DK172810B1 - Process for producing ready-to-eat, salted meat products with reduced water content - Google Patents

Description

in DK 172810 B1

The present invention relates to a process for preparing ready-to-eat salted meat products with reduced water content, in which the meat is dried under reduced pressure.

Dried hams and similar ready-to-eat salted meat products with reduced water content 5 are prepared by salting trimmed meat cuts (whole raw muscles) and air-drying the meat until it has reached the desired dryness and water activity that makes it durable for a longer time. Eg. dried to a water content of 50 to 70%. The products obtained are soft and can e.g. cut into thin slices and used as cold cuts or for lunch and dinner dishes. The products are usually stored in a refrigerator as they still contain so much water that they are perishable at room temperature.

Preparation of dried meat products of e.g. The ham type is a time consuming process as it can take several months to air dry the muscles to the desired water content. Throughout the drying period, the process must be closely monitored and controlled to provide the desired product characteristics (taste, texture, texture, color, uniform appearance, etc.).

15 IDE-C2-39 12 071 (Frits Kortschach) describes a method for ripening and drying, among other things. sausage sausages and ham. Sausages or ham muscles are filled in a water-permeable form in which the material is subjected to increasing pressure and matured under vacuum until the desired maturation is provided. Eg. ripen and dried salami in the molds at controlled temperature and pressure. The process takes 14 to 20 days and causes a loss of fluid of 22%. The drying is thus relatively slow.

Dried meat, which has almost unlimited shelf life at ordinary temperature, can be prepared by cutting fresh meat into smaller pieces with a thickness not exceeding 2 cm and then freeze-drying the pieces to a very low water content of 5 to 10%. The pieces of meat obtained are hard and inedible. Before the meat can be used, the dry pieces of meat must be rehydrated until they again get the same water content as the original meat. In the rehydration process, an attempt is made to restore the natural quality of the meat, which is, however, rarely successful. IEP-A1-0223 887 (Stephano & Co.) discloses such a process.

DK 172810 B1 2

The rehydrated product thus differs not only from dried, fresh meat, but its chewing properties, structure, appearance, texture, taste, etc. is also quite different from the first-mentioned ready-to-eat salted meat products, which are air-dried to a water content of 50 to 70%. In addition, the process of preparation, storage and use of rehydrated meat 5 is quite different from that of the salted, partially barreled meat products.

US-A-4,265,918 (Swift & Co.) discloses an improved process for preparing meat products in which the spray salted meat is dried under reduced pressure until the weight is reduced to 70-95% of the original weight. The object of the method is to provide a meat product suitable for frying and having substantially less roasting 10 than raw meat. It can for example. revolve around raw bacon slices. The meat is kept in the frozen state during drying, which takes place in a drying cabinet at a pressure of 5 - 1 hPa. The drying used is relatively time consuming for such products.

The object of the present invention is to provide a process for preparing ready-to-eat salted meat products with reduced water content, wherein the process of drying can be performed substantially faster than the known drying processes for such products where the meat is dried in the frozen state and one can avoid the disadvantages of freeze-drying in the form of a deterioration of the desired properties of the product. These may be meat products that look and feel like the traditional salted products, or new edible meat products that have a reduced water content.

The process according to the invention is characterized in that a drying of the meat is first carried out under freeze-drying conditions and then a drying of the meat is carried out in the frozen state.

The drying process in question can achieve a significantly faster drying to the desired water content than traditional air drying. For ham muscles and the like, the drying 25 can be e.g. is performed over one to three days, while air drying of the same muscles usually lasts a week or more.

In addition, the combined freeze-drying and vacuum drying is faster than a vacuum-drying alone and does not suffer from the disadvantages of freeze-drying alone.

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DK 172810 B1 3 of the meat (deterioration of the meat's properties and / or long equalization times). The advantage of combining the two drying methods in the present process is that one can utilize the speed of the freeze-drying with the uniformity of the vacuum drying of the product. It is first lyophilized to form a drying strip of a certain thickness, and then vacuum-dried for a period of time sufficient for the drying strip to soften and the meat to achieve the desired dryness.

The drying under freeze-drying conditions is carried out at a water vapor pressure of less than 6.1 hPa, e.g.

0.1-6 hPa. At these pressures, the water is bound like ice and goes directly from the solid form into the vapor mold. It can be dried directly on frozen meat, so that the meat eventually freezes due to the cooling of the water evaporation. Preferably, however, the meat is frozen before drying to keep the meat structure intact as much as possible. After freeze drying to a reduced water content, the residual water is evenly distributed in the meat, forming an outer drying edge and an almost dried out core.

