EP1611158A1

EP1611158A1 - Method for producing starch networks and initial products

Info

Publication number: EP1611158A1
Application number: EP04723489A
Authority: EP
Inventors: Rolf Müller; Federico Innerebner
Original assignee: Innogel AG
Current assignee: Innogel AG
Priority date: 2003-03-28
Filing date: 2004-03-26
Publication date: 2006-01-04
Also published as: WO2004085482A2; US20090275531A1; CN1697840A

Description

Process for the production of starch networks and intermediate products

The present invention relates to the production of starch networks by means of new methods and preliminary products for the simple production of starch networks and sets out the advantageous properties of such starch networks.

State of the art

Patent application WO 03/035026 A2 describes the production of new starch networks based on mixtures of existing starches (VS) and networkable starches (NS). The NS and their preparation are primarily decisive for the advantageous properties of the starch networks obtained. Through the various parameters of the preparation, the potential of the NS to form networks, in particular by heterocrystallization with VS, can be optimally converted into advantageous product properties. The NS are processed separately from VS, whereby the essential processing steps include at least partially dissolving these strengths and, if necessary, overheating or hypothermia. In a next step, the prepared NS are mixed with completely or partially plasticized VS, so that a network-compatible starch fluid (NSF), ie a network-compatible solution or melt, is obtained, which can subsequently be obtained as a network under suitable conditions. After the NSF has been processed, it can be shaped into a shaped body, with or after which the network formation begins, usually triggered by a reduction in the temperature and / or the plasticizer content, in particular the water content of the NSF. This process, in which VS and NS components are prepared separately (split), mixed and then processed directly (continuous) to the end product, is known as the split continuous process (SCP). In addition to the advantage of versatility and the fact that the NS can be optimally prepared for starch networks (e.g. stabilization of the NS solution, hypothermia, generation of germs for network formation under difficult conditions), this SCP process has the following disadvantages, which are quick and broad large-scale implementation complicate: A. The separate reprocessing of VS and NS is compared to a procedure, whereby the components are reprocessed together (Together Continuous Process, TCP), more complex, common reprocessing procedures have to be modified accordingly. The separate preparation of NS compared to a TCP method is also more complicated and more susceptible to failure, since significantly more process parameters have to be optimized and controlled. This also complicates the broad industrial implementation of the new technology for the production of novel starch networks. The simpler a new process is, the easier it is to implement it on an industrial scale.

B. Since the preparation of an NSF is directly linked to the further processing to the end product (continuous process), each manufacturer of an end product must master all steps of the preparation. In contrast, a manufacturer of conventional plastic films, for example, does not have to deal with the processing of specific polymer qualities or blends. He can buy such pre-processed materials, for example in the form of granules, and concentrate solely on transforming them into the end product. Such a discontinuous process (DP) is therefore also desirable for the manufacture of products based on starch networks and will also make the broad industrial implementation of the new technology much easier.

A process similar to the TCP process has already been described in the published patent application DE 198 52 826 A1 for the production of thermoplastic polymer mixtures, but no starch network has been obtained. The poly-alpha-1,4-D-glucan (PG) used was plasticized with Glyceπ ^' n, the X-ray spectrum of FIG. 2 of the application mentioned clearly showing that this plasticized PG is present with very high crystallinity (it is a synthetically produced, highly linear starch, which crystallizes very well and forms very stable crystallites). In this state, the PG was mixed into a melt of thermoplastic starch at temperatures around 160-180 ° C., it being mentioned in the description and in claim 10 that the water content in the melt was less than 5%. Under these conditions, the crystallites of the PG are distributed in the TPS melt, but it is not possible to dissolve the PG molecules in the TPS melt, since noteworthy proportions of water> 25% are required and only then in the presence of strong shear forces. Analysis of graded blends of PG with TPS showed a significant decrease in the modulus of elasticity from 184MPa to only 24.2MPa at 25% PG content (Table 1), a clear indication that the PG crystallites were embedded practically unchanged in the TPS matrix and the glycerol of the Glycerin softened PG diffused into the TPS matrix (crystalline PG can only bind small amounts of glycerin and this only on the surface). This is also confirmed with FIG. 1, from which it can be seen that the crystallinity of the mixture increases linearly with the PG portion, which can be expected if the PG is incorporated in the TPS matrix unchanged as a filler in its crystallinity. It is therefore clear that no starch networks have been obtained in the process mentioned in the aforementioned application. In the starch networks which could be obtained by means of the TCP method in the present application, a solution of ^' networkable starch (NS) in a TPS melt with water contents of 35% was obtained, after which a massive increase in the modulus of elasticity was already at 10 % NS share in the entire range of relative air humidity RF resulted (Figure 1 of this application). It should be mentioned at this point that the difficulties in solving NS, ie at least partially crystalline starch, led to the development of the SCP process, where the NS is solved separately from the TPS at water contents of typically 50-95% and overheating techniques complete solution can be applied. When TCP process has now, however, to ensure that NS even at lower water content of typically 25 - 50 is released% in the presence of strong shear forces in a high-molecular starch melt and molecularly dispersed form, thus a network-capable starch fluid is created, ^'be from which received strength networks can.

The problem of producing a solution from PG led to a process that is similar to the SCP process. In the published patent application DE 100 22 .095 A1, starch gels are described which have been obtained by means of PG and a further starch, a solution of PG having been mixed with a solution of starch and a precipitation with gel formation having been successfully carried out (claim 9 of the said application ). Since the highly crystalline PG was considered to be water-insoluble (claim 2), the PG solution was obtained using strong alkalis (example 1). After these dissolved PG-containing alkalis were mixed with a starch solution, the mixture was neutralized with orthophosphoric acid, the PG precipitating out and forming a gel together with the starch macromolecules. Potassium phosphate also formed during the neutralization. The concentration of the solutions of PG and starch in the various examples was 5% (Tab. 1, Tab. 2a, Tab 2b, and 9 and 12% (Tab. 3), higher concentrations were not using this method feasible, as a maximum of 12% PG could be dissolved even with 1 molar KOH lye and only solution temperatures up to 25 ° C could be used with this molarity due to the degradation of the PG. Even at a concentration of 12% starch and 88% water, the gels obtained were extremely weak, so that they could be damaged by simply touching them. They also contained a proportion of glycerin, which was added to the starch solution before the starch solution was mixed with the PG solution, since in the presence of glycerin the solubility of PG is reduced (glycerin binds water, which increases the amount of water accessible to PG is reduced). The glycerol content based on the dry mixture was 50% in most examples. After the precipitation reaction, the thin gels were slowly allowed to stand in the atmosphere, whereby solid films with water contents of around 5-10% were obtained, which could be analyzed in the tensile test.

Against this background, the importance of the SCP process becomes evident, which means that without lyes and their neutralization by acids, molecularly disperse mixtures, i.e. Network-compatible starch fluids (NSF) and starch networks that can be used technically from them, primarily based on heterocrystallization (the crystallites that form the network elements or the connection points of the networks from two or more types of starch molecules, in particular from very small and easily crystallizable starch molecules and from large, normally not or only minimally crystallizable starch macromolecules) could be obtained and this heterocrystallization was possible at much lower water contents than 88% (down to water contents below 20%), which means that much higher network densities can be set, which results in the technical applications, including in the food and pharmaceutical sector (galenics). The processes described in the present invention and especially developed for the broad industrial application, as well as the various preliminary products provide the basis for the large-scale implementation of these new starch networks.

