NL2003442C2 - Cheese with a reduced salt content. - Google Patents

Description

P6023829NL1

Cheese with a reduced salt content 5 Background

The present invention relates to a method for the preparation of cheese with reduced salt content, in particular for the preparation of hard and semi-hard cheeses.

Cheese is generally prepared by separating the solid milk components such as proteins, fats and minerals from the milk liquid. Upon addition of rennet and starter, the 10 milk proteins, in particular caseins, coagulate with fat and liquid being included, which is known as curdling resulting in formation of curd. The curd is subsequently divided into parts, the whey liquid is removed, and the cheese is formed. The cheese may optionally be salted and ripened. The ripening may take place naturally by leaving the young cheese at 12-14°C for four weeks or longer, preferably with one or more aqueous 15 cheese coating treatments applied thereto at regular time intervals (“natural ripening”). Alternatively, the young cheese may be packaged in foil after brining and is then being ripened, usually at a temperature of 4-7 °C (“foil-ripening”).

Common salt, or sodium chloride (NaCl), is widely used as a food ingredient, particularly in meat and dairy products. The sodium intake of humans in Western 20 society is approximately 2-3 times that required to meet the needs of the human body. The general concern is that such a high intake may result in hypertension in susceptible individuals, who may represent as much as 20% of the population. The health risks associated with hypertension are well known and include coronary disease and premature death. It is now policy to move towards a significant reduction in dietary 25 salt.

Salt is the primary source of sodium in natural cheese. Salt is a critical ingredient in the cheesemaking process. It provides taste and texture. It also provides safety as it acts as a natural preservative. It lowers the water activity of cheese, which prevents the growth of undesirable microorganisms.

30 Salt is almost always added after the desired pH is reached. It can be added through a salting step, where it may be added directly to milled curd. Alternatively, it may be added by rubbing salt on formed cheese. Also, salt can be absorbed by the cheese as it soaks in a brine solution.

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Cheese of the Gouda and Edam type are usually brined, i.e., immersed in a salt-bath to receive salt and to form a protective rind. The brining step is considered important for flavour development in cheese. Salt has important flavour-enhancing properties.

5 Important contributors to daily salt intake in humans are bread, milk and milk products (including cheese), meat products and soups. In view of the health concerns associated with dietary salt, it has been proposed to (partially) replace the sodium currently incorporated in cheese with salt replacers, e.g., potassium, magnesium or calcium. The salt replacer most used is potassium chloride, as it most closely resembles 10 sodium chloride. However, these salt replacers have several disadvantages. They do not contribute to the texture of the cheese to the same extent as salt. When potassium chloride is used to replace the sodium chloride, the texture of the cheese becomes inferior and/or the cheese acquires a bitter taste. The present invention intends to obviate one or more of these problems.

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Summary of the Invention

In a first aspect, the present invention is concerned with a method for preparing a cheese of the hard or semi-hard type having a sodium chloride content of less than 2.8 g per 100 g dry matter, said method comprising a) mixing cheese milk with a rennet, a 20 suitable conventional lactic acid starter, and one or more adjunct starters, said one or more adjunct starters comprising one or more lactic acid bacteria species having one ore more of the following properties: i) a higher proteolytic and/or peptidolytic capacity compared to a conventional lactic acid starter, and/or ii) a debittering capacity. Further steps to provide the cheese are known in the art. Preferably, the method further 25 comprises b) allowing the mixture obtained in (a.) to coagulate, and to provide curd, c) placing and pressing of the curd into a desired mould, d) salting the moulded curd in brine to produce the moulded curd mass comprising the sodium chloride content of less than 2.8 g per 100 g dry matter; and e) ripening of the cheese. Herein, the term “rennet” is known to the skilled person and may be equated with the term “coagulant” and vice 30 versa.

In a second aspect, the present invention relates to a cheese obtainable by such method.

3

Also, the present invention pertains to use of a mesophilic or thermophilic adjunct starter in the preparation of cheese having a reduced sodium chloride content.

Detailed Description of Embodiments 5 The present invention provides a solution to one or more problems associated with the preparation of cheese having reduced salt concentration. To this end, an adjunct starter is employed in combination with conventional lactic acid starters.