The drying of the meat in the frozen state is then carried out at a water vapor pressure of 6.1 hPa or 15 more (water vapor pressure is 6.1 hPa at the triple point). This means that the water during that part of the process is movable in the meat and is therefore transported out to the surface of the meat before it evaporates. The sub-process, hereinafter called vacuum drying, requires no or substantially less equalization than freeze drying as the water is constantly transported out to the surface. In this drying with the meat in the frozen state, the water will allow time to fully or partially settle in the freeze-dried portions of the meat. Any complete equalization of the product obtained can then be done at the manufacturing company, at the wholesaler and / or at the retail outlet.

The drying of the meat in the frozen state is preferably carried out at a water vapor pressure of less than 100 hPa, especially less than 20 hPa, as low pressure accelerates the drying. It is preferably carried out at a water vapor pressure of 6.1 to 20 hPa.

The present combined freeze-drying and vacuum-drying are particularly suitable when the meat is to be dried to a shrinkage of more than 25%. The drying process is slower than pure freeze drying, but avoids the long-term equalization needed in pure freeze drying for such shrinkage percentages.

The combined freeze-drying and vacuum drying process is preferably carried out such that between 25 and 75% of the shrinkage is due to the freeze-drying, while the remainder of the shrinkage is provided by the vacuum drying.

In the process of the invention, drying can be carried out to a loss of 5 - 60% relative to the fresh weight of the meat before drying. To produce products that resemble or emulate traditional air-dried meat products, dry to a shrinkage of between 40 and 60%, preferably more than 43%, to obtain products that feel and feel like 10 traditional dried products, such as parma ham.

To facilitate equalization, water / brine can be added to the dried product immediately after drying to partially rehydrate the product. In this case, the meat is dried to a lower water content than desired in the final product and the water / layer is subsequently added in an amount corresponding to the extra drying to give the product the desired water content.

In the process of the invention, pieces of non-heat-treated (raw) meat are dried, especially pork. These pieces can weigh from 10 g to several kilograms and are preferably muscles or larger portions of muscles weighing between 100 g and 3000 g, especially between 500 and 2000 g, such as ham muscles, swine fillets and swine neck muscles. In particular, these are pieces of meat that are more than 4 cm thick. The muscles are preferably trimmed and cut before drying. If desired, multiple muscles or pieces can be portion-packed into a perforated pouch or intestine to provide a composite product of a specific shape and size during the process.

Salt is added to the meat before and / or after drying. The meat can e.g. dry salt before drying. Preferably, however, the salt is added by means of a brine added to the meat after drying, so that the finished product has a salt content of 2% or more. In addition to nitrite salt, the salt layer can also contain flavors and flavors and possibly starter culture.

ΐ DK 172810 B1 5

Before drying, the meat can be sprayed with a brine for an increase of 5-15%. The meat can then be tumbled and / or wrapped in plastic bags and placed at cooling temperature, allowing the layer to spread evenly throughout the meat. Eg. the meat can be placed for equalization for 1-4 days at 2-7 ° C.

The meat pieces / portions are then preferably frozen separately, e.g. to a center temperature between -15 and -25 eC. Before freezing, the pieces of meat / portions can be placed in separate plastic bags to prevent frostbite and freezing.

After freezing, any plastic bags are removed and the meat is placed in a freeze-drying cabinet which is evacuated for air, after which drying can begin. It can be carried out at a vapor pressure of between 0.1 and 6 hPa. The heat needed for evaporation of the water can be supplied to the meat via the drying cabinet plates and / or by heat radiation. Preferably, the surface temperature of the meat is kept between 10 and 40 ° C, especially between 15 and 35 ° C.

The drying time depends on the desired shrinkage and the size of the product. If a small freeze drying of 5 to 25% of the fresh weight of the meat is to be done before the subsequent vacuum drying, it can often be carried out in less than a day.

During the subsequent vacuum drying, the meat is kept in the frozen state, keeping the vapor pressure above 6.1 hPa, which is the water vapor pressure at the water triple point. For example, work is being done. with a pressure of 8 - 10 hPa. Heat is supplied via the cabinet's heat plates or by heat radiation. The surface temperature of the meat is preferably kept between 10 and 20 ° C.

The vacuum drying can continue in the same cabinet as the freeze drying, only under vacuum drying conditions. This requires drying to continue at a steam pressure of more than 6.1 hPa, allowing the meat to thaw.

After drying, the meat can be vacuum packed. The gasket can be refrigerated for a sufficient period of time to allow the water to settle in the product, if necessary. The equalization can be accelerated by adding water or brine to the meat in connection with the package. The outermost, difficult-to-equalize parts of the dryer edge are thereby more quickly equalized. In the case of the combined freeze-drying and vacuum drying, there is no need - or only to a limited extent - for equalization and addition of water or cooking. However, there may be advantages associated with allowing equalization after drying to ensure high uniformity of the product. If meat is added to the meat before packing, the layer should have time to equalize.

