Mixed crystals, method for the production thereof and use thereof in the production of baked goods

Abstract

The present invention relates to mixed crystals comprising a) leavening agent and b) 0.1 to 5000 ppm by weight of crystallization aid, based on the total amount of the leavening agent, in the form of at least polymer, wherein when hydrophilic cellulose derivatives are used as crystallization aid, the amount thereof is reduced to less than 100 ppm by weight, based on the total amount of the leavening agent. The present invention further relates to the production of the mixed crystals and to the use thereof in the production of bakery products, as acid regulator in foods, in the production of cosmetics products, in the synthesis and formulation of pharmaceutical products, and also as blowing agent in industrial processes such as, for example, the production of foam rubber, or for fire-extinguishing formulations. The present invention relates, furthermore, to the production of bakery products.

Claims

1. Mixed crystals comprising a) a leavening agent comprising at least one carbonate and optionally one or more carbamates, and b) 0.1 to 1000 ppm by weight of gelatin, wherein components a) and b) are present during crystallization of the mixed crystals.

2. The mixed crystals according to claim 1, wherein the mixed crystals have a surface with a round shape, wherein the mixed crystals do not intermesh with one another and wherein the mixed crystals do not undergo caking.

3. The mixed crystals according to claim 1, wherein the leavening agent comprises sodium carbonate, sodium hydrogencarbonate, potassium carbonate, potassium hydrogencarbonate, ammonium carbonate or ammonium hydrogencarbonate, or a mixture thereof.

4. The mixed crystals according to claim 1, wherein, the leavening agent comprises ammonium hydrogencarbonate.

5. A method of producing bakery products, which comprises preparing a dough by mixing ingredients for the dough and using the mixed crystals according to claim 1 as a modified leavening agent, or by premixing the mixed crystals according to claim 1 as a modified leavening agent with individual components of the dough prior to actual dough preparation.

6. The method of producing bakery products according to claim 5, wherein the method is carried out continuously.

7. A blowing agent in industrial processes which comprises the mixed crystals according to claim 1.

8. A baked product, a cosmetics product, or a pharmaceutical product which comprises the mixed crystals according to claim 1.

Description

A BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 depicts an ammonium bicarbonate agglomerate, used typically as a leavening agent in the prior art.

(2) FIG. 2 illustrates the baking product according to the comparative test.

(3) FIG. 3A, FIG. 3B, FIG. 4A, FIG. 4B, and FIG. 5 illustrate that the mixed crystals of the invention have a uniform, round, smooth, and hence noncaking crystal structure.

(4) FIG. 4C illustrates where hydrophilic cellulose derivatives are used as crystallization aids, unwanted formation of rod crystals rather than spherical crystals is obtained from a level even of about 100 ppm by weight upward.

(5) FIG. 6 illustrates the results shown in Table 2.

(6) FIG. 7A illustrates the prior art ABC which has undergone severe caking, and relatively large lumps remain even when the powder is moved (loosening attempts).

(7) FIG. 7 B illustrates the mixed crystals of the invention, with pectin, which are very readily flowable and absolutely lump-free.

(8) FIG. 8A illustrates the prior art ABC which has undergone very severe caking, and large, solid lumps remain even when the bag is knocked.

(9) FIG. 8 B illustrates the mixed crystals of the invention, with pectin, are readily flowable. The small lumps disappear when the product is moved.

(10) FIG. 9A illustrates the prior art ABC which has undergone severe caking.

(11) FIG. 9B the mixed crystals with pectin which are readily flowable, without the formation of lumps.

(12) FIG. 10A illustrates ABC with 100 ppm Tylose (comparative example in analogy to EP 1 161 872).

(13) FIG. 10B the mixed crystals with 25 ppm Tylose.

DETAILED DESCRIPTION OF THE INVENTION

(14) The term mixed crystal in the present invention refers to a crystal which consists of at least of two different chemical elements or substances. These extraneous substances may alternatively be lodged in the lattice interstices, replace an atom or substance group of the other element by substitution, or be present on the crystal surface. In order to obtain a mixed crystal, it is mandatory for the at least two elements or substances to be present during the crystallization of the mixed crystal (e.g., in the crystallization mother liquor). The crystallization aid (component b) is located, accordingly, in and/or on the leavening agent crystal (component a), i.e., in the crystal and/or on the crystal surface.

