阅读说明：本技术 无乳糖奶制品 (Lactose-free milk product ) 是由 G·D·霍巴 R·J·皮尔斯 于 2018-03-05 设计创作，主要内容包括：本文所述的是液态的、浓缩的或干燥的无乳糖脱脂奶制品或者无乳糖、含脂奶制品,其由于奶制品的还原性碳水化合物与乳蛋白的比例而在热加工和贮存期间显示稳定性。当与市售乳糖水解的奶制品相比时,本文所述的无乳糖奶制品的渗透压还能够改善营养利用率。(Described herein are liquid, concentrated or dried lactose-free skim milk products or lactose-free, fat-containing milk products that exhibit stability during thermal processing and storage due to the ratio of reducing carbohydrates to milk proteins of the milk product. The osmotic pressure of the lactose-free milk products described herein also enables improved nutrient availability when compared to commercially available lactose-hydrolyzed milk products.)

1. A skim milk product or a fat-containing milk product comprising a concentrated milk protein component and a carbohydrate component, wherein the carbohydrate component comprises:

(i) a DP1 saccharide selected from the group consisting of glucose, galactose, fructose or a combination thereof, the amount of DP1 saccharide amounting to 3.0-18.0% w/w of the total carbohydrate component, and

(ii) a DP2 sugar selected from the group consisting of maltose, lactose, sucrose, difructose or combinations thereof, the amount of DP2 sugar amounting to 2.0-40.0% w/w of the total carbohydrate component, and

(iii) one or more digestible polysaccharide hydrolysates selected from the group consisting of dextrin, maltodextrin, maltotriose, glucose syrup, polyfructose, fructose syrup or a combination thereof, wherein the one or more digestible polysaccharide hydrolysates provide a total amount of DP3 oligosaccharides ranging from 6.0 to 26.0% w/w of the total carbohydrate component, and

(iv) lactose, less than 0.2% w/w on a dry solids basis;

and wherein the milk protein component is between 23.0% and 38.0% w/w of the product on a dry solids basis and the milk product has a mass ratio of reducing carbohydrates (DP1+ DP2+ DP3) to milk protein of 10.0-70.0.

2. The product of claim 1, wherein the mass ratio of reducing carbohydrates (DP1+ DP2+ DP3) to milk protein is 12.0-64.0.

3. The product of claim 1, wherein the mass ratio of reducing carbohydrates (DP1+ DP2+ DP3) to milk protein is 19.0-50.0.

4. The product of claim 1, wherein the mass ratio of reducing carbohydrates (DP1+ DP2+ DP3) to milk protein is 32.0-60.0.

5. The product of claim 1, wherein the mass ratio of reducing carbohydrates (DP1+ DP2+ DP3) to milk protein is 35.0-50.0.

6. The product according to any one of claims 1-5, wherein the one or more digestible polysaccharide hydrolysates have a dextrose equivalent of 8-43.

7. The product according to claim 6, wherein the one or more digestible polysaccharide hydrolysates have a dextrose equivalent of 8-41.

8. The product according to claim 6, wherein the one or more digestible polysaccharide hydrolysates have a dextrose equivalent of 8-31.

9. The product according to claim 6, wherein the one or more digestible polysaccharide hydrolysates have a dextrose equivalent of 15-31.

10. The product according to claim 6, wherein the one or more digestible polysaccharide hydrolysates have a dextrose equivalent of 28-31.

11. The product according to claim 6, wherein the one or more digestible polysaccharide hydrolysates have a dextrose equivalent of 17-20.

12. The product according to any one of claims 1-11, wherein the one or more digestible polysaccharide hydrolysates are maltodextrins.

13. The article of any one of claims 1-11, wherein the article has an osmolality of 170 and 295 mOsmol/kg.

14. The product of any one of claims 1-11, wherein the product is a liquid, concentrated or dried skimmed milk product, or a liquid, concentrated or dried fat-containing milk product.

15. The article of any one of claims 1-14, wherein the total mass of the DP1 saccharide on a dry solids basis is greater than the total mass of the DP2 saccharide on a dry solids basis.

Technical Field

Lactose-free skim milk products (Lactose-free milk products) or Lactose-free fat milk products (Lactose free fat containing milk products) having similar nutritional, organoleptic and functional properties as milk (dairy milk) with the added benefit of reduced osmotic pressure (osmolality) and improved stability during thermal processing, and methods of preparation.

Background

Milk is the lacteal secretion produced by all mammalian species for nutrition of newborns. Dairy products (dairy products) for human consumption are manufactured from the milk of many species of mammals, including cows, goats, sheep, buffalos, camels, llamas, yaks, horses, and reindeer. Mammalian milk contains protein, fat, minerals and lactose, but differs in the relative proportions of the components and in species-specific compositional variations. Milk contains about 38% lactose and 25% protein on a dry solids weight% basis, so the ratio of sugar to protein is about 1.5 for both milk with natural fat content, and commercial skim milk.

Newborns of all mammalian species rely on breast milk to obtain their nutrition until they grow sufficiently that their digestive system consumes other food materials and utilizes the nutrition. Humans have learned to domesticate animals with the aim of producing milk for their own nutrition, particularly for the growth and development of their children. Milk is an important source of minerals; typical contents per 100mL of whole milk (whole milk) are: calcium (110-130 mg); potassium (110-170 mg); phosphorus (90-100 mg); magnesium (9-14mg) and trace minerals including zinc, manganese and fluoride, and also vitamins: thiamine, riboflavin, and B12.

