CN104798885A - Milk powder with high whey protein index II - Google Patents

Abstract

The invention provides a method for producing low bacterial milk powder with whey protein nitrogen index (WPNI) of at least 2. The method is below: (a) removing solids from a raw milk by a known method, and then separating cream; (b) conducting hot infusion on the obtained skim milk; (c) concentrating the heated milk to 30-50 wt.% of dry matter; (d) if necessary, subjecting the obtained concentrate to heat treatment for at least 15 s at a temperature of at least 72 DEG C; and (e) subjecting the product from heat treatment to spraying treatment at 100-120 DEG C to obtain a dry powder.

Description

There is the milk powder of high lactalbumin index II

Technical field

Present invention relates in general to dairy products field, particularly relate to the low new method containing bacterium milk powder that production has high whey protein index (WPNI).

Background technology

Low containing bacterium milk powder in order to produce, such as, the skimmed milk with about 9% dry of pasteurization is evaporated to the concentration of about 40%.But this concentrate is still containing a large amount of thermoduric bacteria and spore, and described thermoduric bacteria and spore are derived from especially feeds to the corn Silage of milk cow, and because of the inadequate health of cowshed in most Zhongdao raw milk.Therefore, be necessary to make described concentrate carry out high heat treatment before the spraying, thus a large amount of eliminating bacteria and spore, produce high-quality sterile product.

But high heat treatment not only affects bacterium and spore; Also make valuable lactalbumin fully sex change (denature) or have very most of sex change, this adversely changes function and the nutritional physiology of product.Lactalbumin belongs to albumin and globulin; They particularly including alpha lactalbumin and beta lactoglobulin, seralbumin, show peptone and immunoglobulin (Ig).From the angle of nutritional physiology, lactalbumin is the milk composition of high value, and it is used in particular for constructing muscle in such as protein supplements.Although the display of undressed skimmed milk as the so-called whey protein index (WPNI) of protein content of whey parameter higher than 6(particularly 6.1), this value drops to lower than 1 in traditional excessive heat processing procedure, and this is very undesirable.

Such as, so alternative may be perform heat treatment at a lower temperature, at about 70 DEG C instead of more than 100 DEG C.In fact, the product obtained like this has the WPNI higher than 5, but germ contamination is too high, makes the product obtained also be difficult to the marketization at its best.

Therefore, the object of this invention is to provide milk powder, namely, both skimmed milk power and whole milk powder, described milk powder be aseptic or low---only have so far and just obtain through too high heat treatment---containing bacterium and, the milk powder using low by the use of thermal means to obtain has the high WPNI of at least 2, particularly at least 4, especially 5.5 to 6, although always these two parameters deviate from mutually.In addition, also expect that this technique low technical makes great efforts to perform.

Summary of the invention

Theme of the present invention is the low method containing bacterium milk powder for the production of the whey protein index (WPNI) with at least 2, particularly at least 4 and especially 5 to 7, wherein

A () removes solid by known method itself from raw milk, then butterfat is separated,

B () makes the skimmed milk obtained like this carry out heat perfusion,

C () will be concentrated into 30 % by weight to 50 % by weight dry by the breast heated,

If d () needs, make the concentrate obtained like this at the temperature of at least 72 DEG C, stand the heat treatment of the time period of at least 15 seconds, and

What e () obtained like this is processed to dried powder through heat treated product by the temperature spraying process at 100 DEG C to 120 DEG C.

Be surprisingly found out that, by carrying out heat perfusion at the temperature of about 135 DEG C, bacterium can be realized quantitatively from the separation in Ruzhong, and does not make whey-proteins denature, therefore no longer needs excessive heat process.

Can by the temperature of spraying in order to newborn concentrate being heated to it, the temperature of about 70 DEG C is enough---in this temperature, lactalbumin does not also have sex change.Technically, it is very simple for performing this technique, and it provides the low of high WPNI that have of hope to contain bacterium product.Table A below summarizes the low typical specification containing bacterium milk powder and requires and utilize the result that method of the present invention obtains:

Table A

The low specification containing bacterium milk powder

Pasteurization

The initial heat treatment of the raw milk performed in step (a). preferably performs in a heat exchanger, and wherein particularly heat-exchangers of the plate type has been proved to be and is particularly suitable for.Heat exchanger has thermograde, but carrying out selection to it makes raw milk be heated to temperature to be about 70 DEG C to 80 DEG C, and more especially from about 72 DEG C to 74 DEG C, minimum 20 seconds to the maximum 60 seconds time of staying, preferably about 30 seconds.

