AU709952B2 - Liquid colostrum for dairy products - Google Patents

Description

WO 97/16977 PCT/AU96/007 0 8 1 LIQUID COLOSTRUM FOR DAIRY PRODUCTS The present invention relates to dairy compositions and, more particularly, to dairy compositions containing colostrum.

Raw milk contains between 0% and 1.0% immunoglobulin. However, for safety reasons milk for human consumption is pasteurised typically at 720C for seconds or 1320C for at least one second (UHT). Each of these heat treatments is sufficient to denature the immunoglobulin found in raw milk and also to denature certain other milk proteins such as, for example, certain growth factors.

The maximum cfu/mL allowed in milk (Australian Food Standard H1) that has been pasteurised according to the accepted methods is 50,000 cfu/mL. In practice the counts in pasteurised milk at time of manufacture are usually less than 10,000 cfu/mL.

Colostrum is the secretion obtained from female mammals just before and for a short period after giving birth. Raw colostrum contains up to immunoglobulin as well as other proteins such as growth factors. However, colostrum is routinely excluded from milk processing due to its very different composition which negatively affects processing efficiency and dairy product quality. Raw colostrum cannot be added to milk products for human consumption due to its bioburden. Colostrum cannot be pasteurised by standard methods without denaturing biologically active proteins such as antibodies. When subjected to heat treatment of greater than approximately 650C, colostrum will typically undergo severe chemical change leading to the failing of dairy processing equipment.

It is an object of the present invention to overcome, or at least alleviate, one or more of the difficulties or deficiencies associated with the prior art.

The applicant has discovered that colostrum can be processed so as to reduce the bioburden of liquid colostrum while retaining the biological activity of certain proteins including the immunoglobulin fraction. By this process it is possible to introduce liquid colostrum into pasteurised and unpasteurised dairy products including, for example, milk, skim milk, flavoured milks, other modified milks, yoghurts (natural, flavoured, drinking, frozen), other probiotic formulations, cheese formulations such as cheese sticks, and ice creams.

Accordingly in a first aspect of the present invention there is provided a process for the preparation of a liquid colostrum product, suitable for inclusion in dairy products, which process includes subjecting colostrum to a combination of flow-centrifugation to substantially reduce the microbial content thereof and heat treatment wherein the centrifugation is performed by controlling throughput and residence time of the colostrum during centrifugation and conducted at a temperature of less than 640C.

The colostrum may be freshly harvested colostrum or frozen colostrum. The colostrum may be bovine, ovine or caprine colostrum harvested from freshly calved animals. The colostrum may be harvested using modern milking equipment.

Preferably the colostrum is from one or more of the approximately first to tenth milkings after calving. The colostrum may be antibody enriched. For example the colostrum may be from a mammal hyperimmunised against specific pathogens of relevance to human or other diseases.

Specific pathogens which may be used to hyperimmunise the mammal include one or more of: 1) Cryptosporidium enteridies, 15) Toxoplasma gondii, Cryptosporidium parvum, 2) Isoporo belli, 16) Colstridium sp., 3) Giardia sp, 17) Campylobacterjejuni/coli, 4) Cytomegalovirus sp, 18) Entamoeba histolytica, 5) Salmonella sp, 19) Human immunodeficiency virus 6) Shigella sp, 20) Helicobactor pylori, 0. 2 7) Candida sp, 21) Cholera sp., S. 8) Rotavirus, 22) Respiratory syncitial virus S9) Blastocystis hominis, 23) Heamophilus influenzea Herpes simplex virus, 24) Astrovirus 11) Entero-toxigenic E. Coli, 25) Adenovirus 12) Aeromonas sp, 26) Mycobacterium spp.

