CZ282388B6 - Process for preparing soft or semi-hard pressed mozzarella cheese - Google Patents

Abstract

Mozzarella cheese (I) is prepd. by (a) pasteurising cows' milk of 1.5-3.5 wt.% fat; (b) fermenting with lactic bacteria; (c) coagulating the cheese milk formed to obtain a coagulum of curd and whey; (d) cutting, and draining off the whey; (e) heating, kneading and stretching until it is a homogeneous fibrous mass of unripened (I) of 45-60 wt.% moisture and at least 30 wt.% fat (w.r.t. dry solids); (f) cooling in cold brine and (g) removing the prod. from the brine. Steps (a)-(g) are such that the prod. has a combined moisture and wet milk fat content of at least 70 wt%. The cheese is frozen within 48 hrs. of step (g). During (e) 0.5-1.5 (0.8-1.5) wt.% NaCl is mixed into the curd. The final prod. has moisture 50-60 (52)% and wet milk fat 16-30 (18) %. Cooling (f) is pref. to core temp. of 75 deg. F or less, and the cheese is comminuted and frozen within 48 hrs. of (g). Heating (e) is to 125-155 deg. F cooling (f) to a core temp. 55-75 deg. F and comminution is before freezing. The particles of comminuted cheese are independently quick frozen. Freezing is esp. within 2 hrs. of (g). The brine is 3-60 wt.% NaCl at 0-25 deg. F until the core temp. is below 100 deg. F and a second 50-98 wt.% NaCl brine at 35-55 deg. F is then used. The heated cheese is extruded into the first brine as a continuous ribbon and is cut into sections before removal from the second.

Description

Process for making a mozzarella soft or semi-soft fibrous cheese

Technical field

The present invention relates to a process for the production of soft or semi-soft fiber cheese of the mozzarella type. In particular, the invention is directed to obtaining cheese that can be used without prior ripening and other processing. The invention also relates to the composition of the cheese thus obtained. The main feature of the invention is to adjust the milk fat content, protein and moisture content of the cheese to achieve the desired cheese processing properties.

BACKGROUND OF THE INVENTION

In the dairy industry, especially in the cheese industry, there has been an effort for many years to reduce the time required in the production process to achieve the desired processing properties of cheese. The term 'processing characteristics', when used in conjunction with various types of mozzarella cheese, refers to the characteristics applicable to the baking of these types of cheese on pizza. These properties include melting properties such as degree of blistering, degree of melting, ductility and softness. Reducing or fully eliminating the ripening process would entail substantial economic benefits directly linked to the cost of ripening the cheese.

Soft or semi-soft fibrous cheeses of the mozzarella type are produced worldwide under various names such as mozzarella, filata paste, provolone, scamorze or under the simple name pizza cheese. For simplicity, all such cheeses are referred to as mozzarella cheeses. The actual production method of these cheeses is sometimes referred to as the paste filata process (see Draft New Intemational Individual Standard for Mozzarella, November 8, 1995 for Codex Alimentarius). Some of these cheeses are referred to in the industry as soft cheeses, others as semi-soft cheeses. Where the cheese contains at least 20% milk fat by weight and not more than 60% water by weight, it is referred to as whole cream soft cheese (Cheese Regulations 1970 (No 94) of the United Kingdom (Part II (R) (2) (a)).

Various types of mozzarella cheese are produced by a process that involves:

(a) pasteurized cow's milk with a fat content of approximately 1,5 to 3,5% by weight (Indian buffalo milk is also used in some countries);

(b) the milk is fermented using one or more lactic acid producing bacteria to produce fermented milk;

(c) the fermented milk is coagulated to form a precipitate containing curd and whey;

d) separating the precipitate and allowing the whey to drain, producing industrial curd;

(e) the industrial curd is heated, kneaded and spread until a homogeneous fibrous mass is obtained having a moisture content of about 45 to 60% by weight and a milk fat content of at least about 30% by weight, based on dry matter;

f) The resulting mass is placed in a cold salt bath, where it is left until it has cooled and the salt has penetrated into it; and

(g) the cooled cheese is removed from the salt bath.

-1GB 282388 B6

The resulting unripe mozzarella cheese is aged for about 7 to 21 days at a temperature of about 1.7 to about 7.2 ° C after processing in a salt bath in traditional production methods to develop its characteristic flavor and texture and to achieve suitable properties during its baking. (The maturing process is sometimes referred to as aging or simply lying down). During ripening, all major ingredients of the cheese, ie carbohydrates, protein and fat, are subject to change. By a number of complex metabolic processes, such as enzymatic lipolysis and proteolysis, these major components are metabolized to lactic acid, peptides, amino acids, and fatty acids.

After ripening, mozzarella cheese is often pulverized and frozen to stop ripening processes. The cheese is transported in refrigerated containers. Cheese can also be frozen in blocks, but this procedure is rarely used.

The baking properties of mozzarella are very important. Mozzarella cheese is mostly used for making pizza. In pizza making, tomato paste and cheese (in comminuted form) are applied to the surface of the pizza corpus, and then the resulting pizza is baked in an oven at a temperature in the range of about 204 to about 539 ° C, often in the range of about 232 to about 344. about 455 ° C. Many different kinds of other foods such as strips of pepper, sliced mushrooms, ground beef, sausages, pineapple, etc. can be used to form the top of the pizza as it is known. evaporation of water, oil release and blistering. It is desirable that the cheese melts perfectly before the pizza corpus is lit. The formation of many large blisters when melting cheese is undesirable. The blisters that are formed from the protein can burn, resulting in dark, hard scabs that deteriorate the appearance and taste of the pizza and the mouthfeel that results from the pizza being consumed. In order to be satisfactory for pizza production, the cheese must be melted with minimal blistering during corpus baking.

