EP2306842A1

EP2306842A1 - Method for prolonging crust crisping

Info

Publication number: EP2306842A1
Application number: EP09777418A
Authority: EP
Inventors: Klaus LÖSCHE; Macias Cama Marta; Rainer Domani; Wolfram Ungermann
Original assignee: Verein Zur Forderung Des Technologietransfers An Der Hochschule Bremerhaven Ev; Wolfram Ungermann Systemkalte & Co KG GmbH; LSG Lufthansa Service Holding AG
Current assignee: Verein Zur Forderung Des Technologietransfers An Der Hochschule Bremerhaven Ev; Wolfram Ungermann Systemkalte & Co KG GmbH; LSG Lufthansa Service Holding AG
Priority date: 2008-07-26
Filing date: 2009-07-24
Publication date: 2011-04-13
Also published as: DE102008035068A1; WO2010012421A1; DE102008035068B4

Abstract

The present invention is intended to provide a way of significantly prolonging the crisping of the crust of baked or deep-fried products. This is achieved by maintaining a high relative atmospheric humidity during the entire dough processing and working process and subjecting the finished hot baked products to a vacuum cooling process, in particular vacuum enthalpy cooling.

Description

'Method of Extending the Crusted Roe'

The invention relates to a process for the preparation of baked goods and / or deep-frying products. The quality of baked goods, but in some cases also of fried foods, is determined especially by small bakery products, such as bread rolls, mainly by their crispness. It is usually a major problem to maintain the desired crunchy, crumbly-brittle pastry crust for a long time. As a rule, the so-called Krustenrösche stops for a maximum of 4-5 hours, after which it loses, the pastry surface, i. the crust softens until the whole bun becomes poppy and collapses before finally drying out.

Deep-fried products are products that are heated in a cooking process where the product floats in a fat bath. The cooking temperature is after a holding time at 100 ° C. (evaporation of water) about 150 ° - 160 ° C. Frying is used for potato products (French fries, chips), breaded vegetables, biscuits (pancakes, donuts) ... "(H. -A short neck (ed.): "Lexikon Lebensmitteltechnik AK", Behrs-Verlag, Hamburg 2003).

In the prior art, for example DE 41 20 807 A1, WO 96/41538 A1 and US Pat. No. 3,438,791 A, the dough processing under high atmospheric humidity and from DE 25 07 003 A1, DE 29 02 270 C2 and EP 0 748 163 B1 the procedure of vacuum cooling baked baked goods known.

There are already numerous attempts to extend the Rösche; However, these have so far led to no satisfactory results. In addition to a change of the recipes in that e.g. As there are more Maillard reaction products, there are also attempts to positively influence the crustaceans via so-called "pre-doughs".

BESTATIGUNGSKOPIE influence. Thus, in the specialized textbook for bakers "technology of bakery production" by Claus Schönemann and Günther Preu, 1st edition 1984, to bring about a tender splintery Rösche of long-lasting duration good Krumenlockerung with delicate pores, a high proportion of crust and a strong crust caused a slightly longer baking time, recommended. Weber / Lehmann / Hempelemann recommend in their essay "Die Rösche - A Quality Feature of Dauerbackwaren" in: "cereal technology" 59 (2004) 4, p 229 - 233 a "Rösche module" as a measure of crispness and moistening the baked goods within the manufacturing process until a water activity of a _w = 0.6 in the crust is reached. In a diploma thesis in the degree program "Food Technology" on the influence of different packaging materials on the freshness and shelf life of bread and rolls, it was shown in 2007 that the loss of crusted crust (dry structure) is dependent on its ambient humidity during storage, the crust strength Crumb humidity, ambient temperature, formulation and technology (air conditioning), and preservation of the rumps is a problem of desorption and sorption of the crust.

Accordingly, DE 10 2006 046 658 A1 also proposes to a co-applicant a process for the production of baked precursors, such as green, partially cooked, at least half-baked or full-cooked dough pieces, in which the baked products introduced into an air-conditioned goods room are moistened. According to the invention, an aerosol with a defined droplet size is added to the air stream of the refrigeration device, so that the air stream mixed with the aerosol substantially completely flows around the respective back precursor and the aerosol penetrates into the surface of the respective back precursor in such a way that substantially homogeneous moisture tion of the respective back-precursor. Hereby, a desorption of the dough pieces is prevented in any case, thereby bringing about an increase in quality of the baking precursor and of the later baked product. The drying effect of refrigeration (air conditioning) is hereby canceled or reduced.