Description of the invention

The Together Process (TP) and the Discontinuous Process (DP) The disadvantage of the SCP process mentioned under A was overcome by the successful development of a Together Process (TP), which eliminates the separate preparation of VS and NS for many applications. Appropriate process control ensured that the potential of NS to form networks, in particular by heterocrystallization with NS, can also be implemented when VS and NS are processed together, ie the process whereby NS previously at least partially before mixing with VS dissolved, possibly overheated and / or supercooled, could be eliminated. This was achieved on the one hand through specific process measures and on the other hand through the development of suitable recipes. '-

The essential procedural measure, which enables a TP process, concerns the joint transfer of VS and NS to an NSF with water contents in the range of 25 - 50% (process water, the proportion is strongly dependent on the type of NS), at high temperatures and especially at high shear rates (high speeds, high energy consumption), which can release the potential of NS to form networks and make a separate preparation of a solution of NS unnecessary. After an NSF has been obtained, part of the process water is usually removed again (whereby the NSF is retained), for example by means of evacuation techniques, which at the same time can lower the temperature of the NSF again. An important advantage of the separate preparation of NS and VS is that the solution of the NS can be adjusted to a desired number of bacteria by overheating and / or undercooling. After mixing with VS, these germs are then important for setting high network densities. In the TP process, on the other hand, the number of germs can be set in such a way that when the NSF is processed, the NS still has residual structures which can act as germs. In addition, foreign nucleating agents can be added, as is also possible with the SCP process Recipes suitable for TP processes were found to be suitable as NS, in particular NS types with a network-active chain length CLn.na in the range 7-300, preferably 10-100, more preferably 14-50, in particular 16-30, most preferably 18-28 The crystallites of such NS are correspondingly small and can also be dissolved in the TP process. With larger network-active chain lengths, higher water contents and higher temperatures have to be used, which can be problematic (thermal degradation), but with very short process times, such NS are still processable network-active chain length too long, the crystallites are correspondingly large and stable. The CLn.na of amylose is e.g. reduced by branching, which is why the practically completely linear PG of the published patent application DE 100 22 095 A1 is particularly problematic. Natural amyloses or amyloses obtained from starches have significantly higher degrees of branching than the synthetically produced PG. In addition, the ^' CLn, na also by substitutions such as hydroxypropylation, acetylation et. reduced, which is why appropriately modified amyloses are well suited. Amyloses which have high CLn.na can also advantageously be used as NS, if they are predominantly amorphous, as is the case with many amyloses in native starch, which facilitates the dissolving process. With regard to the kinetics of network formation, short chain amyloses are particularly advantageous since they have a high mobility when dissolved in a starch melt and can therefore form networks quickly. Furthermore, the TP process as VS starches with a high molecular weight are advantageous because they result in highly viscous melts, which enable the transfer of high shear forces to the NS.

The disadvantages of the SCP process mentioned under B could be overcome by developing a discontinuous process. In a first step, a preliminary product (VP) is produced, which is storable and can be transported and which already contains the components of VS and NS that are essential for starch networks, in particular in a state that is favorable for subsequent further processing to the end product, for example , as frozen NSF (inhibited intermediate, IVP).

The DP process can be carried out both as an SDP process (split discontinuous process) and as a TDP process (together discontinuous process). With regard to the separate preparation, in particular of the NS, in the SDP process, reference is made to the SCP process described in patent application WO 03/035026 A2. The splintering of the preparation of NS and VS in the SDP process leads to a more complex process, but also allows greater process latitude and has the advantage that the preparation of the starch mixture does not have to be done by the end user, but by a specialized manufacturer of preliminary products can, so that the end user can then process this preliminary product using a common process. The TP process, which eliminates the separate preparation of NS and VS, contains two sub-variants, according to which the network-compatible starches are fed together for preparation (one feeding, OF) or separately (split feeding, SF). The OF variant is preferred if both NS and VS are available as powder or granules and can therefore be mixed beforehand in a suitable mixing ratio. The SF variant is preferred if NS and VS are difficult or difficult to dose in the appropriate mixing ratio. The split feeding variant also has the advantage that there is the possibility of feeding VS and NS spatially and / or at different times to the processing. So for example it is advantageous to supply the NS to the method, when the ^'VS is already plasticized at least partially. The SF variant also enables NS and VS to be supplied with different plasticizer contents, in particular with different water contents. It is advantageous if the NS is dosed in the swollen state (for example as a suspension or paste), which facilitates the implementation of the potential of the NS to form networks. Another possibility of the SF variant is to mix the NS with the VS in an at least partially plasticized state. The plasticization of the NS advantageously uses high water contents, high temperatures and high shear forces. This is done, for example, with an extruder, ie the NS is processed in a side extruder and the VS mixed. The difference to the SCP procedure is that the NS is not solved, but plasticized.

The possible process variants, which come into play depending on specific boundary conditions, needs and the type and the desired properties of the specific starch network, make it possible to meet the requirements of the manufacturers with regard to simple implementation as well as the requirements regarding the properties of the end product , The process variants developed for this purpose are summarized in Figure 1. ,

Intermediate products (VP)

The preliminary product (VP) can have VS or NS or VS and NS with regard to the starch components, with NS all NS groups listed below under NS can be used. The preliminary product is obtained in a form that can be stored and transported, for example as powder, spray-dried powder, granules, pellets and the like, which results in the advantageous possibilities of the DP process. The following states or variants of the preliminary product are set both via the composition of the network-compatible starch fluid (NSF) and via the parameters of the process:

VVP: on the one hand, the production of the preliminary product can be controlled in such a way that the NSF (NSF1) obtained during processing already forms a network to a significant extent when it is converted to the preliminary product, whereby a partially cross-linked preliminary product (WP) is obtained. This option is particularly useful if the crystallites forming the connection points of the network have a relatively low melting point, so that the network can be dissolved again during the subsequent conversion to an NSF (NSF2) and then re-formed under controlled conditions. On the other hand, the VVP, the bsw. has a water content of 7% and a plasticizer content of 25% due to the high viscosity can be plasticized with high shear forces, whereby a network can be released again. Such relatively easily plasticizable WPs are preferably based on short-chain amyloses (short chain amylose), gelling dextrins, debranched maltodextrins or hydrolyzed starches.

IVP: on the other hand, it is often advantageous if the preliminary product has not yet developed a network or has only formed it to a very limited extent, which facilitates the processing of the preliminary product, i.e. it is not necessary to dissolve an existing strength network. In this case, the preliminary product is called an inhibited preliminary product (IVP). The essential process measures for the production of an inhibited preliminary product are the rapid reduction of the water content of the NSF, preferably with a simultaneous reduction of the temperature, so that the NSF can be kept frozen in an amorphous state. Under appropriate conditions, such an IVP can be made based on any NS.

CIP: in a third type of the preliminary product, a network is specifically set so that the parts of ordered structures obtained, which can act as network elements or as potential network elements, are used in the subsequent processing of the preliminary product as nuclei for the desired strength network in the end product can be. Such a preliminary product is referred to as a preliminary product containing germs (CIP). Instead of these germs, too Foreign nucleating agents are used, but they are somewhat less effective. The production of a KVP can be based on any NS, the process parameters are decisive, the network formation is minimal and the NSF containing the resulting germs is then frozen. In the subsequent plasticization of CIP, the process parameters, in particular plasticizer content, temperature and shear, are set so that the germs contained in the CIP are not destroyed. The use of a KVP makes sense if the network formation in the end product is to take place under difficult conditions, ie, for example. at low water contents, in which case very high network densities can be achieved and correspondingly high mechanical strengths, even when swollen (low swelling capacity). Such networks, particularly if they are additionally subjected to a heat treatment, have astonishing strengths of up to several MPa even after storage in water (where TPS swells and then disintegrates and finally dissolves).

