FOOD PRODUCTS CONTAINING ALDOBIONIC ACID

FIELD OF INVENTION

The present invention relates to a food product, e.g. cheese, which contains an aldobionic acid (such as lactobionic acid) or a salt thereof, and a method for preparing such a food product.

BACKGROUND OF INVENTION

Lactobionic acid (4-O-beta-D-galactopyranosyl-D-gluconic acid; CAS Reg. No. 96-82-2) is a water soluble, white crystalline compound and can be synthesized from lactose by oxidation of the free aldehyde group in lactose as carried out catalytically, chemically, electro- lytically, or enzymatically, cf. Harju, Bulletin of the IDF 289, ch. 6, pp. 27-30, 1993; and Satory et al., Biotechnology Letters 19 (12) 1205-08; 1997.

Enzymatic conversion (LAO = Lactose oxidase) of lactose into lactobionic acid via the lactone:

Lactobiono-LS-lactone Lactobionic acid

The use of lactobionic acid or its salts as additives in food products has previously been suggested for several specific applications. Calcium or iron chelate forms of lactobionic acid have been described for dietary mineral supplementation, cf. Riviera et al., Amer. J. Clin. Nutr.; 36 (6) 1162-69, 1982.

Calcium lactobionate, a salt form of lactobionic acid, has been approved for use as a firming agent in dry pudding mixes, cf. 21 C. F. R. § 172.720 (1999).

Also, the possible use of lactobionic acid as a general food acidulent has been proposed, albeit without exploration or illustration, cf. Timmermans, Whey: Proceedings of the 2nd Int'l Whey Conf, Int'l Dairy Federation, Chicago, October 1997, pp. 233, 249. This article generally describes lactobionic acid as being useful as an antibiotics carrier, an organ transplant preservative, mineral supplementation, growth promotion of bifidobacteria, or as a co-builder in detergents in its K-lactobionate salt form.

US patent 6916496 (Kraft Foods) discloses a process for manufacturing a cheese product containing lactobionic acid, comprising the steps of: preparing a liquid cheese mix comprising a dairy component, lactose, and lactobionic acid or a dietary acceptable salt or neutralized form thereof; and coagulating the cheese mix to obtain the cheese product.

US2005271789A discloses a method for preparing a cheese, comprising :

(a) providing a slurry that comprises a plurality of analog cheese ingredients;

(b) separately preparing a heated cheese mass;

(c) mixing the slurry with the cheese mass to form an admixture; and (d) shaping and cooling the admixture to form the cheese.

It is mentioned that an acid (such as lactobionic acid) can be incorporated to adjust the pH of the finished cheese to a desired level. The acid may be introduced into the final soft or firm/semi-hard ripened or unripened blended cheese product via the slurry or during the mixing stage.

US2006008555A discloses a method wherein calcium lactobionate powder, produced by enzymatic conversion of lactose, was incorporated into cheese apparently by grinding or by means of a manufacturing process that utilizes a slurry. The cheese was manufactured conventionally using starter cultures, modified food starch, and 2% calcium lactobionate. The cheese was then shredded and frozen.

However, these methods of making cheeses with a content of lactobionic acid and/or a salt thereof has not been satisfactory, especially for other types of cheeses than pizza cheeses of the pasta filata type. There is a need for a method for producing cheeses with a content of lactobionic acid, said method being independent of the production technology for the particular cheese.

SUMMARY OF INVENTION

The present inventors have found that it is possible and convenient to manufacture cheese with a content of lactobionic acid by introducing the lactobionic acid to the cheese curd by injection after the cheeses have been shaped, especially when the cheese curd comprises a firm substance of curd.

In accordance with this finding, the present invention relates to a method for producing a food product with a content of an aldobionic acid, said method comprising injecting aldobi- onic acid into the food product, e.g. by using at least one needle or jet stream.

An advantage of injecting the aldobionic acid into the food product is that it is possible to calculate or determine the amount of aldobionic acid introduced and/or absorbed by the

food product. Furthermore, as the aldobionic acid is introduced into the food product relatively late in the manufacturing process, there is only a minor loss of aldobionic acid during the manufacturing process.