From EP 1 161 873 Al a further approach is known. There it is proposed to make bakery products, e.g. Bread and biscuits, while baking 40 - 50% of the usual baking time, and then subjected to vacuum cooling and bake the baked goods ready for sale or ready for consumption after interim storage or transport. The total baking time should be significantly shorter, but the shelf life should be longer. Also should be a crunchy crust.

Finally, EP 0 930 013 B1 also proposes a method for the production and storage of partially baked bakery products in which optimal dextrin formation takes place in the crust prior to treatment with water. However, the total baking time increases by about 25% in this process. The baked good is treated immediately after the first partial baking on the surface with water vapor and / or water, so that forms a layer with increased water content on the outer surface of the baked good, which is approximately equal to the thickness of the crust produced during partial baking. This is followed by deep freezing of the so-treated baked good, in particular a blast freezing to form a deep-frozen thin layer on the same and a continuous freezing of the baked good in a second step. The application of the water or additive is carried out by steaming, misting or contacting.

All the above methods have in common that no finished Baking product is produced in a continuous, uninterrupted baking process, but that the baking process is interrupted and the baked good in a hot state with considerable energy expenditure, partly by shock freezing, is placed in a frozen state, or that semi-finished bakery goods are produced, stored, transported and then ready-baked. By none of the methods mentioned so far has the stability of baked goods, especially the Krustenrösche sustainably increase and extend.

The object of the invention is therefore to provide a solution with which the Krustenrösche can be significantly extended. This offers considerable advantages for the entire logistics chain and the available sales times. For example, even on longer trips, especially flights, boat trips or bus and train rides, a baked good can be made available, which still tastes crisp even at the time of their consumption.

To achieve the object, the invention proposes that throughout the dough processing and maintained a relative humidity at least in the vicinity of the relative humidity of the respective baked goods and / or the respective Frittierprodukts and the finished baked hot baked goods a vacuum cooling process at a pressure of approx. 20 mbar - 180 mbar for approx. 5 min. is subjected. In particular, a vacuum enthalpy cooling is preferred in which a maximum of 20 mbar and a minimum of 180 mbar are maintained. In this one exploits the evaporation enthalpy of water in a vacuum. By reducing the absolute pressure in a vacuum body, the water begins to evaporate at correspondingly lower temperatures and thus withdraws energy from the water-containing product and thus cools it down almost abruptly. speed Molecules evaporate, slow molecules remain. In addition to the rapid cooling down to eg 4 ° C storage temperature, the storage life of food is extended accordingly, without having to freeze.

Baked products generally have a core temperature of> 95 ° Celsius. When cooling with the vacuum-enthalpy cooling, the critical temperature range from 65 ° Celsius to 20 ° Celsius is crossed very quickly. The accelerated growth of microbes, such as bacteria, viruses, spores and molds is inhibited and therefore allows a longer shelf life of eg baked goods. The water vapor emerging from the rolls, for example, which would normally be deposited on the cool walls of the cooling cells, is sucked off during the vacuum enthalpy cooling. The water vapor migrates at high speed to all points in the system, where there is a lower temperature than in the pastry to be cooled. The temperature reduction takes place, for example, in the bun, not only from the outside as in the application of Umluftkühlverfahren, but at the same time at all points in the pastry. In the rapid cooling in a closed chamber no new, additional germs are brought by means of inflowing air to the dough. Only at the end of the cooling process is air, which has been freed of germs in an absolute filter, let into the cooling cell. As a result, the dough remains a larger volume. The loss of water during vacuum enthalpy cooling is compensated during the cooling process. The rehydration of the products during the vacuuming was successfully tested in a detailed research project of a co-applicant. There is no phase separation in the bun due to ice formation, no chipping in the crusted product, it remains a typical uniform pastry color and a smooth product surface and in particular the desired good crust structure with long-lasting. tender crust and a pronounced storage stability over a long period of time.

However, these advantages can only be achieved to the desired extent and with the surprising result of an actually doubled reboiling time of 10 to 12 hours if a high relative humidity is maintained throughout the dough processing and processing, which is preferably ≥ 96%. The Rösche is in principle a function of the water content, as well as the water activity. Both morphological and receptor-related aspects play a role. Since raking is a function of porosity, a correspondingly high porosity and the accompanying water content, in conjunction with specific material properties, provide significantly improved raking properties. Therefore, a method is required which ensures a high porosity of the baked goods in the edge zone area. In contrast to the prior art, in which desorption processes are provoked in the dough and baked goods edge area, in particular on the surface crust, with the result of water losses on the dough surface, a method is necessary to solve the task before, in the desorption in all phases before baking is largely or completely avoided.