For the production of the IVP and KVP types, it is important that the preliminary product is brought to a temperature around or below the glass transition temperature Tg as quickly as possible, since the state of the NSF obtained until then is frozen. Surprisingly, it was found that an NSF is inhibited with respect to network formation, even at or even slightly above Tg, is quasi-frozen, which results in interesting application possibilities, since the NSF can be reshaped very well in this state. In practice, however, the temperature is often determined by the room temperature and it does not make sense to use an IVP or similar. to be brought to the end user in a refrigerated truck. Since the glass transition temperature Tg is strongly dependent on the water content, with Tg increasing rapidly with decreasing water content, the water content can be set to a value instead of the storage temperature during storage, so that Tg is in the region of room temperature and thus the state of the NSF at this temperature remains frozen.

Both WP, IVP and KVP can contain, in particular - also contain foreign nucleating agents, stored, transported and then processed by an end user into end products based on starch networks. Additional plasticizers and. Are generally used to convert the preliminary product into an NSF, which in most cases involves plasticization especially water supplied. In addition, additives can also be added in this processing step, as well as other starches (VS, NS).

Important process parameters

The following information on the suitable process parameters is to be understood as a guideline. Depending on the VS and NS used (or mixtures of VS and NS) and the type of preliminary product or end product, the parameters for each recipe must be optimized specifically and deviations from the guide values can also occur.

The water content of the NSF before any process water is removed is based on the dry starch and water in% by weight in the range from 15-70, preferably from 20-60, more preferably from 25-50, most preferably from 30-45. The lower values are used when high mass temperatures and high shear rates are used, the higher values when NS are used with high CLn.na, which are present with high degrees of crystallinity. Water contents higher than 70% can also be used for easy-to-prepare NS if the preliminary product is to be obtained in freeze-dried form.

The plasticizer content of plasticizers other than NSF water is primarily not determined by the process, but by the application of the end product to be produced from the preliminary product. The plasticizer content, based on the dry starch and plasticizer in% by weight, is in the range 0-70, preferably 0-55, more preferably 0-45, most preferably 0-40. The content of the plasticizer remains in contrast to water approximately constant during the process or only decreases comparatively slightly if parts of the plasticizer are also removed from the process with the process water (in the case of evacuation techniques), the plasticizer content is usually set so that it corresponds to the target plasticizer content of the end product, which consists of the preliminary product is produced. However, it is also possible to add further plasticizer to the VP to adjust the plasticizer content to higher values during the final processing. Lower plasticizer contents in the manufacture of the VP are used in particular in the manufacture of IVP and KVP, The water content of the NSF after any process water has been removed is an important variable which has a significant influence on the type of VP, it is 0 - 35, preferably 0 - 25, more preferably 0, based on the strength and water in% by weight - 20, most preferably 0 - 15. Comparatively low water contents are particularly important for the production of IVP and KVP in order to suppress network formation. Significantly higher water contents can also be used here if the preliminary product is to be obtained in freeze-dried form.

In many cases ^" after the removal of process water, the water content is subsequently reduced further, whereby the VP is dried. In the case of water contents, where network formation is possible, the drying speed is an important parameter which reflects the more or less strong or inhibited formation of a network in the VP.

The maximum mass temperature in ° C. during the preparation of the NSF is approximately in the range from 80-220, preferably from 100-180, more preferably from 105-170, most preferably from 110-160. The importance of the mass temperature has already been discussed.

heat treatment

After the production of moldings, heat treatment or conditioning may be advantageous. Networking of the NSF is usually triggered by a reduction in the temperature of the NSF and by a reduction in the water content. On the one hand, the cooling conditions can be set so that the desired network density is obtained during the cooling process. In certain cases it is desirable that the network formation is not complete, this can be achieved by an accelerated cooling so that the NSF is kept in a frozen state (IVP, KVP) before the network formation is completed. Usually, however, a low network density is set by the proportion of the network-compatible strength used. In most cases, network formation that is as complete as possible is desirable, at least in the end product. With short cooling times and especially with low plasticizer contents, as well as when using VS and NS with high molecular weights, this is not always guaranteed. Then suitable heat treatment makes it possible to increase the network formation subsequently. In addition, this is also advantageous in order to anticipate later changes in the starch network, thus maintaining constant product properties. In the production of the end product, the procedure is advantageously such that heat treatment is unnecessary or takes place automatically without further influence, but this is not always possible and, in particular for high-strength starch networks, heat treatment has so far been unavoidable. The following information on advantageous heat treatments and conditioning conditions are to be understood as approximate guide values, the optimal values for a recipe are strongly dependent on the recipe and the water and plasticizer content.

The temperature of the heat treatment in ° C. is in the range 0-160, preferably 20-140, more preferably 40-120, most preferably 60-110. The high temperatures are used in particular when the NS has a high molecular weight (for example Long Chain amylose) and the plasticizer and water content is low (e.g. 20% water, 0% plasticizer), the low temperatures if the NS has a low molecular weight (e.g. short chain amylose) and the plasticizer and water content is high (e.g. sufficient a temperature of 20 ° C for a complete formation of the SCA network with 30% glycerol and 18% water for around 24 hours, while practically no network formation takes place when the water content is reduced to 14% at room temperature)

The time of the heat treatment ranges from minutes to days and is strongly dependent on the temperature. With an increase "of 10 ° C in each case, the network formation rate is approximately doubled. In most cases, short heat treatment times, which are correspondingly obtained at high temperatures, are preferred.

The water content can also be kept constant during the heat treatment or have a chronologically defined course, increase or decrease. For example, in a heat treatment at a given relative humidity, the water content gradually approaches the equilibrium water content as the water content increases or decreases, depending on the relative humidity and the initial water content of the sample. By means of a Heat treatment at a given relative humidity can also be used to set a desired water content.

Present strength (VS)

In principle, any starch or even a flour in any state, as well as physically and / or chemically modified, can be added to the process as the present starch, they can be used in native form or have been modified by physical processes, for example by gelatinization (partially to complete), plasticization or inhibition.

Examples of present starches or flours are of the following origin: cereals such as corn, rice, wheat, rye, barley, millet, oats, spelled, roots and tubers such as potatoes, sweet potatoes, tapioca (cassava), maranta (arrowroot), legumes and seeds such as Beans, peas, mongoose, lotus. In addition, starches and flours of other origins, such as bsw. Sago or Yams Glycogen can also be used. The existing strengths may have been changed by breeding or genetic engineering methods such as. Waxy maize, waxy rice, waxy potato, high amylose corn, indica rice, japonica rice.

Starches or mixtures of such starches which have been modified by the following treatments or combinations of these treatments can also be used as VS:

Oxidation (for example periodate oxidation, chromic acid oxidation, permanganate oxidation, nitrogen dioxide oxidation, hypochlorite oxidation: oxidized starches); Esterification (for example acetylated starches, phosphorylated starches (monoesters), starch sulfates, starch xanthates); Etherification (for example hydroxyaikyl starches, in particular hydroxypropyl or hydroxyethyl starches, methyl starches, allyl starches, triphenylmethyl starches, carboxymethyl starches, diethylaminoethyl starches); Cross-linking (e.g. diphosphate starches, diadipate starches); Graft reactions; Carbamate reactions (starch carbamates).

