CA1182410A

CA1182410A - Method for production of malt

Info

Publication number: CA1182410A
Application number: CA000416337A
Authority: CA
Inventors: Katsuhiko Yamada
Original assignee: Kirin Brewery Co Ltd
Current assignee: Kirin Brewery Co Ltd
Priority date: 1981-11-26
Filing date: 1982-11-25
Publication date: 1985-02-12
Also published as: JPS58101677A; GB2112017B; AU556682B2; FR2516933A1; AU9077682A; DE3243547C2; JPH0139750B2; GB2112017A; DE3243547A1; FR2516933B1

Abstract

ABSTRACT OF THE DISCLOSURE

A novel method for production of malt is provided, in which the yield of malt, yield of extract and diastatic power as well as the fermentability and color ing of wort produced from the malt are markedly improved, comprises subjecting cereal grain for malt to water absorption and germination and is characterized in that abscisic acid or its functional derivative is applied to the cereal grain which is in the steeping process or the germination process, If desired, gibberellin or its functional derivative can be used in combination with abscisic acid or the functional derivatives thereof.

Description

METHOD FOR PRODUCTION OF MALT

BACKGROUND OF THE INVENTION
This invention relates lo a method for production of malt. `
Malt, which is useful as a starting material for brewing,is being produced by a method which comprises subjecting cereal grain for malt to steeping and ge~mination. In such a conventional process, the quality of the malt is lowered when the yield of the malt is increasad. Therefore, a method which compxises applying gibberellln to the cereal grain in the malting process step to shorten the period for germination and thereby to seek an increase in malt yield and decrease in cost and, moreover, to prevent deterioration of quality has been reduced to practice. Gibberellin is also being utilized to produce malt of high quality from barley of low ~uality.
The use of gibbexellin, however, is not desirable because the woxt prepared rom the malt produced by the use of gibberellin has defects such as the deepened color of wort.
In order to solve such problems wi~h respect to the use of gibberellin, KBrO3 has been practically used in combination with gibberellin. However, K~rO3 is said to have mutagenicity, and thus the use thereof is not desired from the viewpoint of food hygiene. The use of various chemicals other than KBrO3 has also been proposed, but in all these ca,ses the use of these chemicals has low practlcal value because of fcod hygiene problems and the like.
SUM~ ~ QF THE INVENTION
It is an object of the present invention to solve the aboYe described problems. This obejct has been accomplished by the use of abscisic acid or a functional derivative thereof instead o~ KBrO3 or other chemicals.
Thus, ~he method for produc~ion of malt in accordance with the present invention comprises subjec,-ing cereal grain for malt to steeping, vi~.. water-absorption,and germina~ion and is characterized in that an abscisic compound which is abscisic acid or a functional derivative thereof is applied to the cereal grain which is in the steeping process or the germina-tion process.
A feature of the present invention resides in the use of abscislc acid or a functional derivative thereof, which can be used if so desired in combination with other chemiclas as lcng as this feature is not impaired.
One group of such chemicals is gibberellin or a functional derivative thereof.
Thus, -the method for production of malt in accord-ance with the presen. invention in another aspect thereof comprises subjecting cereal grain for malt to steeping and ~ermination, and is char~cterized in that both the abscisic compound and a gibberellic compound which is gibberellin and/or a functional derivative thereof are applied to the cereal grain which is in a process stage of steeping or ger~ination.
The term "cereal grain for malt" herein refers to cereal grain for use in brewing. Among -the grains that so named are barley, wheat, rye, oats, and various other cereal grains such as millet and soryham. Barley is the most typical~
DETAILED DESCRIPTION OF THE INVENTION
.. ... . _ _ Abscisic acid to be used for malting in accordance with the present invention is not a syn~hetic compound but a plant hormone which is g~nerally contained in cereals, vegetables, fruits and the like. Thus, there is no food hygiene probl~m or risk in operations as in the case o~ K~rO3 and other chemicals. Furthermore, abscisic acid or the like can exhibit a marked effect at a very low concentration in comparison wikh KBrO3 and the like. For example, KBrO3 has been used in a quantity o~ about 100 ppm on the basis of barley weight, but abscisic acid or the like is effective even in a quantity of 0.1 to 1 ppm, as described ~elcw in detail.