If the mozzarella cheeses are not subjected to the ripening process, they tend to form blisters significantly when used in baking pizza. The higher the temperature in the furnace, the greater the risk of blistering.

Ripening mozzarella cheese requires considerable time, space and energy, which significantly increases the cost of the finished product. The same applies to other types of cheese, some to a greater extent and others to a lesser degree. For this reason, efforts have been made to speed up the ripening process of various types of cheese for a considerable time.

Lederer (1953) reported that the maturation time of American cheddar cheese can be shortened by rapidly freezing unripe cheese, leaving the cheese frozen for 60 to 180 minutes, and then transferring the cheese to a suitable maturation chamber in which the temperature is maintained at 7.2. to 15.6 ° C. The process so treated reportedly achieves good consistency, texture and flavor after only 9 days of maturation, which contrasts with the period of at least 6 weeks required for conventional procedures. (Lederer, U.S. Patent No. 2,816,036, entitled " Cheese Production ", priority May 1, 1953, patent granted December 10, 1957.)

Freeman (1959) reported that cheddar cheese maturation can be accelerated by using mixed cultures and higher temperatures (15.6 ° C) in the first four weeks. (Freeman, Accelerating the Aging Process in Cheddar Cheese, Kentucky Agric. Experiment Station, U. Kentucky, Bulletin 666 (June 1959)).

Kristofferson (in 1967) reported that the addition of reduced glutathione and porcinlipase to a cheese suspension is able to accelerate cheddar maturation in cheese paste production. (Kristofferson et al., Cheddar Cheese Flavor. IV. Directed and Accelerated Ripening Process, J. Dairy Sci. Vol. 50, No. 3, 292-297 (1967)).

-2GB 282388 B6

Singh (1969) reported that the ripening of cheddar industrial curd in the form of a suspension can be accelerated by the addition of sodium citrate and a mixture of vitamins and minerals. (Singh et al., Factors Affecting Flavor Development in Cheddar Cheese Slurries, J. of Dairy Sci. Vol. 53, No. 5, 533-536 (1969)).

Procházka (in 1971) published that by adding sodium citrate to mozzarella cheeses, the ripening period can be reduced by at least one third (CS patent no. 141 283, Method of making cheeses with accelerated ripening, 15 May 1971).

Sullivan et al. (1973) reported that so-called American cheese and Swiss cheese would mature in two to five times less time if adenosine-3 ', 5'-cyclic monophosphate was added to the curd to make it. (Sullivan et al., U.S. Patent No. 3,859,446, Method for Rapid Curing of Cheese, priority September 26, 1973, issued January 7, 1975.)

Sutherland (1975) reported that the time required to ripen cheddar cheese suspensions can be shortened by adapting a number of different conditions, including the oxygen content of the enclosure of the container in which the ripening takes place. (Sutherland, Rapidly Ripening Cheese Curd Slurries in Processed Cheese Manufacture, Australian J. of Dairy Tech., Vol. 30, 138-142 (1975)).

Shehata et al. (1977) reported that the addition of sodium citrate to fresh milk of Bubalus bubalis cattle accelerates lipolysis and proteolysis of ras cheese produced from milk. (Shehata et al., Effect of Adding Sodium Citrate to Buffaloes' Milk on Chemical and Organoleptic Properties of Ras Cheese Dairy Sci. Abstracts, Vol. 41, No. 9, 550 (1979)).

Lee (1979) suggested shortening the ripening process of mozzarella cheese by injecting a pregastric esterase solution into the cheese. (Lee, Hyong Joo, Acceleration of Cheese Ripening: High Pressure Injection and Diffusion of Curing Components in Italian-Type Cheese, doctoral dissertation, University of Wisconsin-Madison, 1979). Lee's dissertation provides an overview of the literature on accelerating cheese maturation (ids 2 to 45). Lee states that the maturation process, like most chemical reactions, can be accelerated by elevated temperature, but that in many cases undesirable reactions also occur, resulting in products with a reduced taste (id 17).

Abdel Baky (1982) reported the results of experiments showing that the addition of sodium citrate, proteinase, and lipase to cheese suspension of ras cheese can accelerate the ripening period from two months to 7 days. (Abdel Baky et al., Ripening Changes in Cephalotyre 'Ras' Cheese Slurries, J. Dairy Research, Vol. 49, pp. 337-341 (1982)).

Law (1987) wrote that the maturation of various cheeses can be accelerated by the addition of exogenous proteolytic enzymes. (Law, Barry A., Proteolysis in Relation to Normal and Accelerated Cheese Ripening, Cheese: Chemistry, Physics and Microbiology, Elsevier Applied Science, New York, NY 1987, ed. PF Fox, Vol. 1, Chapter 10, 365-392) ). The addition of lipases or esterases has been a common practice in the production of Italian-type cheeses since the 1950s.

In all these prior art processes, however, a certain maturation time is always necessary.