Milk is a highly desirable component of the human diet not only because of its well-recognized beneficial balanced nutritional attributes, but also because of its organoleptic properties and function as an ingredient in a wide range of applications. The milk can also be carefully dried without significant loss of nutrition or other properties into a dry skimmed (low fat) or full fat (fat containing) milk product, the composition of which is shown in table 1.

Table 1: typical nutritional specifications for milk powder products.

Consumer desirability factors for liquid milk include nutritional characteristics, digestibility, flavor (including sweetness), color, texture, aroma, and function in applications such as custards, soups, cakes, yogurt, milk chocolate, and ice cream. The functions of dairy products in food applications include water binding, emulsifying, whipping, foaming and gelling or thickening. Appeal to food processors includes dryness for storage and shipping, minimal hygroscopicity of the dried product, and ease of reconstitution.

Lactose, the main component of milk, primarily provides energy to the consumer, but it also contributes to other aspects of the desirability of milk as a food product that can be processed and preserved and used in a wide variety of food products including beverages, cheeses, yogurts, desserts, baked goods, milk chocolates, and the like. In such foods, lactose can provide sweetness and flavor, fermentability, viscosity, a major contribution to osmotic pressure, and can affect the colloidal behavior of other milk components such as micellar casein (micellar casein). (Walstra, P., Jenness, R. & Badings, H.T. (1984) Dairy Chemistry and Physics publ Wiley; Fox, P.F. & McSweeney, P.L.H. (1998) Dairy Chemistry and dBiochemistry, pub Springer Science & Business Media.). Thus, replacing lactose with alternative digestible carbohydrates has the potential to affect a wide range of physical, organoleptic and functional properties of milk compositions. For example, if glucose oligosaccharides are used as a lactose substitute in a lactose-free milk product, the presence of glucose oligosaccharides can significantly alter the emulsifying and thickening properties.

In certain geographical areas and within certain anthropological types, many people lose or do not gain the ability to completely digest lactose in milk after weaning, and thus incomplete digestion can lead to adverse symptoms including intestinal fermentation, distension, malaise and diarrhea. It is estimated that the incidence of lactose intolerance is between 5% in europe to more than 90% in asia and africa.

In addition, the penetration of the food composition can adversely affect the efficiency of the utilization of the available nutrients. Ingestion of a hypotonic food composition providing improved nutritional availability will result in more rapid gastric emptying. See, for example, Vist, G.E. and Maughan, R.J (1995) Journal of Physiology 486(2),523-531, which describes the effect of osmotic pressure and carbohydrate content on the rate of gastric emptying of fluids in humans.

It is now known that some individuals are unable to digest milk comfortably due to the rapid decline in post-weaning production of the gut digestive enzyme lactase (β -D-galactosidase), which converts the disaccharide lactose to its monosaccharide components, i.e. glucose and galactose. (see Yang Yuexin, Mei He Hongmei Cui and Zhu Wang (2001) The Prevalence of Lactase Deficiency and lactose intolerance in Children of Different Ages in China (The Prevalence of lactose Deficiency and lactose Intolorance in Chinese child of Difference Agents.) Chinese Medical Journal113(12): 1129-. Lactose is not absorbed by the small intestine, but both glucose and galactose are absorbed. Thus, certain individuals are at a disadvantage in their food and nutritional options due to this condition known as lactose intolerance. This led to the development of carbohydrate modified milk products with reduced lactose content. A carbohydrate-modified milk product is characterized as lactose-free if it contains less than 0.2 wt.% lactose on a dry solids basis in the product.

Several methods have been described for producing reduced lactose dairy products with similar characteristics compared to natural milk. Lactose-reduced milk products typically contain 2-20% by weight of the natural content of lactose after removal of lactose by filtration (which results in a change in the nutritional balance) or by enzymatic or chemical hydrolysis of lactose into combined equal weights of glucose and galactose. Glucose and galactose produced by lactose hydrolysis result in about a four-fold increase in sweetness of the product and double the reducing power of the sugars. The reducing power of sugar in a dairy product refers to the ability of sugar to react with protein in the maillard reaction that can cause browning of the dairy product. It is generally understood that reducing sugars such as glucose and galactose react with milk proteins by means of Maillard reactions and the resulting loss of nutritional value, especially at elevated temperatures, and that negative organoleptic properties develop, such as moisture absorption, caking and loss of nutritional value due to greater hygroscopicity, as summarized by van Boekel (1998) "the Effect of heating on Maillard reactions in milk (Food Chemistry, Vol.62, No.4, 403-414). Since Lactose, glucose and galactose are all reducing sugars, Lactose hydrolysis can have a significant effect on the sensitivity of Lactose-reduced milk to maillard reactions during both heat processing and storage, as discussed in Jansson, t, Clausen, m.r., Sundekilde, u.k., Eggers, n, Nyegaard, s., Larsen, l.b., Ray, c, Sundgren, a., Andersen, h.j., and Bertram H.C (2014) in comparison to conventional Ultra High Temperature (UHT) milk, Lactose-hydrolyzed milk is more susceptible to chemical changes during storage (UHT), j.agricultural product to chemical change of storage of raw milk, uh. milk hydrolysis-high-temperature (t) and chemical modification of milk, 7886, vonsson, et al, 7896.