Starches with partially substituted hydroxyl groups show advantageous film-forming properties for use, high elongations, as are required in particular for the production of films. These properties usually increase with the degree of substitution DS and the size of the substituted group. Are preferred therefore starches with DS> 0.01, more preferably> 0.05, in particular> 0.10, most preferably> 0.15. However, the water sensitivity of these starches also increases with the degree of substitution, so that TPS based on these plasticized starches hardly have measurable strengths even at RF above 50% (at high DS). However, good mechanical properties can still be obtained in starch networks even at the highest RF and thus these excellent film formers can only be used properly. The upper limit of the DS for pharmaceutical applications and food applications is given by regulatory provisions. For non-edible applications, however, modified starches with higher DS are also suitable and advantageous. Examples of substituted starches of particular interest are hydroxypropylated or hydroxyethylated or acetylated or phosphorylated or oxidized root and tuber starches or waxy starches.

Also of particular interest in terms of viscosity are stabilized VS, i.e. chemically cross-linked starches such as distarch phosphates, distarch adipates or inhibited starches (novation starches). Chemically crosslinked and simultaneously substituted starches are particularly preferred, with higher degrees of substitution being advantageous for film applications. An advantage of using substituted and at the same time chemically cross-linked starches is that a wide range of types with different degrees of substitution and cross-linking of these inexpensive commodity starches are commercially available in food quality. Examples are hydroxypropylated distarch phosphates, hydroxypropylated distarch adipates, acetylated distarch phosphates or acetylated distarch phosphates, which are based on starches of various origins such as corn, wheat, millet, rice, potato, tapioca et. are available.

Also of interest are dextrins, in particular pyrodextrins such as white dextrins, yellow or canary dextrins, modified dextrins, co-dextrins or British gums. They also have good film-forming properties and, due to their irregular structure and the high degree of branching Qb of typically> 0.05, they are partially or practically completely stable with respect to retrogradation, so they are very long-term stable, i.e. resistant to aging and can still be used for heterocrystallization, especially when using SCA as NS. In addition, the use of dextrins has a positive effect on the welding properties, since they have good adhesive properties as long as the network formation has not yet taken place to any significant extent. Dextrins with low to medium degrees of conversion can be used as sole VS or together with other VS, while dextrins with high degrees of conversion are preferably used together with other VS. in the

White dextrins are preferred in terms of optical properties.

A next group of starches of interest are hydrolyzed starches, such as acid-hydrolyzed starches or enzymatically hydrolyzed starches, and chemically modified hydrolyzed starches. These strengths can be used as both VS and NS.

Finally, starches of particular interest are of particular interest whose amylopectin fraction has an average chain length CL of> 20, preferably> 22, more preferably> 24, most preferably> 26, since side chains of this size together with NS, in particular together with SCA of the same size can heterocrystallize very well, whereby high network densities are obtained.

Present starches are used, for example, in powder form, in principle all preparation forms can be used, for example spray-dried forms, drum-dried forms, granules, pellets and the like. Mixtures of different existing starches can also be used as the present starch.

Networkable strength (NS)

Starches containing or consisting of amyloses or amylose-like starches are used as NS. A mixture of different NS types is also referred to as NS. The amyloses can be linear as well as branched and optionally modified. Examples of NS are amyloses from native starches, in particular amyloses obtained by fractionating starches with an amylose content> 23%, modified amyloses, in particular substituted amyloses or hydrolyzed amyloses, synthetic amyloses, cereal starches, pea starches, high amylose starches, in particular with an amylose content> 30, preferably> 40, more preferably> 60, most preferably> 90, hydrolyzed starches, in particular hydrolyzed high amylose starches or sago starches, gelling dextrins, fluid starches, microcrystalline starches, starches from the field of fat replacers. In addition, NS can also have an intermediate fraction, as described, for example, in starches containing high amylose are contained and can be obtained by fractionation. In terms of their structure and properties, the intermediate fraction lies between amylose and amylopectin.

For amylose, the distinction between long chain amylose (LCA) with DPn> 100 and short chain amylose (SCA) with DPn <100 is common. Network-capable strengths can have LCA and / or SCA.

Short chain amylose (SCA)

Examples of SCA are amylodextrins, linear dextrins, nagenü dextrins, linned starches, erythrodextrins or achrodextrins, which represent different names and subgroups of SCA.

SCA can be obtained, for example, by hydrolysis of LCA, LCA-amylopectin mixtures or amylopectin mixtures. SCA which is particularly suitable for advantageous networks is obtained, for example, by hydrolysis of starches originating from roots and tubers or from heterowaxy or waxy starches. The hydrolysis can be carried out chemically, for example acid hydrolysis and / or enzymatically, for example using amylases or combinations of amylases (alpha-amylase, beta-amylase, amyloglucosidase, isoamylase or pullulanase). Amylose-containing starches are obtained as SCA by combined acid / enzyme hydrolysis, and the two hydrolyses can be carried out simultaneously or in succession. Depending on this, different types of SCA can be obtained from the same strength. In addition, the characteristics of SCA are also influenced by the state of the native starch during hydrolysis, for example by the degree of swelling of the starch granules. Therefore a wide range of suitable SCA is available. Other types can be obtained from waxy starches by acid / enzyme hydrolysis or enzyme hydrolysis starting, wherein ^■ ■ SCA hydrolysates are typically obtained with DPn to 22, which are particularly suitable. Also of particular interest is SCA, which is formed during the process of processing the starches into the NSF and ultimately the starch network, e.g. through pullulanase.

Long chain amylose (LCA) The amylose contained in native starch is usually LCA with DPn> 100. However, the degree of polymerization DPn of LCA can be reduced to values <100, for example by acid hydrolysis and / or enzymatic hydrolysis and / or oxidation, so that appropriately modified native starches also have SCA can.

Numerous processes for producing SCA, LCA and mixtures of SCA and LCA are described in the prior art. Both types of amylose are available on the one hand in pure form and are also present in different, optionally hydrolyzed, commercial starches in different proportions.

It is pointed out that in certain cases, in particular in the case of SCP and SDP methods, VS and NS can be materially identical, since in principle every NS can also be used as VS. The difference between VS and NS is therefore not material in all cases, rather the terms must also be understood in connection with the process. NS is treated in such a way that its potential for forming networks is optimally released, whereas this does not have to be the case with VS.

The formation of a starch network consisting of NS and VS has a positive influence on the mechanical properties, especially the modulus of elasticity and strength, the more pronounced the higher the network density. The network density is primarily dependent on the type and proportion of NS, on the specific combination of NS and VS, as well as on the processing conditions (temperature, plasticizer content, water content, shear rate), the cooling conditions (cooling time) and any heat treatment that may have taken place. On the basis of starch networks, significantly improved mechanical properties can therefore be obtained compared to conventional thermoplastic starch (TPS).

Activation and stabilization of the NS in the SCP and SDP procedure

To set a defined network, NS and possibly VS are activated and, in particular, stabilized before or during mixing with VS. The activation ensures that the amylose contained in NS is in an amorphous state, so that after mixing with VS a recombination can take place, which leads to a Network leads. The stabilization makes it possible to influence the start of network formation and the type of network.