13) Mycobacterium Avium 27) Calici virus intracellular, l 4) Yersinia entero-colitica, 28) Toro virus SS :\WINWORDUJOANNE\DYF\NODELETE\7 2 706.DOC Ai- O+Uj PCr/Au 9 6 0 0 7 0 8 RECEIVED 2 6 SEP 1997 -3- The colostrum may be from a mammal hyperimmunised against specific proteins or enzymes such that the specific antibodies produced are of relevance in the. prevention or treatment of human diseases or metabolic disorders.

The bacteria-removing centrifugation may be performed at a speed of approximately 7000-8000 rpm, preferably approximately 7400 rpm, to generate approximately 11,000 g to 14,000 g at approximately 1100 L per hour, preferably 12,000 g at approximately 1100 L per hour. An Alfa Laval Bactofuge has been found to be suitable.

Ideally, it is preferable that the centrifugation is performed by controlling throughput and thereby residence time of the colostrum such that the microbial content is reduced to less than 500 organisms per ml, preferably 200 organisms per ml, most preferably less than 50 organisms per ml.

Preferably, the centrifugation is conducted at a temperature of approximately 500C to approximately 64 0 C. More preferably, the centrifugation is conducted at a temperature of approximately 550C to approximately 630C.

Following centrifugation, the colostrum may be chilled to below approximately 100C, preferably to below approximately In a preferred form, the process of this aspect of the invention may include the preliminary step of separating the colostrum. Preferably the colostrum is separated into a light phase (cream) and a heavy phase (skim).

Preferably the light phase is discarded and the heavy phase is processed according to the present invention.

Any suitable separation apparatus may be used. A preferred separation apparatus is a self desludging type apparatus.

Preferably the colostrum is pre-heated to a temperature of approximately 500C to approximately 640C, more preferably approximately 550C to approximately 630C, for a period of approximately 3-60 minutes, more preferably approximately 30 minutes, post the separation step. Any suitable means may be used to preheat the colostrum, for example a plate heat exchanger.

SVAT:\Winword\Violet\Nodelete\p3cl 8nth.doc H ET

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RFprcEi~vn 2 2 FP 9Q7 3a It will be understood that the steps of the process of this aspect of the present invention-may take place in any suitable order. Other steps may also be included in the process of the present invention. For example in preferred embodiment of the process casein is removed from the colostrum by precipitation.

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JPEA/AU

WO 97/16977 PCT/AU96/00708 4 Preferably this step takes place after the colostrum has first been subjected to a separation step and the light phase has been discarded, and then subjected to centrifugation according to the present invention.

In a further preferred embodiment of the process the colostrum is concentrated by means of ultrafiltration and/or evaporation and/or reverse osmosis. Preferably this step takes place after either the centrifugation or, if relevant, after the casein removal.

In a still further preferred embodiment of the process the colostrum is sterile filtered. Preferably this step takes place after the casein removal.

The method according to the present invention gives results that are consistently better than the results gained with standard pasteurisation and allows for the addition of colostrum to pasteurised dairy products and/or the processing of dairy products including a colostrum component with little or no diminution of the shelf life/stability expected with normal dairy products. For example, colostrum may be added to dairy products including raw or pasteurised whole milk, skim milk, or modified milk products including flavoured milks, and the resulting mixture processed as described above.

Applicant has found that the total microbial count in liquid colostrum treated according to the process of the present invention is reduced by at least approximately 80%, preferably at least approximately 90%, more preferably at least approximately 95%. For example, a combination of gentle heat treatment at 550C and bactofugation typically renders a minimum 99% reduction in total microbial count. Moreover, a substantial proportion of the antibodies and/or growth factors in the liquid colostrum produced according to the method of the present invention remain undenatured following the treatment.

Because of the high concentration of immunoglobulin in the fresh, processed colostrum, only a relatively small proportion of colostrum is required to be added to milk or dairy products to bring the resulting product up to the level of antibodies normally found in pre-processed milk, eg., approximately colostrum processed according to the invention will typically provide 100% as much immunoglobulin or more as pre-processed milk.