SUMMARY OF THE INVENTION

It has now been found that various types of mozzarella cheese with the desired processing properties can be produced by a process that does not involve a separate stage of ripening. In the process according to the invention, the usual production steps are used, but the ingredients and production conditions are controlled so that the cheese obtained from the salting step has a total moisture content and a milk fat content based on

% Wet basis, at least about 70% by weight. Methods for controlling the moisture and milk fat content of the finished cheese are known in the manufacture of mozzarella cheese. For example, the milk fat content can be controlled at the time the excess fat is separated from the milk in the separator. This is done just prior to pasteurization. The moisture content can be controlled, for example, by controlling the amount of acid formation during fermentation, in addition to controlling the temperature and the length of the cooking step.

SUMMARY OF THE INVENTION The present invention provides a process for the production of soft or semi-soft fiber mozzarella cheese, which is carried out by:

(a) pasteurizes cow's milk with a fat content of between 1,5 and 3,5% by weight;

(b) the milk is fermented using one or more lactic acid producing bacteria to produce fermented milk;

(c) the fermented milk is coagulated to form a precipitate containing curd and whey;

d) separating the precipitate and allowing the whey to drain, producing industrial curd;

(e) the curd is heated, kneaded and spread until a homogeneous fibrous mass of heated, unripe mozzarella cheese is obtained, which has a moisture content of 45 to 60% by weight and a milk fat content of at least 30% by weight, based on dry matter;

(f) the heated cheese is cooled in a cold salt bath; and

(g) the cooled cheese is removed from the salt bath;

whose essence lies in being

(i) steps (a) to (g) are such that the cooled cheese extracted from the salt bath has a sum of 70 to 80% by weight of the moisture content and milk fat content, and (ii) the cheese is frozen within 48 hours after removal from the salt bath to obtain mozzarella cheese with acceptable baking properties.

The currently marketed mozzarella cheeses most often have a sum of moisture content and milk fat content on a wet basis of less than 70%, for example in the range of about 65 to 69.5%. These cheeses are naturally also mature. Typical examples of the four most common types of mozzarella currently on the market are the following table.

Type ¹⁷ Moisture Content ²⁷ (% by weight) Milk fat content on wet basis ³⁷ (% by weight) Milk fat content tvs ⁴⁷ (% by weight) Mozzarella 52 or more 21.6 or more 45 or more mozzarella with low moisture content 46 24.8 46 partly skimmed mozzarella 52.5 16.6 35

-4GB 282388 B6 Low moisture mozzarella from partly skimmed milk 50 18,25 36,5

Comment:

1 / As defined in U.S. Pat. Code of Federal Regulations, Chapter 21, Sections 133.155 to 133.158

2 / Sum of bound water and free water content, ie the percentage weight loss on drying in an oven at 200 ° C overnight.

3 / Percentage of milk fat, which is based on the whole cheese and not only on its dry matter.

4 / Percentage of milk fat, based on the dry weight of the cheese.

In the context of the invention, it has been found that the mozzarella cheese produced by the proposed process can be used immediately to produce a satisfactory pizza. No maturation is required, but maturation may even be undesirable. The cheese has suitable properties when used in the production of baked food even in a state where it has not undergone ripening. The cheese can be frozen and transported immediately after production. When frozen, the cheese retains satisfactory processing characteristics for up to 12 months.

The cheese should be used or frozen within 48 hours after the end of the salting stage. If the cheese is not used or is not frozen by that time, the controlled properties of the cheese in the melt may be partially lost. Thereafter, the cheese will tend to burn and blister during baking unless it is first ripened, i.e. if it is not left to rest for at least 5 days or more. In a particularly preferred embodiment of the invention, the process can be carried out in a continuous manner in which the cheese is ground and frozen only 2 hours after its removal from the salt bath.

The cheese may be formed into blocks and frozen in this form, but preferably the cheese is ground before freezing. If the cheese is frozen in the form of blocks, the whole process from the milk pasteurization stage to the packaging stage of the cheese blocks and their dispatch can be carried out in such a short time as 36 hours. If the cheese is processed into cubes or crushed prior to freezing, and if the freezing is carried out by independent rapid freezing, then the entire process from pasteurization to dispatch may take less time, for example as short as about 8 hours. This is contrasted with prior art processes which require an additional 7 to 21 days of maturation to achieve the desired processing properties of the cheese.

Mozzarella cheese produced by the process of the invention can be used immediately in the pizzerias to which it is delivered. No additional time is needed to set it down. If the cheese has been freeze-dried independently in the manner disclosed in U.S. Patent No. 4,753,815 (Kielsmeyer et al.), It may not even be thawed in advance; it can be placed in the furnace in a frozen state. Under the typical baking conditions currently used in the production of pizza, the cheese according to the invention has the same or better properties than the mozzarella, whose sum of moisture content and milk fat content on a wet basis is less than 70% and which has been left maturing in the usual way, ie 7 to 21 days.

Mozzarella cheese with a significantly lower total moisture and milk fat content than 70%, which was immediately frozen and dispatched after removal from the salt bath, should be thawed and kept in a refrigerator at about 1.7 to 7.2 before being used in pizza production. ° C for 7 days or after

-5GB longer than this. Only in this way can the satisfactory properties of this cheese be achieved under the typical conditions currently used in baking pizza. Such cheese must either be ripened for at least a week before freezing, or, if immediately frozen, thawed and then ripened for at least a week, otherwise it does not have satisfactory pizza-baking properties which are carried out under current conditions. While it is conceivable that cheese with less than 70% total moisture and milk fat content can achieve acceptable melt properties under particularly limited atypical baking conditions, this would be impractical. From a practical point of view, it is necessary to have a mozzarella type of cheese that could be used in pizzerias under standard baking conditions that include time and temperature. The cheese according to the invention satisfies these requirements even though it is not aged.