(15) The mixed crystals of the invention, accordingly, constitute a modified leavening agent.

(16) The mixed crystals of the invention are advantageously loosenable or flowable after storage for a month under a load of one tonne. Preferably, the mixed crystals of the invention are loosenable or flowable after storage for two months, preferably four months, more particularly six months, very preferably twelve months, after a load of one tonne, preferably two tonnes, more particularly four tonnes.

(17) The term flowable in the context of the present invention means that the stored product is lump-free (caking-free) after storage, for example, or transport in bags, after the bags have been opened, and constitutes a free-flowing powder (exhibiting free mobility and flow behavior). In illustrative terms, flowable means that the product, after the bags are opened, does not fall out of the bags in the form of one or more clumps (having undergone severe lumping), but instead flows/trickles freely from the bags.

(18) The term loosenable in the context of the present invention means that after 1 to 5 loosening attempts, preferably after 1 to 3, more particularly after only one loosening attempt, the stored product is flowable and therefore lump-free; a loosening attempt in this context entails a single dropping of the product-filled bags (typically 25 kg) from a height of 1.5 m. Plural loosening attempts, accordingly, denote repeated dropping of the product-filled bags.

(19) The term lump-free in the context of the present invention means that the flowable powder is free from agglomerates which have formed in the course of storage.

(20) The mixed crystals of the invention have a uniform, round, smooth, and hence noncaking crystal structure (see FIGS. 3 A/B, 4 A/B, and 5). The mixed crystals of the invention are generally compact, without pointed accretions on the crystal surfaces. Consequently, the mixed crystals of the invention are unable to intermesh with one another (undergo caking). As a result of the rounded surfaces, moreover, caking is unlikely, even under relatively high pressure, since there is no contact area between two spherical crystals, but instead only a contact point.

(21) Under a pressure load, crystals with pointed accretions form large and very firm packed structures, owing to the high contact area. The same effect occurs with crystals having a rodlet form, since they have very large contact areas between the crystals, unlike the spherical mixed crystals of the invention.

(22) Even a slight mechanical loading (loosening attempt) separates the mixed crystals of the invention, but the separation of agglomerates of rodlet-shaped crystals or crystals with accretions is no longer possible.

(23) On account of the compact, relatively uniform, round crystal morphology, storage and application are accompanied by the formation of caked lumps and agglomerates that are substantially fewer in number and, moreover, are easier to loosen again than in the case of leavening agents from the prior art.

(24) The leavening agent (component a) comprises at least one carbonate. Selected as carbonate are carbonates whose use in foods is unobjectionable and which, both as themselves and as their decomposition products, do not result in an unpleasant taste in the bakery products. Suitable carbonates, present individually or in a mixture, are known to the skilled person, and, typically, alkali metal carbonates and hydrogencarbonates, more particularly sodium carbonate, sodium hydrogencarbonate, potassium carbonate and potassium hydrogencarbonate, and ammonium carbonate and ammonium hydrogencarbonate are used.

(25) Also suitable is the mixture of ammonium carbonate and ammonium hydrogencarbonate which is referred to customarily as salt of hartshorn and which may also contain ammonium carbamate as well.

(26) The carbonate is preferably ammonium hydrogencarbonate and/or ammonium carbonate. With particular preference the carbonate is ammonium hydrogencarbonate (also called ammonium bicarbonate, ABC for short).

(27) The average particle diameters of the carbonates used are generally 50 to 1000 m, preferably 75 to 700 m, more preferably 150 to 500 m.

(28) The leavening agent optionally further comprises one or more carbamates. Selected as carbamate are carbamates whose use in foods is unobjectionable and which, both as themselves and as their decomposition products, do not result in an unpleasant taste in the bakery products. One suitable carbamate is ammonium carbamate, for example.