Due to the economy and effectiveness of this approach it is now possible to WO 97/16977 PCT/AU96/00708 safely provide dairy produce which contains undenatured antibodies and growth factors. The undenatured immunoglobulins may be targeted against specific human diseases or metabolic disorders by hyperimmunising the mammal, providing a very effective palatable form of therapy.

Accordingly, in a second aspect of the present invention there is provided a method of preparing a dairy composition including undenatured antibodies and/or growth factors which method includes adding to a dairy product a liquid colostrum product.

Preferably the liquid colostrum product is from a bovine, ovine or caprine source. Preferably the liquid colostrum product is produced by the process of the present invention. The liquid colostrum product may be added to the dairy product at any time. Preferably, the addition occurs after the dairy product has been pasteurised.

The dairy product may be of any suitable type and includes pasteurised and unpasteurised dairy products such as milk, for example raw or pasteurised full-cream, skim, modified, flavoured milk; yoghurt, for example natural, flavoured, frozen or drinking yoghurt; tonics and sports drinks; and other dairy products such as custards, cheese and cottage cheese formulations, and ice creams.

Preferably the colostrum is added in an amount of approximately 1% w/w to approximately 50% w/w, more preferably approximately 2% w/w to approximately w/w, most preferably approximately 5% w/w to approximately 10% w/w.

In this manner it is possible to provide a milk or other dairy product containing a measurable quantity of undenatured antibodies, preferably at a concentration similar to or greater than that found in raw milk prior to a normal pasteurisation process (eg. approximately 0.2% IgG). Alternatively or in addition the milk or other dairy product may contain undenatured growth factors.

In a still further aspect of the present invention there is provided a dairy composition for human consumption including liquid colostrum that has not been subjected to a drying process.

Preferably, the liquid colostrum product is from a bovine, ovine or caprine source. Preferably the liquid colostrum product is produced by the process of the present invention.

WO 97/16977 PCT/AU96/00708 6 The dairy product may be of any suitable type and includes pasteurised and unpasteurised dairy products such as milk, for example raw or pasteurised full-cream, skim, modified, flavoured milk; yoghurt, for example natural, flavoured, frozen or drinking yoghurt; tonics and sports drinks; and other dairy products such as custards, cheese and cottage cheese formulations, and ice creams.

Preferably, the dairy composition includes approximately 1% wlw to approximately 50% w/w, more preferably approximately 2% w/w to approximately w/w, most preferably approximately 5% w/w to approximately 10% w/w of liquid colostrum.

In this manner it is possible to provide a milk or other dairy product containing a measurable quantity of undenatured antibodies, preferably at a concentration similar to or greater than that found in raw milk prior to a normal pasteurisation process (eg. approximately 0.2% IgG Alternatively or in addition the milk or other dairy product may contain undenatured growth factors.

The present invention will now be more fully described with reference to the accompanying Examples. It should be understood, however, that the description following is illustrative only and should not be taken in any way as a restriction on the generality of the invention described above.

Example 1 Centrifugation of Colostrum Materials: skimmed colostrum whole colostrum Apparatus: Alfa Laval D-3187M-60 Bacterial centrifuge

SUMMARY

This study was designed to test the suitability of the Alfa Laval D3187M-60 at reducing bacterial loads in colostrum. The equipment was installed in-line (between Past I and UFS-2) to reduce total bacterial counts with the aim of reliably producing a product with less than 1000 organisms/gram.

PURPOSE

To evaluate the suitability of the Alfa Laval D3187M-60 at reducing total bacterial load in colostrum.

WO 97/16977 PCT/AU96/00708 7

PROCEDURE

Bactofuge D3187M-60 was installed and commissioned on H 2 0. Flow rates were set at: inlet 672 Iph outlet 600 Iph bactofugate 72 Iph i) Skimmed colostrum Skim colostrum was heated to 550C for 30 minutes (not pasteurised) and passed through the bactofuge using the parameters outlined above.