Methods have been proposed to address the issue of increased sweetness and increased browning in lactose hydrolyzed dairy products, including the removal of glucose and galactose by filtration. Lactose hydrolyzed Milk with low sweetness was developed Using Nanofiltration technology at Choi, s.h., Lee, S-B, and Won, H-R (2007) (Development of lactose-hydrolyzed Milk with lowsweentless use nanofiltation) asset-aust.j.anim.sci 20: 6,989-. Although the sweetness of the composition is reduced compared to lactose hydrolyzed milk, the carbohydrate content is not restored, resulting in a loss of nutritional balance and a substantial reduction in production efficiency.

There remains a need for a lactose-free milk product that despite the lack of lactose has a similar nutritional balance and sweetness to milk. There is also a need for a lactose-free milk product with reduced osmotic pressure to improve nutrient availability. There is also a need for a lactose-free milk product that can be mechanically and/or thermally processed and stored without encountering the problems of browning, discoloration, degradation of milk proteins, and hygroscopicity exhibited by commercially available lactose hydrolyzed milk products.

Disclosure of Invention

According to a first aspect of the present invention there is provided a skim milk product or a fat-containing milk product comprising a concentrated milk protein component and a carbohydrate component, wherein the carbohydrate component comprises:

(i) a DP1 saccharide selected from glucose, galactose, fructose or a combination thereof, the amount of DP1 saccharide amounting to 3.0-18.0% w/w of the total carbohydrate component, and

(ii) a DP2 saccharide selected from maltose, lactose, sucrose, difructose or a combination thereof, the amount of DP2 saccharide amounting to 2.0-40.0% w/w of the total carbohydrate component, and

(iii) one or more digestible polysaccharide hydrolysates selected from dextrin, maltodextrin, maltotriose, glucose syrup, polyfructose, fructose syrup or a combination thereof, wherein the one or more digestible polysaccharide hydrolysates provide a total amount of DP3 oligosaccharides between 6.0 and 26.0% w/w of the total carbohydrate component, and

(iv) lactose, which is less than 0.2% w/w on a dry solids basis.

The milk protein component of the milk product according to the first aspect is between 23.0% and 38.0% w/w of the product on a dry solids basis and the milk product has a mass ratio of reducing carbohydrates (DP1+ DP2+ DP3) to milk protein of between 10.0 and 70.0.

According to a second aspect of the invention, the milk product has a mass ratio of reducing carbohydrates (DP1+ DP2) to milk proteins of 7.0-56.0.

According to a third aspect of the invention, the milk product has a mass ratio of carbohydrate mass (DP1+ DP2+ DP3) to milk protein of 0.20-1.15.

According to a fourth aspect of the invention, the milk product has a ratio of the mass of sugar (DP1+ DP2) to the mass of milk protein of 0.08-0.80.

According to a fifth aspect of the invention, the total mass on a dry solids basis of the DP1 saccharide of the dairy product is greater than the total mass on a dry solids basis of the DP2 saccharide.

One or more of these aspects of the invention may be combined to characterize the dairy products described herein.

Detailed Description

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The documents mentioned in this specification are herein incorporated by reference in their entirety.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that prior art forms part of the common general knowledge in australia.

The present invention relates to a lactose-free skim milk product or a lactose-free fat-containing milk product comprising a concentrated milk protein component and a carbohydrate component. The term "skim milk product" as used herein is understood to comprise no added fat, but may comprise low levels of material containing inherent fat that is not collected with cream in a standard dairy industry centrifugation process for separating cream from skim milk. The term "lactose-free" as used herein is understood to include milk products comprising less than 0.20% w/w lactose on a dry solids basis, more specifically less than 0.15% w/w lactose on a dry solids basis, even more specifically less than 0.10% w/w lactose on a dry solids basis, and even more specifically between 0-0.05% w/w lactose on a dry solids basis.

The concentrated milk protein component of the skim milk product described herein is, for example, a milk protein concentrate, a microfiltered milk protein concentrate or a milk protein isolate obtained from the milk of a domesticated mammal such as a cow, sheep, buffalo, camel, llama, reindeer, horse, yak or goat. The concentrated milk protein component is preferably between 23.0-38.0% w/w on a dry solids basis of the dairy product.

The concentrated milk protein component may comprise 50-95.0% milk protein by weight ratio (w/w), more specifically 60.0-92.0% milk protein by w/w, and even more specifically 70.0-91.0% milk protein by w/w. The concentrated milk protein component may contain 0.005-20.0% carbohydrate, e.g. lactose, on a dry solids w/w basis, more specifically 0.05-16.0% carbohydrate on a dry solids w/w basis, and even more specifically less than 10.0% carbohydrate on a dry solids w/w basis.

As mentioned above, milk proteins can react with reducing sugars via maillard reactions, particularly during heating. The present inventors have found that a carbohydrate-modified dairy product having a specific ratio of sugar reducing capacity to milk protein content enables mechanical and/or thermal processing and storage stability of the dairy product, while avoiding or minimizing the occurrence of browning, discoloration, milk protein degradation and/or hygroscopicity, when compared to commercially available lactose-hydrolysed dairy products.

Lactose and its hydrolyzed derivatives, glucose and galactose are all reducing sugars. Other sources of reducing sugars in the lactose-free milk products of the invention are polysaccharide hydrolysates that are digestible by humans and animals. Examples of digestible polysaccharides that may be partially or fully hydrolysed include starch and inulin (polyfructose). Those resulting from partial hydrolysis of starch may include dextrins, maltodextrins, maltotriose and glucose syrups.