DETAILED DISCLOSURE In a first aspect, the present invention pertains to a method for producing a food product with a content of an aldobionic acid and/or a salt thereof, said method comprising injecting aldobionic acid or a salt thereof into the food product. The food product may be a dairy or bakery product, e.g. selected from the group consisting of: a curd, a cheese (such as continental type cheese, fresh cheese, pasta filata, cheese curd, emmentaler type cheese, or cheddar type cheese), and a dough (such as bread dough, bagel dough, biscuit dough, and cake dough).

The aldobionic acid is e.g. lactobionic acid, maltobionic acid, isomaltobionic acid, gentiobi- onic acid, and cellobionic acid, but a salt of the aldobionic acid may also be used, such as a salt with an inorganic base, e.g. ammonium -, magnesium-, calcium-, sodium-, iron- (especially ferri-), and potassium salt. Examples are: sodium lactobionate, calcium lactobion- ate, ammonium lactobionate, magnesium lactobionate, ferri lactobionate, and potassium lactobionate. It is presently preferred to inject calcium lactobionate.

In an embodiment of the present invention, the aldobionic acid or salt thereof is injected in the form of a solution, such as an aqueous solution. The solution may comprise 20% to 80%, (such as 30%-70% or 40%-60%) (w/w) aldobionic acid or salt thereof. Conveniently, in case of an aqueous solution, the water content of the solution should be substantially the same as in the food product to be subjected to injection, e.g. the water content of the solution should be within +/-20%, within +/-10%, or within +/-5% (w/w) relative to the water content in the food product.

It is presently preferred that the food product is injected with O.lg to 1Og (such as 0.5g to 6g or 2g to 4g) aldobionic acid or salt thereof per lOOg of food product.

According to embodiments of the invention, a needle or a jet/jet stream is used for injecting. It is presently preferred to inject the aldobionic or salt by means of an apparatus that have a plurality of needles. The solution to be injected may contain a further substance (such as brine) to be injected into the food product together with the aldobionic acid or salt thereof. In order to obtain a sufficient distribution of the aldobionic acid in the food product or in order to introduce the further substance at the same time, it is particularly useful to use a plurality of means for injection, and/or to tumble the food product. The injection may be performed as a single injection, or as two or more successive injections.

In a specific embodiment the invention relates to a method for producing a cheese comprising the steps of: producing a cheese curd by coagulating milk (which is optionally acidified) and separating the curd from the whey; cooking and/or knitting the curd; injecting lactobionic acid or a salt thereof, either before or after the cooking/knitting step; packing the resulting cheese.

In a further embodiment of the invention the food product is further processed after the injection, such as baked, cooled, heated, pressed, moulded, salted, tumbled, maturated, flavored, and packed (incl. vacuum packed).

Especially when the food product to be produced is a cheese, the treatment with the aldo- bionic acid can be performed after cutting and pressing of the cheese curd, either before or after cooking/heating and/or knitting steps.

In a second aspect the present invention relates to a food product obtainable by the method of the invention. The food product obtainable by the method of the invention includes - in accordance with the food product to be subjected to injection - a dairy or bakery product, e.g. selected from the group consisting of: a curd, a cheese (e.g. as defined above) , and a dough (e.g. as defined above), but includes also a more processed food product, e.g. when the dough is baked/cooked to obtaining a cake, bread, bagel, biscuit etc, or when the curd is processed to a cheese, e.g. as defined above.

DEFINITIONS

In the present context, the term "needle" is used in the conventional meaning and relates to any types of needles such a hollow needle, a hypodermic needle, a cannula or a syringe needle. It will be appreciated that the form of the needle depends on the dimension of the food product (e.g. cheese curd) to be injected. According to the invention, one needle may be used for the injection, but it is preferred that a plurality (such as an array) of needles is used. Convenient apparatus is disclosed in US5012728 (Injection needles for injecting brine and the like into meat), US3661072, US2006201343 (Device for introducing brine into an animal product).

The term "jet stream" or "jet" as used herein is meant to describe a solution containing the aldobionic acid/salt that has passed a nozzle under pressure. The velocity of the jet should be sufficient to penetrate the surface of the food product, but not so high that the jet trav-

erses the product. Convenient apparatus is disclosed in US5200223 (Method and an apparatus for injecting a liquid into meat) and US3649299.

