates thereof.

Exarnples ofthefruit juices are orange, lemon, apple, pineapple, grape, pear, peach, strawberry and plum juices and concentrates thereof.

Examples of the vegetable juices are tomato, Chinese cabbage, cabbage, carrot, horseradish and shiitake mushroom juices and concentrates thereof.

Examples of the honey juices are those obtained from Chinese milkvetch, orange or buckwheat honey and concentrates thereof.

In the process ofthe present invention, an aqueous solution of an extract containing appropriate starch hydrolyzate(s) in an appropriate amount to give an appropriate solid content wherein an appropriate amount of carbon dioxide gas is dissolved is sprayed under pressure into a drying chamber, whereby the sprayed liquid drops are not broken but instantaneously expanded to give hollow spheres each having an enlarged surface area to be dried. Thus a hollow-granular dried product which has extremely improved drying characteristics and large and uniform particle size can be obtained. The granular dried extract prepared by the process of the present invention has a bulk specific gravity of approximately 0.1 to 0.4 and an average particle size of approximately 200 to 1,00011. The particles are highly uniform in size and few are broken.The product has excellent drying characteristics. In addition, since it can be simultaneously dried and granulated in an extremely short period (i.e.approximately 1/10 sec), it little suffers from deterioration ofthe flavor. Accordingly the process ofthe present invention provides an instant dried extract having betterflavor and a higher solubility, flowability and caking resistancethan prior granular products prepared by drying and granulating in conventional manners.

in the process of the present invention, a thick aqueous solution of an extract containing an appropriate amount of a starch hydrolyzate which has an average degree of polymerization of approximately 4 to 20 is prepared. Another starch hydrolyzate (i.e.

cyclic dextrin) of a degree of polymerization of 6,7 or 8 is further added thereto. These starch hydrolyzates are very effective in readily drying the aqueous extract solution without damaging its properties including flavor, in accelerating the dissolution of the carbon dioxide gas and in keeping the quality of the granular dried product thus obtained in the process of the present invention.

When starch hydrolyzates each having an average degree of polymerization higher than 21 are employed, the viscosity of the aqueous solution thus prepared is too high to adequately dissolve the carbon dioxide gas and to spray dry the solution. As a result, anyhollow-granulardried productof a large and uniform particle size can not be obtained. On the other hand,when starch hydrolyzatreseach having an average degree of polymerization lowerthan 3 are employed, the viscosity ofthe aqueous solution thus prepared is too low while its hygroscopicity is too high. As a resultthe dried productthus obtained has ground particleswhicharedifficulttodry.Theproduct further exhibits poor flavor as well as an excessive hygroscopicity.

The content of the starch hydrolyzates is approximately 20 to 70 % by weight based on the total solid matters contained in the aqueous solution comprising an extract essence and the starch hydrolyzates depending or the properties ofthe starch hydrolyzates of an average degree of polymerization of 4to 20 and the extract contained in the solution. A content outside the range as defined above might hinderthe subsequent steps to thereby make it impossible to achieve the object of the present invention.

When fruit or honey juice which contains a large mount of highly hygroscopic sugar and/or organic acids and exhibits extremely poor drying characteristics is dried by the process of the present invention, a highly moisture-proof starch hydrolyzate of a high degree of polymerization (i.e. 20to 60) and a relatively low viscosity prepared by slightly hydrolyzing waxy starch comprising amylopectin may be used. In this case, said starch hydrolyzate may be added to give a content of 10 to 50% by weight based on the total solid matters contained in the aqueous solution depending on the solid content and properties of the aqueous solution comprising the extract and the starch hydrolyzates. A content thereof higher than 50% by weight may excessively raise the viscosity to thereby make it impossible to achieve the object ofthe present invention.

The average degree of polymerization of a starch hydrolyzate as described herein means the average degree of polymerization as calculated from the DE valuethereof in the case of an acyclic dextrin orthe derived from each degree of polymerization in the case of a cyclic dextrin.

The thick aqueous solution comprising an extract and starch hydrolyzates should be prepared to give a solid content of approximately 20 to 55 by weight. A content outside the range as defined above may hinder the subsequent steps to thereby make it impossible to achieve the object of the present invention.