This can be achieved by using an ultrasonic cold mist generator. By means of such ultrasound-generated aerosols, relative humidities of more than 96% (a _w = 0.96) can be maintained. In this way it is possible for the first time to minimize undesired desorption or to completely prevent it. It is therefore necessary to design all relevant process steps after the kneading process and before the baking process in such a way that desorption-like changes do not occur or, if possible, do not occur primarily porosity, and thus produce sufficient biological, chemical and physical reactivity. Otherwise, in the course of biological loosening, for example due to yeasts or bacteria or chemical loosening by baking powder or ammonium bicarbonate, only limited and in some cases greatly reduced porosity can be developed. As a result of such water losses on the dough surface whose flexibility and mechanical deformability as well as the gas-retaining capacity is reduced, with the result that fewer gas cells are created and these are prevented mainly from their three-dimensional expansion.

To bring about and maintain the porosity necessary for the Rösche a high relative humidity in all sub-process steps such as dough, Teigbe- and processing but also fermentation and fermentation control including freezing is required. In the baking process itself, a corresponding gas expansion is possible with high surface moisture, which increases the overall porosity. As a precautionary measure, a desorption situation must be avoided so that sufficient gas cell expansion is also generated in the edge area. The avoidance of dehydration of the dough surface also brings the retention of thermal conductivity with it. In addition, heat and mass transfer processes are accelerated, for example during cooling, freezing, fermenting and baking, so that in addition to the overall improved quality features of baked goods, corresponding energy savings are also possible.

When using the method according to the invention arise baked goods or dough pieces, which have a very good thermal conductivity and improved heat transfer as well as very good browning properties. It is a uniform color distribution on the pastry surface, a very good shine and a very good formation. The porosity of the crust is pronounced, especially pronounced is the Krustenrösche. The layer thickness of the crust is significantly increased as a result of the optimized heat and mass transport, since the drying zone between the crumb and crust is very low or not at all present. Furthermore, a pronounced "fenestration" of the crust or pronounced brittle material reaction of the crust is determined, so that a pleasant setting without hard material properties. This alone increases the preservation of the soils from 4 to 5 hours to now 6 to 7 hours with open storage, at room temperature and normal relative humidity. Even then, the Rösche loses only after a considerable delay.

As already mentioned, it is possible to further extend the preservation of crusted crust when the hot baked goods are subjected to a special vacuum cooling process, in particular in a range of 20-180 mbar. Under such conditions, the boiling point of water and other substances decreases so far that the enthalpy of vaporization causes corresponding cooling effects. In addition to the cooling effect here is the moisture removal primarily from the crust of importance. The heat and mass transfer processes take place at a high speed in the vacuum cooling, so that the cooling process, e.g. in buns with a core temperature of e.g. + 90 ° C to about + 10 ° C within a few minutes (about 5 - 10 minutes) is completed.

The loss of moisture in the baked good, associated with such vacuum enthalpy cooling, occurs primarily and appreciably in the crust, so that the crust has, in particular, a reduced water content and a reduced a _w , which in comparison to the catch water content is more pronounced than is the case in the crumb. For example, the a _w value of the crust before vacuuming has dropped from about 0.60 to about 0.55 after vacuuming, while the crumb has an a "value of 0.97 on average.

Such baked goods have a very long-lasting Krustenrösche of at least 11 - 12 hours in open and cool storage of about + 4 ° C, without hard fracture properties were found. The typical desired rye, i. a slightly crusty brittle material property is preserved until then, without forming a dry crust. Even after about 10 hours of storage, the baked goods still have good chewing properties and a pronounced crispiness, even if they are cut and coated. Goods packaged in film may also be stored under the same conditions and surprisingly over a period of more than 10 hours, during which time they may be labeled as rubbish, i. fresh goods are still consumed.

The specific heat conduction and high porosity of the crust of correspondingly produced bakery products are the reason that no pure dehydrating effects, i. a hard, tough material reaction, but a primarily clearly brittle and delicate material reaction is produced, which characterizes the overall quality and significantly improved.

