Mailing loss prediction method based on beer wheat quality

Abstract

The invention provides a beer malting loss prediction method based on beer malting quality, and belongs to the technical field of beer malting. The malting loss prediction method based on the beer wheat quality, provided by the invention, is calculated through the following formula: malting loss% = amylose loss ratio% + amylopectin loss ratio% + prolamin loss ratio% + hemicellulose loss ratio%, wherein the amylose loss ratio (%) is equal to (0.528 * amylose content-6.1986) * 100%; the amylopectin loss ratio (%) is equal to (0.2564 * amylopectin content minus 3.4823) * 100%; the prolamin loss ratio (%) is equal to (0.2818 * prolamin content minus 0.1166) * 100%; the hemicellulose loss ratio (%) is equal to (0.3004 * hemicellulose content minus 1.5879) * 100%. The method can predict the malting loss after malting by acquiring a small sample amount of barley and detecting the physicochemical indexes of the barley, shortens the time, has guiding significance for purchasing the barley, and provides technical support for improving the economic benefit of a malt factory and selecting the beer wheat with low malting loss.

Description

Technical Field

[0001] The invention belongs to the technical field of beer malting, and in particular relates to a method for predicting malting loss based on beer malt quality. Background Art

[0002] Malt is prepared from barley through soaking, germination, drying and root removal. Malting loss refers to the percentage of dry matter loss in malt after soaking, germination, drying and root removal. The quality of barley can be judged by measuring malting loss. Among them, malting loss includes the following aspects: soaking loss, respiratory loss and root loss.

[0003] Steeping loss refers to the loss of dry matter content during the soaking stage due to dust removal, partial filtration of raw materials and metabolism of grains (release of carbon dioxide and ethanol). The presence of microorganisms may promote the dissolution of grain husks. In addition, husk fragments and floating materials are mostly removed during the soaking process.

[0004] Respiratory loss usually refers to the loss caused by the consumption of dry matter by respiration during the soaking, germination and drying processes. Respiratory loss mainly comes from the formation of carbon dioxide (a small amount of other volatile metabolites). The degree of respiration is different in different stages. During the soaking stage, the respiration gradually increases with the germination of barley. The respiration intensity and heat release of germination are gradually changing. The respiration intensity and heat release are not only related to the different stages of the malt, but also to the kilning conditions. Root bud loss refers to the process after the soaking is completed. During the germination stage, large molecules are dissolved, including starch, protein, and glucan, which are decomposed into small molecules of sugar and amino acids. The small molecules of sugar and amino acids are synthesized into root buds through root bud anabolism. The loss is calculated by collecting the mass of the root buds after the roots are removed after kilning. For barley malt, this part of the loss mainly comes from the removal of the roots.

[0005] Malting loss is crucial to the economic performance of beer barley. The higher the malting loss, the worse the economic performance. For malt factories and maltsters, it is another indicator that needs to be considered in addition to malt quality. However, malting loss usually needs to be calculated after malting by weighing the difference in malt quality before and after malting, and then comprehensively considering the change in moisture content to calculate the malting loss of the entire malting process, which has a lag. Summary of the invention

[0006] The present invention provides a method for predicting malting loss based on malting barley quality. The method obtains a small sample amount of barley and detects the physical and chemical indicators of the barley to predict the malting loss after the malting is completed. The prediction method is fast and highly accurate, has guiding significance for the purchase of barley, and provides technical support for improving the economic benefits of malt factories and selecting malting barley with low malting losses.

[0007] In order to achieve the above object, the present invention provides a method for predicting malting loss based on malting barley quality, which is calculated by the following formula:

[0008] Malting loss % = amylose loss % + amylopectin loss % + alcohol-soluble protein loss % + hemicellulose loss %; where:

[0009] Amylose loss percentage = (0.528*amylose content-6.1986)*100%;

[0010] Amylopectin loss percentage = (0.2564* amylopectin content-3.4823)*100%;

[0011] Prolamin loss percentage = (0.2818*prolamin content-0.1166)*100%;

[0012] Hemicellulose loss percentage = (0.3004*hemicellulose content-1.5879)*100%.

[0013] Preferably, the content of amylose=[(△A+0.0073)÷1.2693×V1]÷(W×V1÷V)=7.878×(△A+0.0073)÷W, wherein:

[0014] The unit of amylose content is mg / g, V—total volume of sample extract, 10 mL; V1—volume of sample taken during measurement, 0.05 mL; W—sample mass, g; △A=A 测定 -A 空白 .

