Starch products with a sweet taste are obtained using the ability of starch to saccharify under the action of acids and enzymes. During the acid hydrolysis of starch under the action of hydrogen ions, a-1,4- and a-1,6-glycosidic bonds are broken. At the point of rupture, the hydrogen atom of water with the oxygen of the glycosidic bridge forms an aldehyde group in the hemiacetal form at the first carbon atom of the glucose residue. With an increase in the number of breaks, the reducing ability of hydrolysates increases. The end product of acid hydrolysis of starch is glucose. The conversion of starch to glucose is expressed general equation: Depending on the conditions and duration of acid hydrolysis, starch hydrolysates are obtained, differing in carbohydrate composition: the content of dextrins, tetra- and trisaccharides, maltose, glucose.
Starch hydrolysates with high GE are sweeter, hygroscopic, increase osmotic pressure have a preservative effect. Hydrolysates with low HE are characterized by high viscosity, anti-crystallization action, and are capable of stabilizing foams and emulsions.
Everything is currently greater value acquires the hydrolysis of starch with the use of enzymes. They act in a specific way. Therefore, hydrolysates with a given carbohydrate composition are obtained. Starch hydrolysates are also obtained by a combined acid-enzymatic method.
The general stages of the production of starch hydrolysates are: preparation of starch for processing - washing, cleaning from impurities; starch hydrolysis - gelatinization, liquefaction and saccharification to the desired stage (checked by iodine test); acid neutralization or enzyme inactivation; purification of hydrolysates from insoluble and soluble impurities, including colorants; concentration - evaporation of products obtained in liquid form, evaporation and drying or crystallization of powdered products.
starch molasses
Starch syrup is produced from cereal and potato starch.
Molasses is a product of incomplete hydrolysis of starch; is a sweet thick, very viscous liquid, colorless or with a yellowish tinge. Molasses is one of the main types of raw materials for confectionery production, it is used for the preparation of commercial syrups, in bakery. The main substances that make up the molasses: dextrins, glucose, maltose. The reducing ability of molasses is due to glucose and maltose. The sweetness of molasses and its hygroscopicity depend on the glucose content. Molasses, in which the reducing substances are represented to a greater extent by maltose, are less hygroscopic. The more dextrins in the molasses, the higher its viscosity and ability to delay the crystallization of sugars.
Depending on the purpose, molasses is produced low-saccharified, with an average degree of starch saccharification - caramel and highly saccharified - glucose. Mass fraction of reducing substances (in terms of dry matter,%) in molasses: low-saccharified - 30-34, caramel - 34-44 and high-saccharified glucose - 44-60.
In the confectionery industry, molasses with a reduced glucose content is used to make products that can easily absorb moisture from the environment - caramel, halva, and with a high one - for products that dry quickly during storage - lipstick, whipped sweets, biscuits, etc. and the quality of molasses is significantly affected by the method of hydrolysis of starch.
Molasses acid hydrolysis. Upon receipt of molasses, the hydrolysis of starch under the action of of hydrochloric acid carried out at excess pressure and a temperature of about 140 °C.
Low-sugar acid hydrolysis molasses along with glucose contains high-molecular dextrins varying degrees polymerization, including those approaching the properties of starch. Such dextrins are capable of rapid retrogradation. Molasses easily loses transparency, becomes milky in color. Its high viscosity and stickiness make caramel production difficult.
With deeper acid hydrolysis of starch, along with its saccharification, side reactions of reversion and decomposition of glucose occur. Reversion of glucose - reversible process its polymerization with the formation of mainly disaccharides - gentiobiose, isomaltose and others, as well as trisaccharides and more complex oligosaccharides: 
In starch hydrolysates, glucose reversion products can be 5% or more. They delay the crystallization of sucrose in sugar syrups by increasing the solubility of the mixture of sugars.
The decomposition of glucose during the hydrolysis of starch is due to the acidic reaction of the medium and high temperature. Under these conditions, dehydration of glucose is possible. When three water molecules are separated from glucose, hydroxymethylfurfural is formed - an unstable 
compound capable of decomposing to levulinic and formic acid. During the polymerization of hydroxymethylfurfural, yellow-brown dyes are formed.
