AT413798B - Production of microencapsulated volatile substances (especially in feedstuff manufacture) involves spray drying an O/W emulsion containing water, a solvent aid, natural polymers and the volatile substance - Google Patents

Abstract

Production of volatile substances in microencapsulated form involves spray drying an o/w emulsion containing water, a solvent aid, natural polymers and the volatile substance to give a flowable powder, the difference between the inlet and outlet temperatures being 70-100[deg]C.

Description

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AT 413 798 B

The invention relates to stable plant extracts, especially temperature-stable plant extracts.

In the animal food industry, especially in the diet of useful but also domestic animals, feed supplement supplements have also been used in the past in the form of antibiotic additives. These additives should increase the performance, in particular in livestock nutrition, whether with regard to the quality or quantity of meat or the nature or quantity of the usable products. Due to the risk of cross-resistance (not only in livestock but also in domestic animals) or the risk and side effects of residues in meat or products (milk, cheese, eggs and the like) on the end user, the use of antibiotic agents as a performance promoter is controversial and led to numerous prohibitions on the use of such funds. As an alternative to such antibiotic performance enhancers, feed additives produced on a plant basis have been contemplated for some time, with current experience and research on uptake, digestive tract utility, immune system impact, and the like being positive. Residues in the meat of livestock and their products are harmless to humans. 20

In the compound feed industry, antibiotic additives for premixes or finished products are usually used in the form of granules, which granules may be present as pellets or extrudates. As a result, a convenient handling, in particular miscibility and relatively exact dosing in connection with dry food preparations and the like can be achieved.

The use of herbal additives, however, involves the problem that many effective phytogenic additives are present in the form of oils, especially essential oils. These additives volatilize rapidly under the influence of temperature. During the pelleting or 30 extrusion process, high temperatures, high pressure and / or high shear forces act, so that such additives can not be processed or only at high losses. Essential oils, which are sprayed onto pellets or extrudates, in particular sprayed incompletely, adhere only incompletely, in particular only to the surface of the pellets or extrudates, so that upon storage, or under the influence of moisture or by friction, they segregate and thus to a non-uniform distribution in the feed comes.

As a result, the use of these herbal additives, especially due to the processing losses considered as unprofitable.

To stabilize volatile substances, such as vegetable substances and essential oils, the technique of spray-drying is used in the art. In this process, the finest droplets of the material to be processed are produced in an o / w emulsion 45 and sprayed in a stream of hot air. The resulting powder consists of encapsulated particles and is relatively stable in the dried state to evaporation losses. With a suitable solvent, such as water, the encapsulated particles are relatively easily back emulsified. However, such processes are unsuitable for the stabilization of volatile substances, in particular volatile plant constituents, such as essential oils and the like, since, owing to the steam treatment used in these processes, an increased water content and, in turn, too high evaporation losses occur. 55 Object of the invention was therefore to provide a method in which even volatile 3

AT 413 798 B

Substances such as essential oils and the like can be stably prepared in encapsulated form without high evaporation losses.

The invention therefore provides a process for producing volatile substances in a microencapsulated form, characterized in that in a first step an o / w emulsion is prepared which contains water, a solubilizer, natural polymers and the volatile substance to be encapsulated, and a second step, this emulsion is converted by spray drying in a free-flowing powder, wherein the difference between the inlet and outlet temperature is 70-100 ° C. 10

As polymers it is possible to use natural polymers or polymer mixtures. Thus, for example, starch hydrolysates, such as dextrins, modified starches, gum arabic, alginates, natural resins, such as shellac, wood rosin, cellulose derivatives, such as hydroxypropylcellulose, sodium carboxylcellulose, methylcellulose, ethylcellulose, animal and / or vegetable proteins or their hydrolysates, such as gelatin , Collagen, egg protein, wheat protein, caseinates, milk protein, soy protein, pea protein and the like and / or mixtures thereof.

Depending on the composition of the polymer or polymer mixture, mineral acids such as HCl, H 2 SO 4, organic acids such as formic acid, acetic acid, propionic acid, butyric acid, ammonia or alcohols such as methanol, ethanol, propanol, 2-propanol and the like can be used as solubilizers become.