The layer, which may be added to the meat after drying, may contain flavoring, if desired, which gives the product a changed taste characteristic. Eg. a brine containing fermented hydrolyzate may be used.

The meat product obtained by the above processes can, if desired, be heat-treated (e.g. smoked in oven), but preferably used in non-heat-treated form (e.g. cold-smoked). It has an extended shelf life and is preferably stored in the refrigerator. The product can be cut into slices 10 and vacuum packed.

In the present case, all percentages are by weight unless otherwise indicated.

The invention is further illustrated in the following examples with accompanying drawings, in which: 1 and 4 show the drying of muscles as a function of time at different temperatures and salt concentrations; 2, 3, 5, 6 and 7, the equalization in dried meat as a function of time at various surface temperatures, shrinkage percentages, salt concentrations and molding methods; and FIGS. 8 equalization in dried meat as a function of the percentage of shrinkage.

Example 1 20 In this example, the importance of the temperature of the meat surface for the drying rate and the degree of compensating for freeze-drying of meat is investigated. Four test series with surface temperatures of 0, 10, 20 and 30 ° C are performed. For each batch (batch), 20 pork tenderloins (unit weight 250 - 400 g) are used.

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DK 172810 B1 7 Drying speed:

Immediately after delivery, the pieces of meat are sprayed using a 21% nitrite salt mixture and the growth is calculated. The pieces of meat are vacuum packed and placed for 4 days at 4 ° C to equalize the injected layers.

5 The thighs are placed in separate pouches. A thermocouple is placed in the middle of the largest thigh tongue in a batch. Four other thermo sensors are placed in the surface, bottom and end edge of random thigh tongues in the batch, the pieces of meat are frozen at -20 ° C, then the bags are removed and the thigh tongues are placed on trays between the heating plates in a drying cabinet. After vacuum (0.5 hPa) in the cabinet is dried to a shrinkage of approx. 40% of the fresh weight. During the drying, the surface temperature of the meat is kept at 0, 10, 20 and 30 ° C respectively.

Weigh each piece of meat in fresh condition, after spray salting and after freeze drying. Spray growth, salt content before drying and drying loss are calculated from the measurements.

° C Growth before drying Salt content before Decrease after drying in relation to fresh weight drying ratio to total weight 15 (%) (%) (%) 0 14.2 2.6 25.3 10 5.8 1.2 35.5 20 6.4 1.3 36.3 20 30 6.7 1.3 28.1

During drying, the weight of the meat is recorded as a function of time. The recordings are depicted in FIG. 1. It is seen that a temperature of the meat surface of 20 or 30 ° C gives the shortest drying time. The drying is slowest at 0 ° C. The drying rate is not increased by increasing the surface temperature from 20 to 30 ° C, and this may be due to the fact that the meat surface at 30 ° C undergoes a structural collapse forming a drying edge which inhibits further steam release.

DK 172810 B1 8

The curves are clearly seen to run exponentially with the greatest decrease at the beginning, after which they flatten out. This is because the transition between dried and non-dried meat (ice front) initially lies completely in the surface of the product and then extends inwards towards the center, so that the formed steam creates a further path to the meat surface and the heat further 5 way into the meat. .

Compensation degree:

After drying, the pieces of meat are vacuum packed and placed for equalization at 4 ° C. For the first seven days, two thighs are taken for examination at least one day apart. The degree of compensation is assessed on the basis of the surface of the thighs. For each of the two 10 thighs, the percentage of the equalized part is made up of the total surface and then the average is calculated.

The equalization ratios found are depicted in FIG. 2 along with their regression line. As these are estimates, the curves must be reserved. However, it is seen that there is no clear difference in the compensatory rate of the females, although they have been dried at different surface temperatures. Within the selected temperature range, the temperature does not appear to play a role in the equalization.

The vacuum-packed pieces of meat quickly settle. Already after two days, the compensatory rate of the females is up to 60%. The edges are the most difficult to level.

Example 2 20 In this example, the significance of the shrinkage percentage for drying time and equalization is investigated. Trials are performed with three different dry wastes of 7, 28 and 42% respectively.

The procedure is the same as in Example 1 above. The meat is freeze-dried to the desired shrinkage at a surface temperature of the meat of 10BC. The dried thigh tongues are offset in a vacuum pack at 7 ° C.

25 Spray growth, salt content before drying and drying can be seen in the table below.

DK 172810 B1 9 Desired Growth before drying Salt content before Drying after drying in shrinkage in relation to fresh weight drying in relation to total weight (%) {%) <%) (%) 5 7 14.2 2.6 7.0 28 12.2 2.3 28.4 42 14.2 2.6 42.7

The time required to achieve 7, 28 and 43% shrinkage is 4, 20 and 30 hours respectively.