By the acldition of abscisic acid to barley in the course o th~ malting process, the growth of rootlets is inhibited to increase the yield of maltO ~t the same time, excessive decomposition of proteins is controlled, and the amount of free amino acids is decreased in the wort prepared from the resulting malt because formation of protease is innibited. Further, the degree of coloring wort due to formation of melanoidine is de-creased because o decrease in the content of glucose or maltotriose in the wort which is caused by inhibi-tion of ~-amylase formation. Moreover, fermentability is improved because of increase in the maltose content in the wort, and the extract content is also increased by the concomitant use of gibberellin.
It is known that the biosynthesis of ~-amylase in the aleurone layer of barley is promoted by gibberellin (especially GA3) but abscisic acid (hereinafter sometimes referred to as ABA) hinders the biosynthesis ~Plant Physiol. 42, 1008 (1967) and ~ature, 205, 1270 ~1965)].
It has also been made clear that the mechanism of inhibition of the a amylase-biosyntheSis by ABA is not due to the hindrance of m-P~NA induction of ~A~ but due to the hindrance of translation of m-RNA into protein ~Cell, 20, 479 (198Q)]o In these reports, the effects of ABA on the induction of m-RNA and formation of ~ amylasa were researched by adding GA3 and ABA in com-bination to the endosparm or isolated aleurone layer of barley.
These researches, however, do not ~each or suggest ~he manifestation of special effects achieved according to the presen~ inven~ion, that is, by addition of both GA3 and ABA to barley in a mcllting stage, (i) the yield o malt, yield of extract ancl diastatic power can be increased, and, moreover, (ii) the fermentability of the resulting wort is improvad, and also the decomposi-tion of proteins and the colc,r of wort can be controlledat will, and other effects~ In this connection, general reports which teach that. the balance of certain four plant hormones is required in the formation of ~-amylase are known [European Brewery Convention Proceed-ings of the 14th Congress (Salzburg), p.757 (1973), (and that of the 16th Congress (Amsterdam), P.63 (1977)]. The special effects mentioned above, however, also could not be anticipated from the above named reports.
The method of producing malt will now be described in specific detail.1~ Maltin~ process The present invention can be applied to conventional malting processes. With reference to the present inven-tion, the malting process is defined to comprise causing grain for malt to absorb water and germinate.
The methods for pxoduction of malt which comprise causing the grain to absorb w~ter and germinate are well known in the art, and thus no description thereof in detail will be needed hereinO If necessary, one can refer to, for example, "Barley and Malt Biology, Bio-chemistry, Teehnology, Ed. A.~. COOK, Academic Press, 1962, p.p. 271 -302." for the details of the malting method. In addition to the essential stages of steeping and germination which are closely related to the present invention, additional stages before, between or after these two stages such as drying, removal of malt rootlets and other treatment may be conducted.
The present invention can also be applied to the processes for produc-tion of germinated products of other grain ~such as rice, beans and Indian corn), other seeds, and starchy tubers such as various potatoes.

2. Abscisic compounds .
Abscisic compounds which are abscisic acid and its Eunctional deriva-tives are known plant hormones, the details of which are given in, for example, ANNUAL REVIEW OF PLANT PHYSIOLOGY Vol. 25, p 259-307 (lg74) published by ANNUAL
REVIEWS INC. Palo Alto, California, U. S. A.
By the functional derivatives of abscisic acid are meant the deriva-tives with respect to the carboxylic acid moiety of abscisic acid, especially water-soluble salts and esters. Among the salts are included the salts thereof which are allowable in view of food hygiene such as the alkali metal salts, alkaline earth metal salts and ammonium salts thereof. Included among the esters are the esters with lower alcohols and especially monohydric lower alkanols having 1 to about 4 carbon atoms as well as the esters with sugars, lower alkyl (Cl-C4) esters being preferable.
Other functional derivatives of abscisic acid to be used in the pre-sent invention are the derivatives wi~h respect to the moieties other than the carboxylic acid moiety. Such derivatives include, for example, xanthoxic acid, hydroxyabscisic acid, phaseic acid, and dihydrophaseic acid. Moreover, xanthoxins are other functional deriva~ives of abscisic acid which contain both an aldehyde moiety instead of the carboxylic acid moiety and a 6-membered ring substituent moiety. The acid and esters thereof can also be used in the present invention.