Optionally, the emulsion may contain natural plasticizers or flow agents. 25

Examples of such plasticizers are waxes such as beeswax, candellava, carnauba wax, cottonseed oil wax, hydrogenated vegetable oils, ceresin and the like.

As the flow agent, amorphous silicas, talc, calcium silicates, calcium phosphates and the like may optionally be used.

Suitable volatile substances are, for example, natural or nature-identical aromas or aroma mixtures (orange, lemon, vanilla, coconut, peppermint, banana, strawberry), natural or nature-identical essential oils (aniseed oil, basil oil, cedarwood oil, lemon oil, eucalyptus oil, fennel oil, chamomile oil, camphor oil, Garlic oil, marjoram oil, menthol, clove flower oil, peppermint oil, rosemary oil, thyme oil, cinnamon leaf oil, onion oil) and the like.

Further, as volatile substances messengers, such as pheromones, allomones, kairomones, such as sexual attractants of butterflies, consisting of, inter alia, of 40 aliphatic straight-chain alcohols, their acetates, aldehydes, ketones, hydrocarbons and epoxy compounds; Pheromones of the beetles comprising, inter alia, terpenoid compounds or transformation products of food-borne terpenes, pheromones of ants, bees, wasps and bumblebees, consisting inter alia of heterocyclic aromatic compounds and terpene derivatives, fly pheromones consisting of, among others, monounsaturated hydrocarbons, spiro compounds, heterocyclic aliphatic compounds, Termitenpheromone, consisting inter alia of terpene compounds, long-chain alkanes and alkenes, nitroalkenes, vinyl ketones, Ketoaldehy-den and macrocyclic diterpenes, pheromones of insects from other orders, such as the aphid, including, inter alia, Farnese, pine and bicyclic so lactones and the German cockroach consisting, inter alia, of aliphatic and monounsaturated straight-chain alcohols, their acetates and formates, or mammalian pheromones consisting, inter alia, of steroid and thiaza compound en, as well as polycyclic ethers. 55 The solids content of the emulsion depends on several parameters and must be 4

AT 413 798 C onend. The solids content of the emulsion is dependent in particular on the emulsion behavior of the polymer or the polymer mixture, the viscosity of the emulsion and the amount and type of volatile substance to be encapsulated. Likewise, the technical requirements of the spray tower, with regard to emulsion atomization, tower dimensions and drying parameters, must be taken into account.

Preferably, the solids content is between 20 and 50%, more preferably between 35 and 45%. To produce the emulsions, commercial pressure homogenizers or dispersing machines can be used in order to achieve the corresponding droplet size spectrum. The process can be carried out either continuously (in-line operation) or discontinuously (batch or batch operation). The atomization of the emulsion can be carried out by means of a rapidly rotating disk (preferably 15,000-22,000 rpm) or a single-fluid or two-fluid nozzle.

To dry the emulsion particles, the supply air and exhaust air temperatures are selected so that the residual moisture content of the dried product is less than 2%. The difference between the inlet and outlet temperature is 70-100 ° C, preferably 70-90 ° C, to avoid evaporation losses of the volatile substances to be encapsulated.

The products encapsulated in this way are not emulsifiable in water, mechanically stable and heat resistant. They may be pelleted, extruded or granulated in the usual way and used as feed additives.

Examples:

Example 1: 30

A solution of water (93.4-94.7% by weight), sodium caseinate (4% by weight) and sodium stearate (0-1.3% by weight) is mixed with oregano oil in a double-jacket mixing vessel with a high-speed stirrer, and 25 ° C at 1000-300 rpm mixed. The mixture is orbitally dispersed at 11000 rpm (Ultraturrax Inline Rotos Stator Type IKA) and so emulsified until an average droplet size of < 1 pm is achieved. After addition of CaOH (3.5-4% by weight), acetic acid (50% in H 2 O) is continuously metered in at 300-500 rpm over a period of 25 minutes until the pH of the mixture has reached 4.7. 40 The mixture is allowed to stand for 3 - 5 h at 10 - 15 ° C, wherein there is a sedimentation of the encapsulated Oreganoölpartikel.