With the method according to the invention, a complex and novel possibility is available with which bakery products, inter alia, can extend their racks by more than twice the usual consumption time (10 to 12 hours instead of the previous 4 to 5 hours). The combined use of ultrasonically generated air conditioning of the sub-processes before baking with A vacuum enthalpy cooling of hot goods after baking thus leads to surprisingly positive effects. Ultrasonic air conditioning prevents unwanted desorption, while vacuum drying primarily serves to dehumidify the now porous crust, while at the same time achieving high physical stabilization of the baked goods, and opens up completely new development potentials. The combined use of an ultrasonic cold mist air conditioning and applied after baking vacuum cooling thus leads to significant synergy effects. In contrast, according to the experiments carried out a pure Ultraschallkaltnebelklimatisierung of dough pieces without the subsequent bakery only to an extension of the Röschezeit to 6 - 7 hours, while a pure Pastriesvakuumierung without cold mist to a Roschezeit 5-6 hours against 4-5 hours in the prior art leads.

The invention is explained in more detail below by way of example with reference to the drawing. This shows in:

1 is a flow chart for a dough processing method according to the prior art and according to the present invention,

FIG. 2 is an overview drawing of the present invention. FIG.

3 shows a flowchart of the method according to the invention together with further processing,

4 shows a flow chart for the further processing of a baked good prepared according to the invention, 5 shows a table for the water content and for the a _w values of crumb and crust for rolls produced in different ways,

Fig. 6 is a table for the influence of an ultrasonic cold mist air conditioning of dough pieces and a vacuuming of hot biscuits on the Rö-- receipt of a baked good.

Fig. 1 shows an overview and comparison of the flow chart of a dough processing method according to the conventional art and the inventive method.

While in both cases a dough a "= 0.96 results after the - unchanged - kneading process, a desorption with a relative dough moisture of approximately 75% conventionally already occurs in the subsequent dough resting, which takes place at a temperature of 24 ° Celsius. one. This relative humidity of 75-80% also remains during the subsequent dough processing and processing, inter alia during rounding and intermediate cooking. During the subsequent main cooking or during the corresponding fermentation control and freezing by various methods, the relative humidity rises - at different temperatures - to 80 - 90%. At the same time the desorption proceeds until the baked good at subsequent baking at a temperature of about 200 ° - 260 ° Celsius, especially 220 ° Celsius, only has a reduced thermal conductivity.

On the other hand, in the process according to the invention, the cold vapor mist maintains a relative ambient humidity of ≥ 96% during all substeps. All process steps are conducted in such a way that no desorption occurs. Depending on which flour qualities have to be processed, or depending After which production processes are used, the properties of the Rösche and overall quality characteristics of the baked goods can be significantly improved or influenced. In this context, suitable enzyme management also increases the quality of the pastry. For example, wheat starters with a share of 5 - 20% have a favorable effect. Long-term guidance or fermentation delays in the range of + 5 ° to -5 ° Celsius leave relatively much room for enzymatic reactions, while fermentation interruptions (-5 ° to -15 ° Celsius) or freezing (colder than -18 ° C) of frozen dough pieces trigger enzyme reactions stronger stop. Therefore, methods such as long-term guidance at temperatures of + 10 ° to + 30 ° Celsius and the fermentation delay in addition to the application of doughs are particularly suitable for producing premium quality baked goods.

Some typical fermentation control procedures are briefly outlined below, each using ultrasonic cold mist.

A typical fermentation delay temperature-time profile or fermentation process looks like this:

1.

Doughs (uncooked) directly after working up at -5 ° C,

100% relative humidity

Second

Storage at -5 ⁰ C for 24 to 48 hours (100% relative humidity)

Third

Thawing at 26 ° to 38 ° C (100% relative humidity) 4.

Baking: as usual as partially baked or normal (turn off)

A typical proofing temperature-time profile is exemplified as follows:

1.

Doughs (uncooked) directly after working up at -15 ° C

Fermentation interruption, 100% relative humidity

Second

Storage at -15 ° C and 70 - 100% relative humidity for about 72 hours

Third

Storage at +/- 0 ° C to + 5 ° C and 70 - 100% relative

Humidity for 6 to 12 hours

4th

Fermentation phase at approx. + 19 ° C to 32 ° C and 70 - 100% relative

Humidity for 30 - 80 minutes

5th

Bake as usual, as a half-baked or normal baked

(baked)

A typical proofing temperature-time profile is exemplified below:

1.

Doughs (uncooked) directly after working up to + 0 ° C until

5 ° C fermentation delay, 70 - 100% relative humidity 2.

Storage at + 0 ° C to + 5 ° C / 70 - 100% relative humidity during approx. 6 to 12 hours

Third

Fermentation phase at approx. + 15 ° C to + 32 ° C / 70 - 100% relative

Humidity during 30 minutes up to 80 minutes

4th

Bake as usual, as a half-baked or normal baked

(Baked)

A typical proofing temperature-time profile is exemplified below:

1.