N.B. heating to 55C reduced bacterial count from 2.65 x 107 to 4.9 x 106 or 81.5% reduction, which is not suitable for human consumption.

ii) Whole colostrum batch 2B02 Whole colostrum was processed as a complete batch and various microbiological samples taken.

iii) Whole colostrum batch 2B03 Whole colostrum was processed as a complete batch through to powdered stage.

RESULTS

i) Skimmed Colostrum Raw colostrum Heat treated skim (55°C, 3 min) Centrifuged skim Total reduction ii) BATCH 2B02 Raw colostrum Heat treated (600C, 30 min) Centrifuged skim Total reduction 2.65 x 107 4.9 x 106 1.86 x 103 99.99% cfu/mL (81.5% reduction) (99.96% reduction) 1.22 x 10 4 cfu/mL 6.65 x 102 (94.5% reduction) 16 (97.6% reduction) 99.9% WO 97/16977 PCT/AU96/00708 8 iii) BATCH 2B03 Raw colostrum 1.42 x 105 cfu/mL Heat treated (63 0 C, 30 min) 3.2 x 102 (99.8% reduction) Centrifuged skim 33 (89.7% reduction) Total reduction 99.98%

DISCUSSION

The results indicate that the Alfa Laval DM-3187M-60 Bacterial Centrifuge is effective at removing up to approximately 99% of heat resistant organisms (ie.

those organisms surviving heat treatment), providing a total reduction in bioburden from raw colostrum of at least 99.9%.

With a good quality colostrum it is possible to produce good quality concentrate (<100 cfu/mL).

CONCLUSIONS

The Alfa Laval D-3187M-60 Bacterial Centrifuge is effective at removing organisms from colostrum to an extent that it is acceptable for inclusion in dairy products such as milk.

Example 2 Reduction of colony forming units after bacterial centrifugation Samples of colostrum were collected. The colostrum was sampled and then treated by firstly separating the colostrum into a light phase (cream) and a heavy phase (skim) before bacterial centrifugation. Samples of each batch (treated and raw) were removed at various stages, including before and after separation into light (cream) and heavy (skim) phases, and before and after bacterial centrifugation. Bacterial counts measured as colony forming units (CFU)/mL were assessed to determine overall reduction of CFU's.

PROCEDURE

Bactofuge D3187M-60 was installed and commissioned on H 2 0. Flow rates were set at approximately: inlet 1600 Iph outlet 1440 Iph bactofugate 160 Iph PCTM.U 9 a/ i o 7 0 d RECEIVED 2 1 JUL 1997 9 i) Skimmed colostrum Skim colostrum was heated to 55C for 3 minutes (not pasteurised) and passed through the bactofuge using the parameters outlined above.

RESULT

Thirty seven samples of colostrum were processed as outlined above. After bacterial centrifugation the average CFU/ml was 44.97 CFU/ml which represented a 99.86% overall reduction of CFU's from raw colostrum to the processed colostrum product.

CONCLUSION

Clearly the combination of skimmed colostrum heated to 550C and centrifuged at the 1600 Lph flowthrough rate is an effective means of reducing bacterial load whilst reducing the incidence of denaturing the biologically active proteins by exposure to high temperatures.

Example 3: Dairy Composition

PROCEDURE

The colostrum was processed as described in Example 2. Two separate experiments were conducted. The first was from batch 6F01 which was a batch of low litre colostrum of all failed materials, such that its original bacteriology was very dirty prior to bactofugation. The second was from batch 6F03 which was high titre colostrum of all grade materials such that its original bacteriology was very clean.

The figures for the raw and bacterial centrifuged samples are given in Table 1 below.