The starch hydrolyzates may be previously added to thewaterwith which a material such as tea leaves or roasted beans is extracted. Alternately they may be addedto the aqueous extracted solution. Then the aqueous solution comprising the extract and the starch hydolyzates is adjusted to an appropriate solid content, e.g. approximately 20 to 55 % by weight (i.e.

the solution contains 80 to 45 % by weight of water) depending on the properties ofthe extract, the amount of the carbon dioxide gas to be dissolved in the subsequent step and the particle size of liquid dropsto beformed by spray drying. When the solid content in the aqueous solution is lowerthan 20 % by weight, the obtained dried product is in the form of broken dust-size particles, while when it is higherthan 55 % byweight, the carbon dioxide gas is hardly dissolved, which makes the achievement of the object ofthe present invention impossible.

In the process of the present invention, the aqueous solution comprising an extract and starch hydrolyzates is cooled to an appropriate temperature and carbon dioxide gas is dissolved therein under adequately elevated pressure. In order to achieve the object ofthe present invention, the carbon dioxide gas is dissolved in an amount of 0.2 to 2.4 % byweight based on the water ofthe solution depending on the concentration of the aqueous solution, the properties of the extract and the desired particle size of the granular dried productto be formed.The carbon oxide gas dissolved in an amount less than 0.2 % byweight can not bring about any improvement is the drying characteristics resulting in a small particle size and a large bulk specificfravity. On the other hand, when the amount ofthe dissolved carbon dioxide gas exceeds 2.4 by weight, the particles are broken, whereby the object of the present invention can not be achieved.

The carbon dioxide gas is dissolved in the aqueous solution by cooling the thick aqueous solution comprising the extract and the starch hydrolyzates to Oto 30"C and contacting carbon dioxide gas therewith in a conventional mannerwith the use of an appropriate apparatus under a carbon dioxide pressure of 1 to 15 kg/cm2g. The amount of the dissolved carbon dioxide gas in the aqueous solution is calculated from the temperature ofthe aqueous solution and the gas pressure at the dissolution.

In the process of the present invention, the aqueous solution comprising the extract and starch hydrolyzates containing dissolved carbon dioxide gas is subsequently introduced into a spray equipped with a pressure nozzle with a high-pressure pump and sprayed into a drying chamber of a spray dryer in a dry atmosphere. The bore ofthe pressure nozzle and the spraying pressure and temperature are adequately selected depending on various factors such as the particle size and bulk specific gravity ofthe aimed product.

The process of the present invention is epochmaking since it enables drying and granulation to be carried out simultaneously and can be widely available in aqueous solutions containing extracts. In addition to the starch hydrolyzates, the aqueous solution ofthe extract mayfurthercontain high molecular substance(s) such as gelatin, gum arabic, starch treated with acid(s) or starch derivatives.

To further illustratethe present invention, and not bywayoflimitation,thefollowing Examples will be given.

Example 1 520 kgof a starch hydrolyzate (CELDEX CH-20: a product of NIHON SHOKUHIN KAKO Co., Ltd.), which comprises 60% of acyclic dextrin of an average degree of polymerization of 5, 15% of cyclic dextrin and 25% of water, and 80 kg of ss-cyclodextrin (CELDEX N: a product of NIHON SHOKUHIN KAKO Co., Ltd.) were dissolved in 9,4001 of water at 60 C and 2,000 kg of toasted tea leaves were added thereto and extracted at 60 C for 30 min with occasional stirring. Aftersqueezing and filtering, approximately 9,000 kg of an aqueous extract solution of a solid content of 8.9% was obtained.The extract was concentrated with a concentrator in vacuo at a material temperature of 45"C to give approximately 2,400kg of or a concentrated aqueous solution of a solid content of 33% by weight containing 48% by weight of starch hydrolyzates based on the total solid matters.

The concentrated aqueous solution thus obtained was divided into five aliquot portions, which were respectively subjected to Tests A E wherein each aliquot portion was injected into a carbon dioxide gas dissolverwith a pump while cooling to 12.5 C with a continuous coolertothoroughly dissolve the carbon dioxide gas underthe condition as shown in Table 1 and the concentrated aqueous solution containing the carbon dioxide ofthe corresponding concentration thus obtained was spray dried under a spraying pressure of 30 kg/cm2 and at a chambertemperature of 95"C. The result is shown in Table 1.