` 1-The amount of abscisic acid or a derivative thereof to be used in the present invention is given below.

3. Gibberellic compounds Gibberellic compounds which are gibberellin and its functional deriva-tives, W]liC}I can be used in combina-tion with the abscisic compounds in accord-ance with the present invention, are also lcnown plant hormones.
As the gibberellin are known a compo~md called GA3 as well as com-pounds called GAl, GA4~ GA7 and GA9. It is also known that the gibberellin used actually in malt-production industries consists essentially of a mixture of these gibberellin compounds [J. Inst. Brew. ~0, 13-30 ~1974)]. The term "gibberellin" used herein encompasses both any single compound ~e.g. GAl~and any mixture thereof. The term "the functional ... ..
., derivatives" of gibberellin encompasses the saLts and esters thereof, as described in the corresponding paragraph for abscisic acid~

4~ Treatment o ra ~ malt The abscisic compound is applied to grain for malt either (i) in khe steeping process of the grain, viz.
when the grain is in the water~absorption stage~ that is, in the period from the start of the step of contacting the grain with water, ordinarily by steeping in water or sprinkling with wa~er,to the point of ~ime just before the grain begins to germinate with absorption of a required amount of water, which may be about 37 to about 46% of water content in the grain, or (ii) in the germination process, viz. when the grain is in ~he germination stage, or in the stage of from the start to the termination o~ genmination. In other words, the abscisic compound is applied to grain from the stage of starting the water-absorption by contacting the grain with water to the stage of terminating the germination.
More specifically, the abscisic compound can be _applied to the grain for malt, by dissolving the abscisic compound in the water in which the grain is to be steeped, or by sprinkling an aqueous solution of the abscisic compound onto the grain and especially the ~5 grain which has absorbed water by steeping.
The quantity of the abscisic compound to be used can be an optional value as long as it is reasonable.

More specifically, the quantity to be used is approxi-mately ln the range of 0.001 to 100 ppm, preferably 0.01 to 10 ppm and ordinarily 0.1 to 1 ppm on the basis of the weight of cereal grain (before steeping), in the case of sprinkling the ~queous solution onto cereal grain which has absorbed water by immersion. When the abscisic com-pound is applied by other methods, the amount thereof to be taken up in the cereal grain can be selected to fall witbin the above~defined range.
The quantity of gibberellic compound, when it is used in combination with the abscisic compound, can be an optional value as long as it is reasonable. More speci-fically, in the case of sprinkling an aqueous solution of these compounds onto cereal grain which has absorbed water through immersion, the quantity is approximately in the range of 0~001 to 10 ppm and preferably 0.01 to 1 ppm on the basis of the weight of the cereal grain (before water-absorption~. When it is applied by other methods, the quantity thereof to be taken up in the cereal grain can be 2Q selected to fall withîn the above described ran~e.
After application of the abscisic compound to the grain for malt, it is necessary to keep the contact of the abscisic compound ~-ith the grain until the effect of the physiological activity of the abscisic compound on the grain is exhibited as expected. Also in this respect, it is preferclble to apply the abscisic compound to the grain before the stage of germination~ When the abscisic g_ compound is applied near the termination o. the germination stage, it is necessary to allow the treated grain to stand under the conditions or about 12 hours after the termina-tion of the germination stage.,