Since starch is a polymer of glucose, its partial hydrolysis produces maltodextrins with a variety of components of different Degrees of Polymerization (DP). Maltodextrins may include glucose (referred to herein as the DP1 saccharide because it is a monosaccharide), maltose (referred to herein as the DP2 saccharide because it is a disaccharide), maltotriose (referred to herein as the DP3 oligosaccharide because it is a trisaccharide), and oligosaccharides with more than four saccharide molecules (DP4 +). Since lactose is a disaccharide (DP2), its hydrolysis produces equal amounts of glucose and galactose (both DP1 sugars). Other DP2 sugars that may be included in the carbohydrate component of the milk products described herein include sucrose and difructose, both of which are disaccharides. The established carbohydrate polymer nomenclature summarized by Cummings and Stephen is as follows: DP1 and DP2 carbohydrates are sugars, DP3-DP9 carbohydrates are oligosaccharides, and polymers greater than DP10 are polysaccharides (Cummings and Stephen (2007) Carbohydrate nomenclature and Classification) European Journal of Clinical Nutrition Supplement 1, S5-S18).

The total amount of DP1 sugar (selected from glucose, galactose, fructose or a combination thereof) present in the milk products described herein is 3.0-18.0% w/w of the total carbohydrate component. The total amount of DP2 sugar (selected from maltose, lactose, sucrose, difructose or combinations thereof) present in the milk products described herein is 2.0-40.0% w/w of the total carbohydrate component. The total amount of DP3 oligosaccharides (which may be provided by one or more digestible polysaccharide hydrolysates including dextrin, maltodextrin, maltotriose, glucose syrup, polyfructose, fructose syrup, or a combination thereof) present in the milk products described herein is 6.0-26.0% w/w of the total carbohydrate component.

The total amount of DP1 sugar in the dairy product described herein may also be expressed in terms of mass per unit volume, for example between 0.18 and 1.00g/100mL in an aqueous skimmed milk product containing 10.0% w/w total solids. The total amount of DP2 sugars may be between 0.13 and 2.20g/100mL in an aqueous skimmed milk product containing 10.0% w/w total solids.

In the dairy products described herein, the reactivity of milk proteins is effectively consistent due to their consistent source and processing steps, but the reactivity of the digestible polysaccharide hydrolysate(s) may vary depending on the composition of the carbohydrate component selected in place of lactose.

Digestible polysaccharide hydrolysates such as maltodextrin are commercially characterized by their Dextrose Equivalent (DE), which is a measure of the reducing sugar content of carbohydrate materials, and can be more precisely chemically defined by quantifying individual monosaccharides, disaccharides, trisaccharides and higher sugars by well established methods such as HPLC. DE may also be obtained from a supplier or may be determined by redox titration. Table 1a below provides the theoretical and observed DE values for glucose polymers as disclosed in the handbook "nutritional Sweeteners From Corn" (2006), Table III, page 31, published by the American Corn refiner Association (US Corn Refiners Association).

Table 1 a: the theoretical and observed DE values for glucose polymers summarized in the handbook "nutritional Sweeeners From Corn" (2006), Table III, page 31, published by the American Corn Refiners Association (US Corn Refiners Association) and are here reprinted as Table 1a

Carbohydrate compound	Theoretical glucose equivalent	Observed dextrose equivalent
			Monosaccharides	100.0	100.0
Disaccharides	52.6	58.0
			Trisaccharides	35.7	39.5
Tetrasaccharide	27.0	29.8
			Five-sugar candy	21.7	24.2
Six-sugar candy	18.2	20.8

Determined by corn refiner association analysis method E-26

The milk product described herein may comprise one or more digestible polysaccharide hydrolysates having a DE of from 8 to 43, more particularly a DE of from 8 to 41, even more particularly a DE of from 8 to 31, even more particularly a DE of from 15 to 31, and even more particularly a DE of from 28 to 31, and even more particularly a DE of from 17 to 20.

The source of digestible polysaccharide hydrolysate may for example be corn, rice or any other hypoallergenic plant material. Preferably, the digestible polysaccharide hydrolysate is selected from a range of commercially available starch hydrolysate materials including Dextrins, maltodextrins, glucose syrups and sugars as described by Sun et al (2010) (Sun J., Zhao R, Zeng J, Li g. and Li X. (2010) characterization of Dextrins with different glucose Equivalents (characteristics of dextrose with different dextrose Equivalents. molecules.15, 5162-5173). Preferably, the digestible polysaccharide hydrolysate is maltodextrin. The U.S. food and drug administration (US FDA) defines maltodextrin as a non-sweet, nutritive sugar polymer having an average DE of less than 20 and a nutritive sugar polymer having an average reducing sugar content of greater than 20DE as a dry glucose syrup. The term maltodextrin as used herein is understood to mean dry nutritive sugar oligomers or polymers having a DE value between 8 and 43. Dry glucose syrups with a DE greater than 43 are more difficult to manufacture due to their enhanced hygroscopicity and therefore more expensive and difficult to handle, especially in dry products.

