DE2354475A1 - Reducing lactose content in milk - by ultra-filtration and reverse osmosis, washing and mixing, and processing - Google Patents

Abstract

Diet milk having a modified lactose content is prepd. by (i) subjecting starting milk to ultra-filtration to recover a concentrate (I), consisting of milk pt. which does not pass through ultra-filter, and a permeate (II), consisting of milk pt. passing through ultra-filter; (ii) combining at least pt. of (I) and (II) having reduced lactose contents and (ii) subjecting prod. obtd. to at least one processing treatment. Lactose content in (II) may be reduced by reverse osmosis, to obtain a concentrate (III) contg. water, lactose, salts and low mol. wt. substances and a 2nd permeate (IV) consisting of water with a low salt content. Lactose content in (I) may be reduced by washing, esp. with deionised water or with (IV). Lactose content in (III) may be reduced by consecutive evaporation and crystallisation steps. Mixing conc. soln. from reverse osmosis with washed (I) may be preceded by enzyme-treatment of residual lactose with beta - galactoxydase and gal-l-P-uridyl transferase.

Description

Process for the production of a diet milk with modified lactose content The present invention relates to a method for producing a diet milk with Modified lactose content through ultrafiltration and reverse osmosis0 Furthermore the invention relates to the product obtained by this process.

It has already been shown to a large extent that there are many forms of tolerance reactions of humans towards milk for an intolerance to that present in milk Lactose are due. This will be congenital or acquired intolerance caused by the lack of the hydrolptic lactose enzyme (0-calactoxidase) in the intestine and disappears after a diet during which the lactose is quantitatively reduced This intolerance was reported by Fois et al. (Acta Paed0Latina, 13,596,1961), Durand and Lamedica (Helv. Paed. Acta 17, (6), 395, 1962) et alO described some Industries have already tried to produce a milk with reduced lactose content For example, Stimpson (U.S. Patent N4. 2,681,858, 1954, and 2,782 266, 1957) a process for the hydrolytic conversion of lactose into galactose and glucose patented using yeast. However, through this procedure the taste becomes the milk changed.

De Koning uses gel filtration (The Neth.Milk and Dairy Journal, 16, 210-216, 1962), but a completely desalinated product is obtained here.

The lactose removal proposed according to the invention is essentially based on two fundamental, already known physical principles, namely ultrafiltration (UF) and reverse osmosis (OeT.) The ultrafiltration takes place at moderate pressure (0.5-10 atü) through porous membranes (e.g. CUT-OFF-MG 20,000) with Almost complete retention of the seroproteins, but separation of the substances with a molecular weight of less than 20,000 (e.g. lactose, vitamins, enzymes). Reverse osmosis is based on the same principle of ultrafiltration that there will be however, higher gaps (e.g. 40-100 atmospheres) and membranes with very low porosity (Pore diameter 2-5 Å, e.g. a NaCl retention of 98%), an almost complete one Retention of lactose (MW-360,32) and other substances with low molecular weight and separation of H2O and some salts (e.g.

small amounts of NaCl are used. Also bet the osmosis will be two separate Factions received. For example, from an aqueous solution containing lactose, On the one hand, it contains salts and substances with relatively small molecular diameters Lactose and, on the other hand, water, salts and low molecular weight substances The main aim of the invention is to provide a diet milk with changed lactose content or almost completely removed lactose and one Process for the production of the pasta milk according to physical methods without assistance chemical treatment.

methods and avoiding the formation of glucose or galactose.

Another object of the invention is to provide a milk product with greatly reduced lactose content, in which, however, the others continue Starting products of the milk are included.

These and others can be seen more clearly in the following description The method according to the invention for producing a diet milk achieves objectives achieved with reduced lactose content, which is characterized in that the starting milk of an ultrafiltration for the purpose of obtaining a concentrate, consisting of from the part of the milk that did not pass through the ultrafilter, and one Permeate, consisting of the part of the milk that has passed through the ultrafilter, is subjected to at least a portion of the concentrate and permeate with so reduced Lactose content is combined and that the product obtained in this way at least is subjected to manipulation treatment.