5. Examples of Experiments Example l One (l) kg of malting barley (New Golden variety) -rU~n~ in Yamanashi Prefecture, Japan~ was steeped in water at 15C fox 6 hours and then drained for 6 hours.
This operation was repeated several times until the water content of the barley reached 43%, and then the barley was drained for 2 hours. An aqueous solution of abscisic acid having a concentration of 1 x 10 3% or l x 10 2% (g/v) was sprinkled onto the treated barley so that the quantity of abscisic acid sprinkled corresponded to 0.1 or 1 mg. The barley thus treated was subjected to germination for 6 full days in an experimental malting apparatus and then was dried in a kiln to produce malt. The analytical data of the resulting malt are shown in Table l. In the suitable range of abscisic acid concentrationsp the yield of malt was increased in comparison with the control, the decomposi-tion of proteins was inhibited, and the color of wort was lowered. Thus, by the application of abscisic acid to the process for production of barley malt in the case where barley having a germination force strong enough to lower the yield of malt or barley having protein-decomposition power strong enough to deepen the color of wort is used, the yield of malt can be increased~ and th~ decomposi-tion of proteins and the color of wort can be controlled at will.

Table 1 S
~ ... ..
Abscisic acid added \Control ________~ _ *
\0.1 ppm 1 ppm ~ . ..
Yield of malt (d.m., %) 1 90.7 91.0 91.6 ~ .. ___ Content of extract (d.mO, %)79.4 78.8 77.8 - ~ _ _ Formol nitrogen (mg/100 ml 29.6 28.0 22.2 _ A _ . _ _ _~, _ ~ _ _ __ __ ____ _ _ _ _ _ .
Kolbach Index (%) 47.6 44.2 37.1 .__ __ _ .
Color of wort (EBC unit) 4.7 4.4 3.4 ... __ . ._ ...... __ . . _ _ ~ . _ Diastatic power (W.R.) 196 201 170 _ , ,.......... . ____ ~ _ ApparPnt attenuation lim.it 82.2 82.5 81.0 of wort (%) ~ _ .__.
Note: * mg/kg barley (as .is) Example 2 .
As in Example 1, a mixture of abscisic acid and GA3 (O.1 mg per kg of barley) was sprinkled onto barley after ~5 steeping in water to prepare malt~ Analytical data of the resulting malt are shown in Table 2O In the sui~abla range of abscisic acid concentrations, the yield of malt and the content o~ extract were increased, and the decomposi-tion of proteins was satisfactorily controlled. Malt of very good quality, wherein the conventional marked increase in the color of wort caused by addition of GA3 was innibited, was obtained. The malt had high diastatic power and the apparent attenuation limit of wort was normal.

Table 2 ~ ,. ~ ,...... ~ . . . , Quantity of abscisic acid adde~ (ppm*) 0 0 0.1 ._ . .__ __ , Quanti-ty of GA3 added Q 0.1 0.1 O.1 . _ ~ ,. _ .

15Yield of malt (d.m.,~) 90.790.8 91.2 91.2 ~ . . . . __ . .
Extract content (d.mO,~) 79.480.2 80.0 80.0 , __ ....... . ~ . . __ _ , Formol r~tr 29.6 33.5 31.8 25.4 . _ . . .
20Kolbach Index (~) 47.6 51.5 49.7 40.7 . . ~_.,.... - _ . __n Color of wort (EBC unit) 4.7 6.9 5~3 4.1 __ _ ~ _ Diastatic power ( WoK~ ) 196 206 211 213 _ . ___ ._ n ~_ ~ _ . ___ ~ _ __ ____ _ _ .. __ Apparent attenuation 82.2 81.6 82.4 83.1 limit of wort ( % ) _ __ .
_ _ . _ .
Note: * mg/kg barley ~as is) Example 3 As in Example 1, 0.1 ppm of GA3 was sprinkled onto barley arter steeping in water (10 ml of an aqueous solution of 1 x 10 3~ ~g/v) per kg of barley), and the barley thus treated was subjected to germination for 24 hours in an experimental malting apparatus. Then, abscisic acid was sprinkled as described in Example 1 and the germination operation was continued to produce malt. Analytical data of the resulting malt are shown in Table 3. In the suitable concentration range of abscisic acid, malt of a very good quality was obtained as in Example ?, although the effect of GA3 was observed to be stronger than ~hat in the case of ~xample 2.