The separation of the non-newborn particle of solid and the fat content of sloughing about 4 % by weight perform usually in downstream components (preferred separator).Described assembly fully can be understood from the statement of prior art.The separator of GEA Westfalia Separator GmbH company is widely used in dairy processing industry, its allow two kinds of steps conbined usage or be used alone ( http:// www.westfalia- separator.com/de/anwendungen/molkereitechnik/milch-molke .html).Corresponding assembly is also disclosed, such as, at DE10036085C1(Westfalia) in, and be well known to those skilled in the art.Therefore, do not need to illustrate how to perform these processing steps, because they are understood to be a part for general professional knowledge.

Heat perfusion

In the process of heat perfusion, pending product and the steam of superheat are alternately sprayed by concentric ring nozzle in reaction compartment.Substantially, the design of this measure be to realize drop good mixing thus guarantee best heat trnasfer, and avoided by product deposition on the hot wall of infusion containers by the steam pressure gradient externally to internal adjustment from this space, on this hot wall, product will decompose.Heat perfusion needs the holdup time of 0.1 to 5 second usually, thus temperature can be from about 120 DEG C to about 150 DEG C, preferably about 135 DEG C.Product is deposited on the bottom of reactor mutually, and there, it can be collected and be processed further.This technology and corresponding parts are at international patent application WO2010086082A1 and WO2011101077A1(GEA) in be described in detail.The application relates to their instructions in described scope.

Heat treatment and drying

The breast managed through overheated filling point is concentrated subsequently, such as, by evaporimeter, or by conventional film method (such as, hyperfiltration), or passes through the combination of these two kinds of methods.

In another embodiment of the present invention (will obtain whole milk powder in scope preferably), the butterfat be separated in step (a). is added into the Ruzhong through heating again.It is essential, make skimmed milk---instead of rich milk---through perfusion of being heated.If not separation of cream, then higher fatty acid carrying capacity can cause incomplete bacterial kill because of high heat load, specifically optionally.Because butterfat still may comprise bacterium, so before it is combined with skimmed milk, make it through heat-treated at the temperature of 85 DEG C to 138 DEG C, the duration at 1 to 10 second, preferably at 3 to 5 seconds.High temperature is unimportant in this, because butterfat mainly contains lipid and do not have thermo-responsive albumen.

After heat treatment, dried powder is processed to by the concentrate heated.Suitable method is to the belt drying at the temperature within the scope of 120 DEG C, freeze drying, particularly spraying dry at 100 DEG C.

Powder is usually containing 1 % by weight to 5 % by weight, and be preferably the residual moisture of 2 % by weight to 3 % by weight, wherein, fat is more or less evenly distributed in not fatty dry matter and protein, carbohydrate and salt with inclusion form.Before the spraying, also other additives can be joined the concentrate of homogenize, such as, such as lecithin or food emulsifying agent [EP1314367A1, Nestle SA].

Commercial Application

On the one hand, the embodiment of the other two kinds of forms of the present invention relates to low containing bacterium low-heat skimmed milk power with low containing bacterium low-heat whole milk powder, on the other hand, they have separately higher than 2, the preferably whey protein index of 3 to 7.5 and particularly 5 to 7.

Skimmed milk power obtains through the following steps

A () removes solid with known method from raw milk, separation of cream,

B () makes the skimmed milk obtained like this carry out heat perfusion,

C () carries out pasteurization to what obtain like this through heated milk,

(d) by obtain like this through pasteurization breast be concentrated into 30 % by weight to 50 % by weight dry,

If e () needs, the concentrate that obtains like this is made at the temperature of 80 DEG C, to stand at least 15 seconds, the preferably heat treatment of time period of 15 to 20 seconds at least 72 DEG C, preferably 72 DEG C, and

F () is processed into dried powder by what obtain like this through heat treated product.

Whole milk powder obtains in the same way, and first different just carries out high heat treatment to the butterfat be separated in step (a). as previously mentioned, is then added to the product obtained in hot instillation process.In this case, preferred WPNI is between 5 and 6.5.