(29) If the leavening agent contains carbamate, the amount of carbamate is preferably 10% to 90% by weight, based on the total amount of the leavening agent, more preferably 30% to 70% by weight, more particularly about 50% by weight. The mixture of equal parts of ammonium carbamate and ammonium bicarbonate is also referred to as ammonium carbonate.

(30) If the leavening agent used includes components which on heating to typical baking temperatures of 100 to 200 C., for example, do not decompose or do not decompose sufficiently, it is advantageous for the leavening agent further to comprise an acid or an acid-former. The acid or acid-former is a compound or mixture of compounds known for this utility, examples being potassium, sodium, potassium hydrogen and/or calcium tartrate, citric acid, calcium hydrogenphosphate, sodium hydrogenpyrophosphate and/or sodium aluminum phosphate. If the leavening agent includes acid or acid-former, the amount of acid or acid-former is preferably as much as is needed for the reaction of the leavening agent and hence for the release of carbon dioxide. Depending on acid strength, number of protons per molecule, and molar weight of the acid and of the leavening agent, this amount may differ greatly. As an example, when using sodium bicarbonate and for customary acid carriers, a range from 60% to 250% by weight is the case, based on the total amount of the leavening agent, preferably 75% to 225% by weight.

(31) If the leavening agent includes an acid or an acid-former, it is preferably admixed with a release agent as well, which prevents the premature formation of carbon dioxide through reaction of the carbonate with the acid or acid-former. Release agents of this kind are known, preference being given to flour and/or starch.

(32) The average particle diameters of the acids or acid-formers used is generally 50 to 1000 m, preferably 75 to 700 m, more preferably 150 to 500 m.

(33) The stated carbonates, carbamates, acids or acid-formers, and also release agents, are available commercially.

(34) The crystallization aid (component b) preferably comprises at least one crystallization-influencing polymer. The term crystallization-influencing is understood in the present invention to mean that the added polymer influences the crystal morphology of the resultant crystals in a suitable way. Under the action of the crystallization-influencing polymers, the leavening agent crystals exhibit a smooth and regular structure. This structure is in contrast to the crystal structure without crystallization-influencing polymer, which is characterized by disruptive accretions and different crystal morphologies with an irregular and rough surface.

(35) Furthermore, the polymer is preferably hydrophilic. It is possible to use uncharged, anionic and/or cationic crystallization-influencing polymers.

(36) Furthermore, besides individual polymers, it is also possible for mixtures of different uncharged, different anionic and/or different cationic polymers to be used. Besides these, uncharged polymers may also be used as mixing components for anionic and/or cationic polymer mixtures.

(37) For obvious reasons, these polymers are advantageously selected such that not only the polymer itself but also any thermal breakdown products, in the amounts typically present or formed, are suitable as food additives and do not adversely affect the taste of the bakery products produced. It is preferred to use polymers of natural origin or those formed by modification of natural polymers, with a neutral taste and with approval under food law.

(38) Preferred charged natural polymers are hydrophilic polymers based on sugar derivatives and/or peptides, more particularly from the areas of the (hetero)polysaccharides and/or (poly)peptides.

(39) These heteropolysaccharides are obtained typically by fermentation or by isolation from natural sources.

(40) Particularly preferred are charged (hetero)polysaccharides with carboxyl or sulfonate side chains, more particularly with nonmodified carboxyl groups (e.g., pectin and/or alginate) and with modified carboxyl groups (e.g., amidated pectin).

(41) Advantageous anionic polymers are, for example, polyacrylic acid and salts thereof with ammonium, sodium or potassium, polymethacrylic acid and salts thereof with ammonium, sodium or potassium, acrylic acid and salts thereof with ammonium, sodium or potassium, methacrylic acid copolymers and salts thereof with ammonium, sodium or potassium, and acrylic acid-maleic acid copolymers and salts thereof with ammonium, sodium or potassium.

(42) The stated anionic polymers may further comprise vinylsulfonic acid in variable proportions.