Sample Total Count Coliform Staphylococcus 6F01 Raw 50o,o000 670 380,000 6F01 Bactofuged 1 0 0 I 6F03 Raw 1.400 SF03 Bactofuged 5 0 0 Tabe I AMENDED

SHEET

IPEA/AU

WO 97/16977 PCT/AU96/00708

RESULTS

The results for the bacterial centrifuged colostrum from batch 6F01 when added to whole milk and skim milk at 10% are given in Table 2 and compared with milk and colostrum controls: Sample Time Time 0 2 days 4 days 6 days 8 days days 12 days 14 days Neat 10% Col./ 10% Col./ Colostrum Whole Milk Skim Milk 11 1,100 1,300 15 1,200 1,200 12 1,200 1,400 16 1,200 1,500 13 1,500 1,400 12 1,200 1,400 18 1,100 1,300 7 1,000 1,200 9 1,000 1,600 Whole Milk Skim Milk Control Control 1,400 1,400 1,100 1,400 1,300 1,600 1,400 1,400 1,200 1,600 1,200 1,400 1,200 1,600 1,100 1,100 Table 2 All samples in experiment 1 showed no changes to bacterial load over the test period. Furthermore the neat colostrum and the 10% colostrum in full cream milk sample (samples 1 and 2) continued to be tested. Sample 2 took 30 days to reach 58,000 cfu/mL and sample 1 showed no growth at the 46 day mark.

The results for the bacterial centrifuge bactofuged colostrum from batch 6F03 when added to whole milk and skim milk at 10% are given in Table 3 and compared with milk and colostrum controls.

WO 97/16977 PCT/AU96/00708 Sample Time Time 0 2 days 4 days 6 days 8 days days 12 days 14 days Neat Colostrum 5 7 9 9 4 13 500 74,000 10% Col./ Whole Milk 1,600 1,400 1,100 1,400 1,200 7,700 180,000 32,000,000 10% Col./ Whole Milk Skim Milk Skim Milk Control Control 1,500 1,700 1,700 1,500 1,500 1,400 1,500 1,400 1,600 1,300 1,500 1,500 1,200 1,500 1,600 6,200 5,100 15,300 140,000 200,000 400,000 27,000,000 45,000,000 61,000,000 Table 3 Samples in experiment 2 showed no difference in bacterial loading between dairy compositions with colostrum processed and those without.

Considering both experiments together it can be seen that the addition of colostrum to full cream or skimmed milk has no affect on the shelf life of those products.

Example 4 Stability of Antibodies in Dairy Compositions

AIM

The aim of the study was to assess the stability of colostral antibodies at 4°C for 14 days.

MATERIAL AND METHODS Two batches of colostrum 6F01 and 6F03, including high and low titre of antibodies was used for this study. From each batch 10% of colostrum was mixed with whole milk as well as with skim milk. Samples were withdrawn on day 0, 2, 4, 6, 8, 10, 12, 14 from 4°C and frozen -20OC until assayed.

The experiment was performed using standard SOP10.01 and each sample was tested three times.

RESULTS

The two tables below showing the result of rotavirus antibodies titre over 14 WO 97/16977 PCT/AU96/00708 days, in two batches of colostrum.

BATCH 6 F03 TABLE 4 Day Neat Colostrum 10% Colostrum in Whole Milk 4841 0 48960 2 56378 4 50937 6 56898 10% Colostrum in Skim Milk 4874 3963 4348 5415 4544 4841 5008 8 61612 5063 5750 61612 5154 4829 12 55024 3927 5803 14 66839 5063 5334 BATCH 6 F01 TABLE Day Neat Colostrum 10% Colostrum 10% Colostrum in Whole Milk in Skim Milk 0 3263 491 472 2 2979 468 458 4 2737 468 485 6 3062 493 430 8 2840 464 462 3255 549 463 12 3115 463 459 14 3179 541 465

I

DISCUSSION

Table 6 shows the summary of the results from this study.

WO 97/16977 PCT/AU96/00708 13 TABLE 6: Results of testing rotavirus antibodies in high and low titre milk samples by ELISA.