Table 1

Test A | Tes H | Test C THHH H st b t HH. dissDIUtlon(sc)la 12 5'C 12.5C 12 5'C 12 5-C 12 I2.5C dHH1HH1HH(C5 CO2 HIH p=H f02 0.1 2 1.1 2 7.0 6HH2 10.0 b,. 2 diHHH1HHiHH (kgia2s) 0 1 kH 2g 4 0 10.(1 7 0 g 10 H 13.0 g 13 0 sizes D tio Of dissolw d CO2 gas t 0.25 ulv H.M ulu 1.11 .,2 H.92 1 I 2.LO ulu Z 9. solo. (Z by 60115 So . undrled 111,5 Of dvin6 pass Jdhereiog Cuad CIHI (hod I o d ro ehuber lls.

Bulk Hp. gg, of 0.29 0.23 0.18 0.15 0.10 dried product (vlv) 105 21.1 1 8.1 1 1.0 1 7.41 29.6 11 Parricle 105 s 210 P 41.9 1 15.0 2 1.2 11 11.0 1 40.9 1 si?e of 211.1 p..- 210 ~ 297 H 22.0 1 16.31 5.0 2 12.5 1 21.1 1 Z 2.11 (Z) 297 ~ 420 P 5 2 20.1 Z 15.1 1 20 1 0.2 1 129 2100 15Z 2H.2 2 02.011 13.51 l2Z 210 2.2 2 lZ 11 1.1 11 > P iele s 11 1... .19.. and Hpb.11- H.l1,, HH -- IHIl Nost p7r espanded and 611 pander than those ca1 gt I HI-HI.. par- are l.H1'.1H1 Foes of 111,1 pend4ct tls le ss or H?.. Cd and hav 3ve p reticle HIl. .1 HO 190 U 1i. of HI 450 p sis Hf 610 P ..H1 rricles ca She average or 190 0. dried 110 H. bHHhHHpI11iHlHH. H. flovabilL HI or denied Th f g ~ CDDd 6bod HH 250 S.1.b1111y HO dHf.d dly '.1.11. 11,1 HiHI H HH' pIHIHI in ill fHHHHiHH lumps. 0-1 600d HIll HH111H l p di.',I.d I-p'. C..d d1'..ld IH.

Table 1 indicates that the dried productofTestC is the best instanttoasted tea product because of its excellent drying characteristics, good flavor, large and uniform particles, appropriate bulk specific gravity, high flowability and high solubility in water and those of Tests B and D come next. On the other hand,the dried product of Test A containing 0.23% by weight of dissolved carbon dioxide gas based on the water contained in the concentrated aqueous solution was in the form of dust size particles and showed poor drying characteristics, which brought about poorsolubility, while that of Test E containing 2.60% byweight of dissolved carbon dioxide gas based on the water comprised excessively expanded and ground dust-size particles, which brought about poor solubility,flowabilityand caking resistance.

Example 2 600 kg of a starch hydrolyzate (CELDEX CH-20: a product of NIHON SHOKUHIN KAKO Co., Ltd.) comprising 60% of acyclic dextrin of an average degree of polymerization of 5,15% of cyclic dextrin and 25% of water was added to 4,4001 of water at 550C. 1000kg of or blacktea leaves (a product ofJapan Black Tea Co., Ltd.) were added thereto and extracted at 55 C for 30 min with occasional stirring. After squeezing, additional 1000 kg of the same black tea leaves as described above were added to the obtained extract solution and extracted under the same condition as described above.After squeezing and filtering, approximately4,000 of or a blacktea extract solution of a solid content of 17% byweight and containing approximately 8.5% by weight ofthe starch hydrolyzate, i.e. corresponding to 50% of the total solid matters, was obtained.