(43) All of the stated anionic polymers may have partially esterified groups, in which case not only aliphatic components but also derivatized components based on endgroup-capped polyalkylene glycols may be present as alcohol components. For the preparation of the polyalkylene glycols it is possible to use not only ethylene oxide but also propylene oxide and higher alkylene oxides, alone or in the form of random or block polymers.

(44) Preference is given, furthermore, to polyaspartite acid and the salts thereof with monovalent and divalent cations. Particularly preferred are the salts of polyaspartite acid with ammonium, sodium, and potassium.

(45) Advantageous cationic polymers are, for example, polyamines, polyvinylamines and copolymers with polyvinyl alcohol and/or polydimethylallylammonium chloride.

(46) Advantageous nonionic polymers are, for example, polyethylene glycols, polypropylene glycols, random and block polymers based on ethylene oxide with alkylene oxides, more particularly propylene oxide and/or butylene oxide. Optionally, these polymers further comprise an additional endgroup cap on one or both sides, with aliphatic endgroups. Preference is given, furthermore, to polyvinylvinylpyrrolidone and/or polyvinylpolypyrrolidone.

(47) Preferred more particularly are those polymers which already have approval as food additives, such as, for example, the following: alginic acid (E 400), sodium alginate (E 401), potassium alginate (E 402), ammonium alginate (E 403), calcium alginate (E 404), propylene glycol alginate (E 405), agar-agar (E 406), carrageenan (E 407), processed Eucheuma algae (E 407a), carob bean meal (E 410), guar seed meal (E 412), tragacanth (E 412), gum arabic (E414), xanthan (E 415), karaya (E 416), tara gum (E 417), gellan (E 418), konjak gum/konjak glucomannan (E 425), soybean-polyose (E426), pectin/amidated pectin (E 440), microcrystalline cellulose/cellulose powder (E 460), methylcellulose (E 461), ethylcellulose (E 462), hydroxypropylcellulose (E 463), hydroxypropylmethylcellulose (E 464), ethylmethylcellulose (E 465), carboxymethylcellulose/sodium carboxymethylcellulose (E 466), crosslinked sodium carboxymethylcellulose (E 468), enzymatically hydrolyzed carboxymethylcellulose (E 469), polydextrose (E 1200), polyvinylpyrrolidone (E 1201), polyvinylpolypyrrolidone (E 1202), pullulan (E 1204), oxidized starch (E 1404), monostarch phosphate (E 1410), distarch phosphate (E 1412), phosphated distarch phosphate (E 1413), acetylated distarch phosphate (E 1414), acetylated starch (E 1420), acetylated distarch adipate (E 1422), hydroxypropylstarch (E 1440), hydroxypropyldistarch phosphate (E 1442), starch sodium octenyl succinate (E 1450), acetylated oxidized starch (E 1451).

(48) Particularly preferred are crystallization aids selected from the group consisting of alginic acid (E 400), sodium alginate (E 401), potassium alginate (E 402), ammonium alginate (E 403), calcium alginate (E 404), propylene glycol alginate (E 405), pectin (E440), amidated pectin (E440), carrageenan (E 407), gellan (E418), gum arabic (E414), karaya (E 416), tragacanth (E 412), xanthan (E 415), and/or gellan (E 418); especially preferred are crystallization aids selected from the group consisting of alginic acid (E 400), sodium alginate (E 401), ammonium alginate (E 403), pectin (E 440), amidated pectin and/or gellan (E418); more particularly preferred are pectin (E 440) and/or amidated pectin (E 440).

(49) Further preferred as crystallization aids are linear and/or branched (poly)peptides. Particularly preferred in the area of the (poly)peptides are gelatin products.