The decomposition products of glucose accumulating in molasses worsen its composition, color, and increase hygroscopicity. The content of 0.002-0.008% hydroxymethylfurfural was found in molasses. Impurities present in starch promote high temperature and other side reactions to form dark colored compounds. Molasses boiled in a vacuum apparatus to 78% solids is quickly cooled to 40-45 °C. The acid method produces mainly caramel molasses - an average degree of saccharification.
High sugar - glucose syrup obtained acid hydrolysis, unstable during storage due to crystallization of glucose. It has a bitter taste due to the content of reversion products, increased color.
In addition to reducing substances, ash content is normalized (in terms of dry matter), ash content is not more than 0.4-0.55%, acidity, depending on the variety and type of starch, is from 12 to E7 ml of 1 N. NaOH solution, molasses pH - not lower than 4.6. When cooking a caramel sample from molasses, a transparent candy should form without dark spots and veins.
Molasses enzymatic hydrolysis. The hydrolysis process proceeds at a low temperature (about 60 °C). Enzymes of sprouted grains of cereals, mold fungi and bacteria are used. Amylolytic enzymes break down, liquefy and precipitate starch. They act specifically, so they get hydrolysates with a given carbohydrate composition.
The α-amylase enzyme cleaves α-1,4-glycosidic bonds predominantly in the middle of amylose and amylopectin macromolecules, forming low molecular weight dextrins and some maltose. P-amylase also hydrolyzes a-1,4-glycosidic bonds of starch, but sequentially cleaves off two glucose residues - maltose - from the non-reducing ends of the chains. This enzyme hydrolyzes amylose almost completely, amylopectin - by 50-55%, as it stops the action of the branches of molecules with a-1,6-bond, leaving high-molecular dextrins unsplit. Glucoamylase completely hydrolyzes starch.
/Low-saccharified starch syrup of enzymatic hydrolysis obtained using the enzyme a-amylase. Molasses is characterized by a reduced content of reducing substances, especially glucose. It consists mainly of low molecular weight dextrins. pH at 5.6. This molasses remains clear and liquid when stored. It is used in the production of low hygroscopic caramel and other confectionery products for which it is important to reduce hygroscopicity.
High sugar molasses produced by acid-enzymatic hydrolysis. First, the starch is hydrolyzed with acid to a content of 42-50% reducing substances, then the a-amylase enzyme preparation is added to the neutralized hydrolyzate cooled to 55 ° C and the glucose content is adjusted to 41-43%. With this method, the formation of products of reversion and decomposition of glucose is reduced. Molasses has a clean sweet taste. It can be used to partially replace sugar in the production of marshmallows, fondant sweets and other products.
High sugar molasses with more high content glucose (47%) and total reducing substances (68-75%) can be obtained using the enzyme gluco-amylase. This molasses is used in bread baking, in brewing.
Umaltose molasses better known as a product that is obtained from starch and starch-containing raw materials - corn, millet, high-quality flour. To saccharify starch, malt containing the malt-forming enzyme p-amylase is added. The color of this molasses is brown, the smell is slightly malty, the taste is sweet, with a malty flavor. Reducertrugotdtghh veshcheet" contains at least 65%, ash - no more than 1.3% in terms of dry matter. Maltose syrup is used in baking or as a sweet syrup. Developed new technology obtaining maltose syrups. They are prepared from starch using enzyme preparations. Due to the low glucose content (up to 10%), the maltose syrup obtained in this way is low-hygroscopic, has a low viscosity, and is suitable for making candy caramel.
High maltose syrup is used to produce new products - hydrogenated starch syrups. Depending on the carbohydrate composition of the molasses, these syrups contain maltitol, sorbitol and polyhydric alcohols. They are sweeter than the original molasses. By sweetness, maltitol approximately corresponds to sucrose, it is not absorbed by the body, therefore it can be used in the manufacture of high-calorie food products. Dextrin-maltose syrup obtained mainly from potato starch under the action of malt extract enzymes. It is a viscous thick liquid of amber-yellow color with a malty smell and taste, contains approximately equal amount maltose and dextrins, some glucose (not bo / iee 10% by weight of dry matter of molasses).
Maltose-dextrin molasses is produced with a dry matter content of 79 or 93% (dry). This molasses is used to prepare food for children early age- dairy mixtures, etc.
