CZ2018567A3 - A method of treating a cereal to prepare malt and / or malt prepared from it to reduce the foaming potential of the malt - Google Patents

Abstract

A method of treating a cereal for the preparation of malt and / or malt prepared therefrom to reduce the foaming potential of the malt, wherein the cereal and / or the malt prepared therefrom are treated for 1 to 5 minutes with low temperature plasma, wherein the cereal and / or The malt delivers energy of 80 to 620 kJ / kg, thereby eliminating its possible fungal contamination and consequently reducing the foaming potential of the malt prepared from the cereal thus treated, respectively. malt treated in this way.

Description

Technical field

The invention relates to a method of treating cereal for the preparation of malt and / or malt prepared therefrom to reduce the foaming potential of malt.

BACKGROUND OF THE INVENTION

Foaming (more often gushing) is a phenomenon observed in carbonated beverages such as beer, when the beverage is massively foaming when opened. The essence of this relatively complex phenomenon, which is influenced by many different factors (see, for example, Christian et al .: "New cognitions on gushing in the wort production process and in quantifying the gushing potential of malt", Cerevisia, Volume 35, Issue 2, July 2010, pp. 35-37, DOI: 10.1016 / j.cervis.2010.06.005) is the immediate release of carbon dioxide when the bottle is opened (see, eg, Shokribousjein et al., "Hydrophobins, beer foaming and gushing", Cerevisia, Volume 35) , Issue 4, 2011, pp. 85-101 (DOI: 10.1016 / j.cervis.2010.12.001). In terms of causes, over-foaming can be divided into "primary" and "secondary" (see, for example, Gjertsen, P., Trolle, B., Andersen, K .: "Weathered barley as a contributory cause of gushing in beer.", In Proceedings of The 9 th Congress - European Brewery Convention (Brussels, 1963, Amsterdam: Elsevier, 1964, pp. 320-341), the primary over-frothing of beer being related to the quality of malt, the secondary to its processing at the brewery. It is well known that the most important factor for inducing primary foaming is the infection of cereals with filamentous fungi that produce surface-active proteins, the so-called hydrophobins (see, for example, Postnikova et al. Food Science & Technology, Volume 49, 2016, pp. 64-73, DOI: 10.1016 / j.tifs.2015.12.006).

Various physical methods have been tested in the past to suppress fungal contamination of cereals prior to the malting process. These include, for example, electron-beam irradiation of malting barley (see, for example, Kottapalli, B., Wolf-Hall, CE, & Schwarz, P .: "Effect of electron-beam irradiation on the safety and quality of Fusarium-infected malting barley ', International Journal of Food Microbiology, Volume 110, Issue 3, 2006, pp.224-231, DOI: 10.1016 / j.ijfoodmicro.2006.04.007), which has eliminated fungal organisms in barley, but also to deteriorate its malting parameters and increase mycotoxin concentrations. Other methods were, for example, the use of a static magnetic field to inhibit Fusarium fungi (see, for example, Albertini et al. 963-970, D01: 10.1016 / j.biochi.2003.09.017) or ozonification (see, eg, Piacentini, KC, Savi, GD, Scussel, VM): vulgare L.) grains ”, Quality Assurance and Safety of Crops & Foods, Volume 9, Issue 4, 2017, pp.383-389, DOI: 10.3920 / qas2016.0881). The disadvantage of these methods is that they only suppress the manifestations of fungal contamination, but do not completely eliminate them, and the fungi that survive the treatment are able to re-spread during the malting process. At the same time, it is proven that molding during malting is required for foaming (see, for example, Gjertsen, P., Trolle, B., Andersen, K .: "Gushing caused by microorganisms, specifically Fusarium species", In Proceedings of the 10th Congres - European Brewery Convention: Stockholm, 1965; Amsterdam: Elsevier, 1966, pp. 428-438; at the same time, it has not been established that malt produced from such treated cereals retains all malting parameters.