The term "milk" refers to products that include whole milk, skim milk, cheese, whey, whey retentate, milk retentate, permeate, lactose, and delactose permeate, among other products.

The term "aldobionic acid or a salt thereof" refers to aldobionic acids (an aldobionic acid is a sugar substance (e.g. any cyclic sugar comprising at least two saccharide units) wherein the aldehyde group (generally found at the Cl position of the sugar) has been replaced by a carboxylic acid) and aldobionate salts. These may include, for example, aldobionate salts such as sodium aldobionate, calcium aldobionate, ammonium lactobionate, magnesium aldobionate, ferri aldobionate, and potassium aldobionate. The aldobionic acid is in equilibrium with the corresponding lactone, and therefore the invention also encompasses a method wherein the corresponding lactone (e.g. lactobionolactone) is injected. The term "salt" as used herein includes, besides a salt (between e.g. the negatively charged aldobionate and a positively charged ion or molecule), a complex, and a chelate, as some references refer to the product prepared by mixing e.g. lactobionic acid with calcium hydroxide as a calcium complex (or calcium chelate) of lactobionic acid. Thus, the term "aldobi- onic acid or a salt thereof" embraces all mixtures of an aldobionic acid or aldobionate and a positively charged ion or molecule.

The term "food product" as used herein includes firm/semi-hard products that are mixed together of one or more ingredients and are optionally processed further after injection of the aldobionic acid or salt thereof. Exemplary food products of this type include curd, cheese, dough (bread dough, bagel dough, cake dough), etc.

The term "cheese" as used herein refers broadly to all types of cheeses including, for example, cheeses as defined under the CODEX general Standard for Cheese and as defined under various state and national regulatory bodies. Exemplary classes of cheeses include, but are not limited to, firm/semi-hard cheeses, soft cheeses, analog cheeses, blended cheeses, and pasta filata cheeses, among other types of cheeses.

The term "firm/semi-hard cheese" includes cheeses having a percentage moisture on a fat- free basis (MFFB) of between 54% and 69%. Examples of firm/semi-hard cheeses include Colby, Havarti, Monterey Jack, Gorgonzola, Gouda, Cheshire, and Munster, low-moisture Mozzarella, and part-skim Mozzarella, among others.

The term "soft cheese" includes cheeses having a MFFB of greater than 67%. Examples of

soft cheeses include standard Mozzarella, among others.

The term "analog cheese" includes cheeses in which the milk fat and/or a protein source is substituted with a source that is not native to milk.

The term "blended cheese" includes cheeses made from blends of soft or firm/semi-hard cheese with analog cheese. Conventional methods of preparing blended cheeses include blending raw ingredients for an analog cheese with a soft or firm/semi-hard cheese curd, or reworking a soft or firm/semi-hard cheese.

The term "pasta filata cheese" includes soft or firm/semi-hard cheeses made by a process in which a cheese curd is heated and kneaded to improve the stretchability or stringiness of the final cheese. This process is sometimes referred to as the pasta filata process of manufacturing a cheese. Examples of pasta filata cheeses include mozzarella, provolone, Mexican style, scamorze, and pizza cheese.

The term "whey" generally refers to the liquid substance that is obtained by separating the coagulum from milk, cream, or skim milk in cheese making. The two major protein components in whey are alpha-lactalbumin and beta-lactoglobulin. Other major components are lactose and various minerals. "Acid whey" generally refers to whey obtained from a process in which a significant amount of the lactose has been converted to lactic acid, or from the curd formation by direct acidification of milk. "Sweet whey" generally refers to whey obtained from a procedure in which there is insignificant conversion of lactose to lactic acid. "Concentrated whey" is the liquid substance obtained by the partial removal of water from whey, while leaving all other constituents in the same relative proportion. "Dry or dried whey" generally refers to the dry substance obtained by removal of water from whey, while leaving all other constituents in the same relative proportion as in whey.

The use of the terms "a" and "an" and "the" and similar referents in the context of describ- ing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms "comprising", "having", "including" and "containing" are to be construed as open-ended terms (i.e., meaning "including, but not limited to,") unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., "such

as") provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

EXAMPLES

Example 1

Mozzarella cheese is extruded and formed after the warm stretching process (Cheese Chemistry, Physics and Microbiology). The dry matter content of the cheese is approx. 52%. The cheese blocks are added to saturated brine at 4 degrees C for 3 hours before final packaging to obtain the final cheese. This cheese is the control cheese.