Maltz- extract - a dietary food product, which is a boiled down water extract of the malt itself.
Storage and transportation of starch syrup. Molasses is stored in tanks with a capacity of up to 2000 tons, inner surface which are covered with ishchevy varnish. It is transported in railway tanks, wooden and metal barrels with an internal coating of lacquered zinc. Table molasses is packed in glass jars.
During storage, it is unacceptable to get moisture into the molasses, since in places of liquefaction it easily ferments. High storage temperatures cause the molasses to darken and promote fermentation. Molasses should be stored at a temperature of about 10 ° C and relative humidity up to 70%. Maltodextrins. The products of enzymatic hydrolysis of starch also include maltodextrins - polymers, the molecule of which is composed of five to ten glucose residues. The share of reducing substances in maltodextrins is about 5-20%. Maltodextrins are tasteless, odorless; at concentrations above 30% / form viscous solutions that can slow down crystallization. Maltodextrins are used in the production food products as fillers. Gel-forming maltodextrin - maltin - is able to melt like fats. Its gel forms stable emulsions. Maltin as an additive is used in the production of ice cream, creams.
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Starch is the main reserve polysaccharide of plants, which is the most important carbohydrate component of the diet. Starch is stored in cereal seeds, tubers, rhizomes in the form of starch grains, which, depending on the type of plant, have different shape(spherical, ovoid, lenticular or irregular) and size (1 to 150 microns, 30-50 microns on average).
Starch grains of various plant species:
A - potatoes; B - wheat; B - oats; G - rice; D - corn; E - buckwheat.
1 - simple starch grain, 2 - complex, 3 - semi-complex.
Starch has complex structure and consists of two homopolysaccharides: water-soluble amylose and insoluble amylopectin. Their ratio in starch may vary depending on the plant and the type of tissue from which it was isolated (amylose 13-30%; amylopectin 70-85%).
Amylose consists of unbranched (linear) chains containing 200-300 glucose residues linked by an α(1→4) glycosidic bond. Due to the α-configuration at C-1, the chains form a helix with a diameter of 13 nm, in which there are 6-8 glucose residues per turn. The molecular weight is 50000 Da.
Amylopectin has a branched structure, in which, on average, one of 20-25 glucose residues contains a side chain attached by an α(1→6) glycosidic bond. This creates a tree structure. The molecular weight is as high as 1-6 million Da.
Starch hydrolysis is present in many food technologies as one of necessary processes ensuring the quality of the final product. For example:
In bakery, the process of preparing dough and baking bread;
In the production of beer - obtaining beer wort and drying malt;
In the production of kvass;
In the production of alcohol - preparation of raw materials for fermentation;
In obtaining various sugary starch products - glucose, molasses, sugar syrups.
There are two methods of starch hydrolysis:
Acid - under the action of mineral acids;
Enzymatic - under the action of enzyme preparations.
In the hydrolysis of starch under the action of acids, weakening and rupture first take place. associations between macromolecules of amylose and amylopectin. This is accompanied by a violation of the structure of starch grains and the formation of a homogeneous mass. Next comes the cleavage of α(1→4) and α(1→6)-glycosidic bonds with addition at the site of the rupture of the water molecule. In the process of hydrolysis, the number of free aldehyde groups increases, and the degree of polymerization decreases. At intermediate stages, dextrins, tri and tetrasugars, maltose are formed. The end product of hydrolysis is glucose. Acid hydrolysis has a number of significant disadvantages due to the use of high concentrations of acids and high temperature(over 100 °C), which leads to the formation of products of thermal degradation and dehydration of carbohydrates, transglycosylation and reversion reactions.
Compared to acid hydrolysis, enzymatic hydrolysis is more promising and has the following advantages:
1) High quality manufactured product, because less is formed by-products;
2) The specificity of the action of enzymes allows you to get a product with the desired physical properties(for example, sweetness);
3) High product yield is achieved with lower economic costs.
Enzymatic hydrolysis of starch is carried out with the help of amylolytic enzymes. This group includes α-amylase, β-amylase, glucoamylase, pullulanase and some other enzymes. Each of them has its own specific features.