The higher the water content and the greater the shear forces during the plasticizing or dissolving process, the lower the temperatures required. Activation combined with stabilization of the NS is of particular importance. Stabilization is achieved by overheating the amylose to temperatures above the melting or dissolving process. In addition, foreign nucleating agents and / or methods for generating suitable germs can be used by supercooling the activated NS. With regard to activation, stabilization, nucleation, hypothermia and foreign nucleating agents, reference is made to the patent applications WO 03/035026 A2 and WO 03/035044 A2 for detailed information.

The temperature of the recombination of the amylose to the desired network can be adjusted to low temperatures by the stabilization. The higher the stabilization or overheating temperature, the lower the temperature for recombination or network formation with the same water and plasticizer content.

softener

With regard to plasticizers (WM) there is a wide range of known starch plasticizers to choose from which have been described many times in the prior art (cf. for example WO 03/035026 A2 or WO 03/035044 A2). The polyols glycerol, erythritol, Xylitol, sorbitol, mannitol, galactitol, tagatose, lactitol, maltitol, maltulose, isomalt. These and other plasticizers can each be used alone or in various mixtures. It has been found that plasticizers particularly suitable for starch networks have melting points <100 ° C., preferably <70 ° C., more preferably <50 ° C., most preferably <30 ° C. Water is by far the most important plasticizer, around 2.5 times more effective than glycerin. Here, however, water is usually not called a plasticizer to distinguish water from the other plasticizers.

Plasticizers are added to the starches at the beginning of the process; they are required to plasticize the starches and convert them into a fluid. softener can also be added to the process at a later time or partially removed from the process. The plasticizer water plays a special role in this regard, on the one hand because water is the cheapest and most efficient plasticizer, and on the other hand because the water content can be easily varied during the process. For example, in the case of TCP and TDP, processes for plasticizing VS and especially NS are initially worked with high water contents, which at the same time releases the potential for network capability of NS at high temperatures ... Then the water content is reduced. reduced again by evacuation techniques. A further variation of the water content is possible when conditioning the preliminary or final product. Thus, the plasticizer water allows a large process margin, while other plasticizers are difficult to remove from the process.

sugars

Sugar types such as glucose, galactose, fructose, sucrose, maltose, trehalose, lactose, lactulose, raffiniose, glucose syrup, high maltose com syrup, high fructose com syrup, hydrogenated starch hydrolysates are used on the one hand if water solubility or a disintegration of the network in aqueous media is desired or to improve the barrier properties. Some of them also influence sorption behavior.

Additives and blends

With regard to additives such as foreign nucleating agents, additives, fillers, blowing agents, with regard to a list of hydrocolloids which can be mixed with an NSF and with regard to the synthetic polymers with which starch networks are processed into blends which can also be obtained as a preliminary product or with a preliminary product is produced, reference is made to patent application WO 03/035026 A2, only the most interesting synthetic polymers are mentioned here by name: polyvinyl alcohols, both partially and fully hydrolyzed types, polyethylene glycols, polyethylene oxides, polyvinyl pyrrolidones, polycaprolactones.

Examples characteristics

The following discussion of illustration 1 relates to a specific recipe and different processes for the production of starch networks in an end and preliminary product and shows the difference between starch networks and thermoplastic starch. However, the situation is basically valid for different formulations for starch networks and TPS, whereby the characteristics of the modulus of elasticity shown in Figure 1 remain the same due to the choice of VS, NS, plasticizers and plasticizers and the use of other substances. The parameters mentioned primarily cause a displacement of the curves along the RF axis and / or along the modulus of elasticity and / or an extension or compression along these axes. It is also possible that the area of the quasi-plateau of the elastic module is more or less pronounced, or is completely eliminated.

In illustration 1, the course of the modulus of elasticity as a function of the air humidity for a formulation based on hydroxypropylated starch with medium DS containing 10% NS and 32% plasticizer for different manufacturing processes, and for a comparable formulation but not containing NS, i.e. for TPS, shown. The modulus of elasticity is a material property that is of great importance for the application on the one hand and on the other hand, the modulus of elasticity, particularly in the case of medium to high RF, is clearly influenced by a strength network, with a proportionality between the size of the network or the Network density and the modulus of elasticity exists. The modulus of elasticity and its course with the RF is therefore a suitable parameter to illustrate the network formation.

The comparison of the modulus of elasticity for the SCP process (SC77) with TPS (SC83) clearly shows the difference between thermoplastic strength (TPS) based on the same strength and strength networks. With a low RF of 23%, the difference is relatively small, although due to the contribution of the network, the modulus of elasticity of SC77 is slightly increased. With increasing humidity, water is absorbed from the atmosphere, which has a strong softening effect. The result is that the TPS modulus of elasticity decreases practically linearly with increasing RF in the semi-logarithmic representation, quickly becomes very soft and takes on the character of a highly viscous liquid. The decrease in the modulus of elasticity is not particularly pronounced in the case of substituted starches which have excellent film-forming capacity Substituted starches have a flatter course of the modulus of elasticity and can still have measurable moduli of elasticity even at high RF, but they only show low elongation at break and pronounced brittleness at low RF. Compared to TPS (SC83), the modulus of elasticity is due to the developed network of SC77 at significantly higher values and surprisingly high values are obtained even at high RF. With SC77, the modulus of elasticity at medium RF could be stabilized over a wide range even at around 10MPa, since the contribution of the network to the modulus of elasticity is comparatively little dependent on the RF or water content. As a result, even at 75% RF, SC77 still has an E-module that is comparable to the E-module of analog TPS at around 40% RF. The advantage of strength networks over TPS is therefore evident.

While SC77 was produced in the SCP process, the NS first being dissolved and then fed to a starch melt consisting of VS and the test specimen obtained directly from the homogenized mixture of VS and NS, ie from the network-compatible starch melt (NSF), The moduli of elasticity of the experiments SC183 and SC184 show that the same advantageous results, ie fully developed strength networks, can also be obtained with a simplified method, in which VS and NS have been prepared with one another without prior dissolution of NS. Corresponding process parameters are important for this, in particular a high water content (process water that is at least partially removed from the process again), high temperature and high shear forces, as a result of which the partially crystalline NS can be distributed in a molecularly dispersed manner in the VS melt. With SC183, according to a first sub-variant of the TCP process, the NS in powder form was fed to a VS melt containing plasticizer and process water using split ^' feeding, while with SC184 both NS and VS were metered together in powder form using Together Feeding, mixed with plasticizer and process water and then plasticized.

In the experiment SC184 L2, less process water was used compared to SC184, whereby only a part of the NS could be dispersed molecularly in the VS melt and a part of the NS could still be retained in crystalline or semi-crystalline form as dispersed particles in the starch melt. Therefore, an NSF with a reduced content of molecularly disperse and thus networkable NS molecules was obtained and thus a reduced network density in the end product, ie the potential of the NS was only partially implemented in the SC184 L2 experiment. When trying The same amount of process water was used for SC184 L1 as for SC184, but the test was carried out at lower speeds, which reduced the shear forces and lower the mass temperatures. The result is comparable to that of the SC184 L2. Overall, by varying the process parameters, i.e. continuously reducing the proportion of process water and / or the temperature and / or the shear forces compared to SC77, the entire range of moduli of elasticity between SC77 and TPS (SC83) can be obtained, which means that all states between a fully trained starch network and no starch network. Fully developed networks are of course preferred for the end product, but the products of SC184 L2 and L1 can be useful as preliminary products, whereby the dispersed NS particles can be used in a next processing stage as germs for optimal network formation in the end product, in particular germs consisting of SCA in the preliminary product for network formation under difficult conditions in the end product (with low water content), e.g. with the simultaneous use of LCA, which is added as a solution and is distributed in a molecularly dispersed manner in the preliminary product, but is virtually frozen in this state (inhibited with regard to network formation) and cannot yet form a network.