Overview of the drawings

FIG. 1 is a schematic view of a portion of a production line used in a continuous process of the present invention.

Figures 2, 3 and 4 show photographs of pizza made using unsatisfactory immature mozzarella cheese (Figure 2), conventional mature mozzarella cheese (Figure 3) and mozzarella cheese produced by the method of the invention without ripening (Figure 4).

Figure 5 is a graph of the total moisture and milk fat content of the apparent heat capacity of a cheese produced by the process of the invention.

Fig. 6 is a graph of total moisture and milk fat content versus melt properties of non-matured mozzarella cheese.

A detailed description of the invention follows.

When making pizza, mozzarella is used as one of the main ingredients. Different forms of pizza (ie pizza with a thin dough body, pizza with a thick dough body) and the different types of oven used significantly affect the processing properties of mozzarella cheese, ie its melting properties. The baking time of the pizza and the baking temperature will also have a similar effect on the cheese's properties. When baking mozzarella cheese on pizza, the amount of energy available to achieve the desired melting properties is dictated and limited by baking conditions.

The processing characteristics of the cheese, in particular its melting properties, such as blistering, melting and ductility, are important for the pizza manufacturer, since these are the most visible on the finished pizza and contribute most to the overall enjoyment of the pizza consumer . As mentioned above, it has hitherto been generally believed that in order to achieve such melting properties, mozzarella cheese, regardless of its composition, must be aged for 7 days or more. The process of the invention eliminates the requirement for ripening and any further processing of mozzarella cheese, yet still achieves the same melting properties as the prior art cheese that has been aged.

The melting properties of mozzarella cheese are influenced by three main components, namely moisture, milk fat and protein. It has generally been considered that all these ingredients, both individually and in combination, have a role in achieving the processing properties of mozzarella cheese. Of these three components, the major factor limiting the melting properties of cheese is protein, namely the complexity of the protein structure. The protein structure requires the most heat (ie most energy) of all cheese components to melt or become liquid when baking pizza. Upon liquefaction, long strings-like protein molecules must unravel. In order for such unraveling, the cheese is usually heated to a temperature in the range of about 66 to about 93 ° C. This temperature range overlaps

-6GB 282388 B6 with the temperature range that is most commonly achieved when baking pizza. The desired melting properties of the cheese can only be achieved by unraveling the protein structure.

It is well known that temperature is a measure of the average kinetic energy released by a substance, and therefore the temperature of the molten substance is a function of the amount of energy absorbed, the melting point of the substance and the energy released. In order to reach the temperature required to unravel the protein structure and melt the protein in the cheese, some energy must be absorbed in the cheese. Once the cheese has melted, the energy is released and the temperature of the cheese continues to rise faster. When baking pizza, the other ingredients of the pizza, ie dough, paste, etc., require energy to achieve the characteristics that are characteristic of the baked product. The amount of energy available and the transfer of energy are limited and depend on the particular form of pizza and the particular baking conditions, ie the oven residence time and temperature. The pizza cannot be left in the oven for a long time to bake the cheese, otherwise the properties of the dough corpus and other ingredients would be impaired.

It has hitherto been assumed that the energy available under the conditions typically used in pizza baking is not sufficient to fluidize the complex protein structure of mozzarella cheese unless it has been ripened. Upon maturation, the protein structure is partially broken due to proteolysis. Smaller regions of the protein (peptides) whose structure is less complex do not require as much energy to unravel. The secondary effects of ripening on the processing properties of mozzarella cheese are the equilibrium penetration of salt into the cheese and the change in the ratio of free water to bound water in the cheese. Bound water means water that is chemically or physically bound to other ingredients of cheese. The rest is free water. Both of these factors affect the final melting properties of mozzarella.

The formation of blisters on the surface of baked pizza cheese is, as is generally believed, caused by the burning and drying of the protein present. Accordingly, it is believed that when baking cheese on pizza, it is necessary to ensure that the protein structure retains moisture during melting, since otherwise blisters will occur. However, if there is too much free water in the cheese, this water evaporates rapidly during baking, resulting in a considerable amount of blistering. On the other hand, a cheese that contains a significant amount of bound water, as is typical of a cheese that has been aging, will not have such a blistering tendency because the bound water does not flow out so easily and the protein structure thus retains its moisture.

In the process according to the invention, it is assumed that excessive evaporation of free water is prevented by the following measures:

1. During mixing and molding, salt is mixed into the raw material. The salt has the ability to bind water, thereby causing some of the free water that would otherwise evaporate quickly during baking to remain in the cheese.

2. By adjusting the correct moisture and milk fat content, the heat capacity of the cheese is adjusted to such a high level that the protein and milk fat fluidize sufficiently early in the baking process so that the free water remains trapped in the cheese and does not evaporate violently.

