JP2005245263A - Method for evaluating malt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To discover a relation between the nonenal potential of malting and the condition of the malting because the improvement of flavor stability of a malt alcoholic beverage is an anxiety term over a long time in a business world because it is generally known that the flavor of the malt alcoholic beverage using the malt as a raw material such as beer and a sparkling liquor is deteriorated by a preservation condition. <P>SOLUTION: The method for evaluating the malt used for the production of the malt alcoholic beverage comprises preparing wort from the malt in a small scale under a condition under which oxidation of a lipid and a fatty acid is suppressed, and using the nonenal potential of the walt as an index. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a method for evaluating malt, which is a raw material for producing a malt alcoholic beverage.

It is generally known that malt alcoholic beverages made from malt such as beer and happoshu deteriorate in flavor due to storage conditions, and improving the flavor stability of malt alcoholic beverages has long been a concern in the industry It is a problem. As an index for evaluating the flavor stability of a malt alcoholic beverage, there is known a method for measuring the trans-2-nonenal amount of a malt alcoholic beverage stored at a constant temperature and time. When this value is high, it becomes a malt alcoholic beverage with an unfavorable flavor as expressed, for example, as a cardboard odor.

Trans-2-nonenal is produced via a precursor by linoleic acid in malt or a lipid containing linoleic acid in the side chain being enzymatically oxidized or autoxidized by lipoxygenase in malt. Accordingly, the influence of malt quality on the flavor stability of malt alcoholic beverages is great, and the inventors have developed a method for quantitatively evaluating this. A method that uses the nonal potential of wort prepared from malt at a small scale under certain conditions as an index. This analytical index is called malt nonenal potential and has a high correlation with the amount of trans-2-nonenal in stored product beer. (See Patent Document 1).

Note that the nonenal potential is the amount of trans-2-nonenal when the wort adjusted to a certain pH is boiled for a certain time, and is useful as an index of the amount of trans-2-nonenal in the stored product beer. Has been reported (see Non-Patent Document 1). Although trans-2-nonenal and its precursor are mixed in normal wort, it is thought that the trans-2-nonenal precursor is converted to trans-2-nonenal by the above pH adjustment and boiling treatment. Yes.

It is considered that there are mainly two processes in which linoleic acid or a lipid containing linoleic acid in the side chain is oxidized to produce a trans-2-nonenal precursor. One is a malting process for producing malt from barley, and the other is a charging process for producing wort from malt. Since both involve enzymatic oxidation by malt lipoxygenase, malt quality affects the production of trans-2-nonenal precursors in both processes. Therefore, the malt nonenal potential analysis method evaluates the quality of the malt by analyzing the wort that has undergone the small-scale wort preparation (preparation) process as described above. FIG. 1 shows an image diagram of the production process of trans-2-nonenal and its precursor and the evaluation range of malt nonenal potential.

In recent beer factories, technology to reduce the trans-2-nonenal precursor produced during the charging process may be implemented by using an antioxidative charging method such as the use of degassed water. Has a certain effect. However, on the other hand, it is impossible to reduce trans-2-nonenal and its precursor produced by the malting process by antioxidant charging. In order to reduce trans-2-nonenal and its precursors produced by the malting process, it has become necessary and important to improve the malting process. Was not developed.
JP 2002-253196 A Bee. W. Dr. BW Drost, 5 others, “Flavor Stability”, Journal of the American Society of Brewing Chemists, 1990, Vol. 48, No. 4, p. 124-131

As a result of intensive research aimed at developing an index for quantitatively grasping trans-2-nonenal and its precursor produced by the malting process, the present inventors have developed malt under conditions that inhibit lipid or fatty acid oxidation. The present invention was completed by extracting the trans-2-nonenal and its precursor which malt has by preparing wort from a small scale and using the nonal potential of the wort as an index. Hereinafter, the index of the malt evaluation method according to the present invention is referred to as malting nonenal potential. FIG. 1 shows an image diagram of the relationship between the production process of trans-2-nonenal and its precursor, the evaluation range of the malting nonenal potential, and the evaluation range of the malt nonenal potential.

The first object of the present invention is to investigate the malting non-nal potential of the malt produced at each wheat mill.For example, if the malt non-nal potential is equivalent, but the malting non-nal potential is different, By giving priority to the purchase from a factory that produces malt with a low nonenal potential, it is more effective in improving the flavor stability of malt alcoholic beverages by antioxidant charging. The second object of the present invention is to find the relationship between the malting potential and the malting conditions, and to take appropriate improvement measures for factories that produce malt with a high malting potential based on this knowledge. By improving the flavor stability of the malt alcoholic beverage.