[0015] Preferably, the amylopectin content = [(ΔA-0.0416) ÷ 0.9799 × V1] ÷ (W × V1 ÷ V) = 10.21 × (ΔA-0.041)) ÷ W, wherein:

[0016] The unit of amylopectin content is mg / g dry weight, V—total volume of sample extract, 10 mL; V1—volume of sample taken during measurement, 0.25 mL; W—sample mass, g; △A=A 测定 -A 空白 .

[0017] Preferably, hemicellulose content = (ΔA-0.0306) ÷ 0.3968 ÷ (W ÷ V 样总 )=1.01×(△A-0.0306)÷W, where:

[0018] The unit of hemicellulose content is mg / g dry weight, W is the sample mass, g; V is the sample mass, g. 样总 - Add extraction liquid, 0.4mL; △A = A 测定 -A空白 .

[0019] Compared with the prior art, the advantages and positive effects of the present invention are:

[0020] 1. The present invention obtains a small sample of barley and detects the physical and chemical indicators of the barley to predict the malting loss after the malting is completed. The prediction method is fast and accurate, has guiding significance for the purchase of barley, and provides technical support for improving the economic benefits of malt factories and selecting beer barley with low malting losses.

[0021] 2. The prediction method provided by the present invention is simple, easy to operate, requires relatively simple reagents and instruments, and is time-consuming. The time can be shortened from the original 7 days to only 6 hours for detection, and the accuracy is high.

[0022] 3. Most of the existing barley purchasing standards in the malt industry are quality indicators, without economic performance indicators. The prediction method provided by the present invention can be used as a new economic performance indicator to provide pricing support for malt factory purchases. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A function diagram of amylose loss (%) in the process of converting barley into malt provided by an embodiment of the present invention;

[0024] Figure 2 A function diagram of amylopectin loss (%) in the process of barley to malt provided by an embodiment of the present invention;

[0025] Figure 3 A function diagram of alcohol-soluble protein loss (%) in the process of barley to malt provided by an embodiment of the present invention;

[0026] Figure 4 A function diagram of hemicellulose loss (%) in the process from barley to malt provided by an embodiment of the present invention;

[0027] Figure 5 A schematic diagram of correlation analysis provided in Example 1 of the present invention;

[0028] Figure 6 This is a schematic diagram of correlation analysis provided in Example 2 of the present invention. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Example 1

[0031] The malting process is a physiological and biochemical process from barley to malt. The dry matter in barley is driven by both decomposition and synthesis during the preparation of malt. Therefore, the dry matter contained in the barley itself is both decomposed and synthesized during the malting process. The reduction of all types of dry matter from barley to malt constitutes the loss of dry matter in the entire malting process.

[0032] There are two difficulties in the above technical ideas. The first is to determine the source of dry matter loss in the malting process; the second is to determine whether the corresponding dry matter loss can be inferred by testing the dry matter content of barley. Based on the difficulties of the technical ideas, two technical solutions were determined.

[0033] Technical Solution 1: Determine the sources of dry matter loss during malting

[0034] Through malting of 9 varieties of barley from different producing areas, tracking their physical and chemical indicators, testing the amylose, amylopectin, alcohol-soluble protein, glutenin, globulin, salt-soluble protein, cellulose, hemicellulose, pentosan, lipids, soluble gum, miscellaneous sugars, amino acids, peptides, nucleic acids, ash, and other substances in the process from barley to malt, it was found that amylopectin, amylose, alcohol-soluble protein and hemicellulose were the most reduced after the malting process, and other substances did not change much. After the malting process, these carbon substances are dissolved and finally removed through respiratory consumption and root bud growth, so the dry matter loss in the entire malting process can be calculated by the sum of the losses of these four dry substances.

[0035] Malting loss (%) = amylopectin loss (%) + amylose loss (%) + alcohol-soluble protein loss (%) + hemicellulose loss (%)

[0036] Among them, the detection methods of amylose, amylopectin, alcohol-soluble protein and hemicellulose are as follows:

[0037] 1. Amylopectin detection:

[0038] 1.1 Sample extraction

[0039] ① Dry the sample, grind it and pass it through a 100-mesh sieve for testing. Accurately weigh 0.01g of the sieved sample into a 2mL EP tube, add 1mL of 85% ethanol, mix thoroughly, extract in a 50℃ water bath for 30min (shake it a few times every 3min), cool it, centrifuge it at 8000rpm, 25℃ for 10min, discard the supernatant (try to keep the precipitate), and keep the precipitate.

[0040] ② Add 0.5 mL of petroleum ether to the precipitate, mix and oscillate for 5 minutes, centrifuge at 8000 rpm, 25°C for 10 minutes, discard the supernatant (try to retain the precipitate), keep the precipitate, place the EP tube at 95°C for 10-20 minutes to evaporate the petroleum ether completely.