The method and the cheese according to the invention preferably relate to a semi-hard or hard foil-ripened cheese. It has been found that in the absence of the adjunct 10 culture(s) employed in the method of the invention, especially a foil-ripened cheese having a reduced salt content, especially when ripened at a ripening temperature of between 3-8 °C, more preferably of 4-7 °C, possesses an inferior taste. Surprisingly, the method according to the present invention may provide a foil-ripened cheese having a significantly improved taste. It is noted that also higher temperatures may be used in 15 foil ripening, preferably up to 18 °C, in which case the presence of at least the adjunct culture having the debittering capacity is preferred.

The skilled person is aware of which type of cheeses are of the hard of semi-hard type. Non-limiting examples of a cheese of the hard or half-hard type are Gouda, Edam, and Cheddar cheese. In an advantageous embodiment, the cheese is of the Gouda or 20 Edam type. The cheese may be foil-ripened or may be naturally ripened. In an embodiment, the cheese is foil-ripened. Cheese ripened in this manner loses no moisture during ripening which is of economic advantage. Moreover, foil-ripened cheese is often of rectangular shape, which provides advantages with cutting to slices or bars (no cutting losses). By comparison, cutting losses can run up to 15% for 25 standard natural ripened cheese.

The cheese of the invention will have a sodium chloride (NaCl) content of less than 2.8 g per 100 g dry matter, preferably 0.5-2.8 g, more preferably 1-2.8 g, yet more preferably 2-2.8 g, and even more preferably 2.2-2.8 g, 2.3-2.8, 2.4-2.8 or 2.5-2.8 g of NaCl per 100 g cheese calculated as dry matter. The NaCl content in wt.% comprised 30 by a moulded curd mass or by a cheese may be preferably determined as a Na+ content in wt.%, wherein the determined Na+ content should be multiplied by a factor of (1/0.3933) to arrive at the NaCl content of the moulded curd mass or cheese. A standard Gouda-type cheese has a sodium chloride content of approximately 3.5 wt.% 4 (as NaCl), based on dry weight of the cheese. Such a standard Gouda-type cheese may thus be analysed to have a sodium content of 1.38 wt.% (as Na+) based on dry weight of the cheese. In an embodiment, up to 75 wt.%, more preferably up to 50 wt.% of the sodium chloride comprised by the brine may be replaced with potassium chloride, so 5 that the sodium chloride content of a moulded curd mass after brining may be further reduced. Preferably, the relative amount of NaCl, by weight, is equal to or higher than the relative amount of KC1, by weight.

In step a) cheese milk is mixed with inter alia a suitable conventional lactic acid starter. Such conventional lactic acid starter is inter alia important for the conversion of 10 lactose into lactic acid, for the promotion of curdling, and for the improvement of the taste and shelf life of the cheese. As used herein, the term “conventional lactic acid starter” is used to denote a culture of lactic acid bacteria which is added to milk or a milk product with the aim of lowering the pH thereof by fermentation and contributing to the ripening by release of proteolytic and lipolytic enzymes. Different species of 15 lactic acid bacteria may be used, depending on the desired type of cheese. The lactic acid starter may be added as bulk starter or as direct starter. The term bulk starter has its ordinary meaning and relates to a starter culture prepared by inoculating a suitable medium with a mother culture, and allowing the mother culture to grow in the medium. Typical examples of suitable mother cultures include, without limitation, DL-type 20 cultures like BOS, A, Ur, C02, C07, CIO (all ex CSK, Leeuwarden, The Netherlands), L-type cultures like Frl8, Frl9, HB26, Cl8, Cl9, C92, C93 (all ex CSK, Leeuwarden, The Netherlands) or O-type cultures like Frl9p, Fr48Zl, Fr57Zl (all ex CSK, Leeuwarden, The Netherlands. The term direct starter relates to a starter which is without prior fermentation directly added to the cheese vat, preferably in the form of 25 frozen pellets. Typical examples suitable direct starters are Z502, Z410, Z320, U102, U110 (ex CSK, Leeuwarden, The Netherlands).