The first invention of the present invention that solves the above-mentioned problems is characterized in that wort is prepared from malt on a small scale under the condition where oxidation of lipids and fatty acids is suppressed, and the nonenal potential of the wort is used as an index. The present invention relates to a method for evaluating malt used for producing a malt alcoholic beverage.

The second aspect of the present invention is that malt according to the first aspect of the present invention is implemented in a low oxygen concentration atmosphere using water with a low dissolved oxygen concentration as a condition for inhibiting lipid and fatty acid oxidation. It relates to the evaluation method.

The third feature of the present invention is that the conditions for suppressing the oxidation of lipids and fatty acids are that the dissolved oxygen concentration of the water used is at most 0.5 ppm, and the oxygen concentration in the atmosphere is at most 1%. The present invention relates to a malt evaluation method according to the first aspect of the invention.

The fourth aspect of the present invention is characterized in that the dissolved oxygen concentration of the water used is at most 0.05 ppm and the oxygen concentration in the atmosphere is at most 0.1% as a condition for suppressing lipid and fatty acid oxidation. The present invention relates to the malt evaluation method according to the first aspect of the present invention.

5th of this invention is related with the malt evaluation method of any one of 1st-4th of this invention which the preparation process of wort consists of the process of the following (1)-(5).
(1) A step of pulverizing malt using a disk-type pulverizer or a roller-type pulverizer to set the disk interval or roller interval to 0.1 or more and less than 0.8 mm, (2) 1 part by weight of malt and the temperature is 40 A step of mixing 4 parts by weight or more and less than 6 parts by weight of hot water having a hardness of 5 ° C. or more and less than 60 ° C. and a hardness of 5 ° dH or more but less than 15 ° dH, (3) a mixture of malt and warm water at a temperature of 40 ° C. or more and less than 60 ° C. (4) a step of holding the mixture at a temperature of 60 ° C. or more and less than 75 ° C. for 30 minutes or more to less than 60 minutes, and (5) a step of holding the mixture at 75 ° C. or more for 1 minute. The process of holding above.

A sixth aspect of the present invention is a book in which malt is pulverized by setting the disk interval or roller interval to 0.2 mm, and 1 part by weight of malt is mixed with 5 parts by weight of hot water having a temperature of 50 ° C. and a hardness of 10 ° dH. The present invention relates to a malt evaluation method according to the fifth aspect of the invention.

As described above, the present invention relates to a malt evaluation method for quantitatively grasping trans-2-nonenal produced by the malting process and its precursor, and the effects exhibited by the present invention are as follows.
(1) In the conventional malt nonenal potential evaluation method, even if the malt quality is the same, cases where the malt nonenal potential is different have been clarified. In this case, it has become possible to more effectively improve the flavor stability by antioxidant charging at a beer factory by preferentially purchasing malt with a low potential for malting.
(2) By discovering the relationship between the malting potential and the malting conditions, and taking appropriate improvements to factories that produce malt with high malting potential based on this knowledge, It became possible to improve flavor stability.

The present invention will be described in detail below. The present invention is characterized in that trans-2-nonenal and precursors of malt are extracted by inhibiting wort oxidation of lipids and fatty acids, and the potential of the resulting wort is used as an index. And

As a method of suppressing lipid and fatty acid oxidation, the dissolved oxygen concentration of water used for wort preparation is reduced, and the oxygen concentration in the atmosphere is reduced and maintained during wort preparation. In this case, the dissolved oxygen concentration of the used water is at most 0.5 ppm, the oxygen concentration in the atmosphere is at most 1%, preferably the dissolved oxygen concentration of the used water is at most 0.05 ppm, and the oxygen concentration in the atmosphere is high. In both cases, 0.1% is desirable.

Other wort preparation conditions are not limited, but the analysis method of malt nonenal potential is optimized to increase the value of nonenal potential, so trans-2-nonenal and its precursor in malt can be efficiently used. In order to extract, it is desirable to carry out according to this analysis method. Details of the conditions will be described below.

Regarding the pulverization conditions, the type of pulverizer is not particularly limited. In the case of a disc mill or roller mill, the disc interval or roller interval is preferably 0.1 or more and less than 0.8 mm, and most preferably the disc interval or roller interval is 0.2 mm.