After the stretching process three cheese blocks are used for addition of Calcium Lacto- bionate (Ca-LBA). The Ca-LBA is dissolved in water at a concentration corresponding to the dry matter concentration in the cheese block, i.e. 52%. This allows addition of Ca-LBA by injection without changing the dry matter of the cheese. Different amounts of the Ca-LBA solution are added to the cheese: a. 2.0% (1.0%) b. 4.0% (2.1%) c. 6.0% (3.1%)

Amount of Ca-LBA content in the cheese after injection is in brackets. After the injection the cheeses are stored in brine at same conditions as for the control cheese.

The quality of the cheeses are evaluated after 14 days storage and compared to the control cheese. The addition of Ca-LBA by injection enable higher yield of cheese corresponding to the amount of Ca-LBA solution added.

Example 2

Fresh Cheddar cheese blocks are produced by a typical cheddar cheese recipe (Cheese Chemistry, Physics and Microbiology). The dry matter content of the cheese is approx. 61%. The cheese curd is grinded and dry salted before pressing and packaging to obtain the final cheese. This cheese is the control cheese. Three cheese blocks are used for addition of Calcium Lactobionate (Ca-LBA). The Ca-LBA is dissolved in water at a concentration corresponding to the dry matter concentration in the cheese block, i.e. 61%. This allows addition of Ca-LBA by injection without changing the dry matter of the cheese. Different amounts of the Ca-LBA solution are added to the cheese: d. 2.0% (1.2%) e. 4.0% (2.4%) f. 6.0% (3.7%)

Amount of Ca-LBA content in the cheese after injection is in brackets. After the injection the cheeses are stored at same conditions as for the control cheese. The quality of the cheeses are evaluated after 14 days storage and after ripening for 6 months and compared to the control cheese. The addition of Ca-LBA by injection enable higher yield of cheese corresponding to the amount of Ca-LBA solution added.

Example 3

From two vats of 170 kg milk standardized to 3.3% protein and 2.5% fat, low moisture partly skimmed Mozzarella cheeses were made following a standard make procedure. After the stretching process, the hot curd was filled into forms of approx. 2.5 kg and each cheese was weighed. One part of the blocks was, immediately after the stretching process, injected with 2% of a 50% solution of Ca-lactobionate (in this example shortened "LBA") in water. Injection was done manually with a 5 ml syringe, injecting the LBA into the Mozzarella cheese in portions of 2-3 ml in a uniform pattern across the cheese surface. After in- jection the Mozzarella cheeses were put into cold water for 20 minutes followed by brining in saturated brine for 1V2 hour, a drying step and vacuum packaging. Each Mozzarella cheese was weighed before and after injection with LBA and again before packaging and storage at 4-5°C. The results of the weight gain obtained during injection are given in table 1. A slight loss of weight occurs during cooling and brining of the control cheeses, as op- posed to an increase in weight in the cheeses injected with LBA. The addition of LBA by injection enables higher yield of cheese corresponding to approx. the amount of LBA solution added.

Table 1. Weight figures and yield gains thought LBA injection

After seven weeks, control cheeses and cheeses injected with 2% LBA were taken from each vat and evaluated for moisture (see table 1) and functional properties.

No difference was observed in stretchability and metability between control and LBA injected pizza cheeses.

Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

REFERENCES

Patents and patent applications: US20070105200A, US20060008555A, US2006083821A, US2006083822A, US2005249853A, US2005249854A, US2005271789A, US7169429B, US5012728, US3661072, US2006201343, US5200223, US3649299, US5851578. Cheese and Fermented Milk Foods, 3 ^rd ed. 1997, by Frank V. Kosikowski and Vikram V. Mistry

Cheese Chemistry, Physics and Microbiology, 3 ^rd ed. Volume 2 2004 by Patrick F Fox, Paul L H McSweeney, Timothy M Cogan and Timothy P Guinee

All references cited in this patent document are hereby incorporated herein in their entirety by reference.