Subsequently the obtained extract was divided into six aliquot portions. One portion was subjected to the following steps as such (Sample I). Other portions were concentrated in vacuo at a material temperature of 40 C to give solid concentrations of 25.5% by weight (Sample II), 34% byweight (Sample III), 42.5% by weight (Sample IV), 51% byweight (Sample V) and 59.5% by weight (Sample VI), respectively. Each sample was injected into a carbon dioxide gas dissolverwhilecoolingto 15 Cwith a continuous cooling apparatus to thoroughly contact carbon dioxide gas with the aqueous solution under a CO2 pressure of 6.5 kg/cm2g and at a solution temperature of15C,thus dissolving 1.24% by weight of the carbon dioxide gas based onthewatercontainedin the aqueous solution. The obtained solution wasthen introduced into a spray equipped with a pressure nozzle and spraydried undera spray pressure of 25 kg/cm2 and at a chambertemperature of 1 05 C. Table 2 shows the result.

able 2

H 1 H,pl, 10 5wspie H 5a13psr H HHflH Vl Sol d 9. ',HH. 10.11 25 3.HH 42.51 50.0 'Old d 0 OH 5 5 0.5z PHbHH e2rrerS hpd1yH1' X aq~ solo rtj u~ | 51 5zz: OH aulr Hp. H Hf dned 0.23 9.11 1 0 OH 9. HHlH. 0 led proda 0 23 I, 1y '1 H HO,, Hp 1' IHJ I O 1 LAIR 0 - 0 1, H OH H OH Claim H 0 Is I Prt 720 we rase -Ee aPd IHI, of dried fbHHHbHHHHHlH ::b;:, Pa7t s hpe f te 720 1 Hf .a Hf mtrage psrtl- ca 201 ,. 0 714 .

120 Iris ot ca 00 p LZO Ir Hardly 'H RelrTluelp 1 ~ Solroilit7 io under disbo7çed guad bHHd fbOd HHHd S |Ip ps grsnPies Table 2 indicatesthatthe dried product prepared from Sample I of a solid concentration of 17% by weight has a small bulk specific gravity but is in the form of dust-size particles of an average size of approximatelyl20uwhich bringsaboutpoorsolubility. On the other hand, the dried product prepared from Sample VI of a solid content of 59.5% by weight has a relatively large average particle size and is in the form of dense particles of a large bulk specific gravity, which brings about poorsolubility in cold water.In addition, Samples showed adhesion of undried matters on chamberwalls during the drying. Those prepared from Samples III and IVexhibitexcellent drying properties as well as desirable bulk specific gravities and average particle sizes and are highly soluble in water.

Example 3 30 kg of il-cyclodextrin (CELDEX N: a product of NIHON SHOKUHIN KAKO Co., Ltd.) was dissolved in 9701 of water at 50 C and 200 kg of high grade green tea leaves were added thereto and extracted at 50 C for 30 min with occasional stirring. After squeezing, approximately 900 kg of extract solution was obtained. Additional 200 kg ofthe same high-grade green tea leaves as described above were added to the obtained solution and extracted under the same condition as shown above.After squeezing and filtering,700 of or an extract solution of high-grade green tea leaves having a solid content of 15% by weightwas obtained. kg of a starch hydrolyzate (GLISTER P: a product of Matsutani Chemical Co., Ltd.) having an average degree of polymerization of 6.3 and a water content of 5% was dissolved in the above solution to give 735 kg of an aqueous solution which comprised a green tea extract and the starch hydrolyzates, had a solid content of 18.8% by weight and contained approximately39% by weight based on the solid matters ofthe starch hydrolyzates.

Ahalfamount(i.e. 367.5 kg) ofthe aqueous solution thus prepared was spray dried with a spray equipped with a pressure nozzle at a chamber temperature of 95 C. Thus, approximately 70 kg of a dried product in the form of dust-size particles of approximately 10011 in average particle size and having a bulk specific gravity of 0.41 was obtained. This product was hardly soluble even in hotwaterwith forming undissolved lumps.

Approximately kg of the obtained dried powder was dissolved in the residual half (i.e. 367.5kg) ofthe aqueous solution as prepared above to give a concentrated aqueous solution of a solid content of 31 by weight. The concentrated aqueous solution thus obtained was cooled to 8 C with a cooler and introduced into a carbon dioxide gas dissolver, wherein it was thoroughly contacted with carbon dioxide gas under a CO2 gas pressure of 7 kg/cm2g and at a solution temperature of 8 C to thereby dissolve the carbon dioxide gas in a ratio of 1.96% by weight based on the water content ofthe concentrated aqueous solution.The obtained solution was then introduced into a pressure nozzle and spray dried ata chambertemperatureof98 Cto give approximately 114kg of a dried product of a water content of 2.0%.