As for the conditions of the temperature and amount of warm water mixed in the malt, the temperature of the warm water is desirably 40 ° C. or more and less than 60 ° C., more desirably 50 ° C. Furthermore, after mixing warm water with the pulverized malt, in order to maintain the same temperature, the mixture of malt and warm water is kept warm for 10 minutes or more and less than 70 minutes, preferably about 1 hour. Further, the amount of warm water to be mixed is desirably 4 parts by weight or more and less than 6 parts by weight with respect to 1 part by weight of malt. More preferably, the added warm water is 5 parts by weight. The hardness of the hot water is preferably 5 ° dH or more and less than 15 ° dH, and more preferably 10 ° dH.

An example of the temperature adjustment diagram conditions of wort will be described. First, the mixture of the malt and warm water is held at a temperature of 40 ° C. or more and less than 60 ° C. for 10 minutes or more and less than 70 minutes. Next, the temperature is raised to around 65 ° C. over 10 minutes. The miche raised to about 65 ° C. is held at a temperature of 60 ° C. or higher and lower than 75 ° C. for 30 minutes or longer and less than 60 minutes. Next, the temperature is raised to around 76 ° C. over 11 minutes and held at 75 ° C. or higher for 1 minute or longer.

The wort is obtained by removing the malt pulverized product from the prepared mash, and its nonenal potential is measured.

Next, the malt analysis method of the present invention will be described with reference to test examples.
Test example 1
This test was conducted to examine the dissolved oxygen concentration of water used for wort preparation in the malt analysis method of the present invention. The relationship between the dissolved oxygen concentration of the water used and the nonenal potential was investigated.

(1) Preparation of sample The pulverized malt was pulverized by using a disc mill manufactured by Buehler, with the disc interval set to 0.2 mm. Water used for wort preparation was prepared by adding gypsum to distilled water so that the hardness was 10 dH °.

(2) Test method The test was performed as follows. An anaerobic environment test device (COY LABORATORY PRODUCTS) was prepared. This is an experimental facility where the space above the experimental table is covered with a vinyl film and the inside is sealed, and can be replaced with other gases and work can be performed from the outside. An automatic saccharification device (Unitech Corp., UT-P100TB) for preparing small-scale wort was installed in the anaerobic environment test device. After putting the malt into the anaerobic environment test device, repeatedly exhausting part of the internal gas and filling with nitrogen gas, and reducing the oxygen concentration while measuring with an oximeter (Riken Kikai Co., Ltd., OX-94) The oxygen concentration was adjusted.

The water used for wort preparation was boiled to reduce the dissolved oxygen concentration, and then immediately put in an anaerobic glove adjusted to the target oxygen concentration. 300 ml of the water was added to a 500 ml stainless steel beaker installed in an automatic saccharification apparatus, and the mixture was stirred for 15 minutes while being kept at 50 ° C. to equilibrate with oxygen in the atmosphere. Before mixing with the pulverized malt, the dissolved oxygen concentration was confirmed by a dissolved oxygen meter (model 3600 analyzer, manufactured by Orbis Fair Laboratories).

60 g of crushed malt was added to 300 ml of water stabilized at a constant dissolved oxygen concentration, held at 50 ° C. for 60 minutes, and then heated to 65 ° C. over 10 minutes. The miche raised to 65 ° C. was held for 40 minutes and then heated to 76 ° C. over 11 minutes. Finally, after holding at 76 ° C. or higher for 5 minutes, the temperature was lowered to 15 ° C. or higher and lower than 30 ° C. over 5 minutes or longer and less than 10 minutes. The obtained miche was taken out from the anaerobic environment test apparatus, centrifuged with a centrifuge (KUBOTA 7930, manufactured by Kubota) (7500 rpm, 15 minutes), and the supernatant was filtered with a filter paper (Advantech, No. 2). A wort was obtained.