It is an object of the present invention to provide a process for the treatment of cereal for the preparation of malt and / or malt prepared therefrom, which would reduce the foaming potential of the malt but which

At the same time, A3 maintained all the malting quality indicators of the cereal or malt so treated at values that are in accordance with the technological usability of malt in brewing.

SUMMARY OF THE INVENTION

The object of the invention is achieved by a method of treating a cereal (or mixture of cereals) for the preparation of malt and / or malt prepared therefrom to reduce the foaming potential of malt, which is characterized in that the cereal and / or malt prepared therefrom are constantly moving It is treated with low temperature plasma for 1 to 5 minutes. In doing so, it is supplied with an energy of 80 to 620 kJ / kg, preferably 88 to 530 kJ / kg, thereby eliminating its possible fungal contamination. This has the effect of reducing the foaming potential of malt prepared from the cereal thus treated, respectively. malt treated up to 0 g / bottle.

The treated cereal or malt is stored / stored in an open container during treatment and mixed during treatment, or on a conveyor belt of a belt conveyor passing under at least one plasma head and vibrated during treatment, or in a screw conveyor whose groins provided with at least one viewing window for plasma or cereal malt treatment.

Due to the design of the plasma device and the plasma head, it is preferred that the cereal and / or malt be treated with a low temperature plasma generated by a sliding arc electric discharge at a working gas flow rate of 0.57 to 1.72 normal m ³ / h, preferably 0.57 to 1.25 normal m ³ / h, wherein the distance of the treated material from the plasma head (s) of the plasma device is 6 to 10 cm and the power of each plasma head is 220 to 310 W, preferably 220 to 265 W.

DETAILED DESCRIPTION OF THE INVENTION

In the process of treating cereal for malting and / or malt prepared therefrom to reduce the foaming potential of the malt according to the invention, the cereal (or mixture of cereals) and / or malt prepared therefrom is treated with low temperature plasma for 1 to 5 minutes. As will be shown below in specific examples, this method of treating cereal and / or malt prepared therefrom, due to the synergy of the three main plasma components, the discharge channel temperature, the generated UV radiation and the presence of highly reactive oxidizing particles in the discharge, eliminates fungal contamination of this cereal or malt, thereby significantly reducing the foaming potential of the malt. All malting parameters of the cereal, resp. malt at basically default values. During this treatment, the cereal for the preparation of malt and / or the malt prepared therefrom is continuously supplied with energy of 80 to 620 kJ / kg.

Low-temperature plasma generated by any known method can be used for treatment, however, due to the design and principle of the plasma device, the use of plasma generated by a gliding arc-type electric discharge appears to be most preferred. It uses a known plasma device which comprises a high voltage AC source and at least one plasma head in which two divergent metal electrodes (copper, alternatively stainless steel) are stored, between which an electric arc discharge is ignited at the point of the smallest gap. Due to the rapid heating at the discharge channel and the simultaneous generation of a strong gas pressure gradient, the discharge is forced to slide along the electrodes in the direction of the widening gap between them, causing the discharge channel to lengthen. Moreover, this shift is supported by a strong flow of working gas (most often air, possibly argon, nitrogen, or various mixtures) supplied to the space between the electrodes. When the critical discharge channel length is reached, a transition to a strongly unbalanced state occurs and the discharge disintegrates. Then everything repeats from the initial state of ignition at the smallest gap. Strong current

The working gas supplied to the plasma head helps to stabilize the discharge and at the same time allows the plasma flow to be directed towards the treated cereal or malt. The treated cereal or malt is placed / placed, for example, in a mixing vessel under the plasma head, on a conveyor belt which is guided in a closed circuit or linearly under at least one plasma head, or in a screw conveyor in whose wall at least one vista allowing plasma or cereal or malt treatment. In all cases, during the treatment, the individual grains of the cereal or malt constantly move relative to the plasma head (s) - for example due to their mixing, vibrations of the belt conveyor belt, rotation of the screw conveyor spiral, etc.