Doughs (uncooked) cook immediately after processing at + 15 ° C to + 38 ° C at 70 - 100% relative humidity

Second

Storage of the fermentation phase 30 minutes to 80 minutes

Third

Bake as usual, as a half-baked or normal baked

(Baked)

Furthermore, frozen dough pieces of all sizes and weight classes (30 g to 3000 g), which were stored frozen at -18 ° C to -30 ° C, treated over a fermentation temperature-time profile as outlined below:

1.

Doughs (frozen) directly after freezing storage at + 0 °

C up to + 10 ° C fermentation delay, 70 - 100% relative humidity 2.

Storage at + 0 ° C to 10 ⁰ C at 70 - 100% relative humidity During 6 to 12 hours

Third

Fermentation at about + 15 ° C to 32 ° C at 70 - 100% relative

Humidity for 30 minutes to 80 minutes

4th

Bake as usual, as a half-baked or normal baked

(Baked)

An increase in the degree of convenience in bread and bakery products can then be ascertained if, in this connection, dough pieces are not fermented or frozen, but a frosting process is carried out after a baking process of dough pieces.

A number of bakeries follow these procedures and freeze fully or partly baked goods. Still other companies require logistical among other reasons, only cooling temperatures in order to achieve a certain shelf life of the products.

In all the cases mentioned, a further extension of the preservation of the crustaceae is achieved when hot baked goods (as prepared above) are subjected to a special vacuum cooling process (range: 20-180 mbar) (see Figures 2 and 3).

Such conditions reduce the boiling point of water and other substances so far that the enthalpy of vaporization causes corresponding cooling effects. In addition to the cooling effect here is the moisture removal - primarily from the crust - in the center of attention. FIG. 2 shows an overview of the use of cold aerosols from ultrasonic generators in dough processing and in combination with a vacuum cooling of hot baked goods to produce a pronounced, long-lasting crustaceae.

Fig. 3 shows first the process flow for the production of baked goods with long-lasting Rösche and subsequent further processing either by direct sale, or by subsequent cutting, covering and packaging to consumption.

In detail, this is also shown once again in FIG. 5. After the vacuum cooling of the finished baked goods at 20-180 mbar in about 5 minutes, a rest period of about 20 minutes at room temperature followed before the baked goods, for example, electrically cut and, for example. butter, margarine, lettuce, cheese and sausage, and then packaged in perforated foil or paper (open) and stored and transported in typical sales trollies or the like at + 3 ° to 7 ° C for 1-16 hours, before finally consumed by the end customer.

Fig. 4 shows a tabular overview of the water content and a _w values of crumbs and crust in differently produced rolls. The a _w value of the crust has dropped to 0.50 before vacuuming and to 0.55 after vacuuming (crumb: 0.97 a _w ). Such baked goods can be characterized by a low expansion, very good external characteristics such as color, fenestration, gloss, Ausbund and physical stability and a very long-lasting crust at least 11 - 12 hours in open and cool storage and at + 4 ° C. Also, identify hard break properties as by a typical pastry taste (with a slightly reduced smell of pastry) and good chewing properties. Even after 10 - 12 hours storage or transport, the baked goods still have a pronounced crispiness. This is the case even when the vacuumed and cold baked goods produced according to the invention are cut and provided with a coating. Also packaged in film goods can be stored at + 4 ° C surprisingly over a period of more than 10 hours and freshly sorted in this period as Rösche goods.

Of course, the invention is not limited to the illustrated embodiments. Further embodiments are possible without departing from the basic idea.

For example, it is also possible to produce frying products instead of baked goods. Essential is always the synergistic combination of a continuous high air humidity throughout the processing and processing before baking or frying with a subsequent (vacuum) cooling of the baked goods.

Claims

Claims;

1.

A process for the production of bakery products and / or frying products, characterized in that maintained during the entire dough processing and a relative humidity at least in the vicinity of the relative humidity of the respective baked good and / or the respective frying product and the finished baked hot baked goods a vacuum cooling process at a pressure of about 20 - 180 mbar for about 5 min. is subjected.

Second

A method according to claim 1, characterized in that the hot baked good about 5 min. subjected to a vacuum-enthalpy cooling, are maintained at the maximum of 20 mbar and a minimum of 180 mbar.

Third

A method according to claim 1, characterized in that during the entire Teigver- and processing a relative humidity of preferably ≥ 96% is maintained.

4th

A method according to claim 1, characterized in that during the entire Teigver- and processing a relative humidity of preferably ≥ 96% by cold mist, namely by ultrasound-generated aerosols, is maintained.