In the method of the invention, one or more adjunct starters are used. The term adjunct starter is well known in the art. An adjunct starter does not so much play a role in the acidification process of the cheese milk, but rather is involved in improving other 30 properties in the cheese, i.e. an adjunct starter serves to add a package of enzymes to the cheese preparation process. It is added to improve the sensory quality of the cheese, such as taste, colour, smell, or other appearance. According to the present invention, 5 the adjunct starter comprises one or more lactic acid bacteria species that has one or more of the following properties: i) a higher proteolytic and/or peptidolytic capacity compared to a conventional lactic acid starter; and/or 5 ii) a debittering capacity.

It is especially preferred that the adjunct starter comprises one or more lactic acid bacteria selected from the group of thermophilic bacteria, especially thermophilic streptococci and/or bacilli. Surprisingly it has been found that these bacteria have a very favourable effect on taste of a reduced salt cheese.

10 Without being bound to theory, as outlined above, sodium chloride enhances flavour in cheese. A cheese reduced in sodium chloride content will therefore have reduced flavour. Flavour may be enhanced by ensuring a higher proteolytic and/or peptidolytic capacity in the cheese by addition of a suitable adjunct starter.

Potassium, which is mostly used to replace the sodium in salt has the unfortunate 15 property that it confers a somewhat bitter flavour. The adjunct starter preferably comprises all three properties outlined above. However, the adjunct starter may also comprise one or two of properties i) and ii).

In the method of the invention, any type of rennet may be used such as a standard (abomasal) rennet (e.g. Kalase ex. CSK food enrichment) or microbial coagulant (e.g. 20 Milase XQL ex CSK food enrichment). In particular, the invention is particularly advantageous when a microbial rennet is used, especially in combination with foil ripening. Very good results can be obtained in that case.

Salting the curd may be used by any method known in the art. In a useful embodiment, salting is carried out by immersing the curd in a brine solution. Usually, 25 the total amount of salt in the brine is about 15-18% (w/w) NaCl. In order to reduce the sodium chloride content of the cheese, a combination of salt (sodium chloride) and salt replacer may be used in the brine solution. As a salt replacer, conveniently potassium chloride may be used. This has been approved for use in foods and has the same counter ion as does sodium chloride. Thus, preferably, the salt replacer is potassium 30 chloride. The salt may be replaced by the salt replacer in any amount suitable to achieve a salt (sodium chloride) content in the cheese of less than 2.8 g per 100 g dry matter. Thus, in an embodiment, the salting is performed in a brine solution comprising 6 sodium chloride and salt replacer, preferably potassium chloride. The ratio of sodium chloride to potassium chloride is preferably in the range of 1 : 1 or more.

The salting may also be performed for less time than conventionally, e.g., in a brine solution comprising 13-23 wt.% sodium chloride for less than about 44 hours. It 5 is noted that these brine concentrations at this brining time especially pertain to flatcylindrical or rectangular-shaped cheeses having a weight of approx. 10-12 kg. The expression “brine” preferably relates to an aqueous solution comprising NaCl, preferably in an amount of 15-18 wt.% with respect to the weight of the solution. The brining time is preferably at least 1 hour, more preferably at least 5 hours. The brining 10 time is preferably less than 48 hours. In a preferred embodiment, the brining time is less than 44 hours, even more preferably the brining time is less than 40 hours, most preferably the brining time is less than 36 hours or even less than 32 hours. Accordingly, a moulded curd mass comprising a reduced sodium chloride content is obtained. It is noted that these brining times especially pertain to flatcylindrical or 15 rectangular-shaped cheeses having a weight of approx. 10-12 kg. Generally, the skilled person will be able to adjust the sodium chloride content of a cheese by adapting brining times and/or sodium chloride concentration comprised by the brine to the weight and/or the shape of the cheese. Herein, “reduced” means less than 2.8 wt.%, preferably 0.5-2.8 g, more preferably 1-2.8 g, yet more preferably 2-2.8 g, and even 20 more preferably 2.2-2.8 g, 2.3-2.8, 2.4-2.8 or 2.5-2.8 g of NaCl per 100 g cheese calculated as dry matter. The person skilled in the art may preferably adapt the brining time to obtain the reduced sodium chloride content for a moulded curd mass having a different weight and/or shape.