(50) Suitable cellulose derivatives are, for example, cellulose ethers. These are cellulose derivatives which originate formally by substitution of hydrogen atoms on the hydroxyl groups of the cellulose by alkyl groups and/or arylalkyl groups, it being possible for these alkyl and/or arylalkyl groups to be substituted by functional nonionic, anionic and/or cationic groups. The alkyl groups are typically C1-C8 alkyl groups, which may be linear or branched. The alkyl group is preferably a C1-C4 alkyl group, examples being methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert-butyl. The alkyl group may be substituted by an aromatic radical to form the arylalkyl group, such as with a phenyl radical, for example. One preferred arylalkyl group is benzyl. The alkyl or arylalkyl group may be functionally substituted, by hydroxyl, carboxyl or carboxylate groups, for example. Where carboxylate groups are present, corresponding counterions are present as well, examples being alkali metal ions such as sodium or potassium, or ammonium ions. Where reference is made only to carboxymethylcellulose (often abbreviated to CMC), the compound meant is usually sodium carboxymethylcullose (occasionally also abbreviated to Na-CMC). It is also possible to use mixed cellulose ethers, which contain more than one kind of alkyl, arylalkyl or functionally substituted alkyl groups.

(51) Preferred hydrophilic polymeric cellulose derivatives are methyl-, ethyl-, propyl-, carboxymethyl-, hydroxyethyl-, hydroxypropyl-, methylhydroxyethyl-, methylhydroxy-propyl-, methylhydroxybutyl-, ethylhydroxydethyl-, carboxymethylhydroxyethyl- and/or benzyl-cellulose. Among the carboxymethylcelluloses, the sodium compound is preferred. The leavening agent preferentially comprises sodium carboxymethylcellulose.

(52) The cellulose ethers are prepared in a known way, typically by the action of alkyl halides or arylalkyl halides, epoxides or activated olefins on cellulose that has been activated with bases (aqueous sodium hydroxide solution, for example). Cellulose ethers are commonplace commercial products which are used typicallyin foods as wellas thickeners. Cellulose ethers are available, for example, under the brand name Tylose, while high-purity cellulose ethers for food applications are available under the brand name Tylopur, and high-purity Na-CMC under the brand name Tylopur C from Clariant GmbH.

(53) Counterions contemplated, in addition to hydrogen, are alkali metal ions and/or alkaline earth metal ions, and also substituted or unsubstituted amines, ammonia being an example.

(54) The preparation of the stated polymers is common knowledge and can be read up in common technical literature.

(55) The mixed crystals comprise the crystallization aid preferably in an amount of 0.5 to 5000 ppm by weight (0.00005% to 0.5% by weight), based on the leavening agent, preferably from 0.5 to 2000 ppm by weight (0.00005% to 0.2% by weight), more preferably from 1 to 1000 ppm by weight (0.0001% to 0.1% by weight), more particularly from 1 to 500 ppm by weight (0.0001% to 0.5% by weight), very preferably from 1 to 100 ppm by weight (0.0001% to 0.01% by weight), furthermore preferably from 1 to 50 ppm by weight (0.0001% to 0.005% by weight), additionally preferably from 1 to 20 ppm by weight (0.0001% to 0.002% by weight).

(56) If hydrophilic cellulose derivatives are used as crystallization aids, the amount of hydrophilic cellulose derivatives in the leavening agent is preferably less than 80 ppm by weight (<0.008% by weight), based on the leavening agent, preferably between 0.5 and 50 ppm by weight (0.00005% to 0.005% by weight), more particularly between 1 and 20 ppm by weight (0.0001% to 0.002% by weight).

(57) Increasing the amount of crystallization aid beyond a maximum level leads to adverse effects on the desired crystal modification and crystallization propensity. Where hydrophilic cellulose derivatives are used as crystallization aids, unwanted formation of rod crystals rather than spherical crystals is obtained from a level even of about 100 ppm by weight upward (see FIG. 4C). These rod crystals in turn have a tendency to intermesh and hence to undergo caking (see example 4), in a similar way to the ammonium bicarbonate from the prior art (see FIG. 1). In addition, they become moist are a certain time, and then form a sticky mass.

(58) Using more than 5000 ppm by weight of crystallization aid produces predominantly very large crystals and/or crystals having relatively rough surfaces. The large crystals would then have to be ground before being used. Grinding would denote an additionally, cost-intensive step which, furthermore, harbors the risk of production of particles with rough surfaces.

(59) The present invention further provides the method for producing the mixed crystals of the invention, which comprises adding the crystallization aid before and/or during the step of crystallization of the leavening agent.