The obtained dried productwasintheform of hollow and spherical granular particles of a bulk specific gravity of 0.16. The particles were highly uniform in size and 85% thereof were in the range of 24to 48 mesh. The average particle size thereofwas approximately 50011. The granular dried product of green tea extract exhibited a very excellentflowabil ity without any dusting, so that it was readily packed in bottles with an automaticfiller. Itwas further highly soluble not only in hot water but in cold water. The dried product showed similarflavorto that ofthe undried extract.

Example4 0.15kg of an oc-amylase (CLARASE : a product of Kyowa-Miles Co., Ltd.) was dissolved in 3,000 kg of water at 50 C and 500 kg of previously roasted and ground adlaywas added thereto and extracted at 50 C for 60 min with stirring. After squeezing, additional 500 kg of the same adlay as described above was added to the obtained extract solution and extracted under the same condition as described above. After squeezing and filtering, approximately 3,200 kg of an extract solution of a solid content of 12.8% by weight was obtained. 320 kg of a starch hydrolyzate (CELDEX CH-20: a product of NIHON SHOKUHIN KAKO Co., Ltd.) comprising 60% of dextrin of an average degree of polymerization of 5, 15% of cyclic dextrin and 25% of water was dissolved in the above extract solution to give approximately 3,520 kg of an aqueous solution which comprised the adlay extract and the starch hydrolyzates and had a DE of 19.5 and a total solid content of 18.5% by weight.

Subsequently the aqueous solution containing the adlay extract was divided into five aliquot portions.

One portion was subjected to the subsequent steps as such (Sample I). Other portions were concentrated in vacuo ata material temperature of 45 C to give aqueous solutions of solid contents of 28.3% by weight (Sample II), 38,0% by weight (Sample Ill), 48.8% by weight (Sample IV) and 57.5% weight (Sample V), respectively. Each sample was injected into a carbon dioxide gas dissolver while cooling to 1 50C with a continuous cooler to thoroughly contact with carbon dioxide gas under a CO2 gas pressure of 4.5 kg/cm2g and a solution temperature of 15 C. The solution was introduced into a spray equipped with a pressure nozzle with a high-pressure pump and spray dried under a spray pressure of 30 kg/cm2 and at a chambertemperature of 103 C.Table 1 shows the result.

Table 3 indicates that the dried product prepared from Sample I of a solid content of 18.5% by weight has a small bulk specific gravity and an average particle size of as small as approximately 180 u. In addition, many particles therein are broken,which brings about poorflowability and iow solubility with forming undissolved lumps, in particular in cold water. On the other hand, the dried product prepared from Sample V of a solid content of 57.5% by weight showed partial adhesion to chamber walls during the drying step. In had a relatively large average particle size and a large bulk specific gravity and was in the form of dense particles hardly soluble in cold water.

Those prepared from Samples II,III and IV exhibited excellent drying characteristics as well as desirable bulk specific gravities and average particle sizes.

They were highly soluble in water. In particular, that prepared from Sample III was extremely soluble in cold water and showed no dusting and an excellent flowability. Therefore it is available as an instant adlay tea product for cold water which is readily packed without solidification.

Table 3

Sample I Sample II Sample III Sample IV Sample V Solid content in aq. soln.

(% by weight) 18.5 w/w % 38.0 w/w % 38.0 w/w % 48.8 w/w % 57.5 w/w % Batio of dissolved CO2 gas to water content 0.92 w/w % 0.92 w/w % 0.92 w/w % 0.92 w/w R 0.92 w/w % in aq. soln. (% by weight) Bulk sp. gr. of 0.23 0.14 0.18 0.24 0.34 dried product (w/v) < 105 29.2 % 9.1 % 1.2 % 8.2 % 9.2 % 105 ~ 210 41.4 % 14.8 % 4.4 % 10.4 % 15.8 % Particle 210 ~ 297 20.6 % 18.3 % 7.1 % 11.0 % 41.0 % size of 297 ~ 420 7.6 % 19.3 % 10.7 % 28.7 % 20.2 % dried 420 ~ 710 1.2 % 35.4 % 65.2 % 38.1 % 12.4 % product > 710 - 3.1 % 11.4 % 3.6 % 1.4 % Qust-size parti- Hollow and spheri- Hollow and Hollow and Relatively large cles of an cal granular spherical spherical granu- particles of an average particle particles of an granular parti- lar particles of average particle Form of dried product size of ca. 180 average particle cles of an an average par- size of ca. 310 containing many size of ca. 390 average particle ticle size of having a large broken particles. containing some size of ca. ca. 430 having bulk sp. gr.