It has also been found in the context of the invention that the mozzarella cheese produced by the proposed process can be stored for 48 hours after cooling in a salt bath before being comminuted and packaged, yet retaining the desired processing properties. Preferably, however, the grinding of the cheese is carried out within 2 hours of its removal from the salt bath. In this way, the processing properties of the cheese are optimized and the production efficiency which is characteristic of the continuous process according to the invention is maintained. If the cheese is kept frozen for more than about 48 hours, it may result in excessive softening of the cheese to prevent it from being broken down into cheese granules. This is particularly the case when the cheese contains moisture in an amount of from about 52 to about 60% by weight and milk fat in an amount of from about 20 to about 30% by weight, based on the wet product.

-7EN 282388 B6

It has also been found that a product that has been stored frozen for more than 48 hours requires traditional maturation (typically a total of 7 to 21 days) to achieve the desired melting properties.

Without wishing to be bound by theory, they assume that the moisture content and protein state are such that the desired melting properties can be achieved within the first 48 hours of salting out, but that after this time, so that the desired melting properties can then only be achieved at the cost of cheese ripening for 1 week or longer. The desired properties in the unripe cheese can usually be maintained by freezing the cheese within 48 hours of its removal from the salt bath. Slow or rapid freezing methods may be used. Preferably, the cheese is frozen to a core temperature of about -4 ° C or lower.

When used for the production of pizza, the cheese prepared by the process according to the invention, together with tomato paste and optionally other ingredients, can be decomposed on a pizza corpus, which is either frozen or not frozen. In addition, the pizza body may be un-baked, partially baked or fully baked. The cheese can usually be thawed up to 14 days before being placed in the oven. However, as mentioned above, it may not be allowed to thaw too long before baking. The cheese has good properties, even if it is thawed only one or two days before use. In addition, if the cheese has been frozen by the IQF process described in US Patent No. 4,753,815, it can be placed in an oven without being thawed pre-thawed and still exhibits the desired baking properties.

In the process of the invention, the ingredients and conditions used are generally selected to achieve a moisture content in the cheese of from about 50 to about 60% by weight and a milk fat content in the moisture of from about 16 to about 30% by weight. Preferably, the composition of the mozzarella cheeses is controlled in the process according to the invention so that the moisture content is at least 52% and the milk fat content relative to the wet product is at least 18% by weight.

As already mentioned, one of the purposes for which the ripening of the cheese serves is to allow the salt (sodium chloride) to diffuse from the outer layer to the center of the pieces of mozzarella cheese, thereby balancing the salt concentration in the cheese. Since ripening in the process of the invention is omitted, preferably about 0.5 to 1.5% salt (based on the weight of the curd) is mixed into the fresh curd. The salt is added during heating, kneading and spreading. It is particularly preferred that at least 0.8% by weight of the salt is added.

After the curd has been processed by heating, kneading and spreading to a homogeneous fibrous mass, salting is carried out in a bath. The mass prepared for the salt treatment operation typically has a temperature of from about 52 to about 68 ° C. The hot mass can be directly extruded into a salting tank, or it can be manually formed into blocks, for example 9 x 18 x 56 cm, and pre-cooled with cold water. In manual molding, the mass is placed in stainless steel molds, which are immersed in cold water (usually at a temperature of 1.7 to 10 ° C) for 20 to 30 minutes. The cheese is cooled to such an extent that it retains its shape. The cheese is then removed from the molds and placed in a salting tank containing a bath at a temperature of about 1.7 to 12.8 ° C and a salt content of about 50 to 98% by weight.

Hand molding is labor intensive and therefore it is preferred to directly extrude the web of hot fibrous mass into a supercooled salt bath. The web is preferably 15 to 20 cm wide and preferably has a thickness of 7.6 to 10 cm. Supercooled brine typically has a temperature in the range of about -18 to about -4 ° C and a salt content of about 30 to 60% by weight. In a super-cold salt bath, the cheese cools quickly so it hardens quickly. If the cheese belt does not harden sufficiently before cutting into pieces, the resulting pieces may become deformed and lose their uniform shape. The cheese web is usually sufficiently hardened when the core temperature drops to about 49 ° C or lower, for example to about 32 to 43 ° C. For this

The cooling time is usually sufficient to stay in the super-cold salt bath up to 10 minutes. The extruded cheese strip can be cut into pieces of 51 x 66 cm after hardening in a super-cold salt bath. These chunks of cheese can then be further cooled in a main salting tank, maintaining a temperature of about 1.7 to 12.8 ° C and a salt content of about 50 to 98%.

Whether the cheese is extruded and chopped or processed by hand, the large chunks of cheese are preferably left in the main salting tank until the core temperature drops to 24 ° C or lower, for example from about 13 to about 13 ° C. Deň: 18 ° C. When using extrusion and two-stage salting, the cheese may be cooled to a core temperature of 24 ° C or lower in about 3 hours.

A core temperature of about 24 ° C or less is necessary to grind pieces of salted cheese into granules. Temperatures above 24 ° C often result in free moisture and liquid milk fat in the cheese. When comminuted, these ingredients are not fully preserved in the cheese granules. In addition, at temperatures above 24 ° C, the cheese tends to stick to the chopping equipment. The time required to cool the heated cheese to a temperature below 24 ° C can be shortened by reducing the thickness of the cheese and / or lowering the temperature of the salt bath.

If the cheese is to be used for making pizza, it is preferably comminuted into particles in which the center (core) is at most 3 mm, preferably 1.5 mm, away from the surface of the particle.