(60) The crystallization aid is preferably added to the mother liquor from which the leavening agent is crystallized. In this case, the crystallization aid is added to the mother liquor, which is usually circulated, and in which the carbonate and optionally hydrogencarbonate and carbamate is prepared and crystallized.

(61) The method of producing the leavening agents has long been known to the skilled person. For example, ammonium compounds such as ammonium carbonate, bicarbonate, and carbamate are prepared by reacting the corresponding amounts of ammonia, typically 10% to 20%, and carbon dioxide added in excess, typically 30% to 65%, in aqueous mother liquor, at the corresponding pressure, typically 1 to 6 bar, and temperature, typically 30 to 65 C., followed by crystallization, isolation, and drying of the precipitate.

(62) A detailed description of the production of leavening agents is found in Ullmann's Encyclopedia of Industrial Chemistry, 2008 edition, for example.

(63) The metered amount of the crystallization aid into the mother liquor corresponds in the case of continuous processes, after a concentration phase, to the amount of mixing component present in the isolated crystals.

(64) Following the preparation of the mixed crystals of the invention, they may optionally be admixed with further auxiliaries; examples are known anticaking agents such as cornflour, magnesium oxide and/or magnesium carbonate, or known release agents such as salts of fatty acids, as for example steric acid, calcium stearate and/or magnesium stearate, silicates, silicon dioxide, talc or other customary anticaking agents. An advantage of the method of the invention, however, is that such additions can be greatly reduced in amount or even not used at all. Metered additions of more than 5000 ppm of magnesium carbonate are generally an advantage only for extreme storage temperatures and storage times.

(65) The present invention further provides for the use of the mixed crystals of the invention for producing bakery products, as acid regulator in other foods, in production of cosmetics products, in the synthesis and formulation of pharmaceutical products, and also as blowing agent in industrial processes such as, for example, the production of foam rubber, or for fire-extinguishing formulations.

(66) The present invention further provides a method of producing bakery products which comprises using the mixed crystals of the invention as modified leavening agent. The method of producing bakery products may for example be carried out continuously (automatic baking line).

(67) The method of producing bakery products is otherwise carried out in a customary way familiar to the skilled person.

(68) The method of producing bakery products is therefore further characterized in that a dough is prepared which typically comprises a starch source such as flour and/or potato starch, a protein source such as egg white, frequently fats such as butter, oil and/or margarine, and usually further ingredients such as sugar, spices, fruits or the like. The ingredients are subjected to intense mechanical mixing in a usual way, as for example by stirring or kneading. In addition to the leavening agent, further ingredients may be used that likewise lead to porosity in the bakery products produced, examples being yeast and/or sour dough, and the porosity can also be increased by the blowing of gases such as air into the dough. The leavening agent can optionally also be premixed with individual components of the dough prior to actual dough preparation. It may be mixed, furthermore, with dry components of the dough, examples being flour, sugar, spices, other flavors and/or dry egg, to form a baking mix, from which, by addition of liquid, a dough is prepared and is then baked.

(69) The amount of the added leavening agent with modified crystal morphology is selected such as to bring about the desired porosity, something which is easily optimized by means of a few routine tests.

(70) The amount of leavening agent is typically selected such that advantageously 1.5 to 3.5 g of gases (carbon dioxide, ammonia and/or steam) are developed per 100 g of the starch source used (e.g., flour and/or potato starch), preferably 2 to 3 g of gases, more particularly 2.35 to 2.85 g of gases.

(71) The mixed crystals of the invention are added typically in an amount of 0.1% to 5% by weight, based on the total dough produced, preferably 0.5% to 2% by weight, more particularly about 1% by weight.

(72) Where less porous bakery products are being produced, the amount should be reduced accordingly, and for more porous products it should be increased accordingly.

(73) The advantage of the present invention is that the mixed crystals of the invention have a circular shape and smooth surfaces. In the course of storage and in the course of the application of the mixed crystals of the invention as a modified leavening agent, therefore, substantially fewer agglomerates which, furthermore, are easier to loosen again are formedin other words, the formation of large gas bubbles in the baking process and, consequently, an inhomogeneous distribution of porosity can be prevented.