E-modulus curves between the curves of SC77 and TPS (SC83) can also be obtained if the NS is dispersed completely molecularly in the VS melt, i.e. if an NSF is in an optimal state for the subsequent network formation, but the process then, for example , by removing process water and / or by reducing the temperature in such a way that the formation of a starch network is partially or completely suppressed and the state of the NSF is frozen. Thus, in terms of network formation, a partial to complete. inhibited preliminary product are obtained (IVP), which can be easily plasticized again at a later time and provides a fully developed network in the end product under suitable conditions.

The different types of preliminary products can thus also be characterized by means of representation 1. The modulus of elasticity of SC77 corresponds to a completely cross-linked preliminary product (VVP), the range of modulus of elasticity between SC77 and SC83 corresponds to increasingly less cross-linked preliminary products (if the NS in the VS melt was completely molecularly dispersed) or increasingly inhibited Intermediate products, while the modulus of elasticity of SC83 completely inhibited one Preproduct corresponds (if the NS contained in the molecularly dispersed NSF is frozen in this state, apart from the recipe there is practically no difference to the TPS, the difference only arises with the onset of network formation). On the other hand, the range of modulus of elasticity between SC77 and SC83 corresponds, if the NS is only partially molecularly dispersed in the VS melt, also contains preliminary products containing germs (KVP).

Figure 2 shows the moduli of elasticity as a function of the RF for end products manufactured using the SDP process with varying proportions of NS. In the SDP process, the NS was prepared separately (split), fed to a VS melt in the extruder and an NSF obtained therefrom, which was formed into a film of 0.5 mm thickness by means of a flat slot nozzle and dried in the atmosphere at 25% atmospheric humidity in the air stream, and so as Intermediate product was obtained. SC77 E was obtained as a partially cross-linked preliminary product (VVP) (with a modulus of elasticity corresponding to sample SC184 L1 from illustration 1), since cross-linking takes place during the drying time until the frozen state is reached (approx. 1 h) could. With SC173 E and SC172 E, a practically completely inhibited preliminary product (IVP) was obtained (with an E-modulus curve almost corresponding to the TPS (SC83), since the concentration of the NS was too low to form a network within the drying time Dry film was then crushed to a grain size of approx. 1 mm and plasticized again with a Brabender kneader with the addition of process water (30%) at around 110 ° C and after the process water had been reduced to 20% by means of atmospheric degassing using a plate press to form the end product a film of 0.5mm thickness.

The course of the modulus of elasticity of SC77 E (SDP process) is somewhat higher than for SC77 (SCP process, illustration 1). The difference is due to the fact that SC77 was produced with a Brabender kneader and the preliminary product of SC77 E by means of an extruder, which resulted in better homogenization of the NSF, so that the molecularly disperse distribution of the NS was obtained more optimally.

Surprisingly, the samples SC172 E and SC 173 E with only 2 or 3% NS already show a modulus of elasticity that is significantly above the modulus of elasticity of TPS (SC83), ie the advantages of the network are already shown with minimal proportions of NS received. Figure 3 shows the modulus of elasticity for various starch networks based on hydroxypropylated starch with medium DS as VS and a plasticizer content of 32% at 10% NS produced using the TDP method, a spectrum of different NS types being examined:

In the TDP process, the NS was supplied in powder form to a VS (split feeding) plasticized by means of an extruder and homogenized with it to form an NSF with a molecularly dispersed distribution of the NS, the water contents (H20) and the maximum mass temperatures Tm being adjusted for the respective NS. The plasticizer content during extrusion was 20%. The NSF was finally extruded as a strand via round dies of 1 mm in diameter. At the higher mass temperatures, the strand was greatly expanded, which means that the water content is reduced very quickly and the amorphous state of the NSF is immediately frozen, meaning that the intermediate product was obtained without a network (IVP). At the mass temperatures of 115 and 110 ° C, the expansion was significantly less and the water content was reduced accordingly less (to around 24%). The strands obtained were then dried in an air stream at 20% RH to a water content of approximately 10%. During the drying time with SC147 F, WS118 F and with SC200 F a partial network formation could take place, so that the corresponding preliminary products were obtained in the form of WP, but the network formation was relatively low, since the corresponding NS with 24% water content and 20% plasticizer was relative slowly form networks. The dry strands were crushed to a grain size of approx. 1mm and then processed further in a Brabender kneader to the end product, whereby plasticizer was also added in addition to the process water, so that the plasticizer content was increased to 32%. After processing to the end product, the water content was in the range of 20 - 25%, so that the network formation could proceed quickly. As Figure 3 shows, a clear effect compared to TPS could be obtained in all NS examined, although there are individual differences between the different NS, especially with regard to the formation of a quasi-plateau and the modulus of elasticity at 75 and 84% RH.

Figure 4 shows the modulus of elasticity for starch networks with 10% NS each (short chain amylose with DPn = approx. 20) based on different VS (not modified, with the exception of the hydrolyzed potato starch)) produced in the TCP process using split feeding, where the NS was added as a suspension in water (but not dissolved) to the plasticized VS in a Brabender kneader at 80 ° C and the molecularly disperse mixture of VS and NS was prepared at around 35% water, at mass temperatures around 115 ° C and a speed of 180 rpm has been. Atmospheric degassing reached a final water content of 25% after a kneading time of around 15 minutes, after which the NSF was formed into a film in a plate press (95 ° C). The illustration 4 shows that the starch networks obtained can be produced on the basis of different VS. The moduli of elasticity of the VS examined without NS (i.e. the analog TPS, not shown) are consistently at lower values, they are around 2 - 8 times lower. In addition, the TPS samples are sticky at RF> 40 - 50%, whereby the stickiness increases with increasing RF. The corresponding networks are not sticky on the entire RF range, which is due to the strength networks set.

Figure 5 shows the strengths and Figure 6 shows the elongations at break of the same samples as a function of the RF. The strengths of the analogue TPS are 2 to 3 times lower, while the elongation at break of the analogue is comparable or somewhat larger.

Figure 7 shows the modulus of elasticity of samples based on pregelatinized potato starch (not modified) containing 0, 10 and 20% NS (short chain amylose with DPn = approx. 20), 0% plasticizer and 34% water after production the time (storage at room temperature with constant water content) reproduced. The preparation was comparable to the samples of representations 4-6, but the water content of the mixture after addition of the NS suspension was 43%. The TPS sample WS140, which was produced analogously to samples WS141 and WS142, initially shows a slight increase in the modulus of elasticity as a function of time, after which the modulus of elasticity remains constant. In contrast, the modulus of elasticity from WS141 takes in the first Hours to more than double the initial value, after which a slower increase in the modulus of elasticity can be observed. This growth in the E-module directly reflects the gradual formation of the starch network. Since WS 142 with 20% NS has a higher NS content, the growth of the modulus of elasticity happens faster over time on the one hand, and on the other hand significantly higher values are obtained. After approx. 24 hours, the network at WS142 and WS142 is practically fully developed. If the network formation is suppressed in the course of this 24h by reducing the water content (whereby the glass transition temperature rises to temperatures above room temperature), the state reached is frozen and precursors are obtained, with a completely crosslinked precursor being present after 24h, before that partially crosslinked precursors, which include decreasing storage time have a decreasing degree of crosslinking. Even with the storage time Oh, i.e. after the samples have cooled in the press, there is already a partial crosslinking of around 50% in both samples (which took place during the pressing and cooling process, the crosslinking takes place faster at a higher temperature, whereby the formation rate of the network is doubled 10 ° C above room temperature, quadrupling 20 ° above et.). In order to obtain samples WS141 and WS142 as completely inhibited precursors, rapid cooling of the NSF and a rapid reduction in the water content are necessary, which can be done, for example, by extrusion with a mass temperature of »100 ° C. and expansion.