According to the invention, the lactose content is reduced in the concentrate by washing the concentrate.

Furthermore, according to the invention, the lactose content of the permeate is determined from the ultrafiltration preferably reduced by the fact that the permeate a reverse osmosis, whereby a concentrate of the permeate from the ultrafiltration, which Water, lactose, salts and low molecular weight substances and a second Permeate consisting of water containing very few salts. This Second permeate is preferably used to carry out the various washing stages of the concentrate from ultrafiltration is used.

The lowering of the lactose content is also in accordance with the invention in the concentrate from the reverse osmosis by preferably successive Evaporation and crystallization stages reached.

The invention preferably includes a possible subsequent enzymatic Treatment of the lactose remaining in solution in the reverse osmosis concentrate by exposure to ß-galactoxidase and Gal-l-P-uridyl transferase prior to mixing or combining the concentrated reverse osmosis solution with the washed one Concentrate from ultrafiltration.

According to the invention, the addition of die is used as a manipulation treatment Lactose-replacing carbohydrates (saocharose, sacharin and / or malt dextrin) such as also possibly the direct atomization of this mixture for the purpose of obtaining a powdery one Product or the addition of water from reverse osmosis for the purpose of extraction of a liquid product and, if necessary, homogenization and sterilization of the product or a freezing treatment, lyophilizing treatment and the like.

Further features and advantages of the method according to the invention are The following description of some exemplary embodiments without the invention to be limited to these, referring to the accompanying drawings, whereby FIG. 1 relates to example 1 and FIG. 2 to example 2.

In addition, further examples are given below with the relevant Analysis data are given, whereby the designations chosen in the drawings are retained became.

Example 1: A starting skimmed milk (protein content 3%, lactose content 5%) becomes an ultrafiltration using porous in a manner known per se Subjects to membranes with pore diameters of 20 2 (Angstroms), with under one Pressure of 2 kg / cm2 is worked. From this ultrafiltration one gains one first fraction (A I) (6% protein concentrate corresponding to twice the concentration the starting milk, lactose content 2.5%; the content of other substances is as at Lactose, reduced by 50) and a second permeate fraction (A II), consisting of a salt solution containing very little protein (below o, l), an amount of lactose of 5% and the same amount of substances contained in the starting milk with little Molecular weight.

The permeate (A II) is subjected to reverse osmosis, which in known membrane filter devices is carried out, which in this Trap have pore diameters of the order of 4 R. The operating pressure is 40-60 at.

A first fraction (B I) is obtained from this reverse osmosis, consisting of a concentrated aqueous solution of lactose (content 19.5%), from which the lactose is easily removed by crystallization and used industrially can be (possibly with extraction of the water and salts), and a second Fraction (B II), which consists only of water, salts contained in milk and all others substances naturally occurring in milk with molecular weights and molecular weighters that are below those of lactose.

According to the invention, the aforementioned dilute salt solution is used at this point (B II) added to protein concentrate A I to dilute the concentrate and reduce the protein content and lactose content. The invention also proposes before, the so diluted concentrate A I further in the course of one of the already explained Handle cycle completely analog cycle. Indeed, the diluted points Concentrate A I has a protein content of 3.2 and a lactose content of 2.6%. The second work cycle results in a further reduction in the lactose content. When the dilute concentrate A I is ultrafiltered, two fractions are again produced received, namely a new concentrate (6% proteins, 1.3% lactose) and a permeate consisting of lactose, water and salts, which are subjected to reverse osmosis to further reduce the lactose content.

When the desired lactose content (0.5%) is achieved in the concentrate then the concentrate will contain fractions B II and other analogous fractions mixed from four different work cycles. The different ones, from milk obtained water and salt fractions, which, as mentioned, the protein concentrate with reduced lactose content had been admixed, result in a milk with the following Properties: protein content 2.9%, lactose content 0.6%, using of the water and the salts resulting from the crystallization of lactose The amount of diet milk that is given is that of the amount of the starting milk and less of the lactose corresponds to the processing salts.