10 The course of the equalization is depicted in FIG. 3. It is seen that low shrinkage drying provides a quick subsequent equalization. By drying to 7% shrinkage, total equalization, even at the edges, is achieved even after 3 - 6 days. When drying with 28 or 43% shrinkage, the equalization time is considerably longer. Even after a very long time (1¼ month), the edges are far from equalized in the thighs, which have dried to a shrinkage of 43%.

Example 3 In this example, the significance of the salt concentration for drying rate and equalization is investigated and two different equalization methods are tested. In one method, the sample is equalized by simply lying. In the second method, the meat is dried to a lower water content than the desired final product and then water is added to the dried product before being added to equalize. Otherwise, the procedure is the same. Salt is added as follows:

Preparation Water Nitrite salt Desired Desired salt Desired salt Desired salt / water No. added before drying after drying after drying (kg) (kg) (%) (%) (%) (%) 25 in 9.00 0.93 12 1, 0 1.4 1.9 2 9.00 2.07 12 2.0 2.7 4.1 3 9.00 2.50 16 3.0 4.0 6.0 4 9.00 2.84 20 4.0 5.3 8.0 DK 172810 B1 10

Half of the females from each bed number are dried to a desired shrinkage of 30% of the fresh weight (actual shrinkage: 21.5 to 33.8%), vacuum packed and placed for equalization. The other half of the females are dried to a shrinkage of 40% and water is added to the dried product so that the total shrinkage becomes 30% of the fresh weight, placing the product in a vacuum bag containing a corresponding amount of water. The bag of dried product and • water is closed under vacuum and placed for equalization.

Spray growth, the salt content before drying and the drying loss after drying to the desired shrinkage of 30% are shown in the table below.

Added Growth before drying Salt content before Drying after drying in 10 layers in relation to fresh weight drying in relation to total weight No. (%) (%) (%) 1 11.1 0.9 33.8 2 14.0 2.3 30, 1 15 3 15.4 2.9 25.0 4 20.4 4.1 21.5 Drying speed:

FIG. 4 shows how the salt concentration before drying affects the drying time. It is seen that the drying process is the same at a salt concentration of 1% and 2%. At 3% salt, the drying rate is reduced and at 4% salt it is further reduced. This is because rising salt concentrations increasingly bind the water in the meat. Small salt bubbles are found in the surface of thigh tongues with 3% salt as well as more and more powerful salt bubbles at 4% salt, which is a sign that the water vapor inside the meat draws the salt out. Such - salt inhibitors subsequently prevent the release of water vapor and may explain the lower drying rate at higher salt concentrations.

Compensation:

The course of the equalization is shown in fig. 5 (without water addition) and fig. 6 (with water addition).

t 0 il «n DK 172810 B1 11

By comparing the figures, it is seen that adding water to the dried product increases the equalization rate, especially at the beginning. When comparing the two regression lines of the figures, it is seen that after just one day the equalization rate is about 40% when no water is added, while it is up to about 80% when water is added.

S The edges are leveled last. However, if water is added, equalization of the edges takes place faster. In the present test series, the degree of equalization does not reach 100%, and this may be due to not having enough water added to cover the entire surface of the females.

When cutting the thighs, which have no water added, a clear drying zone is visible that extends from the surface and some distance into the product. The zone diminishes and protrudes outward toward the surface as the equalization progresses, the equalization occurring from the inside out. When there is water in the vacuum pack, not only does the surface equalize, but the equalizer is also more complete further inside the product. There does not appear to be an internal drying zone in the product in the transition zone between the two water boundaries.

Conclusion: Examples 1-3 show that it is possible to use freeze-drying for partial drying of pieces of meat that are traditionally air-dried. The process requires a subsequent equalization. It can be extremely long lasting, especially if the edges of the product need to be leveled. The equalization time is short in the case of shrinkage of 5 -10% of the fresh weight, the equalization here being complete after only 3 -6 days. The required equalization time can be substantially reduced by drying the product further down than desired in the final product and then vacuum packing with layers in an amount sufficient to cover the entire surface of the product.

High salt concentration and low surface temperature of the meat prolong the drying time. Neither the salt concentration nor the surface temperature appear to influence the subsequent equalization time.

25 The experiments show that by freeze-drying of smaller, regular pieces of meat weighing between 250 and 400 g in a relatively short time, pieces of meat with the same water content as DK 172810 B1 12 can be obtained in traditional air-dried meat. Slices of meat with a shrinkage of 35% shrinkage can be obtained in 24 hours, whereas equivalent air drying will often require a week or more.