broken particles. 600 . a relatively large bulk sp.

gr.

Solubility of dried Hardly soluble Relatively Relatively Hardly soluble product in cold with forming soluble. Highly soluble. soluble. with sertled water (10 C) undisaolved lumps. granules.

Example 5 200 kg of a starch hydrolyzate (CELDEX CH-20: a product of NIHON SHOKUHIN KAKO Co., Ltd.) comprising 60% ofacyclicdextrin of an average degree of polymerization of 5,15% of cyclic dextrin and 25% of water was dissolved in 1,300 kg of waer at 80 C and 200kg of roasted, non-ground barley was added thereto and extracted at 80 C for 30 min with stirring. After squeezing and filtering, 1,410 kg of or an extractsolution of a solid content of 14.0% by weight, which will be referred to as Extract A hereinafter, was obtained.Subsequently 0.5 kg of an a-amylase (CLARASE: a product of Kyowa-Miles Co., Ltd.) was dissolved in 4,000 kg of water at 50 C and 800 kg of roasted, ground barley was added thereto and extracted at 50"C for 60 min with stirring in the presence ofthe enzyme. After squeezing and filtering, 4,080 kg of an extract solution of a solid content of 11.5% by weight, which will be referred to as Extract B hereinafter, was obtained.Extract B was spray dried with a spraydryerata chambertemperature of 102 C to give 470 kg of a dried powder, which was subsequently dissolved in Extract A to give 1,880 kg of a concentrated aqueous solution comprising the roasted barley extract and the starch hydrolyzates and having a solid content of 34.3% by weight. The dried powder obtained by spray drying Extract B was hardly soluble in water with forming undissolved lumps. It was further attempted to granulate the same powder with the use of a fluid-bed granulator. As a result, it was found that the powder was hardly granulated and the granules thus prepared was hardly soluble in water.

The concentrated aqueous solution containing the roasted barley extract was divided into five aliquot portions which were then subjected to the following TestsAto E, respectively wherein each portion was injected into a carbon dioxide gas dissolver with a pump while cooling to 1 55C with a continuous cooler and thoroughly contacted with carbon dioxide gas underthe condition as shown in Table 4 and the solution thus prepared was spray dried under a spray pressure of 30 kg/cm2 and at a chambertemperature of 98 C. Table 4 shows the result.

Table 4 indicates that the dried product of Test C has a uniform and large particle size, an appropriate bulk specific gravity and an excellentflowability as well as a high solubility in cold water and those of Tests B and D come next. On the other hand, that of Test A containing 0.18% by weight of dissolved carbon dioxide gas based on the water content was in the form of dust-size particles of an extremely low solubility while that of Test E containing 2.41% by weight of dissolved carbon dioxide gas was in the form of dust-size particles comprising a large amount of excessively expanded and broken particles, so that it was hardly soluble in water. A spoonful (approximately 1 g) of an instant barley tea product obtained in Test C, B or D was introduced in a cup and approximately 110 ml of ice-waterwas poured thereon without stirring.The product was completely dissolved within 30 min to give a convenient drink for taking as such. It has similarflavorto conventional one prepared by extracting roasted barley by boiling and cooling the extract in a refrigerator.

