RU2265662C2 - Method for preparing nutritive ethyl alcohol - Google Patents

Abstract

FIELD: food industry.

SUBSTANCE: invention relates to a method for preparing nutritive ethyl alcohol. Method involves preparing grain mixture, its aqueous-heat treatment and treatment with liquefying and acid-resistant saccharifying enzyme preparations to obtain a must that is acidified with sulfuric or lactic acid to pH value 3.5-3.9 followed by addition of yeast to the prepared must, its fermentation to obtain a matured mash, distillation of the latter to obtain depleted distillery grains and a distillate and purifying a distillate to obtain the end product. Invention provides stabilizing the process for must fermentation, to exclude its infecting and to enhance the yield and quality of the end product.

EFFECT: improved preparing method.

2 cl, 2 dwg, 2 tbl, 3 ex

Description

The invention relates to the food industry for the production of edible ethyl alcohol.

A known method of producing edible ethyl alcohol, including the preparation of grain kneading, its water-thermal treatment and treatment with diluting and saccharifying enzyme preparations to produce wort, introducing yeast into the prepared wort, fermenting it to produce a mature mash, distilling a mature mash to obtain spent bard and distillation cleaning distillation to obtain the target product (Typical technological regulations for the production of alcohol from starchy raw materials. M., 1998).

However, even slight deviations from the operating parameters provided by this known method lead to infection of the fermented wort, to a deterioration in the quality of the target product due to the accumulation of undesirable impurities in it, to a deterioration in its physicochemical parameters, and to a decrease in the yield of ethyl alcohol.

The technical result achieved by the present invention is the stabilization of the process of fermentation of the wort, the exclusion of its infection, increasing the yield and quality of the target product, reducing the content of undesirable impurities in it.

The specified technical result is achieved by the fact that in the method for producing edible ethyl alcohol, which includes preparation of grain kneading, its water-heat treatment and treatment with diluting and saccharifying enzyme preparations to produce wort, introducing yeast into the prepared wort, fermenting it with a mature mash, distilling a mature mash to obtain spent vinasse and distillation, purification of distillation to obtain the target product, a distinctive feature is that the must is fermented, processed acid resistant saccharifying enzyme preparations and acidified to pH 3.5-3.9.

It is recommended that the wort be acidified with sulfuric or lactic acid.

In the particular case of the implementation of the method, the liquid fraction of the spent vinasse is separated, and the wort is acidified, acidified with a solution of sulfuric or lactic acid in the obtained liquid fraction.

Our own studies have shown that, despite the fact that at low wort pH values (at values of 3.5-3.9), yeast accumulate less biomass during its fermentation than at higher pH values, they unexpectedly maximize contained in the must must sugar in ethyl alcohol and thus form small amounts of unwanted by-products. In addition, under these conditions, acid-resistant saccharifying enzyme preparations used by the method according to the invention retain their activity during the fermentation of the wort, which contributes to the maximum breakdown of starch, the maximum fermentation of the sugar formed by the yeast, and the increase in the yield of the target product. The creation of the initial acidic environment in the production wort prevents the development of extraneous microflora in it during its fermentation with yeast, which also reduces the accumulation of undesirable by-products and improves the quality of the target product. Also unexpected was the fact that only sulfuric or lactic acids can be used to acidify the original production wort. An attempt to replace them, for example, with phosphoric acid, did not lead to a decrease in the content of impurities in the target product and did not improve the quality of the alcohol.

Figure 1 presents a graph of the cell concentration of a 22-hour yeast culture and the accumulation of secondary metabolic products in the mash on the initial pH value in the must.

Figure 2 presents a diagram of the accumulation of impurities in the mash after 72 hours of fermentation of the wort, depending on the initial pH value in it (the results of gas chromatographic analysis of distillation of mash).

The following are examples illustrating the invention.

Example 1. For the preparation of grain kneading used grain grinding of wheat with a degree of grinding - 100% pass through a sieve with cells with a diameter of 1.0 mm The hydromodule of the batch was 1: 4.

As a diluent enzyme preparation in the preparation of the batch at the stage of water-heat treatment used α-amylase Termamil SC company Novozymes in a dosage of 0.2 u / g starch. An acid-resistant complex of α-amylase, glucoamylase and protease in the form of the San Super enzyme preparation of the same company, 6 units / starch, was assigned for saccharification.

Water-heat treatment of grain raw materials was carried out according to the "soft" mode. Kneading was prepared at a temperature of 45 ° C. Exposure time 20 min. Then the batch was placed in an ultra-thermostat and kept for 1 hour at a temperature of 65 ° C. Subsequent kneading was carried out for 1 hour in a water bath. The boiled mass was cooled to a temperature of 56-58 ° C, a saccharifying enzyme preparation was set, and saccharification was carried out at a given temperature in a thermostat for 1 hour.

The solids content in the prepared wort was 16%. Before introducing the yeast into the prepared wort, it was acidified with sulfuric acid to a pH of 3.9.

Wort was fermented with yeast of the genus Saccharomyces cerevisiae of race 12 for 72 hours at a temperature of 30 ° C. After distillation of the obtained mature mash, the volume fraction of alcohol was determined in the distillation. The impurity content in alcohol was determined by gas-liquid chromatography on an HP 6850 gas chromatograph. The determination results are shown in table 1. The data in the table indicate that when the process for producing ethyl alcohol under the conditions of the procedure of Example 1 was carried out, the impurity content in the target product was low. The resulting alcohol had high quality indicators.