DP1, DP2, DP3 and DP4+ carbohydrates are the major contributors to the sweetness of the dairy products described herein. Table 2 below shows the sweetness of various carbohydrates relative to the sweetness of sucrose, as may be derived from:http://owlsoft.com/pdf_docs/ WhitePaper/Rel_Sweet.pdfthe literature entitled "relative sweetness Values for Various Sweeteners (relative sweetness Values for Various sweets)" was obtained. Thus, glucose has a sucrose sweetness in wt/wt74% of degree. Digestible polysaccharide hydrolysates of defined sweetness and composition may also be included in the carbohydrate component of the milk products described herein, in addition to those listed in table 2.

TABLE 2 relative sweetness factor of selected digestible carbohydrates

Carbohydrate name	Relative sweetness factor (sucrose sweetness%)
		Glucose	74
Lactose	16
		Hydrolyzed lactose	65
Maltose	50
		Maltotriose	30
36DE corn syrup (glucose syrup)	30-40
		25DE corn syrup solids (dried glucose syrup)	28
18DE maltodextrin	21
		15DE maltodextrin	17
10DE maltodextrin	11

Since DP3 sugar, e.g. maltotriose, contributes less to the overall sweetness of the dairy product due to its lower relative sweetness value (table 2), DP3 sugar also contributes less to the reduction potential of the carbohydrate component relative to its mass when compared to the reduction potential of DP1 sugar and DP2 sugar (figure 1).

The type and amount of selected carbohydrate components of the carbohydrate component are determined and calculated such that the total carbohydrate content of the milk product is equal or similar to the total carbohydrate content of the skimmed or fat-containing natural milk product when added to the amount of residual carbohydrates that may be present as hydrolysed lactose in the milk protein source (milk protein source) or in any milk derived mineral source (and possibly any fat source).

The combined effectiveness of the quality and reducibility of the carbohydrate component of the dairy product reacted with the concentrated milk protein component is described herein as Reducing Carbohydrates (RC). RC is defined as the product of the DE (dimensionless) of the carbohydrate component and the mass of the carbohydrate component (which may be expressed as units of mass, e.g. grams; or units of mass per volume, e.g. grams/100 mL), as shown in formula (I) below.

RC ═ DE [ carbohydrates ]. (I)

Wherein:

DE-glucose equivalent

Mass of [ carbohydrate ] ═ carbohydrate

Thus, RC has a dimension of mass. RC represents the potential of the individual monosaccharides (DP1 saccharide), disaccharides (DP2 saccharide) and three ponds (DP3 oligosaccharide) present in the carbohydrate component of milk products to react with lysine residues of the milk protein component in the milk product via maillard reactions that contribute to browning during thermal processing. For example, all DP1, DP2, DP3 and DP4+ carbohydrates present in maltodextrin are somewhat reducing sugars according to DP, as each sugar or oligosaccharide has a terminal aldehyde reducing moiety.

The RC of the dairy product can be obtained by summing the RC of the DP1 saccharide, DP2 saccharide and DP3 oligosaccharide present in the dairy product as follows:

RC of DP1 (of DP1) DE (of DP1) mass;

RC of DP2 (of DP3) DE (of DP2) mass;

RC of DP3 (of DP3) DE (of DP3) mass;

and the combination of (a) and (b),

RC ═ RC (DP1) + RC (DP2) + RC (DP3) (of dairy products).

Although oligosaccharides of DP4+ may be present in the dairy products described herein, the reducing potential per unit mass of carbohydrates decreases with increasing DP. Therefore, RC is limited by the sum of RC values DP1 to DP 3. Furthermore, the sum of the masses of DP1+ DP2+ DP3 would not sum to 100, since this sum does not take into account the mass of DP4+ oligosaccharides present.

The RC (of the dairy product) may then be divided by the mass of milk protein present in the concentrated milk protein component to obtain the ratio of the mass of reducing carbohydrates to milk protein. Since the mass of milk protein can be expressed as units of mass, such as grams, or as units of mass per volume, such as grams/100 mL, the ratio of reducing carbohydrate (DP1+ DP2+ DP3) to milk protein is dimensionless. The ratio of reducing carbohydrates (DP1+ DP2+ DP3) to milk proteins of the dairy product described herein may be any value comprised in the range of 10.0-70.0, more specifically any value comprised in the range of 12.0-64.0, even more specifically any value comprised in the range of 19.0-50.0; even more specifically, any value within the range of 32.0-60.0, and even more specifically, any value within the range of 35.0-50.0. Surprisingly, the present inventors have found that by preparing a dairy product with such a ratio, many dairy products do not show browning upon thermal processing, although the total mass of DP1 saccharide on a dry solids basis is greater than the total mass of DP2 saccharide. The total mass of DP1 saccharide on a dry solids basis may be greater than the total mass of DP2 saccharide on a dry solids basis by a factor that is any value falling within the numerical range of 1.05 to 5.00. Thus, the total mass of DP1 saccharides may be 1.05, 1.10, 1.15, 1.20, 1.25, 1.30, 1.35, 1.40, 1.45, 1.50, 1.55, 1.60, 1.65, 1.70, 1.75, 1.80, 1.85, 1.90, 1.95, 2.00, 2.05, 2.10, 2.15, 2.20, 2.25, 2.30, 2.35, 2.40, 2.45, 2.50, 2.55, 2.60, 2.65, 2.70, 2.75, 2.80, 2.85, 2.90, 2.95, 3.00, 3.05, 3.10, 3.15, 3.20, 3.25, 3.30, 3.35, 3.40, 3.45, 3.50, 3.95, 3.00, 4.05, 4.80, 4.70, 4.05, 4.10, 4.15, 4.20, 4.5, 4.70, 4.75, 4.80, 4.45, 4.90, 4.55, 4.70, 4.45, 4.80, 4.45, 4.80, 4.55, 4.45. Specifically, the total mass of DP1 saccharides may be greater than the total mass of DP2 saccharides by a factor of 1.25 to 4.25, more specifically by a factor of 1.35 to 3.50, even more specifically by a factor of 1.40 to 2.65, and even more specifically by a factor of 1.45 to 1.75.