In a useful embodiment, especially useful for providing a flatcylindrical or 25 rectangular cheese of approx. 10-12 kg, the salting is performed in a brine solution comprising 15-21 wt.% sodium chloride for about 12 to about 36 hours, such as in a conventional, e.g., a 15-18 wt.%, NaCl brine solution.

The adjunct starter may comprise thermophilic and/or mesophilic lactic acid bacteria. Lactic acid bacteria are Gram positive non-spore-forming anaerobic, catalase-30 negative cocci or rod forming lactic acid as only or main end product of their carbohydrate metabolism. For cheese preparation, the genera Bifidobacterium, Lactobacillus, Lactococcus, Leuconostoc, Pediococcus, and Streptococcus are highly important. Lactic acid bacteria which are used as starter cultures are divided into 7 mesophilic strams (having an optimum growth temperature of about 30°C) and thermophilic strains (having an optimum growth temperature of about 40-45°C). Mesophilic lactic acid bacteria are used at temperatures between about 18 °C and about 37 °C. Suitable mesophilic bacteria for cheese preparation include, without limitation, 5 Lactococcus lactis spp. lactis, Lactococcus lactis spp. cremoris, Lactobacillus easel, Propionibacterium spp., Leuconostoc mesenteroides, and. Lactobacillusplantarum. Thermophilic lactic acid bacteria are used at temperatures between about 30 °C and 45 °C, in particular 37 °C to 45 °C. Thermophilic cultures suitable for cheese preparation include, without limitation, strains of the species Streptococcus thermophilus, 10 Enterococcus faecium, Lactobacillus delbrueckii spp. bulgaricus, Lactobacillus delbrueckii spp. lactis, Lactobacillus helveticus, Lactobacillus acidophilus, and Bifidobacterium spp.

Suitable adjunct starters include known ripening accelerating starter, such as those mentioned in EP-A-0281167 and in NL-A-8801861. This type of adjunct starters 15 (e.g., APSi3 and LH-B01 and LH-B02) is available from Chr. Hansen (Denmark) and CSK Food Enrichment (the Netherlands).

In an embodiment, said adjunct starter comprises one or more of the cultures B33, C35, C77, C38, CR322, CR213, CR319, CR312, APSi3,LH-B01, LH-B02, L100, L200, L300, L400, L500, L600, L700, L800,1233.

20 The adjunct starter may be added as bulk starter or as direct starter. The term bulk starter has its ordinary meaning and relates to a starter culture prepared by inoculating a suitable medium with a mother culture, and allowing the mother culture to grow in the medium. Typical examples of suitable mother cultures include, without limitation, 1233 (ex CSK, Leeuwarden, The Netherlands). In an embodiment the pH of this fermented 25 starter may be set to neutral, for instance by adding a suitable amount of sodium hydroxide solution, in order to prevent the cheese preparation process from being adversely affected. In another embodiment the starter will be kept at low pH during 4 to maximal 24 hours after normal fermentation until pH 3,8 has been reached. A typical examples of a suitable mother culture for this procedure is APS (ex CSK, Leeuwarden, 30 The Netherlands). The term direct starter relates to a starter which is added directly to the cheese vat without prior fermentation. Typical examples suitable direct adjunct cultures are LI00, L200, L300, L400, L500, L600, L700, L800 (all ex CSK, Leeuwarden, The Netherlands).

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The adjunct starter may be introduced in the cheese milk simultaneously with, before, or after the addition of conventional lactic acid starter. In an embodiment, the adjunct starter is added simultaneously with or after the conventional lactic acid starter.

As outlined above, the adjunct starter does not so much play a part in the 5 acidification process as in the addition of a package of enzymes. Good results are obtained when, based on the weight of the total cheese milk, 0.2 to 5% by weight and preferably at least 0.5% by weight and preferably at most 2% by weight of non-concentrated adjunct starter is added. Also deep-frozen and concentrated adjunct starter may be used such as Direct Vat Starter (DVS) cultures. The skilled person knows how 10 many equivalents of these cultures are needed to obtain results comparable to those obtained with non-concentrated adjunct starters.