Tattle 4

I Tesx 6 Test H T.EL 1 T,. Hf09. 1,. soln. Is.e H' i o70t C) IS C 15'C 15C 15 C 15 C OH "H 3 pres 6.1 kOiH,20 ss 611"2C 6.5 2 2 dIH'HI,IO,, IkKI s) 0) ks S 3 5 9.1 kol 0 12.5 kgla g 9.S kgl 6 RzCio or diss ed C0z g=s ~ di,,'I-d O0H H 1. 6.10 bl o. 0.76 viv: 1 76 '1,, 1 1.12,1, 11 1.41 '1,11 sola. HP' 6, h7 0 1.40 H.35 veighcl 0.40 O.IS 0,1,1 .105 p 11 0.1 1 3.5 1 17.81 35.0 11 Ps 3e 105 z Z10 P 56.9 = 15.4 1 3.1 1 13.5 1 28.2: sis of 110 X 297 P 21.11 10.6 1 4.4 11 13.2 1 26.7 131 1 21.9 5.12 produCL 291;42011 :~~ L.5L ~~~ IB.IL 41U . 110 u 1.5I 33.1 5.3I L1.4I 3.01 no p 14.5 I 5.51 O.IZ tr epmd Le.rendd 4p= mlaph-lf..pa.erof > ss e p nd d Less exp nded noPe no spners- Hollov nd sFberi fr ,., ,. ,, SltiPof U' PiLICI" Fol~ of dried produot des of merasz chove of Tesr C ;Oe7 of prls nsf ensc ining sone ndud=- > > . 170 p. nf n wG se z viu d i r 5- Z is F U- eos perUdes are OH 'Hid H', pmdoct vith fonrdag 1-V,. fHHHl1HHI dO,HH1,,o 1-V,. 1D cold vx 15-C) d1ssolv d IP P=. Es 7pt dis d lunps.

Example 6 50 kg of an enzymatic starch hydrolyzate (GLISTER P: a product of Matsutani Chemical Co., Ltd.) having an average degree of polymerization of 6.7 contain ing 5% of water and 30 kg of ss-cyclodextrin (CELDEX N: a product of NIHON SHOKUHIN KAKO Co., Ltd.) containing 10% ofwaterwere dissolved in 1,600kg of water at 800C. 200kg of or roasted, ground coffee beans were added thereto and extracted at 80 C for 20 min with stirring. After squeezing and filtering, 1,580kg of an extract solution of a solid contentof9.0% by weight was obtained.The obtained solution was concentrated by reverse osmosis concentrate method to give 400 kg of or a concentrated solution of a solid content of 35.2% by weight. The concentrated solution thus obtained was cooled to 1 00C with a plate coolerand introduced into a carbon dioxide gas dissolver wherein it was thoroughly contacted with carbon dioxide gas under a gas pressure of 8 kg/cm2g at 109C,thus giving a solution containing 1.81% by weight of carbon dioxide gas based on the water content ofthe concentrated solution. The obtained solution was introduced into a pressure nozzle under a spray pressure of 20 kg/cm2 and spray dried at a chambertemperature of 92 C.Thus approximately 140kg of a dried product containing 4.6% of water was obtained.

The dried productthus obtained was in the form of highlyflowable spherical granules of an average particle size of 460 C1 and a bulk specific gravity of 0.13.

It showed no deterioration offlavor by drying and washighysoluble not only in hot water but in cold water. Accordingly it was extremely available as an instant coffee product.

Example 7 50 kg of a waxy starch hydrolyzate (Pinedex&num;100: a product of Matsutani Chemical Co., Ltd.) of an average degree of polymerization of 30 and containing 5.0% ofwaterwas dissolved in 500 kg of concentrated orange juice comprising 20% of solid matters and 80% of water prepared by freeze concentration to give 550 kg of an aqueous solution of a solid contentof26.8% by weight.

The obtained aqueous solution was injected into a carbon dioxide gas dissolver with a pump while cooling to 12.5 Cwith a continuous coolerto thereby dissolve carbon dioxide gas therein under a gas pressure of 6 kg/cm2g at 1 2.56C. The resulting aqueous solution containing 1.23% byweight of dissolved carbon dioxide gas based on the water contained therein was spray dried under a spraying pressure of 50 kg/cm2 and at a chamber temperature of 86"C. The drying was carried out very adequately without any adhesion on chamberwalls to thereby give approximately 147 kg of a dried product.

