IE46093B1

IE46093B1 - Food manufacture

Info

Publication number: IE46093B1
Application number: IE2348/77A
Authority: IE
Original assignee: Unilever Ltd
Priority date: 1976-11-23
Filing date: 1977-11-18
Publication date: 1983-02-23
Also published as: DK147152B; SE7713188L; CS235066B2; YU273977A; AU514767B2; AT368841B; NO147818C; LU78570A1; CA1097979A; FR2392675A1; BE861026A; DK147152C; IN147365B; IT1091299B; IE46093L; ZA776963B; ES464337A1; NO147818B; YU43204B; GR66160B

Abstract

The invention provides a process for the preparation of a pre-mix in the form of a free-flowing particulate composition in which a minor but essential foodstuff ingredient such as an oral vaccine, a vitamin or a trace element is dispersed uniformly throughout a carrier material which forms the bulk of the pre-mix, in which the carrier material comprises a dry particulate mixture of an edible inert powder and a lactose source, the lactose content of the mixture having from about 20 to about 50% by weight, and the pre-mix is formed by intensely agitating the carrier material and simultaneously spraying the carrier material with an aqueous solution or slurry of the foodstuff ingredient, the solution or slurry being applied in an amount from about 1 to about 12% by weight of the carrier material. Preferably the solution or slurry applied to the carrier material additionally contains a food-grade colouring agent.

Description

The present invention relates to the preparation of pre-mixes useful in. the manufacture of foodstuffs for humans and for animals, which pre-mixes incorporate mi nor but essential ingredients such as oral vaccines, vitamins and trace elements.

Pre-mixes are used to assist the blending of such minor but essential ingredients into foodstuffs in a homogeneous manner, and the invention is concerned with the preparation of pre-mixes in the form of free10 flowing particulate compositions in which the minor but essential ingredient, or each such ingredient where more than one is to be incorporated in a common pre-mix, is dispersed uniformly throughout a carrier material which forms the bulk of the pre-mix.

I5 For the purposes of this specification, the expression active ingredient is used to mean any of the following: an oral vaccine; an antibiotic; a vitamin or provitamin; a trace element or mineral· a source of calcium, phosphorus, iron, manganese, copper or iodine; a growth promoter; a flavour; or a perfume.

Also for the purposes of this specification, the expression edible inert powder is used to mean any of the following: a flour; a feed meal; an organic .waste or filler used in animal foodstuffs; or an inorganic filler.

Conventional pre-mixes which typically comprise the active ingredient dispersed by mechanical means in a dry carrier such as flour or other milled grain, tend to be unsatisfactory because it is difficult to obtain a uniform dispension of the active ingredient throughout the bulk of carrier by simple mixing, especially where the active ingredient is best handled as a liquid. The invention provides a method of making a pre-mix involving simple steps and which can lead to greater uniformity of distribution of the active ingredient.

The invention provides a process for the preparation of a pre-mix,in which process a dry particulate mixture of an . - 2 46093 as defined above edible inert powder/and a lactose source, the lactose content of the dry particulate mixture being from 20 to . 50% by weight, is intensely agitated and while so intensely agitated is sprayed with an aqueous solution or slurry of an as defined above active ingredient»/, the solution or slurry being applied in an amount of from 1 to 12? by weight of the dry particulate mixture.

Preferably the lactose content of the dry particulate mixture is at least 22? by weight, and ideally the lactose content is at least 25? by weight. Preferably the lactose content of the dry particulate mixture is not greater than 45? by weight, and ideally not greater than ? by weight.

Preferably the amount of the solution or slurry applied to the dry particulate mixture is at least 2? by weight.

Preferably the amount of the solution or slurry is not greater than 10?, and ideally not greater tnan 5?, by weight.

The edible inert powder should comprise, together with the lactose source, the bulk of the dry particulate mixture, although other materials can be present in a total amount not exceeding, say, 15? by weight of the dry particulate mixture provided that any such additional material does not interfere unduly with the flow properties of the dry particulate mixture or with the desired properties of the pre-mix when formed.