2% phosphoric acid was added to the prepared wort to adjust the pH to 4.0, followed by boiling for 2 hours. After centrifugation, derivatization was performed by adding PFBHA (0- (2,3,4,6-pentafluorobenzyl) hydroxylamine hydrochloride) to 10 ml of clear wort. Sep-Pak
Trans-2-nonenal extracted by solid phase extraction using C18 Light (manufactured by Nihon Waters) was quantified by gas chromatography with a mass meter (HP6890 / MSD, manufactured by Yokogawa Analytical Systems). For the solid phase extraction, an automatic solid phase extraction apparatus (EXMULTI, manufactured by MORITEX) that can automatically process a large number of samples was used. After washing the column with 25 ml of distilled water at a flow rate of 10 ml / min, 10 ml of derivatized wort was injected at a flow rate of 5 ml / min and adsorbed on the column. 25 ml of distilled water was removed at a flow rate of 7 ml / min to remove water-soluble unnecessary substances remaining in the column, and nitrogen was injected for 5 minutes to evaporate the water in the column. Thereafter, the substance adsorbed on the column was eluted with 1 ml of hexane at a flow rate of 1 ml / min.

(3) Test result In Table 1, the measurement result of the dissolved oxygen concentration of wort preparation use water is shown with respect to the oxygen concentration in the adjusted anaerobic environment test apparatus. Furthermore, the graph of FIG. 2 shows the relationship between the dissolved oxygen concentration of wort preparation and use water and the nonal potential of wort. The malt nonenal potential of the malt used in this test was 12.0 ppb in a state where the dissolved oxygen concentration was 5 ppm (oxygen concentration 20.9% in the atmosphere) at the time of normal malt nonenal potential measurement. As is apparent from FIG. 2, the wort preparation water decreases with decreasing dissolved oxygen concentration, and the wort preparation water has a non-potential of around 4.6 ppb when the dissolved oxygen concentration is less than 0.5 ppm. However, it was 5.9 ppb at a dissolved oxygen concentration of 1.0 ppm, and the influence of the oxidation reaction during charging was recognized. Therefore, it became clear that the dissolved oxygen concentration of the wort preparation use water is preferably 0.5 ppm or less. The oxygen concentration in the atmosphere for maintaining the dissolved oxygen concentration was about 1%. Furthermore, even when the dissolved oxygen concentration was 0.5 ppm or less, the nonenal potential was in a very small but decreasing tendency. Therefore, the dissolved oxygen concentration was most desirably 0.05 ppm or less. Since the oxygen concentration in the atmosphere for maintaining the dissolved oxygen concentration exceeded the measuring range of the instrument, the exact numerical value was unknown, but was 0.1% or less.

Test example 2
This test was performed to confirm that the dissolved oxygen concentration condition defined in Test Example 1 suppresses the oxidation of fatty acids during wort preparation. Addition of linoleic acid suspension during the preparation of wort for measuring malt nonenal potential increases the nonenal potential. This is because the added linoleic acid is oxidized by enzymatic oxidation by lipoxygenase or auto-oxidation during the wort preparation and converted into a trans-2-nonenal precursor. If the dissolved oxygen concentration condition defined in Test Example 1 is a condition that suppresses oxidation of lipids and fatty acids during wort preparation, the increase in nonenal potential even when linoleic acid suspension is added during wort preparation Thought that was not allowed.

(1) Preparation of linoleic acid suspension After adding 5 ml of 0.5 M borate buffer (pH 9.0) and 0.25 ml of Tween 20 to a 10 ml volumetric flask and mixing, 0.25 ml of linoleic acid, 1 N water 0.65 ml of sodium oxide solution was added, and sonication was performed until it became clear, and then distilled water was added to make a total volume of 10 ml to obtain a linoleic acid suspension.

(2) Test method The linoleic acid suspension was added at the start of wort preparation, and the resulting nonal potential of the wort was measured. The conditions for normal malt nonenal potential analysis were compared with the conditions for analyzing malt nonenal potential with a dissolved oxygen concentration of 0.04 ppm. Three worts were prepared for each level. The analysis method was the same as the test method (2) of Test Example 1.

(3) Test results Table 2 shows the results of the addition amount of linoleic acid suspension and the nonnal potential of wort. As is apparent from Table 2, in the case of normal malt nonenal potential analysis conditions, the nonenal potential tended to increase with the addition of linoleic acid suspension. On the other hand, in the case where the dissolved oxygen concentration of the feed water used was 0.04 ppm, no increase in nonenal potential was observed even when the linoleic acid suspension was added. From this result, it became clear that the dissolved oxygen concentration condition of the feed water used in Test Example 1 suppresses the oxidation of fatty acids during wort preparation.
EXAMPLES Next, although an Example demonstrates this invention still in detail, this invention is not limited to a following example.