The dairy products described herein can also be characterized by dividing the Reducing Carbohydrates (RC) of the DP1 and DP2 sugars by the mass of milk protein present as follows:

RC of DP1 (of DP1) DE (of DP1) mass;

mass of DE (of DP2) RC (of DP3) of DP2

And the combination of (a) and (b),

RC (DP1+ DP 2)/milk protein RC (DP1) + RC (DP 2)/milk protein mass

The ratio of RC (DP1+ DP2) to the mass of milk protein of the dairy product described herein may be any value comprised in the range of 7.0-56.0, more specifically in the range of 13.0-51.0, even more specifically in the range of 23.0-51.0; even more specifically, any value within the range of 23.0-44.0, and even more specifically, any value within the range of 28.0-44.0.

The milk products described herein can also be characterized by the ratio of the sum of the masses of DP1 saccharide, DP2 saccharide and DP3 oligosaccharide to the mass of milk protein present as follows:

[ (mass of DP1+ (of DP2) + (of DP3) ]/mass of milk protein

The ratio of the mass of the dairy product described herein (DP1+ DP2+ DP3) to the mass of the milk protein may be any value comprised in the range of 0.20-1.15, more specifically comprised in the range of 0.30-0.75, even more specifically comprised in the range of 0.40-0.75.

The milk products described herein can also be characterized by the ratio of the sum of the masses of the DP1 and DP2 saccharides to the mass of milk protein present as follows:

[ (mass of DP1+ (mass of DP2) ]/mass of milk protein

The ratio of the mass of the milk product described herein (DP1+ DP2) to the mass of milk protein may be any value comprised in the range of 0.08-0.80, more specifically comprised in the range of 0.30-0.75, even more specifically comprised in the range of 0.15-0.75.

The lactose-free milk products described herein are suitable for people with different dietary and sensory preferences, depending on the amount and kind of fat contained in the product. The lactose-free milk products described herein may achieve isotonic or hypotonic feeding, which may improve the availability of nutrients from the milk product. Note that the normal serum osmolality is 275-295mOsmol/kg (see Mendez et al, 2015FASEB Journal 291 supplement 583.1). The lactose-free milk product described herein may have an osmolality of 170-295 mOsmol/kg. In case the skimmed milk product described herein contains milk derived minerals, the osmolality of the product may be 170-250mOsmol/kg, more specifically 173-243mOsmol/kg, and even more specifically 173-209 mOsmol/kg. The non-dairy derived mineral (non-dairy derived dminerals) containing skim milk product described herein may have an osmolality of 185-295mOsmol/kg, more specifically 191-273mOsmol/kg, and even more specifically 197-230 mOsmol/kg.

The lactose-free milk products described herein may be in the form of a dry powder and may be comparable to the milk fat content (dairy fat-content) of Whole Milk Powder (WMP), or the fat content may be greater or less. The lactose-free skim milk products described herein may be in powder form and may be comparable to the milk fat content of Skim Milk Powder (SMP). If the dairy product comprises fat, the fat may be in the form of lactose-free cream or lactose-free anhydrous milk fat (milk fat), both of which are obtained, for example, from the milk of a domesticated mammal such as a cow, sheep, buffalo, camel, llama, reindeer, horse, yak, or goat. The fat in the dairy products described herein may also be obtained from suitable animal or vegetable sources. A milk product as described herein is considered to be a dry powder if it has a moisture content of 0-10.0% w/w, more specifically 0-6.0% w/w.

The lactose-free milk product described herein may also be a liquid such as a beverage or yoghurt (at a temperature of e.g. 5-25 ℃), a solid such as ice cream or frozen yoghurt (at a temperature of e.g. less than 5 ℃) or a concentrated milk product (at a temperature of e.g. 5-25 ℃). A dairy product as described herein (not comprising fat content) is considered to be concentrated if it has between 15.0-85.0% w/w water.

The lactose-free milk products described herein have similar physical and functional properties as natural dairy products (natural dairy milk products), such as flavor, color, solubility, viscosity, freezing point, and emulsification.

Preparation of lactose-free defatted milk product

The lactose-free skim milk product is prepared as a liquid, liquid concentrate or dry powder suitable for reconstitution. To prepare such lactose-free skim milk powder products (LF-SMP), the ratio of total digestible carbohydrates to milk proteins is preferably comparable to that in full-lactose Skim Milk Powder (SMP), thereby providing a suitable nutritional balance for the adult consumer. When reconstituted from a lactose-free milk powder product, the viscosity of such a skimmed milk product is such that it is comparable to skimmed milk at the same temperature and solids content.

Adding an amount of lactose-free concentrated milk protein as Milk Protein Concentrate (MPC), Microfiltered Milk Protein Concentrate (MMPC) or Milk Protein Isolate (MPI) to the one or more digestible polysaccharide hydrolysates and an amount of minerals. The milk protein concentrate may be produced by filtration techniques to provide a milk protein concentrate containing less than 15.0% w/w and preferably less than 10.0% w/w lactose on a dry solids basis. Preferably, such protein-enriched products contain more than 80.0% w/w protein on a dry solids basis.