Example la: The first ultrafiltration of another milk sample with a protein content of 3.1% is carried out until the concentrate has 12% proteins contains (about four times the concentration) and consequently the amount by weight of the liquid and the lactose corresponds to about half that of Example 1.

In this case there are two working cycles that are completely the same Way to be carried out as described in Example 1, sufficient to make a milk of the same concentration of protein and lactose as in the previous example to obtain.

According to the invention, therefore, the reverse osmosis is used Salt solution used to circulate the concentrate from the ultrafiltration respectively. This is necessary to produce milk with a known and desired lactose content to get, because it is not due to physical reasons (viscosity, osmotic pressure) is possible, with only a first ultrafiltration, a volume reduced in this way To obtain protein concentrate (for example with a protein content of more than 3o%) that a desired small residual amount of lactose is achieved. It is therefore necessary, at least a second ultrafiltration after dilution of the concentrate in the manner indicated.

At the end of the process, the product is made with appropriate quantities mixed with cream to form a milk-like product. This product eventually becomes preferably mixed with a corresponding amount of sweet sugar, after which under the appropriate Pressure is homogenized in order to obtain the necessary fine distribution of the additional products, whereupon finally the product of the heat treatment or

the packaging in bottles or the like. is fed.

The above examples show that the process according to the invention leads to a controlled reduction in the lactose content in milk, in however, all other components continue to do so remain. The milk product obtained by the process of the invention can optionally optionally with taste-modifying substances such as cocoa, fruit lyophilization products and the like.

Example 2: 150 l of skimmed milk (L.M., 4.75% lactose) are made up to approx Concentrated 1: 5, a concentrate (C I) of 30 1 being obtained, which is mixed with three times washed in softened water. A washed final concentrate of do-1 is obtained (C 4) (0.56% lactose). In addition to this concentrate, 120 1 permeate (P I) are obtained, 108 1 of which are subjected to the osmosis treatment (O-I) to make 28 L of concentrate (P 2; 17.65% lactose), which is further concentrated to 14 l by evaporation, from which, by crystallization and centrifugation, 3.831 g of lactose was extracted (51% volatility) and 11,290 ml of mother liquor (P 3) are obtained. The latter will then further concentrated by evaporation (1: 2.62) and 4.200 ml of which are obtained after crystallization and centrifugation a further 3,899 g of lactose (wet weight) and 1.456 ml of mother liquor (P 45; 18.50% lactose) result.

In this example, due to the small production volume, and a loss of production during sampling.

Table I Analysis data (g / loo gr) AOAC met.

Sample Ges.N2 lactose ash pH acidity Dornic L M 3.266 4.75 0.75 6.68 1.40 C 1 15.52 4.50 C 2 2.10 C 3 0.95 c 4 16.40 0.56 1.39 P 1 0.19 4.85 o.58 P 2 17.65 1.48 P 3 27.50 2.62 P4 S 18.50 9.60 aob, c, 3.28 o, 29 0.56 6.74 1.1o It Further product examples were produced in the following manner: a) 10000 ml of C4 were with 48.5 ml P 4S, 85 g sucrose + 5 g NaCl + 100 ml cream with 65 fat added. The mixture was dried directly in an experimental spray dryer, with one Amount of powder sufficient to form 5 liters of milk was obtained in this milk the percentage of lactose was o-29ffi.

b) Iooo ml of C4 were mixed with the substances listed under a), whereby however, the 48.5 ml of P 4S previously for 3 hours with β-galactoxidase, blocked in cellulose triacetate fiber were treated. A conversion of 41% of the lactose could be achieved and the end product in this case had a lactose content of 0.17%.

c) 1,000 ml of C 4 were mixed with the substances listed under a), whereby but instead of 85 g sucrose 75 g sucrose and 175 g malt dextrin dissolved in little H20, were used.

d) 1,000 ml of C 4 were mixed with the substances listed under a), whereby However, instead of sucrose, 3 g (0.6%) of saccharine were added; the one analogous to a) Sample was not pulverized, but prepared with H20 from the 0 I to 5 1, homogenized, sterilized and packaged aseptically. After numerous controls showed that the stability of the proteins suspended in the liquid is flawless was.