The edible inert powder can be any such powder which is essentially lactose-free, and which is not more than sparingly - 3 46093 soluble in water. A wide range of materials can be employed, such au feed meals commonly used as ingredients in compound foodstuffs, for example milled grain, bean meal and soya meal provided that not too many oily or water-soluble components are present; organic wastes and fillers used in animal foodstuffs, suoh as beat pulp, potato pulp and feather meal; and inorganic fillers such as kaolin, kaolinite, silica and chalk. Care should be taken to ensure that the inert powder chosen is not one whose maximum permitted level in the final foodstuff to which the pre-mix is to be -added unduly restricts the formulation of the pre-mix. Preferably the inert powder chosen is one that can be included at a level of up to at least 0.5? by weight in the final foodstuff, and ideally at an inclusion level of at least jkbout} 1.5? by weight. Ideal inert powders are commercially-available flours such as wheat flour,' corn flour, rice flour and potato flour. Most commercially-available flours contain about 12? by weight of moisture, and these flours can be used to produce acceptable pre-mixes according to the invention. However, we prefer to use dried flours, ie flours having a moisture content of less than £bou^ 10? by weight. Ihe use of dried flour can impart a longer storage life to the pre-mix.

The lactose source can be any commercially-available lactose-containing composition having a sufficently high 25 lactose content and not containing a significant amount of any other ingredient which can interfere with the formation or properties of the pre-mix. A level of £bo«£ 50? lactose by - 4 . weight can be regarded as a practical minimum in most circumstances, and a higher level will generally be preferred. Fat is an example of an ingredient which can be undesirable in the lactose source, or for that matter in the pre-mix generally, and hence lactose sources of high fat content should be avoided. For this reason, skimmed milk is not recommended for use as a major lactose source, although in some instances minor amounts of skimmed milk powder may be incorporated provided that the bulk of the lactose in the pre-mix comes from some other source. Pure lactose powder can be used as a lactose source, but lactose powder is a relatively expensive commodity and is only preferred where, for taste reasons, other lactose sources would be unsuitable.

In a preferred embodiment of the invention particularly suitable for the preparation of pre-mixes useful in animal feedstuffs, the lactose source incorporated in the dry particulate mixture is whey powder. Whey powder typically contains about 75% by weight of lactose. In this embodiment, the dry particulate mixture should comprise from l!0 to 70? by weight of the edible inert powder and from 60 to 30% of weight of the whey powder. Preferably the edible inert powder comprises at least 50?, and ideally at least 55?, by weight of the dry particulate mixture. Preferably the edible inert powder comprises not more than 55? by weight of the dry particulate mixture. Preferably the whey powder comprises at least 35? by weight of the dry particulate mixture, and preferably the whey powder - 5 Λ609 3 comprises not more than 50?, ideally not more than 45?, by weight of the dry particulate mixture.

A further preferred feature of the invention is the organic incorporation of a small quantity of .an edible / acid in the pre-mix. Preferably this acid should comprise from 1 to ? by weight of the pre-mix. Ideally the acid comprises at least ^bou^ 2? by weight of the pre-mix. Ideally the acid doss not comprise more than 5? by weight of the pre-mix.

Although usually the acid be incorporated in the dry particulate mixture to which the solution or slurry is applied, it can in some instances be practical and useful to incorporate some or all of the acid in the solution or slurry. Citric acid is preferred, but other edible acids such as tartaric acid and ascorbic acid can be used. Edible acid salts such as sodium di-hydrogen phosphate can be used where the presence of the sodium will not lead to undue salt balance problem in the human or animal consuming the foodstuff. We infer from in vitro tests that the presence of the edible acid enhances the release of the active ingredient when the foodstuff incorporating the pre-mix enters the gut.

A further preferred embodiment of the invention is the inclusion of a food-grade colouring agent in the aqueous solution or slurry applied to the dry particulate mixture. Preferably the colouring agent is water-soluble. The objective is to ensure that the distribution of the aqueous solution or slurry throughout .the dry particulate mixture can be seen clearly. Thus the colour chosen should be one that - 6 4609 3 is clearly distinct from the base colour of the dry particulate mixture. In most embodiments of the invention, the base colour of the dry particulate mixture will be essentially white. Apart from this constraint, and the desirability of using a colouring agent that is cost-effective, the selection of the colour is entirely a matter of aesthetics.

The invention utilises the ability of lactose to absorb small quantities of water to form a glass-like solid. In a pre-mix prepared according to the invention, it is observed that the pre-mix comprises a multitude of small hard particles, each consisting of the edible inert powder bound by the lactose glass, distributed throughout the bulk of the dry particulate mixture. It is further observed that the active ingredient is almost wholly located in the lactose-bound particles. This is well demonstrated when a colouring agent is also included, because it is apparent to the eye that the colour is concentrated in the lactose-bound particles.