The pieces of cheese of the desired size are preferably independently rapidly frozen immediately after grinding to form a well-flowed frozen product. The freezing is preferably carried out in a fluid bed freezer using cold air, for example air at a temperature of about -29 to about -40 ° C.

Preferably, a small amount of cheese is present at all times in the freezer to cool each piece of cheese to a core temperature of about -23 ° C in less than about 5 to 7 minutes after entering the freezer. Preferably, the cheese pieces are frozen to a final core temperature of less than -23 ° C, for example to a temperature in the range of about -23 to -32 ° C, before being removed from the freezer.

The rapid freezing step is preferably carried out so as not to significantly decrease the moisture content of the cheese, for example such that no more than about 1% of its total weight is lost as a result of the moisture evaporation.

Optionally, frozen chunks leaving the freezer may be coated with a flavoring agent and / or one or more cheese chemicals such as an emulsifier such as sodium citrate and / or a surfactant such as dimethylpolysiloxane.

A preferred method of applying flavorings, emulsifiers or surfactants to cheese particles is to spray an aqueous solution or emulsion of these ingredients onto frozen pieces of cheese that are rolled in a drum to achieve a uniform coating. The various additives can be applied either simultaneously or in the form of separate solutions. The concentration of the solution and the coating rate are preferably adjusted so that about 10 to 2000 ppm of flavoring agent, about 10 to 2500 ppm emulsifier and about 1 to 10 ppm surfactant are applied to the cheese (all figures are based on cheese weight) and the cheese was coated with approximately 0.5 to 4% water (the latter also being based on the total weight of the cheese). The cheese and water should be sufficiently cold during this operation to allow the spray to form an ice coating almost immediately on the pieces of cheese.

-9EN 282388 B6

DETAILED DESCRIPTION OF THE INVENTION

Example 1

The semi-skimmed industrial cottage cheese intended for mozzarella cheese is produced using the ovemight-curd-hold system described in U.S. Patent No. 3,961,077 (Kielsmeyer). A starter culture containing lactobacillus and streptococcus is used and the fermented milk is precipitated by adding calf rennet. The curd composition is controlled to give a resulting cheese product having a moisture content of greater than 52% and a milk fat content of greater than 18% (the total moisture and milk fat content is therefore greater than 70%).

The industrial curd is kept overnight and after this time the fermentation is complete. FIG. 1 is a schematic representation of a production line in which the method according to the invention is carried out starting from this point. The fermented curd (not shown) is heated in a mixer 10 to 60 ° C while kneading and spreading with the addition of 1.5% salt (sodium chloride) (not shown). After about 5-7 minutes of mixing, the molten cheese is extruded into a pre-salting tank 11 in the form of an endless belt 12 measuring 10 x 18 cm as described in U.S. Patent No. 4,339,468 (Kielsmeyer). The extruded strip is directly fed into a supercooled -12 ° C salt bath with a sodium chloride concentration of 60%. The residence time of the strip in this bath is 8 minutes and then the 10 x 18 cm strip is lifted from the pre-salting bath 11 and chopped in a mower 13 into 51 cm pieces 14. The temperature in the core of the cheese belt at the time of chopping is 49 ° C. The cooled 10 x 18x51 cm sized salted pieces 14 are then allowed to float for 3 hours in the main salting tank 15. The temperature of the salt bath in the salting tank 15 is 7 ° C and the sodium chloride content in the bath is 95%. The temperature in the core of the cheese removed from the main salting tank 15 is 18 ° C.

The cooled partly skimmed mozzarella cheese is then conveyed through a conveyor 16 to a dicing device 17 in which the cheese is immediately processed into cubes 18 measuring 5 x 5 x 7.5 cm. The cubes 18 are immediately fed to a granulator 19 where they are comminuted to cheese granules 20 3x3x3 mm in size. The granules are immediately discharged into an IQF 21 freezer, a Frigosandia model 300 Flo-Freeze fluid bed freezer. It is a freezer of a similar type to that described in U.S. Patent No. 4,753,815. After freezing, the core temperature of the frozen cheese granules is 22 -29 ° C. The cheese is then packaged and stored in a freezer (not shown) at -18 ° C for further testing.

Furthermore, for comparative purposes, mozzarella cheese is produced from partially skimmed milk, which is not treated to achieve a total moisture and milk fat content of more than 70%. The production, grinding, freezing and packaging of this comparative cheese is carried out in the same manner as described above for the production of the cheese according to the invention. This cheese is also referred to as control sample IA. In addition, a portion of the just-described raw skimmed-milk mozzarella cheese is not crushed immediately after cooling but packaged in lump form, placed in a 3.3 ° C refrigerator for 9 days before being crushed, frozen, packed and stored at -18 ° C until evaluation. This cheese is hereinafter referred to as control sample 1B.

The product of the invention and the 2 control samples were placed in the same refrigerator maintained at 3.3 ° C and kept there until an equilibrium temperature of 3.3 ° C was reached for all three products. After tempering of all three products, their composition, apparent heat capacity and melting behavior are determined. The products described above have the composition and apparent heat capacity shown in Table I below

-10GB 282388 B6

Table I 5 Moisture content (%) Sample according to the invention Control sample IA Control sample IB 53.5 52.1 52.1

Moisture content relative to moisture product 18.5 17.5 17.5 Total 72.0 69.6 69.6 Apparent thermal 15 capacity (J / g) -809.9 -593 -492

The apparent heat capacity of the cheese samples is measured by differential calorimetry (DSC) manufactured by Shimadzu Scientific Instruments, Inc, Columbia, Maryland, USA. The figures show the amount of energy in joules required to completely melt 1 g of cheese when heated from room temperature as the starting point (approximately 21 ° C). This energy is considered to be absorbed before the cheese changes phase; for this reason it is given with a negative sign. The lower this number is (the more negative this value is), the higher the apparent heat capacity of the cheese.

