Enzymatic baking agent.

The invention relates to enzymatic baking agents which, as the main component, receive a liquid to pasty baking emulsifier and optionally fats and a baking enzyme dispersed therein. A disadvantage of these known and customary baking agents is the loss of enzymatic activity during storage.

From US-A 3,494,770 baking agents are known which consist of a mixture of a fungal alpha-amylase and a fungal proteinase as well as an oxidizing agent and an ammonium salt with flour. These agents can also be used together with conventional baking emulsifiers, such as calcium stearyl 2-lactylate or sodium stearyl fumarate, in the preparation of the dough. It is not known to mix the baking emulsifier beforehand with the auxiliaries mentioned. The invention has for its object to reduce the loss of activity when storing the enzymatic baking agents mentioned above. This is achieved according to the invention by adding a solid acid-binding agent or a water-binding agent or these two agents together.

The invention is based on the knowledge that the gradual loss of enzymatic activity is due to the action of water or lower carboxylic acids or both on the enzymes. According to the invention, this action is excluded by water- and / or acid-binding agents.

Water can diffuse into the baking emulsifier mixture from the atmospheric moisture or can already be contained in the baking emulsifier during the preparation of the mixture. Baking emulsifiers, which consist of esters of lower carboxylic acids with a polyhydroxy compound, are hydrolyzed by water and thereby release lower carboxylic acids, such as acetic acid, propionic acid, lactic acid or tartaric acid. The enzyme-damaging effect of these lower carboxylic acids exceeds that of water and occurs especially when the enzyme has gone into a state of higher sensitivity due to water absorption.

A baking emulsifier that is particularly common in baking technology is diacetyl tartaric acid ester, whose hydrolytic cleavage leads to the release of acetic acid and tartaric acid. These acids are almost always detectable in commercial baking emulsifiers on this basis. The invention is therefore of particular importance for enzymatic baking agents which contain diacetyl tartaric acid esters as baking emulsifiers.

The water-binding agents used according to the invention protect the baking enzymes from the damaging influence of the water. As long as the enzymes are not swollen by water, their sensitivity to lower carboxylic acids is still relatively low. The acid-binding agents used according to the invention generally have a higher hydrophilicity than the enzymes, so that at the same time they have a water-binding effect and in this way contribute to protecting the enzymes.

According to the invention, the inactivating effect of the lower carboxylic acids can be prevented in two ways. Water-binding agents absorb the water contained in the baking agent or its starting components and the water diffusing in from the atmospheric moisture and thereby withdraw it from the hydrolysis reaction. The second protective effect is based on the acid-binding agents which intercept the carboxylic acids produced by hydrolysis and thereby prevent their action on the enzymes. In the presence of baking emulsifiers which contain esters of lower carboxylic acids, the buffering effect of the acid-binding agents is the predominant protective effect. It is particularly advantageous to use both protective effects simultaneously by using both additives.

Suitable acid-binding solid substances are basic substances or buffer compounds which are able to react with free lower carboxylic acids in the non-aqueous medium of the baking agent and which keep the concentration of these acids below the concentration harmful to the enzymes. They should be in finely divided form and evenly distributed.

Suitable additives are buffer mixtures which are suitable for the pH range from 5 to 8 and are approved under food law. A large number of such substances are known (see “Biochemisches Taschenbuch”, Part II, pp. 90ff, Springer Verlag, 1964) and are commercially available in the appropriate purity and particle size.

Suitable additives with a basic or buffering action are, for example, the oxides or hydroxides of the alkali or alkaline earth metals, in particular sodium or calcium, and their salts with acids which are weaker than the carboxylic acids to be trapped. These acids should have a pKa above 4.5, preferably above 6.0. In the case of polybasic acids, the same applies to the higher levels of dissociation. In an aqueous solution of these acid-binding agents, a pH value of over 5, preferably 6 to 8, is established, however, despite the proven effectiveness of the basic additives, these pH values ​​can often not be determined in the baking agents stabilized therewith. The ammonium salts of the acids mentioned are also suitable. Examples of suitable acid-binding additives are calcium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, disodium and trisodium phosphate, dipotassium and tripotassium phosphate. Diammonium hydrogen phosphate, calcium hydrogen phosphate, tricalcium phosphate, ammonium carbonate, ammonium carbaminate and trisodium citrate. Finely divided solids which bind water chemically or adsorptively in the solid state are suitable as water-binding solids. The first group includes anhydrous salts that absorb water of crystallization, such as sodium sulfate, calcium sulfate or calcium hydroxide. Zeolites and water-free silica gels belong to the group of adsorptive water-binding additives.