[0041] ③ To the precipitation in the previous step (at the same time, prepare a blank EP tube, i.e., blank tube), add 0.1 mL of 95% ethanol to disperse the sample, then add 0.9 mL of reagent 1, shake well (so that the sample is completely immersed in the liquid), seal, and boil at 95°C for 10 min (shake 1-2 times in between).

[0042] ④ After boiling, cool to room temperature, transfer all the liquid in the EP tube to a 10mL EP tube (rinse the EP tube with 1mL of distilled water, transfer all to the 10mL EP tube, repeat three times), then add distilled water to level it out to 10mL, mix well, let stand for 5 minutes, and take the clarified supernatant as the test liquid.

[0043] 1.2 On-machine testing

[0044] ① Preheat the visible spectrophotometer for more than 30 minutes and adjust to zero with distilled water.

[0045] ②Prepare reagent 2 mixed solution.

[0046] ③ Add the following into a 2mL EP tube:

[0047]

[0048] 1.3 Result calculation

[0049] Amylopectin content (mg / g dry weight) = [(△A-0.0416) ÷ 0.9799 × V1] ÷ (W × V1 ÷ V) = 10.21 × (△A-0.041)) ÷ W

[0050] V—total volume of sample extract, 10 mL; V1—volume of sample taken during measurement, 0.25 mL; W—sample mass, g.

[0051] 2. Amylose detection:

[0052] 2.1 Sample extraction

[0053] ① Dry the sample, grind it and pass it through a 100-mesh sieve for testing. Accurately weigh 0.01 g of the sieved sample into a 2 mL EP tube, add 1 mL of 85% ethanol, mix thoroughly, extract in a 50°C water bath for 30 min (shake it a few times every 3 min), centrifuge at 8000 rpm, 25°C for 10 min, and discard the supernatant (try to retain the precipitate).

[0054] ② Add 0.5 mL of petroleum ether to the precipitate, mix and oscillate for 5 minutes, centrifuge at 8000 rpm, 25°C for 10 minutes, discard the supernatant (try to retain the precipitate), keep the precipitate, place the EP tube at 95°C for 10-20 minutes to evaporate the petroleum ether completely.

[0055] ③ In the precipitation of the previous step (at the same time, prepare a blank EP tube, i.e., a blank tube), add 0.1 mL of 95% ethanol to disperse the sample, then add 0.9 mL of reagent 1, shake well (so that the sample is completely immersed in the liquid), seal, and boil at 95°C for 10 min (shake 1-2 times in between);

[0056] ④ After boiling, cool to room temperature, transfer all the liquid in the EP tube to a 10mL EP tube (rinse the EP tube with 1mL distilled water, transfer all to the 10mL EP tube, repeat three times), then add distilled water to level it to 10mL, mix well, let it stand for 5 minutes, and take the clear supernatant as the test liquid

[0057] 2.2 On-machine testing

[0058] ① Preheat the visible spectrophotometer for more than 30 minutes, adjust the wavelength to 620nm, and zero it with distilled water.

[0059] ②Prepare reagent 2 mixed solution.

[0060] ③ Add the following into a 2mL EP tube:

[0061]

[0062] 2.3 Result calculation

[0063] Amylose content (mg / g) = [(△A+0.0073)÷1.2693×V1]÷(W×V1÷V) = 7.878×(△A+0.0073)÷W

[0064] V—total volume of sample extract, 10 mL; V1—volume of sample taken during measurement, 0.05 mL; W—sample mass, g.

[0065] 3. Hemicellulose detection:

[0066] 3.1 Sample treatment: The sample was dried at 80℃ to constant weight, crushed and passed through a 40-mesh sieve.

[0067] 3.2 Test operation table:

[0068]

[0069]

[0070] 3.3 Result calculation

[0071] Hemicellulose content (mg / g dry weight) = (△A-0.0306) ÷ 0.3968 ÷ (W ÷ V total sample) = 1.01 × (△A-0.0306) ÷ W

[0072] W—sample mass, g; V—total sample volume—added extraction liquid, 0.4 mL.

[0073] 4. Gliadin detection

[0074] 4.1. Extraction of alcohol-soluble proteins

[0075] Take 5-10 grains of barley and put them into a 5ml homogenization tube; add 9 times the volume of homogenization medium PBS into the homogenization tube at a ratio of weight (mg): volume (ml) = 1:9, machine homogenize under ice water bath conditions, grind up and down with a tissue crusher at 10000-15000rpm / min to make a 10% tissue homogenate, or use an internal tissue homogenizer (homogenization time 10 seconds / time, interval 30 seconds, continuous 3-5 times, in ice water, the homogenization time can be appropriately extended) The prepared 10% homogenate is centrifuged at about 4000rpm / min in a common centrifuge or a low-temperature low-speed centrifuge for 10-15 minutes, and the supernatant is taken for determination.