Figure 8 shows the development of the networks with the storage time using the corresponding moduli of elasticity for comparable samples, the water content during storage being set to 29%. The comparison of illustration 7 with illustration 8 shows that the moduli of elasticity of the NS. samples with the lower water content of 29% grow over a significantly longer period, which is due to the fact that the formation rate is significantly reduced due to the lower water content. Apparently there was no significant network formation during the pressing process, since the samples WS143, WS144 and WS145 all have the same modulus of elasticity (the modulus of elasticity of analog TPS) at 0h.

The following example shows that the mechanical properties of starch networks have an amazing potential: a sample in the form of a film 0.5mm thick, based on a high amylose (around 60 - 70% amylose) pregelatinized pea starch as VS containing 35% short chain amylose with a DPn of around 20 as NS, which was produced by means of the TCP process (split feeding) on a Brabender kneader, whereby mass temperatures of around 120 ° C were reached and the majority of the process water, initially 50%, had been removed by atmospheric degassing the shape in a plate press still had a water content of around 18% (in addition to water, no other plasticizers were used) and was first annealed in the plate press for 1 hour at 120 ° C, then for 24 hours at 95 ° C and finally slowly cooled to room temperature. After swelling in water at room temperature, this film showed a strength of 4.7 MPa, which achieved a value which almost corresponds to the strength of a pressed polyethylene film (LDPE). This is all the more astonishing since, in contrast, TPS typically disintegrates in water and therefore no longer has any strength, and often the strength of TPS is no longer measurable even at relative air humidities above 75-85%.

method

Illustrations of the processes are shown in Figures 1 to 7.

Measurement methods and conditioning

Tensile test

The tensile tests were determined at 22 ° C. with an Instron 4502 tensile testing machine at a crosshead speed of 50 mm / min on standardized tensile specimens according to DiN 53504 S3, which were punched out from films of about 0.5 mm thickness. The measurement results are to be understood as mean values of at least 5 ^' individual measurements. The water contents of the tensile specimens conditioned at different atmospheric humidity were constant within the measuring accuracy during the duration of the tensile tests. The stress σ was obtained as F / A, where F was the force and A was the sample cross section at ε = 0. The elongation in the tensile test in% was obtained as ε = .100 (. - io) / lo, where l _{0 was} the stretchable length of the sample between the clamps at the start of the tensile test and lι the length of the stretched sample. The modulus of elasticity was obtained as E = σ / ε.

conditioning The conditioning of the samples for the mechanical analyzes at different RF was carried out in desiccators over 7 days over saturated saline solutions. The desiccators were equipped with fans, which significantly reduced the sorption times to equilibrium (7 days) compared to storage in a calm atmosphere.

Symbols and abbreviations

RH relative humidity: 0% <RF <100% RT C] room temperature (22 ° C)

Tg ° C] glass transition temperature

WM.%] Plasticizer content (excluding water) based on starch and

Plasticizer, dsb

W%] water content, based on starch, plasticizer and water dsb dry solid base, based on the dry weight

E MPa] Young's modulus σ _m MPa] maximum strength in tensile test (breaking strength) σιo% MPa] tensile stress in tensile test at ε = 10%% ^" elongation at break in tensile test

DP degree of polymerization DPn number average of degree of polymerization DPw weight average of degree of polymerization Qb degree of branching of macromolecules (number of branched

Monomer units / number of monomer units)

CL chain length (number of monomer units) CLn number average chain length; linear, i.e. unbranched

chain segments

CLn.na f -] number average of the network-active chain length; Chain segments that can crystallize and participate in networks, i.e. unbranched and unsubstituted and non-sterically hindered chain segments

CLw [-] weight average chain length DS [-] degree of substitution: 0 <DS <3.0 DE [-] dextrose equivalent: 0 <DE <100

VS Present strength

NS Networkable strength

WM plasticizer, can be a single plasticizer or a mixture of different plasticizers SCA short chain amylose (NS or part of NS) with DPn in the range of 10 - 100;

SCA cannot build strength networks alone, only in combination with others Strengths of higher degree of polymerization, networks consisting of such

Mixtures can still be formed at low plasticizer contents and low temperatures. LCA Long Chain Amylose (NS or part of NS) with DPn> 100, can LCA1 and / or

LCA2 have LCA1 LCA with DPn in the range of 100-300; LCA1 can be used both alone and in ■. Combination with other strengths form networks, mixtures of LCA1 and - VS can be used at medium plasticizer contents and medium temperatures

Networks form LCA2 LCA with DPn> 300; LCA2 can form networks both alone and in combination with other strengths. Mixtures of LCA2 and VS can form networks at high plasticizer contents and high temperatures. NSF Networkable Starch Fluid; Melt or solution containing a starch or starch mixture and plasticizer; can be obtained as a strength network below under suitable conditions. An NSF has at least one VS and at least one NS VP intermediate product obtained from NSF; If fluid is obtained from a network-compatible starch, it represents an intermediate product in the DP process VVP Cross-linked preliminary product obtained from NSF; has an at least partially developed starch network IVP Inhibited precursor obtained from NSF; has no or only a minimally developed network, the formation of a network is by

Process measures suppressed. An IVP is predominantly to completely amorphous KVP Pre-product containing germs obtained from NSF, "has a slightly developed network, the network elements of which are germs in the

Processing the KVP to produce starch networks SCP Split Continuous Process: VS and NS are processed separately, mixed to form an NSF and the NSF processed directly to the end product TCP Together Continuous Process: VS and NS are processed together to form an NSF and the NSF directly SDP Split Discontinuous Process: VS and NS are processed separately, into one

Mixed NSF and the NSF processed into a VP TDP Together Continuous Process: VS and NS are processed together, mixed to form an NSF and this is processed directly into the end product Legend

1) Mixing container with NS, water and possibly WM

2) liquid pump

3) heating section

4) cooling section

5) check valve

6) Adjustable pressure relief valve

7) extruder

8) Solid dosing device for VS

9) Liquid dosing device for WM and / or water

10) Liquid dosing device with dissolved NS

11) degassing device

12) Granulation device

13) intermediate product (granulate)

14) Solid matter dosing for mixture VS and NS

15) Solid feeder for intermediate product

16) Solid matter dispenser for WM and / or water

17) Processing extruder

18) Molding tool

19) Film 20) Solid dosing device for NS

Claims

claims

1. A process for the production of starch networks, characterized in that the starch network consists of a network-compatible starch fluid (NSF) containing present starch (VS) and network-compatible starch (NS) in a DP process (discontinuous process) in two process steps over a preliminary product is produced or is produced in a TP process (Together Process) in a process and preferably the starch network of the end product is at least partially formed by heterocrystallization.