The dried product, which was in the form of hollow spherical granules having an average particle size of approximately300jiand a bulk specific gravity of 0.24, was highly soluble in cold water and exhibited an excellentflowability and caking resistance without any deterioration offlavor. Accordingly it was highly useful as an instant juice product.

Example 8 50 kg of a starch hydrolyzate (Pinedex&num;1: a product of Matsutani Chemical Co., Ltd.) of an average degree of polymerization of 12.5 and a water content of 5.0% was dissolved in 500 kg of an onion juice concentrate prepared by squeezing and filtering onions and concentrating the obtained onion juice in vacuo to give 550 kg of an aqueous solution of a solid content of 31.4% by weight.

The obtained aqueous solution was injected into a carbon dioxide gas dissolver with a pump while cooling to 15"C with a continuous coolerto thereby dissolve carbon dioxide gas under a gas pressure of 10 kg/cm2g at 15 C. The obtained aqueous solution containing 1.92% byweight of dissolved carbon dioxide gas based on the water contained therein was spray dried under a spray pressure of 40 kg/cm2 and at a chambertemperature of 95 C. The drying was carried out very adequately without any adhesion to chamber walls0 thus giving approximately 172 kg of a dried product of a bulk specific gravity of 0.18.

The obtained dried onion juice was highly soluble and exhibited an excellentflowability, caking resistance and flavor. Accordingly itwas useful as an additiveforvarious instant products such as instant soup.

Example 9 250 kg of a honey concentrate, which was originated from Chinese milk vetch and comprised 80% of solid matters and 20% ofwater, kg of a waxy starch hydrolyzate (Pinedex &num;100: a product of Matsutani Chemical Co., Ltd.) comprising 5.0% of water and having an average degree of polymerization of 30 and 20 kg of a starch hydrolyzate (Pinedex &num;1: a product of Matsutani Chemical Co., Ltd.) comprising 5.0% ofwaterand having an average degree of polymerization of 12.5 were dissolved in 900 kg of waterto give 1,350 kg of an aqueous solution of a solid content of 28.9% by weight.

The obtained aqueous solution was injected into a carbon dioxide dissolver with a pump while cooling to 15 C to thereby dissolve 1.34% by weight of carbon dioxide gas based on the water contained in the aqueous solution under a gas pressure of 7 kg/cm2 at 15"C. The resulting solution was introduced into a pressure nozzle under a spray pressure of 100 kg/cm2 and at a chambertemperature of 86 C and spray dried. The drying was carried out very adequately to give 390 kg of a dried honey product having a bulk specific gravity of 0.35, an average particle size of 210 ,u and a water content of 3.2% . The dried honey productwasveryexcellent in flavor, solubility, flowability and caking resistance.

Claims

1. Aprocessfordrygranulation of an extract, which comprises drying an aqueous solution containing an extract and starch hydrolyzate(s), wherein said aqueous solution is adjusted to a solid content of 20 to 55% by weight, 0.2 to 2.4 by weight of carbon dioxide gas based on the water contained in said aqueous solution is dissolved therein and the obtained solution is spray dried with a spray equipped with a pressure nozzle to thereby give a dried product showing an excellent flavor, solubility, flowa- bilityand caking resistance.

2. Aprocessassetforth in Claim 1, wherein said aqueous solution containing an extract is an aqueous extract solution of tea leaves, roasted beans, roasted cereals, fruit, vegetable or honey juice.

3. A process as setforth in Claim 1 or 2, wherein said starch hydrolyzate(s) comprises acyclic dextrin of an average degree of polymerization of 4to 20 or acyclic dextrin of an average degree of polymerization of4to 20 and cyclic dextrin.

4. A process as setforth in Claim 1,2 or3,wherein said aqueous solution of an extract and starch hydrolyzate(s) contains the starch hydrolyzate(s) in amount of 20 to 70% by weight based on the total solid content thereof.

5. A process as set forth in Claim 1 or2, wherein said aqueous solution contains starch hydrolyzate(s), which are prepared by hydrolyzing waxy starch and have an average degree of polymerization of 20 to 60, in an amount of 1 Oto 50% by weight based on the total solid content thereof.

6. A granular dried product of an extract, which is obtained by a process as setforth in Claim 1,2,3,4 or 5 and exhibits an excellent flavor, solubility, flowabil ityand caking resistance.