To eliminate fungal contamination and reduce the malt-converting potential of malt (up to 0 g / bottle) while maintaining all the major malt quality parameters of the treated cereal or malt at values that are consistent with the technological usability of malt in brewing, a gliding arc type electric discharge necessary to maintain the plasma process parameters at the values given in Table 1 below. When using a plasma generated by another method, the process setting is analogous to achieve the same degree of treatment and heating of the treated material and supply the same energy.

Table 1

Process parameter Applicable range Advantageous range working gas flow 0.57 normal m ³ / h to 1.72 normal m ³ / h (ie 20 to 60 standard cubic feet per hour) 0.57 normal m ³ / h to 1.15 normal m ³ / h (ie 20 to 40 standard cubic feet per hour) power of plasma head 220 to 310 W 220 to 265 W distance between treated material and plasma head 6 cm to 10 cm 6 cm to 10 cm treatment process time 1 min to 5 min 1 min to 5 min delivered energy 80 to 620 kJ / kg 88 to 530 kJ / kg

From an economic point of view, it is advantageous if the working gas flow is in the range of 0.57 to 1.15 m ³ / h, the power of each plasma head is in the range of 220 to 265 W and the energy supplied to the treated cereal or malt is 88 to 530 kJ / kg, because at higher values of any of these parameters, only the energy intensity of the whole process increases without any significant effect on its efficiency and the achieved result.

By way of illustration, four specific examples of cereal treatment for malt preparation and / or malt prepared therefrom are shown below to reduce the foaming potential of the malt according to the method of the invention.

Example 1

In the experimental field of the company Kluky spol. s r.o. Francin malting barley was grown. Prior to sowing, two basic variations were developed with different seed treatment methods:

-3 EN 2018 - 567 A3

(a) seed infested with the pesticidal product Raxil Star

(b) uninfested seed (control sample)

Each variant was grown in four repetitions (on four different plots), from which 2 mixed barley samples were prepared - one of the pickled seed variant, the other of the non-contaminated seed variant. Further, one half of each sample was plasma treated and the other half was left untreated. The four barley samples thus formed (both plasma treated and untreated) were subsequently sweetened, with half of each malt formed, plasma treated and the other half left untreated. A total of 8 malt samples were prepared. For each treatment, a low temperature plasma generated by an electric discharge type gliding arc with the setting of Table 2 was used. Each sample of 150 g was agitated at one time with one mixing propeller rotating at 60 rpm, so that each malt grain was statistically exposed the plasma 3 to 10 times, for a period of about 0.5 to 2 sec, with intervals sufficient to cool it.

Table 2

Process parameter Conditions working gas (air) flow 0.86 normal m ³ / h (normalized flow), ie 30 standard cubic feet per hour power of plasma head 240 W distance between treated material and plasma head 6, 8 and 10 cm treatment process time 4 min delivered energy 384 kJ / kg

For malt samples prepared in this way, according to the method of Vaag et al .: "A simple and rapid test for gushing tendency in brewing materials", In Proceedings of the 24th Congress - European Brewery Conventio: Oslo, 1993, IRL Press: Oxford, 1993, pp. 155-162, ISBN 13: 9780199634668 performed a foaming prediction test and the main malt parameters were determined by standard methods (Kolbach number, diastatic power, β-glucan content in wort, achievable degree of fermentation, malt extract in dry matter, relative extract at 45 ° C and friability). The parameters so obtained are given in Table 3 below (for the variant where the distance between the treated material and the plasma head was 10 cm), 4 (for the variant where the distance between the treated material and the plasma head was 8 cm) and 5 (for the the distance between the treated material and the plasma head was 6 cm).