(74) Since the crystallization aid is present with the leavening agent in a mixed crystal, it is also not possible for unwanted separation to come about, at any time.

(75) Furthermore, the objective of preventing instances of caking is achieved with just a very small amount of crystallization aid. In addition there is no additional step necessary for the production of the leavening agent.

(76) Bakery products with a readily controllable porosity can be produced.

Examples

(77) 1. Crystallization

(78) Ammonium bicarbonate (ABC), water, and additive were heated to 40 C. with stirring, in accordance with table 1. Following complete dissolution, cooling took place rapidly to 0 C., with stirring. The resultant crystals were cooled, dried, and inspected under the microscope at a magnification 20:1.

(79) TABLE-US-00001 TABLE 1 Blank test ABC [g] Water [g] Additive 1. (comparative test) 30.8 131.2 0 FIG. 2 Pectin 2. 30.8 131.2 0.31 (10 ppm) FIG. 3 A 3. 30.8 131.2 1.5 (50 ppm) FIG. 3 B Tylose 4. 30.8 131.2 0.15 (5 ppm) FIG. 4 A 5. 30.8 131.2 0.75 (25 ppm) FIG. 4 B 6. (comparative 30.8 131.2 31 (1000 ppm) FIG. 4 C test, in analogy to EP 1 161 872) Gelatin 7. 30.8 131.2 0.31 (10 ppm) FIG. 5

(80) The results are shown in FIGS. 2 to 5.

(81) Clearly apparent from FIGS. 2 and 4C is the agglomeration tendency of the ammonium bicarbonate crystals. The mixed crystals of the invention (FIGS. 3A/B, 4 A/B, and 5), in contrast, have only individual crystals, which show no agglomeration tendency, at the same magnification.

(82) 2. Penetration Test

(83) Sample 1: Mixed crystals of ABC and 2 ppm of pectin, 3000 ppm of magnesium carbonate as anticaking agent

(84) Sample 2: ABC without addition of crystallization aid (prior art), 3000 ppm of magnesium carbonate as anticaking agent

(85) Both samples were stored under a pressure of 1.25 kPa for 2 weeks. The penetrometer was then placed on the middle of the stored product and gradually loaded with greater weights. A proportional and deep penetration of the cone per unit weight is a reflection of a readily flowable product. The layer thickness was 15 mm. The results are shown in table 2 and in FIG. 6.

(86) TABLE-US-00002 TABLE 2 Weight Sample 1 Sample 2 of the Penetration Penetration cone depth depth [g] [mm] [mm] 0 0 0 170 3 1 350 5 1 531 10 3 713 12 3 896 15 3 1081 3 1267 5 1454 5 1642 5 1831 5 2021 5 2206 5 2391 5 2579 5

(87) Whereas the cone, in the case of sample 2, penetrated the product only sporadically (plateaus in the penetration depth/weight curve) and not deeply even under a relatively high weight load, the cone in the case of sample 1 sank into the product almost proportionally with increasing weight, until the product was completely displaced.

(88) From the results in table 2 it is evident that the mixed crystals of the invention (sample 1), in comparison to the prior art (sample 2), are very readily flowable and do not even start to exhibit instances of caking, even under pressure. The sample from the prior art (sample 2), exhibits instances of caking even under gentle pressure, however.

(89) 3. Flowability after Storage

(90) For the storage test, 25-kg plastic bags were filled with freshly produced product and were loaded with a weight (pallets with storage product). The bags were subsequently opened and inspected. The storage conditions are summarized in tables 3.1 to 3.3.

(91) The degree of caking of ammonium bicarbonate (ABC) was graded on a scale from 1 to 5.

(92) Assessment:

(93) 1=ABC is lump-free and readily flowable

(94) 2=ABC is easily loosenable and then is readily flowable; no small lumps remain

(95) 3=ABC is loosenable and then flowable; small lumps remain

(96) 4=ABC is difficult to loosen and then of limited flowability; larger lumps remain

(97) 5=ABC not loosenable/not flowable

(98) All of the samples in the tables below were admixed additionally, after crystallization, with the stated amounts of magnesium carbonate as anticaking agent.