FIG. 3 shows the results of evaluating various malts using the present malt evaluation method (the malt nonenal potential evaluation method) and the malt nonenal potential evaluation method, and stratified for each malting factory. It was clarified that the average value of the barley nonenal potential varies depending on the barley factory. For example, when the malts of the F, G, and H factories were compared, even if the malt nonenal potential was equivalent, only the malt of the H factories had a very high malt potential. When carrying out antioxidant preparation in a beer factory, it is thought that the effect of improving flavor stability is greater when the F and G factory malt is selectively used. Such a difference in malt quality cannot be discriminated by the conventional malt nonenal potential evaluation method, and was first clarified by the present malt evaluation method.
Moreover, F, G, and H malt have the same barley production area and variety, but different barley mills. This suggests that the malting conditions differ between factories, and the potential for malting nonenal may be affected by the malting conditions.

In order to investigate the influence of the wheat-making conditions on the wheat-making nonenal potential, a test was carried out using a small-scale wheat-making test apparatus (manufactured by Phoenix) having a barley usage amount of 500 g per container.

(Test 1) As the wheat-making conditions, the influence of moisture during the germination process was investigated. The results are shown in Table 3. The higher the moisture during germination, the higher the malting potential and the higher the malting potential.

(Test 2) The influence of moisture during the germination process was investigated in more detail. In the germination process, watering for supplying water may be performed. In this test, the timing of watering was examined. The results are shown in Table 4. Two levels were carried out: the initial sprinkling level that sprinkled before the second day of germination and the middle sprinkling level that sprinkled between the second and fourth days of germination. As a result, it was found that the watering potential in the middle stage of germination was higher in the malting noneal potential, and the malting nonenal potential was similarly high.

As described above, it is possible to investigate the influence of the malting conditions on the malting nonenal potential using the present malt evaluation method. In this example, the moisture content during germination and the timing of water supply are affected. I found it. Based on this knowledge, it is possible to improve the flavor stability of malt alcoholic beverages by applying appropriate improvement measures to a malting factory that produces malt with a high malting potential.

FIG. 1 shows an image of the production process of trans-2-nonenal and its precursor, and the evaluation range of malt nonenal potential and malt nonenal potential. FIG. 2 shows the test results of the dissolved oxygen concentration of the feed water used and the resulting nonal potential of the wort. FIG. 3 shows the average value of the malting potential and malt nonenal potential between the wheat mills. The number in parentheses is the number of samples analyzed.

Claims (6)

A malt evaluation method used for the production of a malt alcoholic beverage characterized in that wort is prepared from malt on a small scale under conditions that inhibit oxidation of lipids or fatty acids, and the nonenal potential of the wort is used as an index. The malt evaluation method according to claim 1, wherein the malt evaluation method is performed in a low oxygen concentration atmosphere using water having a low dissolved oxygen concentration as a condition for suppressing lipid or fatty acid oxidation. The malt evaluation method according to claim 1, characterized in that the dissolved oxygen concentration of the water used is at most 0.5 ppm and the oxygen concentration in the atmosphere is at most 1% as a condition for inhibiting lipid or fatty acid oxidation. . 2. The malt according to claim 1, wherein the conditions for inhibiting the oxidation of lipids or fatty acids are a dissolved oxygen concentration of at most 0.05 ppm and an oxygen concentration in the atmosphere of at most 0.1%. Evaluation method. The method for evaluating malt according to any one of claims 1 to 4, wherein the wort preparation step comprises the following steps (1) to (5).
(1) A step of pulverizing malt using a disk-type pulverizer or a roller-type pulverizer to set the roller interval or the disk interval to 0.1 or more and less than 0.8 mm, (2) 1 part by weight of malt and the temperature is 40 A step of mixing 4 parts by weight or more and less than 6 parts by weight of hot water having a hardness of 5 ° C. or more and less than 60 ° C. and a hardness of 5 ° dH or more but less than 15 ° dH, (3) a mixture of malt and warm water at a temperature of 40 ° C. or more and less than 60 ° C. (4) a step of holding the mixture at a temperature of 60 ° C. or more and less than 75 ° C. for 30 minutes or more to less than 60 minutes, and (5) a step of holding the mixture at 75 ° C. or more for 1 minute. The process of holding above. The malt evaluation according to claim 5, wherein the malt is pulverized by setting the roller interval or the disc interval to 0.2 mm, and 1 part by weight of the malt is mixed with 5 parts by weight of hot water having a temperature of 50 ° C and a hardness of 10 ° dH. Method.