-4 EN 2018 - 567 A3

Table 3

Method of seed treatment Plasma treatment of barley Plasma treatment of malt Foaming potential of malt (g / bottle) Kolbach Number (%) Diastatic cardinality (j.WK) Β-glucan content (mg / 1) Achievable degree of fermentation (%) Malt extract in dry matter (%) Relative extract at 45 ° C (%) Friability (%) stained NO NO 14 40.4 572.5 177.0 79.3 78.3 44.9 61.5 stained NO YES 0 41.3 578.5 172.0 79.5 78.7 44.3 63.7 infested NO NO 27 Mar: 40.7 553.5 180.0 78.9 78.4 44.1 64.1 infested NO YES 0 41.0 551.0 214.0 79.1 78.7 43.8 66.6 stained YES NO 14 41.4 572.5 130.5 79.8 78.3 47.5 64.8 stained YES YES 0 40.7 564.0 140.5 80.2 78.4 46.5 67.0 infested YES NO 0 40.4 549.0 190.0 79.6 78.1 45.7 65.2 infested YES YES 0 41.0 568.5 158.0 79.2 78.3 45.7 65.9

CZ 2018 - 567 A3

Table 4

Method of seed treatment Plasma treatment of barley Plasma treatment of malt Foaming potential of malt (g / bottle) Kolbach Number (%) Diastatic cardinality (j- WK) Β-glucan content (mg / 1) Achievable degree of fermentation (%) Malt extract in dry matter (%) Relative extract at 45 ° C (%) Friability (%) stained NO NO 14 40.4 572.5 177.0 79.3 78.3 44.9 61.5 stained NO YES 0 41.2 568.2 182.6 79.6 78.2 44.4 64.8 infested NO NO 27 Mar: 40.7 553.5 180.0 78.9 78.4 44.1 64.1 infested NO YES 0 40.3 548.6 196.4 78.3 78.9 45.1 65.8 stained YES NO 16 41.0 561.3 186.8 78.8 77.4 45.6 64.6 stained YES YES 0 41.4 542.6 174.8 77.6 77.8 44.8 63.8 infested YES NO 8 40.8 548.4 168.2 78.4 78.2 43.9 65.9 infested YES YES 0 40.6 552.6 189.4 79.5 78.6 46.7 66.2

-6 EN 2018 - 567 A3

Table 5

Method of seed treatment Plasma treatment of barley Plasma treatment of malt Foaming potential of malt (g / bottle) Kolbach Number (%) Diastatic cardinality (j- WK) Β-glucan content (mg / 1) Achievable degree of fermentation (%) Malt extract in dry matter (%) Relative extract at 45 ° C (%) Friability (%) stained NO NO 14 40.4 572.5 177.0 79.3 78.3 44.9 61.5 stained NO YES 0 41.2 568.2 176.8 77.2 77.5 43.9 62.8 infested NO NO 27 Mar: 40.7 553.5 180.0 78.9 78.4 44.1 64.1 infested NO YES 0 40.3 548.6 182.6 80.2 78.1 44.2 65.2 stained YES NO 6 40.8 545.6 188.1 79.9 78.6 45.6 65.0 stained YES YES 0 41.3 549.2 179.6 78.6 77.6 46.8 64.9 infested YES NO 3 39.9 538.9 208.6 77.8 76.9 44.2 64.5 infested YES YES 0 40.2 542.6 169.8 76.9 77.1 43.8 63.8

It is apparent from these tables that malt samples in which malting barley was only treated with pickling, the malt foaming potential decreased by almost half (14 and 16 g / bottle respectively, compared to 27 g / bottle for uninfested barley), but for all samples malt treated with plasma, irrespective of pickling, reduced the foaming potential of the malt up to 0 g / bottle, while maintaining all malt quality parameters at values very similar to the baseline values and in line with the technological usability of malt in brewing.

Example 2

Two samples of barley malt produced at the Malt House in Rajhrad in 2012, which exhibit long-lasting high foaming potential (average value over 90 g / bottle), were treated for 1, 2, 3, 4 and 5 minutes with low-temperature plasma generated by gliding type Each sample of 150 g was mixed with a single mixer propeller rotating at 60 rpm throughout the treatment so that statistically each malt grain was exposed to plasma 3 to 10 times, each time 0.5 to 2 s with intervals sufficient to cool it.