It is preferred that a nisin-producing culture, preferably a nisin-producing direct vat culture, is not employed in the method of the present invention, such that a cheese may be obtained comprising less than about 2 IU/g, preferably less than about 1 IU/g, 15 even more preferably less than about 0.5 IU/g nisin. In an advantageous embodiment, the cheese does not comprise any detectable nisin.

The invention also is concerned with a cheese obtainable by the methods herein described. Such cheese has reduced salt content, and yet has all properties associated with conventional cheese. The cheese may be a low-fat cheese, e.g. a 20+ or 30+ 20 cheese.

The invention also relates to use of a mesophilic or thermophilic adjunct starter in the preparation of cheese having a reduced sodium chloride content.

Further embodiments of the invention 25 The invention further provides a use of a mesophilic or thermophilic adjunct starter in the preparation of a (preferably foil-ripened) cheese having a sodium content of between 0.5-2.8 wt.% based on dry matter for improving the taste thereof. Herein, the adjunct starter is preferably a thermophilic adjunct starter, which further preferably is selected as one or more strains of thermophilic streptococci and/or bacilli.

In the expression “wt.% [of an ingredient] based on dry weight of a composition” the weight percentage [of the ingredient] is specified with regard to the solid matter content of the composition. Said weight percentage preferably relates to the weight 30 9 percentage of the ingredient with respect to the weight of the composition, excluding its water content. The “wt.% [of an ingredient] based on dry weight of a composition” may for example be obtained by determining the weight percentage of the ingredient in the dehydrated composition, and specifying said weight percentage with respect to the 5 weight of the dehydrated composition.

In this document and in its claims, the verb "to comprise" and its conjugations is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. In addition, reference to an element by the indefinite article "a" or "an" does not exclude the possibility that more than one 10 of the element is present, unless the context clearly requires that there be one and only one of the elements. The indefinite article "a" or "an" thus usually means "at least one". The invention will be further elucidated in the following, non-limiting examples.

Examples 15 EXAMPLE 1: Preparation of normal salt and low salt Gouda cheese

Gouda cheese was prepared from 2000 liter cheese milk according to typically Gouda recipe (see for instance Fox PF (ed) Cheese: Chemistry, Physics and Microbiology.

20 Third edition (2004), reprinted (2005), Vol. 2, Gouda and Related Cheeses, pp. 101-140 ). As starter cultures the bulk starters C02 and Cl9 were used together at equal amounts (0.2% v/v).

The composition of the cheese milk was as follows: 25 Fat content (w/v) 1.05%

Protein content (w/v) 3.47%

Lactose content (w/v) 4.54%

To the cheese milk, calcium chloride was added in an amount of 70 grams of a 33%-ish 30 solution in water per 100 liters of cheese milk. A commercially available microbial coagulant was used in common quantities (corresponding to a dosage of 20 grams coagulant of 220 IMCU strength per 100 liter cheese milk). Thermophilic lactobacilli (L400 and C77) and streptococci (C35 and C38) adjunct cultures were added as deep-frozen pellets as follows: Vat #1 (no adjunct), Vat #2 (20 gr C38 per 2000 liter cheese 10 milk), Vat #3 (20 gr C38 and 400 gr L400 per 2000 liter cheese milk) and Vat #4 (20 gr C35 and 400 C77 per 2000 liter cheese milk).

The curdling temperature was 32 °C and the processing time was 60 min. The first 5 whey separation comprised of 40% whey disposal. The curd was then washed with 35% wash water op 36 °C. The procedure provided 10 flat cylindrical consumable cheeses of 11 kg. The cheeses were brined for either 48 hours or 24 hours in a brine bath comprising 17% NaCl at 10-12 °C and pH=4.6. After brining the cheeses were coated and ripened at 13 °C according to a standard protocol.