By pumping out the supernatant aqueous phase, a suspension having a solids content of 20-30%, which is spray-dried (nozzle atomization, Tzu: 200 ° C, 45 tab: 100 ° C) is formed.

This gives a free-flowing powder having a mean particle diameter of 200 pm at a bulk density of 280 g / l. The content of oregano oil in the solid is 24 - 29%. example 2:

A solution consisting of water (60% by weight), modified starch (24% by weight and clove oil (16% by weight) is mixed in a mixing tank with a high-speed agitator at 20-25 ° C. at 1000-3000 rpm Recirculation processes emulsify until an average droplet size <1 pm is achieved

Claims (9)

Wax emulsion consisting of water (73% by weight), a hydrogenated vegetable fat (24% by weight) and ascorbyl palmitate (3% by weight) is stirred into the clove oil emulsion at 60-80 ° C. and the mixture is stirred in a helical stirrer mixed at 100-300 rpm for 15 min. 5 After spray-drying (disc atomization Tmax: 190 ° C., tab: 90 ° C.) of the mixture, a fine, slightly unstable powder having an average particle diameter of 80 μm and a bulk density of 320 g / l is formed. The content of clove oil in the solid is 33-35%. By mixing in 0.1-1% of silica (Aerosil, Degussa), calcium phosphate, magnesium stearate or other commercially available release agents, the flow behavior of the spray-dried clove oil can be improved. Example 3: 15 A solution of water (69% by weight, gelatin (4mPas, 10% / 30 ° C) (15% by weight 9, wheat protein (7% by weight), propionic acid (3% by weight) and thyme oil (6% by weight) is mixed into a double-jacket mixing vessel with a high-speed stirrer (100-3000 rpm) at 35 ° -40 ° C. The mixture is emulsified by means of circulation by pressure homogenization until an average droplet size of <1 μm is achieved with metered-atomization (Tzu: 190 ° C., tab: 100 ° C.) gives a free-flowing powder with an average particle diameter of 150 μm at a bulk density of 294 g / l The thymic oil content in the solid is 20 -21% 25 Patent claims: 1. Process for the preparation of volatile substances in microencapsulated form, characterized in that in a first step an o / w emulsion is prepared containing water, a solubilizer, natural polymers and the volatile substance to be encapsulated t, and in a second step, this emulsion is converted by spray drying in a free-flowing powder, wherein the difference between the inlet and outlet temperature is 70-100 ° C. 2. The method according to claim 1, characterized in that are used as volatile substances äthe rische oils 3. The method according to any one of claims 1 or 2, characterized in that as natural polymers starch hydrolysates, such as dextrins, modified starches, gum arabic, 40 alginates, natural resins, such as shellac, wood rosin, cellulose derivatives, such as hydroxypropylcellulose, Na-carboxylcellulose, Methylcellulose, ethylcellulose, animal and / or vegetable proteins or their hydrolysates, such as gelatin, collagen, egg protein, wheat protein, Casei-nate, milk protein, soy protein, pea protein and / or mixtures thereof. 45 4. The method according to any one of claims 1 to 3, characterized in that as a solubilizer mineral acids, such as HCl, H2S04, organic acids such as formic acid, acetic acid, propionic acid, butyric acid, ammonia or alcohols such as methanol, ethanol, propanol, 2-propanol be used. 50 5. The method according to any one of claims 1 to 4, characterized in that plasticizers and / or flow agents are added for the preparation of the emulsion. 6. The method according to any one of claims 1 to 5, characterized in that the solids content of the emulsion is 20 - 50%. 55 6 AT 413 798 B 7. The method according to any one of claims 1 to 6, characterized in that the spray-drying is carried out by sputtering by means of a rapidly rotating disc. 8. The method according to any one of claims 1 to 6, characterized in that the spray-5 drying by sputtering takes place with a single-fluid or two-fluid nozzle. 9. Encapsulated volatiles prepared by a process according to claims 1 to 8. io 10. Use of the encapsulated volatiles according to claim 9, optionally after pelleting, extruding or granulating as additives in the feed industry. No drawing 15 20 25 30 35 40 45 50