-7 GB 2018 - 567 A3

Table 6

Process parameter Conditions working gas (air) flow 1.00 normal m ³ / h (flow converted to normal conditions), ie 35 standard cubic feet per hour power of plasma head 250 W the distance between the malt treated and the plasma head 10 cm treatment process time 1, 2, 3, 4 and 5 minutes delivered energy 100, 200, 300, 400 and 500 kJ / kg

The foaming prediction test was then performed on these samples in the same manner as in Example 1. In addition, the activity of hydrolytic enzymes (α-amylase and β-amylase) was determined. The parameters thus obtained are shown in Table 7 below.

Table 7

Method of malt treatment Length of plasma treatment Malt foaming potential (g / bottle) Α-Amylase Activity (U / g) Β-amylase activity (U / g) untreated malt 0 min 96 85 5.9 malt treated 1 min 72 83 5.5 1 min 53 81 5.6 2 min 28 82 5.5 4 min 21 80 5.7 5 min 18 81 5.6

As can be seen from this table, plasma treatment significantly reduced the foaming potential of malt, while maintaining both α-amylase and β-amylase activity.

Example 3

The crop of winter wheat of the Bohemia variety was infected with virulent Fusarium culmorum strains in a suitable vegetation phase. Along with the infected variant, it was cultivated concurrently as a control variant without inoculation, with fungicide treatment according to the plant protection methodology. Samples of both variants of wheat were then treated with a plasma generated by a sliding arc type electric discharge with the setting according to Table 8.

-8 GB 2018 - 567 A3

Table 8

Process parameter Conditions working gas (air) flow 1.15; 1.43; respectively. 1.72 normal m ³ / h (normalized flow), ie 40, 50 and 60 standard cubic feet per hour power of plasma head 265, 310, respectively. 300 W distance between treated material and plasma head 8 cm treatment process time 1 min delivered energy 212, 248, respectively. 240 kJ / kg

Malt was then prepared from the wheat samples prepared in this way in the micro-malt of the Research Institute of Brewing and Malting in Brno in the usual way according to the EBC (European Brewery Convention) methodology. They were subjected to an overfeed prediction test in the same manner as in Example 1. Some qualitative indicators of malt (wort turbidity, wort viscosity, wort pH, attainable degree of fermentation, diastatic solidity, dry malt extract, relative extract at 45 ° C, Kolbach number and α-amylase and β-amylase enzyme activity). The parameters thus obtained are shown in Table 9 below. Each 150 g sample was mixed with a single mixer at 60 rpm throughout the treatment, so that statistically each zmo wheat was exposed to plasma 3 to 10 times, always for about 0.5 to 2 s with intervals sufficient to cool it.

-9 GB 2018 - 567 A3

Table 9

ŠjíAp

· '· ’!

£ δ? ; qÝ;

: three (%) S S S A A A A M M 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

O kft σ?

Í73 <>>

r>

: CM J v :: TY 33; e * gi; O: ¢ 5 ^: ¢ 7: ¢ 7 “.................................. re) | gWfBA ^ & ld Wum? £ u is SKQS

.................................................. .................... 1

A ^ ip ^ s £ O

SQ: S5>

<M

4>

^ E £ š ^: 3 $ šy ^ <ÍJ ýO ΰύ s

Š £ j

Áaíp ^ js

S3:

<8:

ŠS!

<s

ÍG <£>

Ěů

SĎ

WITH HER

15 * pure

-------------------- (t | £ g * s>

fx ·.

&> É & £ k

Φ &

* ya &> fi £ S.

-I15

- g š

C &>: · <Λ Λ X «3 $

ÍS

3? >>

QJ fS: es š

O:;

> g

E <k>: -Eft ct <g

Έ:

£ 'j§ (3 &

<«·> § 'sl' δ

From this table it is evident that the wheat malt sample prepared from uninfected plasma treated wheat reduced the foaming potential. A sample of wheat malt from infected wheat had no foaming potential even in the absence of plasma treatment. For malt prepared from plasma-treated wheat, all monitored malting parameters, including hydrolytic enzyme activity, were maintained and ranged in line with the technological usability of malt in brewing.