It goes without saying that only those water- and acid-binding additives may be used which are safe for health and legally permissible in the concentration in which they appear in baked goods. Otherwise, the concentration depends on the required protective effect during the expected storage period. Both types of additives are effectively exhausted if they have absorbed water or acid according to their capacity. The need therefore depends on the type of packaging, the storage conditions, the storage period and the sensitivity of the enzymes.

As a rule, a water binding capacity of 5 to 100 g of water and an acid binding capacity of 20 to 400 milliequivalents of acid per kilogram of the baking agent are sufficient. When used together, correspondingly lower amounts can be used. The total amount of water and acid binding additives is, for example, between 0.2 and 5% by weight, based on the finished mixture.

Amylases, amyloglucosidases, proteases, cellulases, hemicellulases from microorganisms or of vegetable origin are customary as baking enzymes. The baking agent according to the invention can contain one or more such baking enzymes. The additives according to the invention are advantageous if only one of the enzymes contained is sensitive to acids. Amylases, protases, hemicellulases are particularly sensitive to acids, so that baking agents with these enzymes are among the preferred embodiments of the invention.

The concept of baking emulsifiers is not clearly defined in the literature. These are substances that promote the homogeneity of the dough by wetting the dough components and improving their compatibility.

Baking emulsifiers in the sense of the invention are not a chemically uniformly definable group of substances. A common feature of the compounds belonging to this group of substances is the structure of the emulsifier molecule from a non-polar, lipophilic, hydrophobic portion and a polar, hydrophilic and lipophobic portion. The hydrophobic part of the molecule is formed from straight, branched or cyclic hydrocarbon residues, while the hydrophilic part of the molecule can consist of very different polar groups. Another essential characteristic is the lack of toxicity, i.e. harmlessness to health and legal admissibility.

The surface-active properties of the baking emulsifiers can vary in strength. In addition to emulsifiers with a clear surface activity, the scope of the invention also includes less surface-active substances which are known to the person skilled in the art as baking emulsifiers and are commercially available as such. Gregor Schuster and Wolfang Adams give a comprehensive overview of emulsifiers as additives for food in an 18-part series of articles, which appeared in the "Zeitschrift für Lebensmittel-Technologie und Processstechnik" in the years 1979 - 1985 and that in the book "Emulsifiers for Lebensmittel "by the same authors (Springer Verlag, 1985). Particular attention will be paid to those in Annex I to the Council Directive of the 18th June 1974 registered emulsifiers, stabilizers, thickeners and gelling agents which may be used in food (74/329 EEC) and (78/612 EEC).

A preferred class of baking emulsifiers are the mono- and diglycerides of fatty acids esterified with acetic acid, propionic acid, lactic acid, citric acid, tartaric acid, monoacetyltartaric acid and diacetyltartaric acid. In practice, the esters of mono- and diglycerides with diacetyltartaric acid are of particular importance and are therefore preferred for the purposes of the invention. The lower carboxylic acids mentioned can be hydrolytically split off from these ester-like baking emulsifiers and then exert a damaging influence on the baking enzymes present in the mixture with the baking emulsifiers.

The emulsifier can contain 0.1 to 2% by weight of water for production or storage reasons, which would result in a rapid loss of activity in the absence of the additives according to the invention. Such amounts of water can be tolerated in the baking agents of the invention if the amount of the additives is sufficiently high to bind either this water or the carboxylic acid resulting from its hydrolytic action. The binding process can take a long time.

As a rule, the weight fraction of the water and acid binding additives is greater than that of the enzymes. Both together make up, for example, 0.1 to 25% by weight of the finished baking mixture.

The enzymes and the water- or acid-binding additives can be evenly distributed as finely divided solids in the liquid to pasty baking emulsifiers. It is more advantageous to first process the enzymes with the water- or acid-binding agents into a powder product in which the components adhere mechanically to one another so that they are not separated from one another when dispersed in the baking emulsifier. For example, the acid-binding agent can be added to the enzyme solution and spray dried with it to a powder.