α-amylase- an endoenzyme that hydrolyzes α (1-4)-glycosidic bonds within an amylose or amylopectin molecule, resulting in the formation of dextrins - products of incomplete hydrolysis of starch and a small amount of glucose and maltose:
α-amylase is found in animals (saliva and pancreas), in higher plants(germinated seeds of barley, wheat, rye, millet) and microorganisms (fungi of the genus Aspergillus, Rhizopus, bacteria of the genus Bacillus subtilis).
β-amylase- exoenzyme, hydrolyzes α (1-4)-glycosidic bonds from the non-reducing ends of the amylose molecule, amylopectin with the formation of maltose (54-58%), i.e. shows a pronounced saccharifying activity. Another reaction product is β-dextrin (42-46%). This enzyme is distributed in the tissues of higher plants.
Glucoamylase is an exoenzyme, acting from the non-reducing ends of the amylose and amylopectin molecules, it splits off glucose molecules by hydrolyzing α (1-4)- and α (1-6)-glycosidic bonds. This enzyme is most often found in micromycetes of the genus Aspergillus, Rhizopus.
Mechanism of action various types amylase to starch:
Starch technology.
Raw material for industrial production starch are potatoes, corn, wheat, rice, sorghum. Consider the technology for the production of potato starch. It includes the following stages:
Washing potatoes from dirt and foreign matter in a potato washer;
Weighing;
Fine grinding of potatoes on high-speed potato graters to obtain potato porridge (the more crushed it is, the more starch will be released from the cells, but it is important not to damage the starch grains themselves);
Treatment of potato porridge with sulfur dioxide or sulfurous acid (to improve the quality of starch, its whiteness and prevent the development of microorganisms);
Separation of porridge using centrifuges or a hydrocyclone system;
Refining starch milk - cleaning starch from pulp on a refining sieve;
Washing starch in a hydrocyclone.
The result is raw starch with a moisture content of 40-52%. It is not subject to long-term storage, unlike dry production of which consists of the following operations: mechanical removal of excess moisture, drying, pressing and packaging.
In the production of a number of products, the use of modified starches is effective:
- Swelling (pre-gelatinized) starch is obtained by drying the paste in special dryers, followed by grinding the film into powder, the particles of which swell when wetted with water and increase in volume. Swelling starch is used in Food Industry(fast foods, stabilizers and thickeners in foods without heating).
- oxidized starch is obtained by oxidizing starch with various oxidizing agents (KMnO 4 , KBrO 3 , etc.). Depending on the oxidation method, the products have different viscosity and gelling ability. They are used in the paper industry to increase the strength of paper as a tannin, and at a low degree of oxidation (up to 2%) in the food industry. So one of the types of oxidized starch - gelling is used as a gelling agent instead of agar and agaroid in the production of marmalade products.
- Substituted starches:
Monostarch phosphates (monophosphate esters of starch) are obtained by the reaction of a dry mixture of starch and acid salts ortho-, pyro- or tripolyphosphate at elevated temperature. Compared to ordinary starch, they form stable pastes, which are characterized by increased transparency, resistance to freezing and thawing.
Distarch phosphates (cross-linked starches) can be obtained by the reaction of starch with sodium trimetaphosphate, phosphorus oxychloride, etc. They form pastes that are resistant to heat and mechanical stress. They are used in the production of mayonnaise, confectionery, salad dressings, meat products, etc.
Acetylated starch (starch acetate) can be obtained by processing starch acetic acid or acetanhydride. They have the ability to form stable transparent pastes, which dry to form strong films. In the food industry, they are used as thickeners, as well as in the production of frozen foods, instant powders, etc.
Ethanol (ethyl alcohol) C 2 H 5 OH is a clear, colorless liquid with a burning and characteristic odor with a relative density of 0.79067. The boiling point of ethanol at normal pressure is 78.35 °C, the flash point is 12 °C, and the freezing point is 117 °C. Chemically pure ethanol has a neutral reaction; rectified alcohol contains a small amount carboxylic acids, so the reaction is slightly acidic. Ethanol is very hygroscopic; it greedily absorbs water from the air, plant and animal tissues, as a result of which they are destroyed.