Example 4

Freeze drying is a relatively expensive process. Reducing the drying time and better utilization of the capacity of the plant can therefore be of great importance. The purpose of the present experiment is to optimize the drying speed process.

a) It is investigated whether the drying rate is affected by the pressure in the vacuum chamber and the temperature of the hot plates and whether the freezing time has an effect. The following tests are performed: 10 Batch No. Freezing Method Room temperature Room pressure _ίΙΩ_ (hPa) _ 1 fast 60 0.2 2 fast 90 0.9 3 fast 90 0.2 4 slow 60 0.2 15 5 fast 60 0.9 6 slow 60 0.9 7 slow 90 0.9 _8_ slow 90_0.2 In each batch, 12 pork tenderloins that are frozen to -20 ° C are used. In the rapid 20 freezing method, the thighs are placed in a freezer room at -20 ° C and frozen for at least 24 hours.

The slow freezing method consists in first storing the thighs in a freezer at -5 ° C for 16 hours and then transferring to another freezer at -20 ° C for at least 24 hours.

After freezing, the thighs are freeze-dried in a drying cabinet. The surface temperature of the meat in all experiments is 20 ° C during drying. The pressure in the cabinet is 0.2 hPa in some experiments and 0.9 hPa in other experiments. In some of the experiments a plate temperature of 60 ° C and in others 90 ° C are used.

Drying time is 18 hours.

The females are weighed separately before and after drying to determine the shrinkage.

in DK 172810 B1 13

The influence of the parameters on the drying rate (ie, the loss after 18 hours of drying) is analyzed by analysis of variance. It shows that all three parameters have a significant effect on the drying rate (p <0.01). The drying is fastest by slow freezing, high plate temperature and high chamber pressure. However, the increase is only 5%, which is of 5 marginal importance.

b) In the present experiment, drying is sought to be accelerated using a higher plate temperature and surface temperature of the meat than in the above experiments.

The raw materials for this experiment are trimmed inner thighs with a weight of 1500 to 2000 g.

The procedure consists of multi-stitching the pieces of meat using a 15% 10 bacon salt layer to a 10% increment, making equalization in the meat, individually freezing the pieces of meat in the bags and freeze drying to a reduction of 45% relative to the fresh weight ( drying with a plate temperature of 60 ° C, a surface temperature of 0 ° C and a chamber pressure of 0.5 hPa; or by a rapid drying with a plate temperature of 120 ° C, a surface temperature of 30 ° C and a chamber pressure of 0.5 hPa). The obtained dried products 15 are added to 5% of a 15% bacon salt layer and vacuum packed and then equalized at 2 ° C.

Weigh the pieces of meat before and during the freeze drying. When the specified shrinkage is achieved, the drying time is noted. The compensation in the vacuum pack is followed for 28 days. In addition, the water content of the dry edges is determined on a single inner thigh.

The tests show that drying takes place three times as fast at the high plate temperature and 20 surface temperature. However, when using high plate temperatures, care must be taken in controlling the temperature taking into account the most exposed places on the meat, which are the surfaces near the hot plate. Otherwise, burned areas may form.

The equalization course of the meat is shown in FIG. 7. There is no significant difference between the equalization of the two drying methods. The equalization after 7 and 14 days appears to be better by the 25 fast drying method, but the individual determinations show wide spread and the difference is not significant. Therefore, the drying method used (fast or slow) does not significantly affect the equalization.

DK 172810 B1 14

After 28 days, the inner thighs are equalized only 80 - 85% in the surface. The uneven areas are located at the edges of the inner thighs. This is probably due to the fact that the drying goes faster here, so that the drying zone gets deeper and the water gets harder by penetrating all the way to the surface. If the rehydration layer is not sucked into the areas, they probably will not have time to be equalized.

The water content of the completely dry edges is measured at between 3.4 and 4.4%. In a less dry edge where visually greater moisture can be seen, the water content is measured at 8.1%. Dehydration only causes irreversible damage when the water content falls below 2-3%, and it is therefore the water's long way to the surface that is the cause of the failure to compensate.

The dry edges have not been irreversibly altered, as they are actually capable of rehydrating by immersion in water for a few minutes. However, the flesh gets a slightly lighter red color.

Example 5

Freeze drying for partial drying of the meat should be followed by a counterbalance, which can be a problem in large shrinkage. The offsetting in these cases can be time consuming and the 15 edges of the product can be difficult to offset.

As shown above, the equalization can be shortened by immersing the freeze-dried product in water. In the following, it is examined whether the drying loss, the salt content of the layer and the immersion time have any bearing on the inclusion of layers in freeze-dried meat.

20 The following levels are examined:

Shrinkage 35 and 50%

Salt preparation 13 and 23%

Immersion time 1, 5 and 15 seconds

36 thigh tongues, 18 per. batch. Thigh tongues are individually labeled, weighed and packed 25 in bags and frozen at -20 ° C for at least 24 hours. Before freezing a batch, temp sensors are placed in the top, bottom and center of some thigh tongues. It is lyophilized at a plate temperature of 90 ° C, a surface temperature of the meat of 206C and a chamber pressure of 0.9 hPa.