[0076] 4.2 Detection of prolamin content

[0077] (1) After equilibration at room temperature for 20 min, take out the required strips from the aluminum foil bag and seal the remaining strips in a ziplock bag and place them back at 4°C.

[0078] (2) Set up standard wells and sample wells. Add 50 μL of standard of different concentrations to each standard well. First add 10 μL of the sample to be tested to the sample well, and then add 40 μL of sample diluent. Do not add anything to the blank well.

[0079] (3) Except for the blank wells, add 100 μL of horseradish peroxidase (HRP)-labeled detection antibody to each well of the standard and sample wells, seal the wells with a sealing film, and incubate at 37°C in a water bath or incubator for 60 min.

[0080] (4) Discard the liquid, pat dry on absorbent paper, fill each well with washing solution, let it stand for 1 min, shake off the washing solution, pat dry on absorbent paper, and repeat this process 5 times (you can also use a plate washer to wash the plate).

[0081] (5) Add 50 μL of substrate A and B to each well and incubate at 37°C in the dark for 15 min.

[0082] (6) Add 50 μL of stop solution to each well and measure the OD value of each well at a wavelength of 450 nm within 15 min.

[0083] 4.3 Content calculation

[0084] Draw a standard curve: In an Excel worksheet, use the standard concentration as the horizontal axis and the corresponding OD value as the vertical axis to draw a linear regression curve for the standard, and calculate the concentration value of each sample according to the curve equation.

[0085] Combined with the above determination methods, Table 1 shows the loss of amylopectin, amylose, hemicellulose and alcohol-soluble protein from barley to malt for 9 varieties.

[0086] Table 1

[0087]

[0088] From the above table, we can see that by tracking the reduction of various carbon substances such as amylose, amylopectin, alcohol-soluble protein, glutenin, globulin, salt-soluble protein, cellulose, hemicellulose, pentosan, lipids, soluble gum, miscellaneous sugars, amino acids, peptides, nucleic acids, and ash in 9 batches of barley and malt samples after the barley was soaked, germinated, and dried to obtain the finished malt, we found that amylose, amylopectin, alcohol-soluble protein, and hemicellulose decreased the most, and other carbon substances did not change much. We can preliminarily conclude that the loss of dry materials in the entire malting process from barley to malt mainly comes from these four substances, including amylose, amylopectin, alcohol-soluble protein and hemicellulose.

[0089] Technical Solution 2 Determine whether the corresponding dry matter loss can be inferred by detecting the dry matter content of barley

[0090] Furthermore, the dry matter loss percentage from barley to malt of 38 batches in the production process was tested, including the loss percentage of amylose, amylopectin, alcohol-soluble protein and hemicellulose from barley to malt. The results showed that the change pattern of these four key carbon substances in the malting process is in line with the "regularity principle" of grain composition proposed by Briggs in 1978, that is, the reduction of amylose, amylopectin, alcohol-soluble protein and hemicellulose after the barley is prepared into malt can be calculated based on the content of amylose, amylopectin, alcohol-soluble protein and hemicellulose contained in the purchased barley.

[0091] The contents of amylose, amylopectin, alcohol-soluble protein and hemicellulose in 38 batches of barley in the process of malting were tested. Through statistical correlation analysis of the contents of each component in barley and malt, it was found that the content of amylose in barley was directly correlated with the loss of amylose in the prepared finished malt, and the correlation prediction model of the above components could be obtained through data statistical analysis.

[0092] Amylose loss (%) = (0.528*barley amylose content-6.1986)*100%, such as Figure 1 As shown;

[0093] Amylopectin loss (%) = (0.2564*barley amylopectin content-3.4823)*100%, such as Figure 2 As shown;

[0094] Prolamin loss (%) = (0.2818*hordein content-0.1166)*100%, such as Figure 3 As shown;

[0095] Hemicellulose loss (%) = (0.3004 * hemicellulose content - 1.5879) * 100%, such as Figure 4 As shown;

[0096] Combined with the above analysis, the dry matter loss of the entire malting process after malting was calculated based on the quality characteristics of the barley itself, and finally a comprehensive evaluation model for malting loss was obtained.