MPI may be produced by diafiltering MPC with water or a suitable lactose-free aqueous solvent to provide a protein-enriched product containing less than 3.0% w/w lactose on a dry solids basis and preferably greater than 90.0% w/w protein on a dry solids basis. Furthermore, MPC, MMPC or MPI may be additionally modified to achieve specific properties, e.g. by varying the divalent calcium and magnesium ion content by processes that adjust the mineral content, such as cation exchange.

In order to provide a suitable mineral balance in lactose-free skim milk products, it is acceptable to use non-milk-derived minerals as suitable inorganic food-grade chemicals. Alternatively, milk-derived minerals from membranes of milk or whey or mineral-rich byproduct concentrates produced by chromatographic processing may also be used as a mineral source. Such concentrates are treated with lactase in the amounts and conditions described above to hydrolyze residual lactose and render the concentrate lactose-free. The galactose and glucose content of the lactose-free mineral concentrate is determined by any suitable method, preferably by HPLC, as a measure of sweetness and DE. The carbohydrate component of the skim milk product is derived from lactose hydrolysis, one or more digestible polysaccharide hydrolysates, and carbohydrates present in the milk protein component and any milk-derived minerals.

To obtain a lactose-free composition, residual lactose in milk-derived components (dairy derived components) is hydrolyzed with lactase to produce monosaccharides. For example, commercial lactase is added to liquid MPC, MMPC or MPI at a temperature in the range of 0 to 40 ℃, and preferably in the range of 2 to 10 ℃ to minimize bacterial growth. According to the recommendations of the enzyme supplier, lactase is added in an amount relative to the lactose content for a period of time such that the lactose content is sufficiently reduced to obtain a lactose-free state. The galactose and glucose content of the lactose-free MPC, MMPC or MPI is determined by any suitable means, preferably by HPLC, as a measure of sweetness and DE.

The hydrolysates of lactose (i.e. glucose and galactose) are much sweeter than lactose at the same concentration. The sweetness of lactose-derived monosaccharides and the sweetness of maltose and glucose from the selected digestible polysaccharide hydrolysates are combined together additively to provide the overall sweetness of the overall composition. Therefore, predicting flavor outcomes for different lactose-free compositions is technically challenging. For example, maltodextrins with different sugar contributions or milk protein fractions containing low molecular weight fortified flavour components (e.g. minerals and non-protein nitrogenous compounds) may alter the flavour of milk products.

The non-dairy, digestible polysaccharide hydrolysate that provides the desired contribution to composition and sweetness may be a mono-dextrin material of a specified DE and sugar content (e.g. DP1 and DP2 sugar content). Alternatively, the above-mentioned polysaccharide hydrolysate may be a mixture of two or more digestible polysaccharide hydrolysates having different DE and sugar content values (mixed together in appropriate proportions to provide the desired sweetness contribution, DE and sugar content).

Although, as mentioned above, it is mainly the mono-and disaccharide content of the polysaccharide hydrolysates that provide sweetness and DE, the inventors have found that larger saccharide oligomers and polysaccharides may adversely contribute to the viscosity and mouthfeel of lactose-free skim milk products. Therefore, there is a need to select one or more digestible polysaccharide hydrolysates that not only provide the required sweetness and DE, but also provide the desired viscosity and organoleptic properties.

The selected polysaccharide hydrolysate is preferably dispersed in an amount of water sufficient to facilitate its mixing with the aqueous dispersion of the other components of the lactose-free skim milk product. Alternatively, the polysaccharide hydrolysate in dry form is added to the aqueous dispersion of the other components with vigorous mixing. Optionally, other nutrients such as vitamins, trace elements, nutritional cofactors, colorants and flavors may be added to the aqueous mixture of selected components. Additional materials may also be added to enhance the desirability of the lactose-free skim milk product.

Alternatively, all milk-derived components (milk proteins and/or milk-derived minerals) of the lactose-free skim milk product may be combined without prior treatment with lactase, and the combined ingredients subsequently treated with lactase as described above to provide the lactose-free skim milk product. The galactose and glucose content of the lactose-free combined milk component is determined by any suitable method, preferably by HPLC, as a measure of sweetness and DE. Adding the selected digestible polysaccharide hydrolysate to the combined lactose-free milk component mixture.

Alternatively, if the lactose content of the milk-derived component is accurately determined, thereby predicting the content of galactose and glucose resulting from lactase hydrolysis of lactose, and the amount and type of non-lactose carbohydrates can be predicted, a mixture containing all milk and non-milk components can be treated with lactase in combination to provide a lactose-free skim milk product.

The aqueous mixture of the selected lactose-free component can be pasteurized or otherwise heat treated using standard dairy manufacturing methods and facilities to ensure a hygienic product, homogenized to ensure uniform distribution, concentrated by evaporation, and dried. Optionally, the evaporated concentrate can be dried in a multi-stage process as a standard step in the dairy industry, such that the powder product is in an agglomerated form.

From a consumer-acceptability/food-manufacturer-practicality perspective, the lactose-free skim milk products described herein should have similar color, flavor, odor, and mouthfeel/texture as natural milk products, as well as similar ease of use, storage stability, and usability. For food manufacture, functional properties including solubility, dispersibility, emulsification, foaming, viscosity, hygroscopicity, and susceptibility to browning during thermal processing need to be comparable to those of natural milk and dairy products.