After freeze drying, the thighs are weighed individually. For each level combination, three freeze-dried thigh tongues are used, which are immersed in the layer separately. The immersion is performed so that the entire surface of the thigh tongue is covered with layers. The immersion time is followed by a stopwatch. Then the thigh tongues drip for 30 seconds and weighed again to determine the amount of layers recorded.

The significance of the drying loss, the salt concentration in the layer and the immersion time on the uptake of layers into the meat are analyzed by analysis of variance. There is significant effect of the 10 immersion time (p <0.001) and the salt concentration in the layer (p <0.05) while the drying loss is insignificant.

The average uptake is 5.2% of fresh weight at 1 second immersion, 6.9% at 5 second immersion and 9.2% at 15 second immersion. Water uptake is therefore not linear, but occurs most rapidly in the beginning. When immersed in a 23% brine, layer uptake is significantly faster than immersion in a 13% brine. At the short immersion times, it is surprising that the salt concentration has such a large influence. Thus, by changing the salt concentration of the rehydration layer, it is possible to influence the rate of absorption of layers.

20 The dry wastage has no bearing on the layer uptake, and this means that the sheet is absorbed just as easily, whether the product is dried slightly or much. If the drying zone is thick, however, the meat's own water never reaches the surface and layers must be added from the outside.

Example 6

Previous experiments show that freeze-drying losses of less than 35 - 40% are not sufficient to give the product the same texture as certain traditional air-dried products, such as parch worms.

The purpose of the present experiment is to find freeze-drying scales that can give the product the expected texture and to check whether the dried product is satisfactorily equalized.

DK 172810 B1 16

Drying experiments are carried out for a shrinkage of 42, 44, 46, 48 and 50% of the fresh weight.

To get a product that is quick to dry and easy to slice, trimmed fillets are used as meat products. For each of the five experiments, six fillets are used. The fillets are multi-sprayed for 5% growth using a 15% bacon salt layer. The injected layer is allowed to equalize 5 in the meat, after which the pieces of meat are frozen separately in bags. The fillets are then freeze-dried at a plate temperature of! 20 ° C, a surface temperature of the meat of 30 ° C and a chamber pressure of 0.5 bPa with the fat side of the fillets facing up. The pieces of meat are weighed before and during the freeze drying and the drying time is noted. The dried product is rehydrated by adding 5% of a 15% bacon salt layer, vacuum-packed and equalized at 2 ° C.

10

It takes 22.9 hours to dry the fillets to 42% shrinkage and 27 hours to dry them to 50% shrinkage.

The surface equalization is determined by estimation for 28 days after drying. After 14 days equalizing the fillets, each fillet is selected from each team, whose surface equalization is 15 closest to the team's average equalization. The fillet is sliced into 1 cm thick slices and the degree of equalization in each of the slices is estimated. Based on this, there is the overall equalization rate of the file in question, which is assumed to be the same as the team's average value.

The equalization of the fillets goes like in previous experiments. There is no correlation between the shrinkage percentage and the surface equalization, as can be seen in FIG. 8, 20 showing the surface equalization after 14 days for all 30 fillets in the experiment. The correlation coefficient for the regression line shown is only 0.16. It can be seen that at the same shrinkage there is also a large variation in the degree of compensation.

The fill rate of fillets is found to be at least 10% greater than the estimated surface equalization for the same fillet. Due to the very large variation between fillets 25, the overall degree of equalization must only be considered to be directional.

DK 172810 B1 17

From the results, it is seen that between 85 and 95% of a fillet will be offset after 14 days if the fillet has been dried to a loss of between 41 and 44%, while between 75 and 85% of a fillet will be offset, if the decrease has been between 44 and 48%,

An expert panel finds that the consistency of the meat is initially the same as that of similar 5 traditional products at a freeze-drying rate of more than 43%. At lower shrinkage, the meat may be too cohesive and appear liquid so it does not emulate e.g. parma ham.

However, it may well emulate other traditional products that are dry to a lesser extent.

Example 7

In this experiment, it is investigated whether the taste of the dried product is changed using 10 fermented hydrolyzate in the layer used for the rehydration.

The procedure is the same as in Example 6, although drying to a shrinkage of 45%.

In one test series, ordinary bacon salt layer is added to the meat after drying, while in the other, bacon salt layer is added to a hydrolyzate solution which has been fermented by a salt-tolerant, favor-developing bacterium.

15 After 14 days of equalization, a panel of experts at blind tasting assesses the effect of the fermented hydrolyzate on the product. The panel concludes that the addition of hydrolyzate can clearly be recognized in the dried product. When compared to the control product rehydrated with ordinary brine, the hydrolyzate-containing products are judged to be more potent and full in flavor with slight flavor variations that depend on the 20 fermentation bacteria used.