(99) TABLE-US-00003 TABLE 3.1 Mixed crystals ABC as per of ABC and prior art, 2 ppm of pectin, 500 ppm 500 ppm of MgCO.sub.3 of MgCO.sub.3 Load: 1 tonne (FIG. 7 A) (FIG. 7 B) Storage: 1 month Evaluation: 4 1

(100) TABLE-US-00004 TABLE 3.2 Mixed crystals ABC as per of ABC and prior art, 2 ppm of pectin, 3000 ppm 3000 ppm of MgCO.sub.3 of MgCO.sub.3 Load: 2 tonnes (FIG. 8 A) (FIG. 8 B) Storage: 5 months Evaluation: 5 2

(101) TABLE-US-00005 TABLE 3.3 Mixed crystals ABC as per of ABC and prior art 2 ppm of pectin, 8000 ppm 8000 ppm of MgCO.sub.3 of MgCO.sub.3 Load: 2 tonnes (FIG. 9 A) (FIG. 9 B) Storage: 6 months Evaluation: 4 1

(102) FIG. 7: whereas the prior-art ABC has undergone severe caking, and relatively large lumps remain even when the powder is moved (loosening attempts), the mixed crystals of the invention, with pectin, are very readily flowable and absolutely lump-free.

(103) FIG. 8: whereas the prior-art ABC has undergone very severe caking, and large, solid lumps remain even when the bag is knocked, the mixed crystals of the invention, with pectin, are readily flowable. The small lumps disappear when the product is moved.

(104) FIG. 9: whereas the prior-art ABC has undergone severe caking, the mixed crystals with pectin are readily flowable, without the formation of lumps.

(105) 4. Flowability after Storage in Comparison to EP 1 161 872 (as Mixed Crystal)

(106) An approximately 5 mm thick layer of ABC mixed crystals with 25 ppm and 1000 ppm of Tylose with a diameter of about 6 cm was stored for 10 minutes under a weight of 13.75 kg (approximately 500 g/cm2 pressure). Thereafter the compacted product was transferred to a further piece of paper, by lifting of the paper, and the degree of caking was assessed on the basis of the scale from example 3.

(107) TABLE-US-00006 TABLE 4 ABC with 1000 ppm of Tylose (comparative example ABC with in analogy to 25 ppm EP 1 161 872) of Tylose 10 Minutes at 500 g/cm.sup.2 (FIG. 10 A) (FIG. 10 B) pressure Result: 3 1

(108) The ABC mixed crystals with 1000 ppm of Tylose are indeed loosenable and then flowable, but lumps remain which in the baking process can lead to undesirably large gas bubbles and, consequently, to unwanted inhomogeneous pore distribution.

(109) 5. Flowability after Storage in Comparison to EP 1 161 872 (as Tylose-Coated ABC Pure Crystal)

(110) For the storage test, 25-kg plastic bags were filled with freshly produced product and were loaded with weight (pallets with storage product). The bags were then opened and inspected. Comparison was made between ABC coated with 1000 ppm by weight of Tylose, and mixed crystals of ABC and 25 ppm by weight of Tylose. The flowability was evaluated on the basis of the evaluation scale set out in section 3 of the examples.

(111) TABLE-US-00007 TABLE 5 Mixed crystals ABC coated of ABC and with 1000 ppm 25 ppm by by weight of weight of Tylose, Tylose, 500 ppm 500 ppm by by weight of weight of MgCO.sub.3 MgCO.sub.3 Evaluation 1 1 (no storage) Evaluation 5 1 (loading: 2 tonnes, 3 days' storage) Evaluation 5 1 (loading: 2 tonnes, 7 days' storage)

(112) The ABC coated with 1000 ppm by weight of Tylose is no longer loosenable, and also not flowable, after storage with conventional loading, as in the course of transport, for example.

(113) Note: the unit ppm in the examples stands for ppm by weight.