As can be seen from Table 1, the cheese produced by the process of the present invention exhibits a higher heat capacity than any of the control samples. Cheese with an apparent heat capacity of -675 J / g or less is often produced under the conditions and using the ingredients of the present invention.

The melting behavior of the three products is determined by baking 312 g of cheese on a 33 cm diameter pizza (which contains 312 g of unbaked dough and 113 g of tomato paste) in a Middleby Marshall 360S oven for 6.5 minutes at 277 Noc: 2 ° C. Said combination of time and temperature is a combination commonly used in baking pizza of this size made from the particular dough and tomato paste used. After baking, each finished pizza is photographed and the baked cheese is evaluated for blister percent content, blister size, melt, ductility, and softness. The reproductions of these photographs are shown in Figures 2 to 4 in the attached drawings. The behavior of individual products can be characterized as follows:

Control 1A (total water and fat content less than 70%, without ripening)

As is apparent from FIG. 2, the surface of the cheese is covered with numerous blisters ranging in size from small (i.e., point) blisters to large scabs. The surface of the product is very dry and there is no visible milk fat. The melting behavior of this cheese sample is completely unacceptable.

Control sample IB (total water and fat content less than 70%, aged for 9 days)

As can be seen from FIG. 3, the cheese surface contains fewer blisters than in the control sample IA. Pizza contains only blisters. The surface of the product is damp and the presence of milk fat is visible to the naked eye. The melting behavior of this sample of cheese is acceptable, as can be expected from partially skimmed mozzarella cheese, which has been aged for 9 days at 3,3 ° C.

-11EN 282388 B6

Sample according to the invention

As can be seen from FIG. 4, even in this case the pizza surface is covered with a small number of blisters having the character of dots. The surface of the products is visibly damp and the milk fat is clearly present. The melting properties of this cheese sample are comparable to those of the control formula 1B. This cheese sample and control sample 1B are also comparable and acceptable in terms of taste, mouthfeel and ductility.

Example 2

Further cheese samples with different levels of moisture and milk fat content are produced as described in Example 1. A total of 19 batches are produced in which the total moisture and milk fat content is from 68.2% to 77.48%. No cheese is aged and all samples are processed into 3 mm granules which are frozen by IQF as described in US Patent No. 4,753,815 immediately after leaving the main salting tank.

The heat capacity of all cheese samples is measured in the same manner as in Example 1. The melting behavior of the samples is measured in a 33 cm pizza process under the same conditions as in Example 1. Each cheese sample is classified according to the following scale:

Classification degree of melting behavior Importance 1 to 2 slight blister coverage (blisters occupy approximately 10 to 25% of total surface) 2 to 3 medium blister coverage (blisters occupy approximately 25 to 50% of total surface) 3 to 4 considerable blisters coverage (blisters occupy approximately 50 to 75% of total surface)

Classification grades are assigned at half a degree. The evaluation is carried out blind, ie the evaluator does not know which cheese has been used. The results are shown in Table II. Cheeses are listed in the table according to their heat capacity from higher to lower (with the exception of the sample that has been matured at the end of the table).

Table Π

Batch no. Moisture content (%) Milk fat content (%) Total (%) Heat capacity (J / g) Melt Rating (Grade) 209122 52.26 24 76.26 - 1455,7 2,0 109122 53.98 23.5 77.48 - 1328,8 1.5 109131 54.57 20.25 74.87 - 932.1 2,0 209312 53.72 16.5 70.22 - 867.1 2,0 109702 53.56 18.5 72.06 - 809,9 2,0 109312 52.96 16 68.96 - 761,5 3.0 109031 52.75 16.75 69.50 - 661.3 2.5

-12GB 282388 B6

1987221 53.97 15 Dec 68.97 - 609.1 2.5 209031 53.42 16.25 69.67 - 597,2 2,0 209301 52.08 17.5 69.58 - 593,4 2.5 109111 50.2 24 74.02 - 573.8 1.0 109602 52.96 17 69.96 - 570.1 2.5 2987221 54.39 16.25 70.64 - 516.3 2,0 209702 52.7 19.0 71.1 - 463.6 3.0 209011 48.7 19.5 68.2 - 379 3.5 209111 49.1 23.3 72.4 - 328.8 1.0 109011 48.8 19.5 68.3 - 322.2 3.5 209602 54.05 15.5 69.55 - 284.2 2.5 control 52.1 17.5 69.6 - 492 2,0

batch

10931 (maturation 9 days)

As can be seen from the above table, 9 of the cheeses have a total moisture and milk fat content of 70% or more, 9 of the cheeses have a total moisture and milk fat content of less than 70% and the 19th batch represents a control sample that has been subjected to conventional aging. Of the 9 batches that have not been aged and have a total moisture and fat content of more than 70%, they exhibit, in addition to one, an excellent degree of melting behavior, i.e. a degree of 1 to 2. a total moisture and fat content of less than 70%, having only one degree of melting behavior in the range of 1 to 2; Five lots show a generally unacceptable grade of 2.5, one ended with grade 3 and two have a very poor grade of 3.5.