SAMPLE MEAN SDEV COVAR

T-TEST

POSITIVE 1 57282 5908 10% 0.26 BATCH 2 4805 403 8% 0.99 6F03 3 5040 657 10% 0.33 NEGATIVE 1 3054 191 6% 0.72 BATCH 2 492 37 7% 0.57 6F01 3 462 16 10% 0.96 SAMPLE 1 neat SAMPLE 2 10% colostrum in whole milk SAMPLE 3 10% colostrum in skim milk

DISCUSSION

The results of this study indicate that rotavirus antibodies measured by ELISA in colostrum are considerably stable at 4°C over 14 days in the dairy composition according to the invention.

CONCLUSION

This study shows that colostrum prepared according to the invention has very stable rotavirus antibodies and can be stored in the fridge for period of at least 2 weeks with no detrimental effects to the rotavirus antibody titre.

Example 5 Taste testing

PURPOSE

To determine on a small scale if subjects could detect a difference in taste and preference for milk preparations containing various concentrations of freshly processed liquid colostrum.

MATERIALS

Homogenised, full cream milk WO 97/16977 PCT/AU96/00708 Skimmer milk Iced Coffee milk Batch 5F01 colostrum obtained directly after separation and bactofugation.

Numbered cups.

METHODS

Three experiments were carried out to determine the effect colostrum had on the taste of 3 types of milk.

Experiment one Colostrum was mixed with Iced coffee milk product in the proportions: 20%. The different products were put into numbered cups, and subjects asked to taste each product and rank the numbered cups in order of taste preference.

Concentration 0 Cup No.

3

RESULTS:

Person

AS

GP

RP

RR

CC

JP

Ranking 4 2 4 2 1 4 Comments 2 creamiest, 1 more like skim 3 is the iced coffee product, 4 is most like real coffee did not like 2 or 3 no difference all nice all OK The results from experiment one indicate that: 1. Subjects were not able to detect taste difference to ice coffee milk when separated bactofuged colostrum from batch 5F01 was added up to w/w.

WO 97/16977 PCT/AU96/00708 2. Cups 3 and 4 were preferred by two subjects. These products respectively contained 0% and 20% colostrum, again indicating that the addition of colostrum does not significantly affect taste preference.

Experiment two Colostrum was mixed with homogenised full cream milk product in the proportions: 20%. The different products were put into numbered cups, and subjects asked to taste each product and rank the numbered cups in order of taste preference.

Concentration Cup No.

0 2 2 4 8 1 3

RESULTS:

Person Ranking Comments AS 3 2 On first tasting, 3 seemed best.

On second tasting, 2 seemed best PW 3 1 2 4 Not really much difference RP Couldn't tell, all tasted bad.

BC 2 1 4 3 MS 2 3 4 1 All OK, can't tell much difference JT 1= 4= 3= 2 Only 2 seemed worse The results from experiment two indicate that: 1. Subjects were not able to detect taste difference to milk when separated bactofuged colostrum from batch 5FO1 was added up to 20% w/w.

2. Cups 2 and 3 were preferred by two subjects each. These products respectively contained 0% and 20% colostrum, again indicating that the addition of colostrum does not significantly affect taste preference.

3. One person ranked the 20% colostrum worst, while one ranked the 0% WO 97/16977 PCT/AU96/00708 16 colostrum worst. The person ranking the 20% colostrum worst ranked the normal product best. This was the only person to get close to ranking taste preferences according to colostrum content.

Experiment three Colostrum was mixed with skimmer milk product in the proportions: 16%, 40%. The different products were put into numbered cups, and subjects asked to taste each product and rank the numbered cups in order of taste preference.

Concentration Cup No.

0 1 4 2 16 3 4

RESULTS:

Person Ranking Comments AS 1 2 3 4 Colour difference was noticeable, taste OK.

PW 3 3 was least liked RP 2 3 1 4 BC 1 3 2 4 MSp 2 3 4 1 All OK, can't tell which is milk, 4 is richer; 2 is creamier than 1.

MS 1 2 4 3 The results from experiment three indicate that: 1. When colostrum from batch 5F01 was added to skimmer milk, at the higher concentrations, a difference was noticeable, both in colour and mouth feel.