Alcohol is poisonous to humans and animals, as well as microorganisms. Alcohol vapors are also harmful. The maximum permissible concentration of vapors in the air is 1000 mg/cm 3 . Alcohol has explosive properties. The limits of the explosive concentration of alcohol vapors are 2.8-13.7% of the air volume. Ethanol is produced from food raw materials in the form of raw alcohol with a strength of at least 88 vol.% and rectified alcohol with a strength of 96.0-96.5 vol.% in the form of rectified alcohol of grade I, the highest purification, "Extra" and "Lux", Basis, Alpha.
The production of alcohol from starch-containing raw materials consists of the following main technological stages: preparation of raw materials for processing; water-heat treatment (cooking) of grain and potatoes; saccharification of boiled mass; cultivation of industrial yeast; fermentation of saccharified wort and extraction of alcohol from the mash and its purification.
4.1. Preparing potatoes and grain for processing
Preparation of potatoes and grain for processing consists in the delivery of raw materials to the plant, separation of impurities, grinding and preparation of the batch.
Potatoes from the shoulder field are transported by road to spare bins, from where they are fed into production by a hydraulic conveyor. Light, coarse and heavy impurities of potatoes are separated in
scrap and stone traps. Potato washing machines are used for washing and removing the remaining impurities.
The grain going for boiling is cleaned on air-sieve and magnetic separators.
With a periodic method of water-heat treatment, potatoes and grain are boiled as a whole, with continuous schemes, the raw materials are pre-crushed. The degree of crushing affects the temperature and duration of boiling. When grinding potatoes on a sieve with a hole diameter of 3 mm, there should be no residue, and when grinding grain, the residue on this sieve should not exceed 0.1-0.3%. The passage of grinding through a sieve with holes with a diameter of 1 mm should be 60-90%.
The preparation of the batch consists in mixing the crushed raw materials with water and heating it to a certain temperature. 280-300% water is added to the crushed grain, 15-20% water by weight of the raw material is added to the potato porridge. The concentration of solids in the wort should be 16-18%.
4.2. Water-heat treatment of grain and potatoes
The main task of water-heat treatment is the preparation of raw materials for starch saccharification with amylolytic malt enzymes or enzyme preparations of microbial origin. Saccharification occurs most fully and quickly when the starch is available for their action (not protected by cell walls), gelatinized and dissolved, which can be achieved by heat treatment of whole raw materials at elevated pressure, or, as this process is commonly called in alcohol production, boiling; ultra-fine mechanical grinding of raw materials on special machines; mechanical grinding of raw materials to a certain particle size, followed by boiling under pressure (combined method).
Whole starch-containing raw materials in the boiler are treated with saturated steam under excess pressure up to 0.5 MPa (temperature 158.1 ° C). Under these conditions, starch dissolves, the cellular walls of the raw material soften and partially dissolve, and during the subsequent blowing of the raw material into the steam separator (holder), the cellular structure is destroyed due to pressure drop, grinding action of the grate in the blow box of the brewer, as well as other mechanical influences on the path of rapid movement of the boiled masses from one apparatus to another. In the process of boiling, the sterilization of raw materials occurs simultaneously, which is important for the processes of saccharification and fermentation.
When grinding raw materials to a particle size smaller than starch grains, cell structure raw materials and the starch grains themselves, as a result of which they dissolve in water at a temperature of 60-80 ° C and are saccharified with amylolytic enzymes of malt and cultures of microorganisms. The method of ultrafine grinding is not yet used due to the high consumption of electricity and the lack of study of the issue of sterilization of raw materials.
The combined method is widely used, according to which the raw material is first crushed to particles of medium size (1-1.5 mm), and then boiled. In this case, the temperature and duration of boiling is less than in the case of heat treatment of whole raw materials. Blowing the boiled mass of crushed raw materials with a pressure drop contributes to its further dispersion. This method of heat treatment, combined with the continuity of processes, is considered the most progressive. With a relatively small cost of electricity for grinding raw materials, heat for boiling, and due to the "softness" of the cooking mode, which ensures minimal loss of fermentable substances, the method allows you to well prepare the raw material for saccharification.
When boiling potatoes and grains, significant structural and mechanical changes in raw materials and chemical transformations of the substances that make up its composition occur.