Accompanying drawing explanation

Fig. 1 shows and compares EXAMPLE V 1, V2 and 1 diagram in flow charts, and wherein, HT MM=high temperature skimmed milk, the low-temperature defatted breast of LT MM=, wherein, the low-temperature heat in embodiment 1 is only optional step.

Fig. 2 shows low containing low-heat defatted milk (LH SM) powder of bacterium and the production of low-heat whole milk (LH WM) powder, wherein UHE=superhigh temperature firing equipment.

Detailed description of the invention

Comparative example V1

From raw milk, remove solid by itself known method, then pasteurization and degreasing carried out to described breast thus obtain the skimmed milk with the dry of about 9 % by weight.The described skimmed milk of gentle evaporation, obtains about dry of 40 % by weight.The concentrate of such acquisition has the WPNI of 6.1 and carries out high heat treatment at 120 DEG C, about 5 seconds duration, thus destroys spore and other bacterium any.Obtain aseptic concentrate, then sprayed with spray tower.Obtain having the almost aseptic high thermal debinding milk powder of the WPNI of only 1.3.

Comparative example V2

Repeat EXAMPLE V 1; But do not carry out high heat treatment at 105 DEG C, but heat-treat 5 seconds at 70 DEG C.After spraying, obtain the low-heat skimmed milk power of the WPNI with 5.9, but it is contaminated by bacterial, the consumption being thus only applicable to limited extent uses.

Embodiment 1: the low production containing bacterium skimmed milk power

Repeat EXAMPLE V 2, but before the evaporation stage, skimmed milk carries out heat perfusion at 135 DEG C, continues 3 seconds, and the product like this after process is evaporated and heat-treats as mentioned above, and is sprayed.Obtain the low-heat skimmed milk power of the WPNI with 6.8, it is almost aseptic.

Embodiment 2: the low production containing bacterium whole milk powder

From raw milk, remove solid by itself known method, pasteurization and degreasing are carried out to described breast, obtain the skimmed milk with about dry of 9 % by weight.As described in example 1 above, heat perfusion is carried out to it.The butterfat obtained in degreasing process stands high heat treatment at 125 DEG C, and is again added into skimmed milk, obtains rich milk.Obtain the low-heat rich milk of the WPNI with 6.3, it is almost aseptic.

EXAMPLE V 1, V2 and 1 are placed side by side in the flow chart of Fig. 1.Fig. 2 shows the difference of producing skimmed milk power and whole milk powder.

Claims (12)

1. for the production of the low method containing bacterium milk powder with the whey protein index (WPNI) being at least 2, wherein

A () removes solid, then separation of cream by known method itself from raw milk,

B () makes the skimmed milk obtained like this carry out heat perfusion,

C () will be concentrated into 30 % by weight to 50 % by weight dry by the breast heated,

If d () needs, make the concentrate obtained like this at the temperature of at least 72 DEG C, stand the heat treatment of the time period of at least 15 seconds, and

E () obtains so processed thus obtain dried powder by spraying process at the temperature of 100 DEG C to 120 DEG C through heat treated product.

2. method according to claim 1, is characterized in that heat is carried out under being poured in the temperature of 120 DEG C to 150 DEG C.

3. the method according to claim 1 and/or 2, is characterized in that heat perfusion is performed the time period of 0.1 to 5 second.

4. the method according to item at least one in claims 1 to 3, is characterized in that the described butterfat be separated in step (a). stands excessive heat process and is again added into described skimmed milk, then heat-treats.

5. method according to claim 4, is characterized in that described butterfat is heat-treated at the temperature of 85 DEG C to 145 DEG C, 1 to 10 second duration.

6. the method according to item at least one in claim 1 to 5, is characterized in that described concentrate is processed to dried powder by spraying.

7. low containing a bacterium low-heat skimmed milk power, it is obtained by method according to claim 1.

8. skimmed milk power according to claim 7, is characterized in that it has the WPNI of 3 to 7.5.

9. skimmed milk power according to claim 7, is characterized in that it has the WPNI of 5 to 7.

10. low containing a bacterium low-heat whole milk powder, it is obtained by the method described in claim 1 and 5.

11. whole milk powders according to claim 10, is characterized in that it has the WPNI of 3 to 7.5.

12. whole milk powders according to claim 10, is characterized in that it has the WPNI of 5 to 6.5.