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The composition of the cheeses brined for 48 hours was as follows:

Av. Fat content 23.4% ±0.1

Av. Calcium content (mg/kg of cheese as is) 1.03±0.02 Av. Sodium content (g/kg of cheese as is) 5.9±0.25 15 Av. Moisture content 51.2% ±0.8

Av. Salt content 3.3% ±0.1

Where percentage values are given as wt % based on the dry weight of the cheese The composition of the cheeses brined for 24 hours was as follows:

Av. Fat content 23.4% ±0.1 20 Av. Calcium content (mg/kg of cheese as is) 1.03 ± 0.02

Av. Sodium content (g/kg of cheese as is) 4.4 ± 0.3 Av. Moisture content 51.8% ±0.3 Av. Salt content 2.5% ± 0.2

Where percentage values are given as wt % based on the dry weight of the cheese.

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The cheeses were allowed to ripen for 6 weeks prior to evaluation of their properties.

EXAMPLE 2: Improvement of flavor in low salt Gouda cheese 30 After 6 weeks of ripening, taste evaluation of the cheeses took place. The scores for different attributes were determined with the aid of a trained sensory panel (QDA method) where 12 subjects were offered the cheeses in two sessions in a randomized manner and gave a score on a scale from 1 to 10.

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Low salt (LS) 20+ Gouda cheeses made with thermophilic adjuncts (C35, C77) Vat# 4 compared with reference (no adjuncts; Vat#l) respectively scored very well in an internal evaluation. LS cheeses showed a 21 and 27% salt reduction respectively for 5 Vat#l and Vat #4. The lower salt concentration was obtained by decreasing the brining time from 48 to 24 hours. The effect of the adjunct in LS cheeses was quantified using an organoleptic evaluation in the LS cheeses. The organoleptic evaluation reveals that the use of the thermophilic adjuncts (C35 and C77) in low salt Gouda cheeses produces a less bitter and less sour cheese.

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Claims (13)

A method of preparing a hard or semi-hard cheese with a sodium chloride content of less than 2.8 g per 100 g of dry matter, the method comprising: a. Mixing cheese milk with a rennet, a suitable conventional lactic acid-producing starter, and one or more adjunct starters, said one or more adjunct starters comprising one or more types of lactic acid bacteria having one or more of the following properties: i) a higher proteolytic and / or peptidolytic capacity compared to a conventional lactic acid producing starter, and / or (ii) a debilitating capacity. b. curdling the mixture obtained in (a.), and providing curd; C. bringing the curd into a suitable shape and pressing it; d. salting the mold-pressed curd in brine to provide a curd mass formed comprising a sodium chloride content of less than 2.8 grams per 100 g of dry matter; and 20 e. ripening the cheese. The method according to any of the preceding claims, wherein the cheese is a foil-ripened cheese. The method of any one of the preceding claims, wherein the adjunct starter comprises thermophilic and / or mesophilic lactic acid bacteria. The method of claim 4, wherein the adjunct starter comprises one or more bacterial species selected from the group consisting of Lactobacillus acidophilus, Lactobacillus delbrueckii spp. lactis, Lactobacillus helveticus, Streptococcus thermophilus, Lactococcus lactis, Leuconostoc species, and Lactobacillus plantarum. The method of any one of claims 1-5, wherein the adjunct starter comprises one or more cultures selected from the group consisting of B33, C35, C38, C77, CR322, CR213, CR319, CR312, APS] 3, LH- B01, LH-BO2, L100, L200, L300, L400, L500, L600, L700, L800, 1233, and combinations thereof. The method according to any of the preceding claims, wherein the salting is carried out in a brine solution comprising sodium chloride and a salt substitute. The method of claim 7, wherein the salt substitute is potassium chloride. The method of claim 8, wherein the ratio of sodium chloride to potassium chloride is in the range of 1: 1 or higher. The method of any one of the preceding claims, wherein the salting is carried out in a brine solution comprising 12-23% by weight of sodium chloride and for less than about 44 hours. The method of claim 10, wherein the salting is carried out in a brine solution comprising 15-21 wt% sodium chloride and for about 12 to about 36 hours. The method according to any of the preceding claims, wherein the cheese is of the Gouda or Edam type. A cheese obtainable by the method according to any one of the preceding claims. Use of a mesophilic or thermophilic adjunct starter in the preparation of a foil-ripened cheese with a sodium chloride content of between 0.5-2.8% by weight, based on dry weight, to improve its taste.