Data from Table 2 was plotted (see Figure 5) of the total moisture and milk fat content versus heat capacity. The data is subjected to regression analysis, which results in a correlation coefficient (r) of 0.84. The higher the moisture and milk fat content, the higher the heat capacity of the cheese. This result is generally considered a good correlation of biostatistics.

The data from Table 2 is also used to construct a graph of melting behavior versus total moisture and milk fat content (see Figure 6 appended to the drawings). Melting behavior grades ranging from 1 to 2 are generally considered acceptable. A grade of 2.5 or higher is usually considered unacceptable due to the excessively high surface coverage of the blisters. As mentioned above, except for one product, all samples with a total moisture and milk fat content of 70% or more by weight will achieve a melting behavior rating of 1 to 2. Except for one sample, all samples with a total moisture content and Milk fat is less than 70% and which has not been aged, has an unacceptable degree of melting behavior, ie greater than 2.

Claims (18)

PATENT CLAIMS A process for producing a soft or semi-soft fiber cheese of the mozzarella type, which is carried out by: (a) pasteurizes cow's milk with a fat content of between 1,5 and 3,5% by weight; -13GB 282388 B6 (b) the milk is fermented using one or more lactic acid producing bacteria to produce fermented milk; (c) the fermented milk is coagulated to form a precipitate containing curd and whey; d) separating the precipitate and allowing the whey to drain, producing industrial curd; (e) the curd is heated, kneaded and spread until a homogeneous fibrous mass of heated, unripe mozzarella cheese is obtained, which has a moisture content of 45 to 60% by weight and a milk fat content of at least 30% by weight, based on dry matter; (f) the heated cheese is cooled in a cold salt bath; and (g) the cooled cheese is removed from the salt bath; characterized by: (i) steps (a) to (g) are such that the cooled cheese extracted from the salt bath has a sum of moisture content and milk fat content of 70 to 80% by weight on the wet basis; and (ii) the cheese is frozen within 48 hours to obtain mozzarella cheese with acceptable baking properties. Method according to claim 1, characterized in that during step e) 0.5-1.5% of sodium chloride, based on the weight of the industrial cottage cheese, is incorporated into the industrial curd. Method according to claim 1 or 2, characterized in that the cooled cheese removed from the salt bath contains moisture in an amount of 50 to 60% by weight and milk fat in an amount of 16 to 30% by weight, based on the wet base. Process according to any one of claims 1 to 3, characterized in that in step f) the cheese is cooled to a core temperature of 24 ° C or lower, wherein the cooled cheese is ground and frozen within 48 hours after removal from the salt bath. Method according to claim 2 or 4, characterized in that in step e) the industrial curd is heated to a temperature in the range of 52 to 68 ° C, in step f) the non-ripened mozzarella cheese is cooled to a temperature of in the kernel from 13 to 24 ° C and the cooled cheese is ground before freezing. Method according to claim 4 or 5, characterized in that the particles of the crushed cheese are freeze-dried independently. Method according to one of claims 1 to 3, characterized in that the cooled cheese is frozen within 2 hours of its removal from the salt bath. Process according to claim 1 or 3, characterized in that in step f) the cheese is cooled to a core temperature of 24 ° C or lower, wherein the cooled cheese is ground and then freeze-dried independently and both operations are carried out within 2 hours. from removing the cheese from the salt bath. Process according to Claim 3, characterized in that in step f) the heated cheese is first partially cooled in a first salt bath containing 30 to 60% by weight of chloride -14 to -4 ° C, the cheese being held in the bath until the core temperature drops to 38 ° C or below, and the partially cooled cheese is then further cooled in a second salt bath, containing 50 to 98% by weight of sodium chloride at a temperature of 1.7 to 13 ° C, where the cheese is maintained until the core core temperature has dropped to 24 ° C or below. Method according to claim 9, characterized in that in step f) the heated cheese is extruded in the form of an endless belt into the first salt bath and is cut into pieces before being removed from the second salt bath. Process according to claim 10, characterized in that the pieces of cheese from step g) are crushed and independently frozen. Process according to claim 11, characterized in that the chilled pieces of cheese from step g) are ground and then freeze-dried independently, both of which are carried out within 2 hours after removal of the cheese from the second salt bath. The method of claim 12, wherein the chunks of cheese are held in the second salt bath until the core temperature has dropped to a value in the range of 13 to 24 ° C. Method according to one of claims 4, 10 and 13, characterized in that in step e) the industrial curd is heated to a temperature in the range of from 52 to 68 ° C. Method according to claim 1 or 14, characterized in that in step e) 0.8 to 1.5% of sodium chloride, based on the weight of the industrial cottage cheese, is incorporated into the industrial curd. Method according to one of claims 3, 14 and 15, characterized in that the cooled cheese extracted from the salt bath has a moisture content of at least 52% by weight and a milk fat content of at least 18% by weight, based on the wet product. Process according to claim 2 or 15, characterized in that the cooled cheese removed from the salt bath has a moisture content in the range of 52 to 60% by weight and a milk fat content in the range of 20 to 30% by weight, based on the wet product. Process according to claim 3 or 16, characterized in that the cooled cheese removed from the salt bath has an apparent heat capacity of -675 J / g or less.