Example 8

Previous attempts at freeze-drying of pieces of meat show that a white, hard drying edge can be formed in the surface of the meat. Depending on the thickness, this rim may be nearly impossible to remove once formed. Adding layers before the subsequent equalization 25 reduces the problem, but the drying edge can still be long gone.

In this example, it is tested whether the water diffusion in the meat can be promoted during the drying so as to obtain a more uniform water distribution in the product and possibly eliminate the problem of drying edge j.

This is sought to be achieved by drying the meat without freezing. When the water vapor pressure above the meat 5 is raised above the triple point of water (6.1 hPa), the meat can be kept in the frozen state during drying.

Three drying methods are tested: 1. drying the infused meat at a pressure less than 0.5 hPa (general freeze drying), 2. drying the infused meat at a water vapor pressure first, then 10 greater than 6.1 hPa (freeze drying + vacuum drying), and 3. drying of non-frozen meat at a pressure above 6.1 hPa (vacuum drying).

For the experiments, 18 trimmed fillets, 6 fillets per. team. The fillets are cut lengthwise to fit into the drying trays. Then fillets are labeled and weighed.

The fillets are hand-sprayed to a 5% growth using a brine consisting of 15% 15 nitrite salt and 85% water. The fillets are drained for 5 minutes and weighed again. Calculated on the fresh weight of the meat, they have a content of nitrite salt of 0.71% and an increase in the water content of 4.05%.

The fillets are placed in separate plastic bags and equalized at 2 ° C for 3 days. After the equalization, separated layers are poured off, and fillets from holdings 1 and 2 are placed in a freezer room and infused at 20 -20 ° C for at least 2 days, while fillets from hold 3 are not frozen.

Each hold is dried to a loss of 45% of the fresh weight of the fillets. Thermoelectrodes are placed in the center of one fillet (about 3 cm from the surface) as well as in the surface of two fillets and at the bottom of two fillets. The surface electrodes are placed at a depth of 2 nun. The fillets are dried lying on the meat side.

S

i i i i DK 172810 B1 19

For team 1, run the "automatic preset heating program" program with heat plate = 120 ° C, pro temp = 30 ° C and pressure = 0.5 hPa for 24 hours. For team 2, heat plate = 120 ° C, prod temp = 30eC and pressure = 0.5 hPa are used for 6 hours, followed by heat plate = 120 ° C, prod temp = 15eC and pressure = 9.0 hPa for 66 hours. For hold 3, heat 5 plate = 120 ° C> pro temp = 15 ° C and pressure = 9.0 hPa are used for 96 hours.

The drying time for 45% shrinkage is noted for each team. In addition, the temperature, weight loss and chamber pressure are monitored.

The drying time is 1 day when dried on frozen meat at a water vapor pressure less than 0.5 10 hPa. By using combined freeze-drying and vacuum drying, the drying time is tripled while vacuum drying quadruples the drying time. In contrast, the freezing step can be avoided by vacuum thawing alone. Thus, the total process time is 3 - 5 days for all three drying methods.

The fillets are vacuum packed after drying and nitrite brine is added in an amount of 5% of the fresh weight. The nitrite salt layer consists of 15% nitrite salt and 85% water. Layer is poured directly 15 into the vacuum bag and then the dried fillet is placed in the bag which is vacuum closed. The fillets are stored at 2 ° C for equalization.

After 14 days of equalization, three random Filets are selected from each team. The fillets are sliced into 1 cm thick slices and the slicing degree is estimated. The degree of equalization is the surface area that is equalized, relative to the total area of the slices. The difference between equalized and 20 non-equalized meat can easily be seen visually, since the non-equalized areas are whitish, hard and dry. Each file's degree of equalization is found as the sum of all discs equalization divided by the number of slices.

After the 14 days, the equalization in the three teams of fillets is 93 ± 1.7%, 96 ± 1.9% and 98 ± 1.3%, respectively. Teams 2 and 3 are satisfactorily leveled, which cannot be said about team 1.

25 In the visual assessment of the teams, it is evident that the drying stripe has different appearance from team to team. It is white and hard on the freeze-dried fillets. On the freeze / vacuum dried fillets, it is soft as in ordinary, thinned meat and has about the same red color as dried meat, though in a slightly lighter shade.

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Thus, vacuum drying or a combination of freeze and vacuum drying have significant advantages over freeze drying alone, with products with a high drying rate equalizing fully satisfactorily.

Vacuum drying or a combination of freeze and vacuum drying is therefore a suitable process for accelerated drying of meat, since no problems with drying edge occur. The vacuum drying is carried out by keeping the water vapor pressure above the water triple point (6.1 hPa).

The water in the meat can thereby be kept in a liquid state to ensure free water movement.