Arising from the critical selection of the proportions of the lactose to the edible inert powder, the pre-mix of the invention represents a composition which has a uniform! distribution of particles containing the active ingredient throughout its bulk and yet is a free-flowing particulate composition having little tendency to lump or segregate. Moreover, with the aid of the colouring agent when incorporated, it is possible to perceive the uniform distribution of the particles containing the active ingredient. The pre-mix has the additional advantage that the individual -7 4609 3 particules containing the active ingredients can be physically separated from the bulk of the edible inert powder, for example by hand or by screening, and assay of the active ingredient can be performed readily on the separated particles.

The pre-mixes of the invention are useful for a wide variety of active ingredients. However, a preferred use of these pre-mixes is in the incorporation of oral vaccines in foodstuffs. The invention is ideally suited to the preparation of pre-mixes containing endotoxins derived from bacterial strains implicated in gastro-intestinal disorders. Such endotoxins, when substantially free from association with any of the living bacteria, promote when administered orally a highly effective immune response to the bacteria. In particular this has been well demonstrated for Escherichia coli, and other gut-infective bacteria have proved susceptible also. An oral vaccine for pigs has been developed in which the endotoxins are derived from one or more of the E, coli strains 08, 045, 0138, 0139, 0141, 0149 and 0157. An animal feedstuff incorporating such an oral vaccine is described and claimed in our Patent No. 35321 , An analogous oral vaccine for calves contains endotoxins derived from one or more of the E, coli strains 08, 09, 015, 026, 0?8, 086, 0114, 0115, 0137 and 0139. The calf vaccine can in addition usefully contain endotoxins derived from Salmonella-dublin and/or Sg-tenalJa tvphimurlum.- An animal feedstuff incorporating such an oral vaccine is described and claimed in our Patent No. 37042 . A similar oral vaccine for lambs, incorporating - 8 46093 endotoxins derived from the E, coli strains 08, 09, 015, 020, 078, 0114, 0137 and 0139, is described in our British patent No. 1,462,384 and an animal feedstuff containing the oral vaccine is claimed therein.

Alternative active ingredients include antibiotics such as anticoccidial drugs; hormones; vitamins such as A and D, and provitamins such as beta-carotene; trace elements and minerals, such as sources of calcium, phosphorous, iron, manganese, copper and iodine; growth promoters; and flavours and perfumes. The need for such active ingredients to be present in foodstuffs for human and animal consumption is well known and well-documented in the technical literature, as also is the nature of such active ingredients and the extent to which they are available commercially. The nature of such active ingredients per se does not form part of the invention.

The concentration of the active ingredients in the aqueous solution or slurry is not critical, subject to the proviso that . the viscosity of the solution or slurry must be such that the solution or slurry can be sprayed as very fine droplets onto the dry particulate mixture.

Pre-mixes comprising more than one active ingredient can be prepared. All of the active ingredients involved can be included in a single aqueous solution or slurry if desired.

In some instances, the non-siraultaneous application of a separate solution or slurry for individual active ingredients car. be practical and advantageous. Where separate solutions or slurries are used, the incorporation of a distinctly different - 9 4 6 0 9 3 colouring agent in each solution or slurry can enable particles containing the different active ingredients to be identified in the resulting pre-mix.

Physical preparation of the pre-mix of the invention can be accomplished using any conventional equipment capable of intensely agitating a particulate material and simultaneously finely spraying a liquid onto the particulate material. Horizontal ribbon mixers can be used, and vertical spray mixers such as the Schugi mixer represent alternatives. If desired, the pre-mix can be prepared in a fluidised bed equipped with a spray head for the solution or slurry.

It will be appreciated that the particle size of the materials making up the dry particulate mixture, and also the droplet size of the solution or slurry when sprayed thereon, will influence the particle sizes found in the resulting pre-mix. By varying these parameters, it is possible to produce pre-mixes having different particles size distribution and in which the active ingredient is present in a large number of very minute particles, or in a lesser number of relatively large particles. Thus the invention makes it possible for a pre-mix to be tailored to meet different product requirements. The general principles governing the effects of substrate particle size, solution/slurry viscosity, spraying nozzle design and spraying pressure are well known to those skilled in food technology and related arts, and the techniques required for the physical production of a pre-mix in accordance with the invention are in themselves quite standard technology. - 10 4 6 0 9 3 As far as the particle size cf the ingredients in the dry particulate mixture is concerned, we have found that standard commercially-available ingredients are quite adequate.