Preparation of lactose-free fat-containing milk product

Lactose-free fat-containing milk products are prepared as liquids, liquid concentrates or dry powders suitable for reconstitution (lactose-free fat-containing milk powder (FDP)). To prepare such lactose-free, fat-containing milk products, the ratio of milk proteins to digestible carbohydrates is preferably comparable to the ratio in both whole milk powder and skim milk powder, thereby providing the appropriate nutritional balance for the consumer. When reconstituted from a lactose-free milk powder product, the viscosity of such lactose-free fat-containing milk products is such that it is comparable to natural milk having the same fat content at the same temperature and solids content.

Generally, fat-containing milk has a recognizable flavor and sweetness, which is primarily a result of the fat and lactose content. The digestible carbohydrate content and sweetness is similarly provided in the lactose-free, fat-containing milk products described herein. The creamy texture is also provided by a significant emulsified fat content.

An amount of lactose-free concentrated milk protein is produced as a Milk Protein Concentrate (MPC) or Milk Protein Isolate (MPI) or Microfiltered Milk Protein Concentrate (MMPC) product as described above and the content of residual hydrolysed lactose as reducing sugars (galactose and glucose) is determined.

An appropriate amount of one or more of the above lactose-free food grade or milk mineral concentrates is selected to provide the desired content of the particular element and the content of residual hydrolyzed lactose as reducing sugars (galactose and glucose) is determined.

The appropriate amount of lactose-free cream is selected according to the fat content of the cream and the desired fat content of the desired lactose-free fat-containing dairy product. The content of residual hydrolysed lactose as reducing sugars (galactose and glucose) was determined.

The combined contribution to carbohydrate content, sweetness and DE of a lactose-free milk product from milk-derived components (milk-derived components) is provided by the total content of each of galactose and glucose. As a reference number, the sweetness value of the SMP was 8.5, calculated according to Table 2 as (sweetness value of lactose, 16). times.dry solids (ratio of lactose to composition, 0.53).

Residual lactose from milk-derived components such as milk mineral concentrates, cream, and milk protein concentrates, when hydrolyzed, can be used to provide sweetness and other functional characteristics in a lactose-free milk product. Carbohydrate compositions having a higher proportion of monosaccharides than disaccharides may be used and may be used in place of lactose to produce a lactose-free milk product having acceptable taste, appearance and function. Furthermore, it has been found that lactose from the hydrolysis of cream and milk mineral concentrates can allow the use of lower DE maltodextrins in lactose-free, fat-containing milk products, which is advantageous in both cost and manufacturability.

For the preparation of a fat-containing, lactose-free milk product, it is preferred to select milk fat in the form of milk cream (dairy cream) as a component of the composition. Such milk creams vary widely in fat content and therefore lactose content. The milk cream is made lactose-free by adding lactase in the amounts and conditions described above before adding the milk cream to the aqueous mixture of the other components. Since dairy cream contains lactose, the added lactose-hydrolyzed cream contributes to the sweetness and monosaccharide (DP1) content of the lactose-free fat-containing dairy product. The galactose and glucose content of the lactose-free cream is determined by any suitable method, preferably by HPLC, as a measure of sweetness and DE.

Optionally, a milk fat is selected as the anhydrous milk fat or other fat or oil of animal or vegetable origin and added to the aqueous mixture of the selected components.

The non-dairy carbohydrate ingredient that provides the desired contribution to composition and sweetness may be a single digestible polysaccharide hydrolysate of a specified DE if the composition is such that the desired amount of carbohydrate delivers the desired amount of sweetness. Alternatively, the polysaccharide hydrolysate may be a mixture of two or more digestible polysaccharide hydrolysates having different DE values, which together in a suitable ratio will provide the desired sweetness and DE contribution from the desired carbohydrate contribution. Although, as mentioned above, the mono-and disaccharide content of mainly digestible polysaccharide hydrolysates provides sweetness, the larger saccharide oligomers in the polysaccharide hydrolysates may adversely contribute to the viscosity and mouthfeel of the lactose-free milk-containing product. The polysaccharide hydrolysate should not only provide the required sweetness and DE, but also the desired viscosity and organoleptic properties.

Combining an amount of lactose-free MPC, MMPC or MPI, lactose-free mineral, lactose-free cream and a desired amount of a selected digestible polysaccharide hydrolysate, preferably in a concentrated aqueous dispersion. Optionally, the dry component is dispersed in the liquid component to minimize water in the composition and thereby improve the efficiency of further processing steps such as, but not limited to, homogenization, pasteurization, evaporation and drying.

Additional nutrients and the above-mentioned substances which increase the desirability of the lactose-free fat-containing dairy product may also be added.

The aqueous mixture of the selected lactose-free component is pasteurized or otherwise heat treated, homogenized, concentrated by evaporation, and dried using standard dairy manufacturing methods and facilities as described above.

Since the carbohydrate-to-protein ratio in lactose-free fatty milk products is the same as in SMP, a production efficiency of about 100% based on milk protein supplied is achieved, relative to the potential yield of SMP, based on fat-free mass. The actual product yield is higher due to the additional fat.

The following non-limiting examples further describe the dairy product of the present invention and it is understood that modifications and/or variations of the examples that are obvious to a person skilled in the art based on the disclosure herein are also to be considered within the scope and spirit of the invention as defined in the appended claims.