Cereals are the main raw material for the production of alcohol and distillate. First of all, these are barley, oats, rice, corn, wheat, etc. They are used for several reasons:
- Relatively low cost
- Pleasant organoleptic profile of the resulting product
- high output alcohol
Traditional mash is made from sugar and yeast. Yeast is needed to break down sugar, resulting in alcohol. However, there is no sugar as such in the grain, but there is a lot of starch. To get mash from grain, starch must be broken down by enzymes. These are protein substances that enable or accelerate chemical reactions required for the formation of alcohol. Enzymes are contained in sprouted grains (malt) and are sold as preparations in their pure form.
Therefore, there are three ways to make grain mash:
- Use malt to saccharify the starch in the grain. So you can saccharify up to 40% of the bill of unmalted grain.
- Sprout the grain so that the enzymes accumulate in it naturally. That is, to make malt.
- Use the enzyme in the form of a preparation and unmalted raw materials.
The second method is cheaper and allows you to get the result faster.
Grain structure
To understand exactly how grain is processed during mashing, it is necessary to understand its structure. Consider the example of barley.
Internal structure of barley grain
1-stem embryo, 2-leaf embryo, 3-root embryo, 4-scutellum, 5-epithelial layer, 6-endosperm, 7-empty spent cells, 8-aleuron layer, 9-seed coat, 10-fruit coat, 11 - chaff shell
barley grain is a caryopsis, the shell of which consists of several cell layers.
Shells combined into a chaff (or flower) - outer shell, fruit (or pericarp) and seed (or dough).
chaff shell in most barleys, it grows together with the grain. The chaff shell is very durable, it is she who protects the grain from mechanical damage. Mainly composed of cellulose, low content silicic acid, lipids and polyphenolic compounds.
Under the chaff shell are fused fruit and seed coats. The seed coat is semi-permeable, it passes water well, but retains substances dissolved in water. This property of the seed coat allows grain to be treated with water with various chemicals, which do not penetrate into the grain and do not damage the germ.
Endosperm(powdery body) is covered with an aleurone layer. It consists of numerous cells rich in proteins. In germinating barley, the aleurone layer is the site of enzyme production.
The main components of the cell walls of the aleurone layer are non-starch polysaccharides - pentosans (70%) and β-glucan (30%).
Mealy body (endosperm) occupies the entire inner part grains, consists of starch grains different size. About 98% of the dry matter of grains is starch.
Chemical composition
Protein substances in barley contain on average 10.5-11%.
Protein in barley contains:
- aleurone layer - in the form of an enzymatic protein (albumins and globulins);
- On the outer side of the endosperm there is a reserve protein (prolamins);
- endosperm - tissue protein (glutelins).
According to their amino acid composition, barley proteins are quite complete (more than 20 amino acids are included in barley grain).
Carbohydrates are represented by mono- and polysaccharides, mainly starch, the content of which ranges from 50 to 64%. Fiber contains 5–6%, sugars and dextrins up to 6% (including up to 2% sucrose and 0.4% directly reducing sugars), fat - 2.1–2.6%, minerals- 2.5–3.5%. Most of the fiber and minerals are concentrated in the film and shells of the grain.
Grain in alcohol production: theory
Barley grain has a high activity of enzymes (amylase, protease and peroxidase), therefore it is good material for making malt.
Rich chemical composition predetermines the use of cereals as a feedstock for the production of alcohol. These substances are nutritional components for yeast, and therefore fermentation in this environment will be much better and the final product will have excellent flavor.
Carbohydrates are the main source of alcohol during fermentation. In grain, they are represented by starch. Yeast converts only mono, disaccharides and some dextrins into alcohol. Starch is a polysaccharide composed of amylose and amylopectin. Yeast processes starch only if the molecule is broken down into simple carbohydrates(mono and disaccharides). This process requires enzymes.
Starch gelatinization temperature - the temperature at which swelling and destruction of the structure of starch grains occurs, this process allows enzymes to complete starch saccharification.
Accordingly, if the temperature of gelatinization is higher than the working temperature of the enzyme, then first decoction is carried out (the mash is heated to 90-100 degrees) to swell and destroy the structure of starch grains, then they are cooled to the working temperature and the enzyme is added.