With vacuum drying or combined freeze and vacuum drying, it is possible to reduce the drying time of meat by at least 40% over traditional air drying without compromising the quality of the dried products.

Example 9

This example describes the preparation of pork products whose water content is reduced by freeze-drying followed by vacuum drying.

Fillet or ham muscles are multi-sprayed using a 15-24% nitrite salt to a 15 to 5% increase. Alternatively, the muscles may be added 2 to 3% dry salt mixture. The salted muscles are optionally tumbled to accelerate the distribution of the salt. The muscles are placed for 2 to 3 days at 2 to 7 ° C to equalize the salt / layer. The muscles are frozen individually to a center temperature between -15 and -25 eC. The pieces of meat are placed in a lyophilizer and freeze-dried for 2 to 6 hours at a chamber pressure of 0.1 to 6 hPa and a surface temperature of the meat of 15 to 35 eC. The drying is then continued in the same cabinet, but under vacuum drying conditions, increasing the chamber pressure to between 6.1 and 20 hPa. Dry for 2 to 4 days with a surface temperature of the meat of 10 to 20 eC until a shrinkage of 25 to 50% is obtained relative to the fresh weight of the meat. If desired, the dried products are packed with 5 to 10% brine and / or fermented hydrolyzate and then allowed to settle at 2 to 7 ° C. The product is cut into slices that are gas or vacuum packed.

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Example 10

This example describes the preparation of pork products whose water content is reduced by freeze drying and intestinal vacuum drying.

Fillet, ham or neck muscles are cut and trimmed. The muscles are added 2 to 3% 5 dry salt mixture or sprayed salt using a nitrite salt for 5 to 15% growth,

The salted muscles are optionally tumbled for 10 - 20 hours. The muscles are stopped in extra-perforated fibrous intestines with a caliber of 60 to 120 mm and allowed to settle at cold room temperature (5-20 days for dry salted meat and 2-3 days for spray-salted meat). Then, freeze to a center temperature of -15 to -25 ° C. The stuffed casings are placed in a freeze-drying cabinet, which is evacuated to a pressure of 1hPa, after which the meat is dried under freeze-drying conditions for 2 to 8 hours. The meat gradually dries, so that the drying goes into a vacuum drying with a surface temperature of the product of 10 to 20 ° C. Vacuum drying of the product at the stated chamber pressure of 1 hPa is possible because presumed pressure exceeds 6.1 hPa inside the intestine at the meat surface. Vacuum-dry to a shrinkage of 25 to 35%, which lasts 4 to 6 days. If desired, the intestines are packed and allowed to settle at 2 to 7 ° C.

The intestine / packaging is then removed and the dried product is cut into slices packed in e.g. retail bags.

Example 11 20 This example describes the preparation of pork products whose water content is reduced by vacuum drying.

Fillet or ham muscles that have been cut and trimmed are dry-salted with a dry-salt mixture or sprayed-salted with brine (5 to 15% increment), whereupon the muscles are tumbled and, if desired, tumbled at 2 to 7 ° C for 2 to 3 days.

25 The salted muscles are placed in a drying cabinet evacuated to a pressure of between 6.1 and 20 hPa. The muscles are vacuum dried at the specified pressure so that they do not freeze. The surface temperature of the meat is kept between 10 and 20 ° C. After 4 to 7 days, the desired shrinkage of 25 to 50% of the fresh weight of the meat is reached, after which the drying is stopped. If desired, the muscles are packed with a brine or fermented hydrolyzate and placed for equalization at room temperature for 2 to 7 days.

The obtained product with reduced water content, if desired, is cut into slices which are vacuum packed.

Claims (9)

23 DK 172810 B1 A process for preparing ready-to-eat salted meat products with reduced water content, wherein the meat is dried under reduced pressure, characterized in that a drying of the meat is first performed under freeze-drying conditions and then a drying of the meat is carried out in the frozen state. Process according to claim 1, characterized in that the drying of the meat in the frozen state is carried out under a reduced pressure of less than 100 hPa. Process according to claim 2, characterized in that the drying of the meat in the frozen state is carried out at a water vapor pressure of 6.1 to 20 hPa. 10 Method according to claim 1, characterized in that the process is carried out such that between 25 and 75% of the shrinkage is due to the drying under freeze-drying conditions, while the rest of the shrinkage is provided by the drying of the meat in the frozen state. Process according to claim 1, characterized in that drying is carried out to a loss of 5 - 60% in relation to the fresh weight of the meat before drying. Process according to claim 1, characterized in that the dried product is partially rehydrated immediately after the drying by adding water and / or brine to the product. Process according to claim 6, characterized in that water or brine added with flavoring is used. Process according to claim 7, characterized in that a layer containing fermented hydrolyzate is used. Process according to claim 6, characterized in that the brine is added to the meat after drying in such an amount that the finished product has a salt content of 2% or more.