Standard flours, in which, for example, all but a trace of the 5 particles are less than 20Cp in diameter, are perfectly suitable. So too are commercially-available whey powder and lactose powder. In general, it can be stated that each ingredient of the dry particulate mixture should preferably have a particle size such that at least 3C;3 by weight of the 1C ingredient will pass through a 50Cp screen, and ideally at least 90? by weight of each ingredient will pass through such a screen.

Preferably the quantity of solution ar slurry applied to the dry particulate mixture, and the spraying conditions used, should be selected such that the resulting pre-mix contains at least about 1000 lactose-bound particles containing the active ingredients per gram of prs-mix. Ideally a pre-mix of the invention will contain an even higher number of lactose-bound particles containing the active ingredients, and a level of at least about 2000 lactose-bound particles containing the active ingredient per gram of pre-mix should be aimed for. In an ideal pre-mix according to the invention, at least about 95* by weight of the active ingredient will be contained in distinct lactose-bound particles separable from the bulk of the pre-mix.

A pre-mix of the invention can be incorporated in a human or animal foodstuff by simple admixture, the proportion of - 11 >16033 pre-mix per unit weight of the foodstuff being chosen with regard to the concentration of the active ingredient present in the pre-mix and the concentration of the active ingredient desired in the foodstuff. In the preparation of compounded animal feedstuffs, the pre-mix can be added to nutrient materials at the milling stage. The nature of the nutrient materials that comprise the human or animal foodstuff in which the pre-mix is incorporated is not critical to the invention. Any of the usual protein, carbohydrate and fat materials can be used.

The pre-mix of the invention is a vendable product in its own right, as it can be sold for incorporation in foodstuffs made by different manufacturers.

Specific embodiments of the invention will now be described, by way of example only.

. Exawlg_l 250 kg of a dry particulate mixture was prepared by mixing together the following ingredients: Ingredient Dried wheat flour 58 Cheese whey powder 38 Citric acid 4 The dried wheat flour was a commercial product containing 4.8? moisture by weight. Over 99? by weight of the flour passed through a 195p screen. The cheese whey powder was also a commercial product, containing 6.1? by weight of moisture. Over 99? by weight of the whey powder passed through 532p - 12 4 0 0 9 3 screen, and over 68% by weight passed through a 195'J screen.

The dry particulate mixer was fed to a Gardner horizontal ribbon mixer fitted with 6 hollow-cone M2 spraying nozzles. While the dry particulate mixture was intensely agitated in the 5 mixer, it was sprayed with 12.5 litres (5? by weight) of an aqueous slurry of E, coli endotoxin material prepared according to procedure A of Example 3 of Patent specification No. 3532Ί and in which slurry hac been incorporated 125 gm of a commercially-available food-grade red azo dyestuff. Tne i; activity of the slurry was 3000 haemagglutination units of endotoxins for each E, coli serotype per ml. Spraying time was 30 minutes. Mixing was continued for several minutes after completion of spraying, to ensure even distribution of the pre-mix ingredients.

The pre-mix so formed was seen to comprise a free-flowing powder of very pale pink colour uniformly throughout which war. dispersed a large number of tiny, hard, intensely-coloured red particles.

The intensely-coloured particles could be readily serparated from the bulk of the pre-mix, and analysis revealed that over 98% of both the dyestuff and the vaccine activity resided in the intensely-coloured particles.

A particle size analysis of the pre-mix yielded the following result: - 13 V. f> bv weight of Particle diameter (μ) • pre-mix > 1999 0.4 800 - 1999 3.4 600 - 799 2.6 350 - 599 4.0 250 - 349 6.4 J 49 - 249 17.0 125 - 148 11.4 74 - 124 38.6 < 74 16.2 A particle count made on a sample of the pre-mix revealed that there were approximately 5000 intensely-coloured lactose-bound particles per gram of the pre-mix» This pre-mix was incorporated at levels of 0.5, 1.0 and 1.52 by weight in a standard feed composition for young pigs. The feed composition was milled and pelletted to give a creep feed consisting of small pellets, one gram of feed consisting of approximately 10 pellets. On average, each pellet would have contained 2.5 lactose-bound particles at the 0.5? inclusion level. Pigs fed on these feeds accepted them readily, and enjoyed the prophylactic benefits described in our Patent specification No. 35321.

Examples. 2._and 3 The procedure of Example 1 was repeated on two further 250kg batches of a dry particulate mixture of composition identical to that used in Example 1. In this instance, - 14 4 6 0 9 3 however, both batches were sprayed with 7 litres (2.8? by weight) of the aqueous slurry, and in Example 3 the M2 spraying nozzles were replaced by M6 nozzles. The spraying time in Example 2 was 12 minutes, and in Example 3 it was 5.5 minutes.