What is an enzyme
Enzymes are biological catalysts protein nature, capable of activating various chemical reactions in a living organism.
Simply put, this protein molecules, which speed up chemical reactions if placed under their respective conditions (temperature and pH). For each enzyme, these conditions are individual.
According to the specificity of the impact into various high molecular weight grain polymers, enzyme preparations can be divided into 3 groups.
- Amylolytic action - promote the hydrolysis of starch. These include enzymes of liquefying, dextrinating and saccharifying effects.
- Proteolytic action - destroy (hydrolyze) protein molecules.
- Cellulolytic action - hydrolyze non-starchy polysaccharides, such as cellulose.
- Native origin - are formed in the grain during germination;
- Microbial origin - obtained with the help of mold fungi;
- Bacterial origin - cultured by bacteria
Enzymes are also divided into liquid and dry.
If microbial and bacterial enzymes are used, there is no need for grain malting. In addition, these enzymes have a wider temperature range of action compared to native ones.
There are two ways to process crops to break down starch into sugars:
- Mashing with native enzymes contained in sprouted grains. This process is a classic technology for the production of congestion. But it is quite laborious, including the germination of grain, overdoing the temperature limits during mashing, and germinated grain is an order of magnitude higher in price than ordinary grain.
- Mashing with bacterially derived enzymes. This method is progressive and gaining more and more popularity. Its main advantage is the relative cheapness and ease of use. Bacterial enzymes allow the use of unsprouted grain, which reduces the final cost finished products and also saves time and effort. Also, bacterial enzymes have a wider temperature range action that allows you to expand the scope of its application in the process.
Enzymes in Doctor Guber stores
To process grain at home, first of all, amylolytic enzymes are needed. We have them represented by the following enzymes:
- Amylosubtilin is an enzyme preparation of mesophilic bacterial α-amylase. Hydrolyzes internal α-1,4-glycosidic bonds of starch (amylose and amylopectin) and products of their sequential cleavage, which leads to a rapid decrease in the viscosity of gelatinized starch solutions at the stage of liquefaction, thereby ensuring the preparation of the wort for the action of glucoamylase. The activity is 1500 As/g. Temperature optimum of action 30-60°С
- Glucavamorin - obtained by deep cultivation of the strain mold fungus Aspergillus awamori. Hydrolyzes α-1,4 and alpha-1,6-glycosidic bonds of starch, dextrins, oligosaccharides, sequentially cleaving off glucose from non-reducing chain ends. It is used for saccharification of starch. The activity is 1500 Gs/g. Temperature optimum of action 30-60 °С
The preparations are presented in dry form in packing of 20 grams.
To work with unsprouted grains, these enzymes will be enough.
Enzymes in the production of alcohol: practice
Preparing first water solution. To do this, the dry preparation is dissolved with water in a ratio of 1:10, the water temperature is 25-30 degrees and thoroughly mixed, in this state the preparation is stored for no more than 24 hours. Next is calculated required amount enzyme.
Enzyme activity is expressed in units/g. substances.
- Amylosubtilin - 2-4 units. per gram of starch.
- Glukavamorin - 2-4 units. per gram of starch.
Calculation example:
When mashing in a machine with a volume of 60 liters with a water ratio of 1: 3, we use about 15 kg of grain (we assume that the grain in this case is wheat).
Wheat grain contains, on average, from 55 to 65% starch (table data). Let's take the average value of 60%.
This means that 15 kg of grain contains: 15 * 0.6 = 9 kg of starch.
Given the dosage of enzymes and their activity per gram of starch:
- 1 gram of Amylosubtilin contains 1500 Gs units, dosage 2-4 units. (average 3)
- 1 gram of Glukavamorin contains 1500 As units, dosage 2-4 units (average 3)
For 9000 grams of starch we need:
- 9000*3= 27000 AU to reduce viscosity
- 9000*3= 27000 Gs for starch saccharification
What matches:
- 27000/1500= 18 grams of Amylosubtilin
- 27000/1500= 18 grams of Glukavamorin
1 sachet of 20 grams is enough to saccharify 15 kg of wheat.
Calculations were made for mashing at T=60°C. At temperatures below 60°C it is desirable to increase the enzyme dosage by 20-30%.
After calculating and preparing the preparation, it is added together with crushed grain into water and mashing is carried out.