[0097] Malting loss (%) = (0.528* amylose content - 6.1986) * 100% + (0.2564* amylopectin content - 3.4823) * 100% + (0.2818* alcohol-soluble protein content - 0.1166) * 100% + (0.3004* hemicellulose content - 1.5879) * 100%

[0098] Example 2

[0099] The contents of amylose, amylopectin, alcohol-soluble protein and hemicellulose were tested for 20 consecutive batches of barley entering the Copeland malting plant, and the malting loss after the malting was completed was predicted by the comprehensive evaluation model of malting loss. Subsequently, the existing method was used, that is, the barley was subjected to micro-malting tests in batches, and the malting loss was calculated by weighing the barley mass and malt mass before and after malting (this method has a lag, and the malting loss data can only be obtained 7 days after the micro-malting is completed, which has no reference basis for the malting plant to select barley). The results are shown in Table 2.

[0100] Table 2

[0101]

[0102] The corresponding values ​​are obtained by testing the contents of amylose, amylopectin, alcohol-soluble protein and hemicellulose in the incoming barley, and then brought into the comprehensive evaluation model to calculate the malting loss. On the other hand, the samples are tested for micro-wheat at the same time. After soaking, germination and drying, the micro-wheat malting loss is obtained by the quality method. The malting loss calculated by the comprehensive evaluation model is correlated with the micro-wheat malting loss. Figure 5 As shown, the correlation coefficient R 2 =0.9503, with a strong correlation. It can be seen that the comprehensive evaluation model provided by the present invention has high accuracy in predicting malting loss based on malt quality.

[0103] Example 3

[0104] The contents of amylose, amylopectin, alcohol-soluble protein, and hemicellulose in the purchased 5 varieties of barley were measured, and the malting loss after malting was predicted by the obtained malting loss comprehensive evaluation model. Subsequently, the barley was subjected to micro-malting tests in batches, and the malting loss was calculated by weighing the barley mass and malt mass before and after malting for verification. The results are shown in Tables 3 and 4.

[0105] Table 3

[0106]

[0107] Table 4

[0108]

[0109] The malting loss was calculated by testing the contents of amylose, amylopectin, alcohol-soluble protein and hemicellulose in barley and combining them with the comprehensive evaluation model. In addition, the malting loss was obtained by the mass method after the barley samples were soaked, germinated and dried. The correlation analysis was performed between the malting loss calculated by the comprehensive evaluation model and the malting loss obtained by the micro-wheat mass method. Figure 6 As shown, the correlation coefficient R 2 =0.9716, indicating that the comprehensive evaluation model has high accuracy. In addition, the method provided by the present invention is less time-consuming and has universal applicability among different varieties of beer wheat. Therefore, the method has guiding significance for the procurement of barley and can provide technical support for improving the economic benefits of malt factories and selecting beer wheat with low malting losses.

Claims

1. A method for predicting malting loss based on malting barley quality, characterized in that: Calculated by the following formula: Malting loss % = amylose loss % + amylopectin loss % + alcohol-soluble protein loss % + hemicellulose loss %; where: Amylose loss percentage = (0.528*amylose content-6.1986)*100%; Amylopectin loss percentage = (0.2564* amylopectin content-3.4823)*100%; Prolamin loss percentage = (0.2818*prolamin content-0.1166)*100%; Hemicellulose loss percentage = (0.3004*hemicellulose content-1.5879)*100%.

2. The method for predicting malting loss according to claim 1, characterized in that: Amylose content = [(△A + 0.0073) ÷ 1.2693 × V1] ÷ (W × V1 ÷ V) = 7.878 × (△A + 0.0073) ÷ W, where: The unit of amylose content is mg / g, V—total volume of sample extract, 10 mL; V1—volume of sample taken during measurement, 0.05 mL; W—sample mass, g; △A=A 测定 -A 空白 .

3. The method for predicting malting loss according to claim 1, characterized in that: Amylopectin content = [(△A-0.0416) ÷ 0.9799 × V1] ÷ (W × V1 ÷ V) = 10.21 × (△A-0.041)) ÷ W, where: The unit of amylopectin content is mg / g dry weight, V—total volume of sample extract, 10 mL; V1—volume of sample taken during measurement, 0.25 mL; W—sample mass, g; △A=A 测定 -A 空白 .

4. The method for predicting malting loss according to claim 1, characterized in that: Hemicellulose content = (△A-0.0306) ÷ 0.3968 ÷ (W ÷ V 样总 )=1.01×(△A-0.0306)÷W, where: The unit of hemicellulose content is mg / g dry weight, W is the sample mass, g; V is the sample mass, g. 样总 - Add extraction liquid, 0.4mL; △A = A 测定 -A 空白 .

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