As in Example 1, a pre-mix consisting of a large number of minute intensely-coloured particles distributed uniformly through a pale-coloured powder resulted. The M6 nozzle induced the formation of some larger particles, consistent with the larger droplet size associated with this nozzle. However, the pre-mix of Example 3 was in no way inferior to that of Example 2. A particle size analysis of each pre-mix gave the following results: IJaLMigtaLae J2rs=ai2 Sxsmnls-Z. Sam > 1993 0.2 0.4 800 - 1999 0.4 3.6 600 - 799 0.6 3.0 350 - 599 2.2 2.2 250 - 349 6.4 2.6 149 - 249 50.6 29.6 125 - 148 11.4 13.4 74 - 124 15.0 29.6 < 74 13.2 15.4 The pre-mixes of Example 2 and Example 3 were each incorporated in standard pig feed compositions, and gave excellent results in feeding trials. - 15 4609 3

Claims

1. What we claim is:, ! f

1. A process for the preparation of a pre-mix, in which as’herein before defined ι process a dry particulate mixture of an edible inert powder/ and j ί / a lactose source, the lactose content of the mixture being from 5 20 to 50? by weight, is intensely agitated and while so intensely agitated is sprayed with an aqueous solution or slurry of an active ingredient (as hereinbefore defined), the solution or slurry being applied in an amount of from 1 to 12? by weight of the dry particulate mixture. 10

2. A process according to Claim 1 in which the lactose content of the dry particulate mixture is at least 22? by weight.

3. A process according to Claim 2 in which the lactose content of the dry particulate mixture is at least 25? by 15 weight.

4. A process according to any one of Claims 1 to 3 in which the lactose content of the dry particulate mixture is not greater than 45? by weight.

5. A process according to Claim 4 in which the lactose 2θ content of the dry particulate mixture is not greater than 35? by weight.

6. A process according to any one of the preceding Claims in which the amount of solution or slurry applied to the dry particulate mixture is at least 2? by weight. _IG.4 S Ο 9 3

7. A process according to any one of the preceding Claims in which the amount of solution or slurry applied to the dry particulate mixture is no greater than 10? by weight. 3. A process according to Claim 7 in which the amount of 5 solution or slurry applied to the dry particulate mixture is not greater than 6? by weight.

8. 9. A process according to any one of the preceding Claims in which the edible inert powder is a flour.

9. 10. A process according to Claim 9 in which the flour has 10 a moisture content of less than 10? by weight.

10. 11. A process according to any one of the preceding Claims in which the lactose source is whey powder.

11. 12. A process according to Claim 11 in which the dry particulate mixture comprises, by weight, from 40 to 70? of the 15 edible inert powder and from 60 to 30? of whey powder.

12. 13. A process according to Claim 12 in which the dry particular mixture comprises, by weight, from 50 to 65? of the edible inert powder and from 35 to 50? of whey powder.

13. 14. A process according to any one of the preceding 20 Claims in which the dry particulate mixture additionally comprises an edible organic cr an edible acid salt.

14. 15. A process according to Claim 14 in which the weak edible acid Is citric acid.

15. 16. A process according to Claim 14 or Claim 15 in which 25 the weak edible acid comprises from 1 to 10? by weight of the dry particulate mixture. - ιΊ 46093

16. 17. A process according to any one of the preceding Claims in which the solution or slurry incorporates a food-grade colouring agent.

17. 18. A process according to any one of the preceding Claims 5 in which the active ingredient is an oral vaccine comprising endotoxins derived from one or more bacterial strains implicated in gastro-intestinal disorders, the endotoxins being substantially free from association with any living bacteria.

18. 19. A pre-mix according to claim 18 in which the 10 endotoxins are derived from any one or more of the E.coli strains 08, 09, 015, 020, 045, 078, 0114, 0137, 0138, 0139, 0141, 0147 and 0149 and/or Salmonella dublin and/or Salmonella tvphimunium.

19. 20. A process for the preparation of a pre-mix, 15 substantially as hereinbefore described in any one of the Examples.

20. 21. A pre-mix which has been prepared by a process according to any one of the preceding Claims.

21. 22. The manufacture of a foodstuff for human or animal consumption which involves mixing with nutrient material a pre-mix according to Claim 21.

22.

23. A foodstuff for human or animal consumption which comprises nutrient material and a pre-mix according to Claim 21.