2. Cup 4 (40% colostrum) was ranked bottom, taste was acceptable, just noticeably different.

WO 97/16977 PCT/AU96/00708 17

CONCLUSION

Overall the study indicates that fresh, skim, bactofuged colostrum similar to that produced in batch 5F01 should be an acceptable additive to white milk and flavoured milk in the proportion intended (approximately 20% or less). Only when added to skim at 16% or more is there likely to be a noticeable difference.

Finally, it is to be understood that various alterations, modifications and/or additions may be made without departing from the spirit of the present invention as outlined herein.

Claims (29)

1. A process for the preparation of a liquid colostrum product, suitable for inclusion in dairy products, which process includes subjecting colostrum to a combination of flow-centrifugation to substantially reduce the microbial content thereof and heat treatment wherein the centrifugation is performed by controlling throughput and residence time of the colostrum during centrifugation and conducted at a temperature of less than 640C.

2. A process according to claim 1 wherein the centrifugation is performed by controlling throughput and thereby residence time of the colostrum during centrifugation such that the microbial content is reduced to less than 1000 •••organisms per ml.

3. A process according to claim 1 wherein the centrifugation is performed by controlling throughput and thereby residence time of the colostrum such that S S 15 the microbial content is reduced to less than 200 organisms per ml. e.e 4. A process according to any one of claims 1 to 3 wherein the centrifugation is performed to generate a force in the range of 12,000 g to 14,000 g.

5. A process according to any one of claims 1 to 4 wherein the O.o. S. 20 centrifugation is performed with a throughput of 1100 litres per hour.

6. A process according to any one of claims 1 to 5 wherein the centrifugation is conducted at a temperature of approximately 550 C to approximately 630 C.

7. A process according to any one of claims 1 to 6 wherein the colostrum is chilled to below 100C following centrifugation.

8. A process according to claim 7 wherein the colostrum is chilled to below approximately

9. A process according to any one of claims 1 to 8 including a preliminary step of separating the colostrum into a light phase and a heavy phase and wherein the heavy phase is centrifuged. C:\Wlnword\Violet\Nodelete\Northfddoc A process according to any one of claims 1 to 9 including a preliminary step of preheating the colostrum to a temperature of approximately 500C to approximately 64°C prior to centrifugation.

11. A process according to claim 10 wherein the colostrum is preheated to approximately 630C.

12. A process according to claim 10 or 11 wherein the colostrum is preheated for approximately 3 to 60 minutes.

13. A process according to claim 12 wherein the colostrum is preheated for approximately 30 minutes.

14. A process according to any one of claims 1 to 13 including removing casein from the colostrum prior to centrifugation.

15. A process according to claim 14 wherein the casein is removed after 0 separation of the colostrum into a light phase and a heavy phase. 1 16. A process according to any one of claims 1 to 15 including concentrating the colostrum either after centrifugation or after casein removal. S' 17. A process according to claim 16 wherein the colostrum is concentrated by means of ultrafiltration and/or evaporation and/or reverse osmosis.

18. A process according to any one of claims 1 to 17 wherein the colostrum is sterile filtered. 20 19. A process according to any one of claims 1 to 18 wherein the colostrum is freshly harvested or frozen.

20. A process according to any one of claims 1 to 19 wherein the colostrum is bovine, ovine or caprine colostrum.

21. A process according to any one of claims 1 to 20 wherein the colostrum is obtained from a mammal hyperimmunized against a pathogen.