Example 2. According to the method of example 1, ethyl alcohol was obtained. At the same time, rye was used as a grain raw material. At the stage of preparation of the batch, the enzyme preparation α-amylase Amylosubtilin GZH was used as a thinning enzyme. At the stage of saccharification of grain kneading, the acid-resistant enzyme preparation Glukavamorin G18X was used. Water-heat treatment of grain kneading was carried out in the “hard” mode: the kneading was cooked in a water bath for 40 minutes, and then in an autoclave at a pressure of 2.0 atm for 1.5 hours. The prepared wort was acidified to pH 3.5 with a solution of lactic acid in the liquid fraction of spent vinasse. Received alcohol with a low content of impurities and with improved quality indicators.

Example 3. According to the method of example 1, a wort was prepared, but before introducing yeast into it, it was not acidified with sulfuric acid. During the fermentation of the wort, it became infected. The results of determining the content of impurities in the resulting alcohol are presented in table 2 and indicate that infection of the mash contributed to a decrease in the content of higher alcohols (isoamyl, isobutyl). At the same time, infection of the mash led to a multiple increase in the content of organic acids, mainly acetic, propionic and butyric, which, apparently, is associated with the occurrence of acetic acid, propionic acid and butyric acid fermentation. An increase in the content of esters in the mash was also noted.

In this case, there was a significant inhibition of the growth of yeast cells and a decrease in the concentration of alcohol in the mash.

Thus, the method according to the invention allows to obtain high-quality food ethyl alcohol.

Table 1 Gas chromatographic analysis of distilled mash during acidification of wort Impurities, mg / dm ³ pH 6.5 pH 5.0 pH 4.0 pH 3,5 Ethyl ether - - - - Acetaldehyde 733,436 531,616 344,174 219.19 Acetone - - - - Methyl acetate - - - - Ethyl acetate 245,445 224,337 163,746 123,352 EAF * 978,881 777,704 507.92 342,542 Methanol,% vol 0.01620 0.01509 0.01291 0.01011 Methyl ethyl ketone - - - - Methyl propionate - - - - 2-propanol - - - - Ethyl propionate - - - - 2-butanol - - - - 1-propanol 699,218 528,662 368,391 261,544 Crotonaldehyde - - - - Isobutanol 2122.19 1879,572 1589,01 1395.93 1-butanol 3,6378 5,8806 - - Isoamylol 4163,522 4128,743 3544.86 3155,605 1-pentanol - - - - Hexanol - - - - Higher alcohols 6988,568 6542,857 5502,261 4813,079 Acetic acid 1892,455 1235,963 849,827 592,403 Propionic acid 749.1355 671.72 576,791 513,505 Iso-oil to-that 116,696 112,692 107.70 104,372 Oil set 44.17 15,449 7,755 5,257 Isovalerianic acid 64,386 67,031 30,900 15,800 Valerian 6,437 6,496 7,113 7,992 Volatile acids 2894,962 2133,851 1605.11 1239,329 Benzaldehyde 21,683 24,502 25,025 20,725 Benzalcohol 4,158 4,127 3,268 2,268 Phenyl alcohol 843,974 839,695 821,851 801,158 Aromatic alcohols 869,815 868,324 850,144 824,151 General content 11732,226 10322,736 8465,435 7266,101 * EAF - etheroaldehyde fraction

table 2 Gas chromatographic analysis of distilled mash without acidification of wort Impurities, mg / l The control Experience Ethyl ether - - Acetaldehyde 402.58 421,294 Acetone - - Methyl acetate - - Ethyl acetate 268,643 498,081 EAF * 671,223 919,375 Methanol,% vol 0.01727 0.01777 Methyl ethyl ketone - - Methyl propionate - - 2-propanol - - Ethyl propionate - - 2-butanol - - 1-propanol 774,839 619,691 Crotonaldehyde - - Isobutanol 2495,581 1673.12 1-butanol 5,6896 7.7068 Isoamylol 4853,125 3649,435 1-pentanol - - Hexanol - - Higher alcohols 8133,057 5962,311 Acetic acid 975,333 3682,165 Propionic acid 364,984 5043,866 Isobutyric acid 64,048 115,703 Butyric acid 7.2461 24732.25 Izovalerianova 38,313 58,454 Valerian 9,976 27,431 Volatile acids 1474.109 33691.0 Benzaldehyde 14,209 31,133 Benzalcohol 4,158 4.23 Phenyl alcohol 936,413 718,533 Aromatic alcohols 940,571 722,763 General content 11218.96 41295,45 * EAF - etheroaldehyde fraction

Claims (2)

1. A method of producing edible ethyl alcohol, including preparation of grain kneading, its water-thermal treatment and treatment with diluting and saccharifying enzyme preparations to produce wort, introducing yeast into the prepared wort, fermenting it to produce a mature mash, distilling a mature mash to obtain a spent bard and distillation, purification of distillation to obtain the target product, characterized in that the grain batch is treated with acid-resistant saccharifying enzyme preparations, and the resulting wort per units making yeast acidified with sulfuric or lactic acid to a pH of 3.5-3.9. 2. The method according to claim 1, characterized in that the liquid fraction of the spent vinasse is separated, and the wort is acidified, acidified with a solution of sulfuric or lactic acid in the obtained liquid fraction.

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