A particularly effective protection of the baking enzyme by the acid or water-binding agent is achieved if one of these components forms the core of the particles and the other component forms a shell surrounding the core. The core can for example have a diameter of 20 to 150 microns and the shell have a thickness of 10 to 100 microns. Such a structure is achieved if the particulate core material is whirled up in a fluidized bed system known per se and coated with a solution or suspension of the shell material. As a rule, an aqueous solution or suspension is used. In this case, it is difficult to process a water-binding material as one of the components; the process is primarily suitable for processing an acid-binding agent as core or shell material.

For example, an aqueous enzyme solution can be sprayed onto particles of the acid-binding material in a fluidized bed process and dried at an air temperature of 35 to 100 degrees Celsius. It is advantageous to coat the resulting enzyme shell with a further outer shell made of a water-soluble solid material. This can be done in a further operation in the same fluidized bed system in which the enzyme shell has been applied. The further shell can, for example 10th up to 100 µm thick. It can consist of the same or a different acid-binding material as the core, but other solid water-soluble substances without water- or acid-binding effect, such as starch, dextrin, polyethylene oxide (poly wax) or lecithin-oil mixtures, are also suitable. These agents can also be applied in the form of an aqueous solution, suspension or dispersion in a fluidized bed process. The outer shell, which provides additional protection for the baking enzyme, is unnecessary if the baking enzyme itself is used in particle form as the core material and is coated with the acid-binding agent in a fluidized bed process.

The multilayer particles are then incorporated into the baking emulsifier. A water-binding agent can also be processed. It is expedient to mix the baking emulsifier in the molten state, for example at temperatures from 40 to 60 degrees Celsius, with the particulate material and to continue the mixing process by means of a suitable mixing device until it cools down to about room temperature.

Examples

I. Preparation of Particulate Mushroom Amylase Powder

<ul id="ul0001" list-style="none"><li>A. Core material from buffer salt, shell material from mushroom amylase. 500 g of trisodium phosphate with a grain diameter of 20 to 50 µm are warmed up in the fluidized bed granulator with air preheated to 80 degrees C to 38 degrees - 40 degrees C with swirling. 1 l Aspergillus fungal amylase solution (10% dry matter, 5000 SKB / g amylase activity) are sprayed through a nozzle so that the exhaust air has a temperature of about 40 degrees C. 600 g of enzyme product with an activity of 7,500 SKB / g are obtained.</li><li>B. Like A, but with an additional covering layer. The product produced according to A is sprayed in the fluidized bed granulator under the conditions described above with 500 ml of 10% maltodextrin solution. This gives 650 g of enzyme product with 6 900 SKB / g, which contains buffer salt as the core material, the enzyme as the intermediate layer and dextrin as the outer shell.</li><li>C. Enzyme particle core material, buffer salt shell layer 250 g of a powdery mushroom amylase-maltodextrin mixture with 20,000 SKB / g are placed in the fluidized bed granulator, heated to 80 ° C. by warm air at about 40 ° C. and sprayed with 500 ml of 20% trisodium phosphate solution so that the Drain temperature is approx. 40 degrees C. About 350 g of enzyme product are obtained, with 14,000 SKB / g amylase activity, which contains the enzyme as the core substance and buffer salt as the coating material.</li><li>D. Production of particulate baking enzymes as powder mixtures. 500 g of an amylase powder containing 100 g of amylase concentrate and 400 g of maltodextrin with an amylase activity of 8,000 SKB / g are dry-mixed with 500 g of trisodium phosphate, dipotassium hydrogen phosphate, sodium carbonate, sodium hydrogen carbonate, anhydrous sodium sulfate and trisodium citrate to obtain five powder mixtures, designated D1 through D6.</li></ul>

II. Production of baking agents

A pasty technical baking emulsifier is used which contains 20% by weight of mono- and diglycerides of fatty acids, 10% by weight of their diacetyl tartaric acid esters, 30% by weight of glucose and 1.5% by weight of water.

In each case 1 kg of this baking emulsifier is melted by heating to 60 ° C. with stirring, and 14 g of the powdery amylase products prepared according to A to D are introduced and mixed with stirring. The mixture is allowed to cool to room temperature with further stirring. For comparison, in a further batch, 7 g of the amylase powder used in D are mixed in the same way with 1 kg of the baking emulsifier without further additives.

The table below shows the residual amylase activity after a storage period of 30 and 110 days at room temperature, in each case based on the activity (= 100%) measured one hour after mixing and cooling.<tables id="tabl0001" num="0001"><img file="EP0246554A2_D0001.tif" /></tables>