Example 4

The spring barley of the Wiebke variety was infected with virulent strains of 15 Fusarium culmorum in a suitable vegetation phase. Zq of barley samples are subsequently processed in the micro malt house of the Research Institute of Brewing and Malting in Brno in the usual way according to the EBC (European

- 10GB 2018 - 567 A3

Brewery Convention) prepared malts, which were subsequently treated with a plasma generated by a sliding arc electric discharge with the setting according to Table 10.

Table 10

Process parameter Conditions working gas (air) flow 0.57 and 1.43 normal m ³ / h (flow converted to normal conditions), ie 20 and 50 standard cubic feet per hour power of plasma head 220 and 310W distance between treated material and plasma head 6 cm treatment process time 1 and 5 min delivered energy 88 and 620 kJ / kg

The malt samples were subjected to a foaming prediction test in the same manner as in Example 1. Selected malt quality parameters (wort viscosity, wort pH, friability, diastatic power, dry malt extract, relative extract at 45 ° C were determined by standard methods) and Kolbach number). The parameters thus obtained are shown in Table 11 below.

Each sample of 150 g was mixed with a single mixer, which was rotated at 60 rpm throughout the treatment, so that statistically each zmo wheat was exposed to plasma 3 to 10 times, for a period of about 0.5 to 2 ss. intervals sufficient to cool it.

Table 11

Plasma malt treatment Plasma head power (W) Malt foaming potential (g / bottle) Wort viscosity (mPa.s) pH wort Friability (%) Diastatic cardinality (j.WK) Malt extract in dry matter (%) Relative extract at 45 ° C (%) Kolbach Number (%) Barley malt with inoculation NO - 34 1.51 5.9 75.1 382 79.9 49.7 44.1 Barley malt with inoculation YES 220 18 1.48 5.9 80.4 345 79.9 50.0 43.9 Barley malt with inoculation YES 310 8 1.46 5.8 76.3 292 79.5 46.1 43.1

- 11 GB 2018 - 567 A3

As can be seen in Table 11, the foaming potential of the barley malt sample treated with plasma decreased. At the same time it can be stated that there were no negative changes in the malt quality parameters, which would be caused by higher performance of the plasma head.

PATENT CLAIMS

Claims (7)

Method for treating cereal for malting and / or malt prepared therefrom for reducing the foaming potential of malt, characterized in that the cereal and / or malt prepared therefrom is continuously treated for 1 to 5 minutes by low-temperature plasma, wherein This cereal and / or malt provides energy of 80 to 620 kJ / kg and eliminates its possible fungal contamination. Method according to claim 1, characterized in that the cereal and / or the malt prepared therefrom are supplied with energy of 88 to 530 kJ / kg during the treatment. Method according to claim 1, characterized in that the treated cereal or malt is stored / stored in an open container during the treatment and mixed during the treatment. Method according to claim 1, characterized in that the treated cereal or malt is deposited / deposited on the conveyor belt of the belt conveyor during which it passes under at least one plasma head and to which vibrations are applied during the treatment. Method according to claim 1, characterized in that the treated cereal or malt is deposited / placed in a screw conveyor during the treatment, the wall of which is provided with at least one plasma or malt viewing window. Method according to claim 1, characterized in that the cereal and / or malt is treated with a low-temperature plasma generated by a sliding-arc electric discharge at a working gas flow rate of 0.57 to 1.72 normal m ³ / h, the distance of the treated material from the plasma the head (s) of the plasma device is 6-10 cm and the power of each plasma head is 220-310 W. Method according to claim 6, characterized in that the cereal and / or malt is treated with a low-temperature plasma generated by a sliding arc electric discharge at a working gas flow rate of 0.57 to 1.25 normal m ³ / h, the power of each plasma head being 220 to 265 W.