2. Process for the production of starch networks, according to claim 1, characterized in that the starch network is produced in the TDP process (Together Discontinuous Process) or in the SDP process (Split Discontinuous Process) and thereby in a first process zone from a first networkable starch Fluid (NSF1) a preliminary product is obtained, from which a second network-compatible starch fluid (NSF2) and finally a starch network are obtained in the end product from this preliminary product, whereby VS and NS are processed together in the TDP process, in particular VS and NS are fed to the process and prepared together (Together Feeding) or fed separately to the process (Split Feeding), wherein the NS is preferably fed to the at least partially plasticized VS.

3. A method for producing starch networks, according to claim 1, characterized in that the starch network is produced in the end product in the TCP process (Together Continuous Process), VS and NS being processed together, in particular VS and NS fed together to the method and be prepared (together feeding) or fed separately to the process (split feeding), the NS preferably being fed to the at least partially plasticized VS.

4. A method for producing starch networks, according to claim 2, characterized in that the preliminary product is obtained from an NSF1 and has an at least partially formed starch network (WP), which in a second Process zone is at least partially dissolved and then newly formed.

5 ^' Process for the production of starch networks, according to claim 2, characterized in that the preliminary product is obtained from an NSF1 and has an at most partially developed starch network, in particular a) in the preliminary product the network formation is almost completely suppressed, thus the preliminary product in predominantly until completely amorphous state is obtained as an inhibited intermediate (IVP); or b) the preliminary product has a partially formed starch network, the ordered areas or network elements of which are used in the further processing of the preliminary product as germs for the formation of the resulting starch network (germ-containing preliminary product, CIP),

Process for the production of starch networks, according to one of the preceding claims, characterized in that the end product has an NS which is present in the NSF1 or in the NSF1 and / or NSF2 in a predominantly to completely amorphous state, i.e. in the mixture with other starch macromolecules predominantly, preferably completely molecularly dispersed.

7. Process for the production of starch networks, according to one of the preceding claims, characterized in that the preliminary product and the end product are a starch with a network-active chain length CLn.na in the range 7-300, preferably 10-100, more preferably 14-50, has in particular 16-30, most preferably 18-28 and / or the preliminary product and / or the end product has a VS and an NS, the proportion of NS based on NS and VS in% by weight dsb in the range 1-90, preferably 2-50, more preferably 3-30, most preferably 3-15, and optionally the end product has a further starch with a degree of branching Qb> 0.01, preferably> 0.05, more preferably> 0.10, most preferably> 0.15.

8. Process for the production of starch networks, according to one of the preceding claims, characterized in that the preliminary product and the final product a) have an amylose content in% by weight dsb in the range 1-70, preferably 2-50, more preferably 3-40 , most preferably 3-30; and b) the amylose is SCA, LCA or a mixture of SCA and LCA, the proportion of SCA in% by weight based on amylopectin and SCA in the range from 1-35, preferably 2-25, in particular 3-20, being most preferred 4 - 14; and / or the proportion of LCA in% by weight of dsb, based on amylopectin and LCA, is in the range 1-70, preferably 2-50, in particular 3-40, more preferably 4-35, most preferably 5-30.

9. A process for producing starch networks, according to claim 8, characterized in that a) the SCA has a degree of polymerization DPn in the range 5-70, preferably 6-50, in particular 7-30, more preferably 8-28, most preferably 9- 27; and b) the LCA has a degree of polymerization DPn in the range 100-3,000, preferably 100-1,000, more preferably 100-500, most preferably 100-300.

10. Process for the production of starch networks, according to one of the preceding claims, characterized in that the preliminary product and the end product have at least one of the elements of the following group: dextrins, maltodextrins, linear dextrins, amylodextrins, nail dextrins, at least partially branched and / or hydrolyzed starches, dextrins, or maltodextrins; and in particular the at least partially branched and / or hydrolyzed starches, dextrins or maltodextrins have arisen during the production of the preliminary product; and the preliminary product and the end product optionally have at least one additive.

11. Process for the production of starch networks, according to one of the preceding claims, characterized in that a) the water content of the NSF1 and / or the NSF2 before any removal of process water, based on the dry starch and water in% by weight in Range of 15-70, preferably 20-60, more preferably 25-50, most preferably 30-45; and b) the plasticizer content of plasticizers other than water of the NSF1 and / or NSF2, based on the dry starch and plasticizer, in% by weight in the range from 0-70, preferably 0-55, more preferably 0-45, most preferably is from 0-40; and c) the water content of the NSF1 and / or NSF2 after the optional removal of process water, based on the starch and water in% by weight, is 0-35, preferably 0-25, more preferably 0-20, most preferably 0-15; and d) the maximum mass temperature in ° C. during the ripening of the NSF1 and / or NSF2 is in the range from 70 to 220, preferably from 75 to 180, more preferably from 80 to 160, most preferably from 85 to 155.

12. A method for producing starch networks, according to one of the preceding claims, characterized in that the end product is subjected to a heat treatment, the temperature of the heat treatment in ° C in the range 0-160, preferably 20-140, more preferably 40-120 , most preferably 60-110 and the time of the heat treatment is in the range of minutes to days, the heat treatment taking place with constant water content of the starch network or during the heat treatment the water content having a time course.

13. Starch network, characterized in that it has been produced by a method of the preceding claims and in particular a) in comparison with analog TPS at least at a relative air humidity RF> 70% by a factor of> 2, preferably> 3 more preferably> 4, most preferably> 5 higher modulus of elasticity; and / or b) is not sticky in the entire range of relative humidity; and / or c) is practically completely insoluble in water; and / or d) after swelling in water at room temperature has a strength in MPa in the range 0.5-5, preferably 1-5, more preferably 2-5, most preferably 3-5; and / or e) is transparent.

14. Pre-product, preferably produced by a process of claims 1 T, 12, characterized in that the pre-product has a NS and a VS and is used for the production of starch networks which are at least partially ^'formed by heterocrystallization and in particular the pre-product is in a form that can be stored and transported, for example as a film, foil, powder, spray-dried powder, freeze-dried powder, granules, pellets and the like, and preferably the preliminary product has a plasticizer content of <30%.

15. The preliminary product according to claim 14, characterized in that the preliminary product is used for the production of the following products based on starch networks: soft capsule, in particular manufactured in the rotary die or Accogel process; Hard capsule, in particular made by injection molding or immersion; rubber-elastic confectionery, in particular produced in the injection molding process or in the Mughal process; Food containing at least one phase consisting of a starch network such as BSW. Pasta; Food with a reduced glycemic index and / or with a higher prebiol content; Packaging, in particular packaging and barrier for volatile substances such as fragrances and aromas, such as, for example, water-disintegrating sachets for perfumes or capsules containing aromas, fragrances, bath additives, chemicals and the like; Foil; Film, in particular as an edible film; filament; Macro or micro fiber, in particular as an oriented fiber produced in the gel spinning process; Foam; Granules; Powder; Microparticles; Molding; Injection molding; Strand casting; Profile casting; Deep-drawn part; Thermo molding; and / or the preliminary product in the food, galenics, cosmetics, health care, packaging or agricultural sector, etc. as cotton swabs, polystyrene foam replacement, film, bio-oriented film, composite film component, membrane system for the nano, - micro or macro encapsulation, paper laminate, replacement of cellulose, disposable clothing, dishes and cutlery, food tray, drinking straw, mug , Food packaging, foamed heat-insulating food container, chewing bone for the dog, shopping carrier bag, rubbish and compost sack, mulch film, plant pot, golf tip, children's toys and the like is used.