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Example 4 Methyl abscisate and GA3 were sprinkled as in Example 7 onto malting barley (New Golden variety), which had been s'f~e~
in water to have a water content of 42~ and then drained for 2 hours in the same manner as in Example 1, to produce malt. Analytical data of the resulting malt are shown in Table 4. The effect of methyl abscisate was cLearly exhibited. As in the case of abscisic acid (Example 2), by the addition of a suitable quantity of methyl abscisate, the quality of malt could be controlled at will.

Tabl 4 . .. ~ ,, .
Quantity of methyl absci- 0 O
sate added (ppm*) 0.1 _ _ __ .. _ __ _ Quantlty of GA3 added 0 0.1 0.1 0.1 Yield of malt (d.m., ~) 91vl 9102 91.2 91.7 ._ _ ~ _ __ . ,.
Extract content ¦ 79.1 79.9 79.8 79.0 ~ . I _. - ___ Formol nitrogen ¦ 24.1 29.6 26.5 22.0 .~ ~ ~ _ _ __ ___ Kolbach Index (%) ¦44.849.0 47.0 41.5 ~ ~ _ . _ Color of wort (EB~ unit) ¦ 3.1 ¦ 4.9 3.9 3.3 Diastatlc po~er (W.K.) ~ 229 227 232 211 ~pparent attenuatlon limit¦ 83 o83.3 83.4 81.5 Note: * mg/kg barley (as is) Example 5 Abscisic acid and GA3 were sprinkled as in Example 2 onto malting barley (New Golden variety) which had been steeped in water to have a water content of 41% and then drained for 2 hours in t~e same manner as in Example 1. The barley thus treated w~as subjected to germination in an experimental malting apparatus, sampled on the 3rd, 4th and 5th full day~, and dried in a kiln to produce malt. Analytical data of the resulting m~lt are shown in Table 5. When GA3 alone w~s used, the Kolbach Index and color of wort were abnormally increased, although tne period for germination collld be shortened by 1 or 2 days. On thé other hand, when a suitable concentration range of abscisic acid was used iIl combination with GA3, malt of good quality, in which the increase in the Kolbach Index and the wort color was suitably controlled, could be obtained in a higher yield in a shorter germina-tion period in comparison with control samples.

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A method for production of malt which comprises subjecting cereal grain for malt to steeping and germination, wherein an abscisic compound which is abscisic acid and/or functional derivative thereof is applied to the cereal grain which is in the steeping process or the germination process.

2. The method for production of malt according to claim 1, in which the abscisic compound is abscisic acid.

3. The method for production of malt according to claim 1, in which the abscisic compound is a water soluble salt of abscisic acid.

4. The method of production of malt according to claim 1, in which the abscisic compound is a lower alkylester of abscisic acid.

5. The method for production of malt according to claim 1, in which the quantity of the abscisic compound is in the range of 0.001 to 100 ppm on the basis of the weight of the cereal grain for malt before steeping.

6. The method for production of malt according to claim 1, in which a gibberellic compound which is gibberellin and/or functional derivative thereof is further applied to the cereal grain for malt which is in the steeping process or the germination process.

7. The method for production of malt according to claim 6, in which the gibberellic compound is gibberellin.

8. The method for production of malt according to claim 6, in which the gibberellin is GA3.

9. The method for production of malt according to claim 6, in which the quantity of the gibberellic compound is in the range of 0.001 to 10 ppm on the basis of the weight of the cereal grain for malt before steeping.

10. The method according to claim 6, in which the quantity of the abscisic compound is in the range of 0.001 to 100 ppm on the basis of the weight of the cereal grain for malt before steeping.

11. The method according to claim 1 or 6, in which the amount of abscisic acid and/or a functional derivative thereof is from 0.01 to 10 ppm on the basis of the weight of the cereal grain before steeping.

12. The method according to claim 1 or 6, in which the amount of abscisic acid and/or a functional derivative thereof is from 0.1 to 1 ppm on the basis of the weight of the cereal grain before steeping.

13. The method according to claim 6, 7 or 8, in which the abscisic compound is abscisic acid.

14. The method according to claim 6, 7 or 8, in which the abscisic compound is a water soluble salt of abscisic acid.

15. The method according to claim 6, 7 or 8, in which the abscisic com-pound is a lower alkylester of abscisic acid.