22. A process according to claim 21 wherein the pathogen includes one or more of the pathogens selected from the group including: 1) Cryptosporidium enteridies, 15) Toxoplasma gondii, Cryptosporidium parvum, 2) Isoporo belli, 16) Colstridium sp., 3) Giardia sp, 17) Campylobacter jejuni/coli, C:\Wlnword\Violet\Nodelete\Northfd doe 4) Cytomegalovirus sp, Salmonella sp, 6) Shigella sp, 7) Candida sp, 8) Rotavirus, 9) Blastocystis hominis, Herpes simplex virus, 11) Entero-toxigenic E. Coil, 12) Aeromonas sp, 13) Mycobacterium Avium intracellular, 14) Yersinia entero-colitica, A process according to any one processes. 18) Entamoeba histolytica, 19) Human immunodeficiency virus 20) Helicobactor pylori, 21) Cholera sp., 22) Respiratorysyncitial virus 23) Heamophilus influenzea 24) Astrovirus 25) Adenovirus 26) Mycobacterium spp. 27) Calici virus 28) Toro virus of claims 1 to 22 which excludes any 9 9 9 99 S 9..

23. 15 drying *9* 0 99 5 9ee* h0 09 S .9 9 9.. 9 9 1 S. S 9* .9

24. A liquid colostrum product prepared by a process according to any one of claims 1 to 23. A method of preparing a dairy composition including undenatured antibodies and/or growth factors which method includes adding to a dairy 20 product a liquid colostrum product according to claim 24.

26. A method according to claim 25 wherein the liquid colostrum product is added after pasteurisation of the dairy product.

27. A method according to claim 25 or 26 wherein the liquid colostrum product is added in an amount of approximately 1 w/w to approximately w/w.

28. A method according to any one of claims 25 to 27 wherein the colostrum is added in an amount of approximately 2% w/w to approximately 20% w/w.

29. A method according to any one of claims 25 to 28 wherein the colostrum is added in an amount of approximately 5% w/w to approximately 10% w/w.

30. A dairy composition prepared by the method according to any one of claims 25 to 29. C:\Winword\Violet\Nodelete\Northfd.doc 21

31. A dairy composition according to claim 30 including a measurable quantity of undenatured antibodies and/or growth factors at a concentration similar to or greater than that found in raw dairy products prior to normal pasteurisation processes.

32. A dairy composition according to claims 30 or 31 including a dairy product selected from the group including pasteurised and unpasteurised dairy products including milk which is raw or pasteurised, full-cream, skim, modified or flavoured milk; yoghurt, including traditional natural, flavoured, frozen or drinking yoghurt; tonics and sports drinks; and other dairy products including custards, cheese and cottage cheese formulations, and ice creams.

33. A method of preventing and treating a human disease or metabolic disorder including administering an effective amount of a dairy composition according to any one of claims 30 to 32.

34. A method of preventing and treating a human disease or metabolic 15 disorder caused by any one or more pathogens selected from the group including S. 0 00*@ qe@S 0000 00 *0 .06 0* S 5 00 00 S OS* 0000 1) Cryptosporidium enteridies, Cryptosporidium parvum, 2) Isoporo belli, 3) Giardia sp, 4) Cytomegalovirus sp, Salmonella sp, 15) Toxoplasma gondii, 0* 0 S 00 Shigella sp, Candida sp, Rotavirus, Blastocystis hominis, Herpes simplex virus, Entero-toxigenic E. Coli, Aeromonas sp, Mycobacterium Avium 20) 21) 22) 23) 24) 25) 26) 27) Clostridium sp., Campylobacter jejuni/coli, Entamoeba histolytica, Human Immunodeficiency virus Helicobactor pylori, Cholera sp., Respiratory syncitial virus Heamophilus influenzea Astrovirus Adenovirus Mycobacterium spp. Calici virus C:\Wlnword\Violet\Nodelete\Northfd.doc intracellular, 14) Yersinia entero-colitica, 28) Toro virus said method including administering an effective amount of a dairy composition according to any one of claims 30 to 32.

36. A process according to claim 1 substantially as hereinbefore described with reference to Examples 1 to 4. DATED: 1 July, 1999 0 0 6000 S S. 0 56 S 5* 56 0 *S~ PHILLIPS ORMONDE FITZPATRICK Attorneys for: NORTHFIELD LABORATORIES PTY LTD ki C:SnodVoe\odlt\otf~o