The above statements indicate that with the inventive Depending on the procedure, the objectives set at the beginning can be achieved in full The degree of concentration, the number and the volumes achieved in the first ultrafiltration the washing stages, the degree of concentration of the O.Io or conventional Methods obtained permeate and the quality of the crystallized lactose is it is possible to obtain a milk product with the desired lactose content at a time.

In practice, the type of membranes used, as well as the Dimensions of the implementation of a working cycle of the invention Procedure enabling devices to be different from time to time, without the framework of the Invention to exceed.

Claims (12)

P a t e n t a n s p r ü c h e: Process for the production of a diet milk with modified lactose content, it is noted that the starting milk of an ultrafiltration is carried out for the purpose of obtaining a concentrate consisting of the not passed through the ultrafilter Part of the milk that has passed through, and a permeate consisting of the Ultrafilter passed part of the milk, subject to at least one Part of the concentrate and permeate combined with the lactose content thus reduced and that the product obtained in this way is subjected to at least one manipulation treatment subject. 2. The method according to claim 1, characterized in that the lactose content is lowered in the concentrate by washing the concentrate. 3. The method according to claim 1 or 2, characterized in that the Lactose content of the permeate from the ultrafiltration is reduced in that the permeate is subjected to reverse osmosis, a concentrate of the Permeate from ultrafiltration, which contains water, lactose, salts and substances low molecular weight and a second permeate consisting of water with a Contains very few salts. 4. The method according to any one of claims 1 to 3, characterized in that that the washing process of the concentrate from the ultrafiltration or the various Stages of the washing process can be carried out with deionized water. 5. The method according to any one of claims 1 to 4, characterized in that that the washing process of the concentrate from the ultrafiltration or the various Stages of the washing process can be carried out with the mentioned second permeate. 6. The method according to any one of claims 1 to 5, characterized in that that the lactose content in the concentrate from the reverse osmosis in the course of preferably successive evaporation and crystallization stages is reduced. 7. The method according to any one of claims 1 to 6, characterized in that that before mixing or combining the concentrated solution from the reverse Osmosis with the washed concentrate from the ultrafiltration an enzymatic Treatment of the lactose remaining in solution in the reverse osmosis concentrate made by the action of ß-galaxy oxidase and gal-1-p-uridyl transferase will. 8. The method according to any one of claims 1 to 7, characterized gekeenzeich-, that as manipulation treatment, the addition of lactose-replacing carbohydrates (Sucrose, saccharine and / or malt dextrin) as well as possibly direct atomization this mixture for the purpose of obtaining a powdery product or the additive reverse osmosis water to obtain a liquid product is made 9. The method according to any one of claims 1 to 8, dadurcli characterized that as manipulation treatment the homogenization and sterilization of the product or a freezing treatment, lyophilizing treatment or the like. is made 10. Diet dairy product with a changed Laotee content, which according to the method according to one of the claims 1 to 9 was obtained, characterized in that it is as a liquid product or a product that has regressed to a liquid product has a lactose content of o, oi% fluctuates up to 5%, has O 11.Diätmilchpronkt according to claim 10, d a d u r c h g e does not indicate that it is available as a liquid product, frozen product, pasteurized product or sterilized product, powdery product, lyophilized product and the like. is present. 12.Diämilchprodukt according to claim 10 or 11, characterized in that it as a substitute for the lactose carbohydrates such as maizdex trin and / or sucrose or other additives for diabetes drugs, such as saccharine and the like.