USE OF MULTIENZYME COMPLEX OF ENZYME PREPARATIONS RUSFERMENT LLC ON VARIOUS SCHEMES OF WATER-HEAT TREATMENT OF GRAIN RAW MATERIAL IN ALCOHOL PRODUCTION
Company RUSFERMENT LLC has a wide range of enzyme preparations a wide range actions. Having such an assortment, it is possible to select a multi-enzyme complex of preparations that allows you to hydrolyze both the starchy part of the grain and non-starchy polysaccharides and protein.
Starch is the main component of cereals used for the production of alcohol. This polysaccharide (α-1,4-glucan) has a high molecular weight and consists of 10,000-100,000 glucose residues linked by chemical α-glucosidic bonds into long chains. Starch consists of linear amylose (pure α-1,4-glucan) and branched amylopectin (α-1,4-glucan containing 5-6% α-1,6 bonds), and the ratio between them varies depending on the species. grains. AT plant cell starch is in the form of starch grains, which are surrounded by a shell of hardly hydrolysable non-starch polysaccharides - cellulose, xylans (pentosans) and beta-glucans.
In the process of water-heat treatment of grain, the main part of the starch goes into solution, and as a result, viscosity increases by several orders of magnitude (gelatinization effect). At the same time, part of the starch remains in its original state, since non-starch polysaccharides (NPS) form a spatial network around the grains starch and prevent its release into solution.
The breakdown of starch to glucose by enzymes can be divided into 3 stages. At the first stage, the starch grains swell and the polymer molecule dissolves.
At the second stage, the starch is broken down by the action of the alpha-amylase enzyme to form dextrins (oligosaccharides having a molecular weight less than the original starch).
At the third stage, dextrins are converted into glucose and maltose by the action of the enzyme glucoamylase, which are then fermented by yeast into alcohol.
Alpha-amylases, according to the mechanism of their action on the substrate (starch), belong to the class of endopolymerases; they carry out chaotic hydrolysis of internal bonds in the polymeric starch molecule.
Glucoamylases, on the contrary, belong to the class of exopolymerases; they attack the substrate from the end, sequentially cleaving off glucose (and maltose) residues from larger molecules.
Glucoamylases exhibit most active towards small molecules maltodextrins containing 5-50 glucose residues, and very little activity in relation to the original starch. That is why glucoamylases are used after the partial destruction of starch under the action of alpha-amylases.
AT various types grain content and composition of the starch portion and non-starchy polysaccharides (NPS) may vary (Table 1). NPS, despite their similarity to starch, cannot be hydrolyzed by amylases. Therefore, to increase the degree of starch utilization and, naturally, increase the yield of alcohol, it is advisable to use enzyme preparations that hydrolyze NPS.
For the hydrolysis of pentosans, preparations containing the enzyme xylanase are used, for the hydrolysis of beta-glucans - β-gluconase, for the hydrolysis of cellulose - cellulase. It is most expedient to use enzyme preparations containing in their composition a complex of enzymes hydrolyzing NPS.
Table 1 The content of the main components of carbohydrates in grain raw materials (%).
|
Corn |
Starch |
Pentosans |
β-glucan |
Cellulose |
Sahara |
Protein |
Fat |
|
Wheat |
55-65 |
6,0-6,6 |
0,7-0,8 |
2,5-3,0 |
9-15 (up to 25) |
1,7-2,3 |
|
|
Rye |
52-60 |
8,7-10,0 |
2,2-2,8 |
2,2-2,8 |
10-12 |
||
|
Barley |
53-57 |
5,7-7,0 |
|||||
|
Corn |
60-65 |
8-12 |
4,0-8,0 |
It is also known that during the water-heat treatment of grain raw materials, part of the protein goes into solution, and its most of forms stable gels with non-starchy polysaccharides. AT recent times the share of protein in grain has increased - in wheat it reaches 25%, and in rye up to 15%. Undissolved protein is a source of infection, deposited on the equipment and in the form of soot on the BRU. Therefore, the hydrolysis of grain protein - by necessity, allowing:
Save amino acids
- reduce foaming
- facilitate cleaning of equipment
- increase the access of amylolytic enzymes to the substrate
- increase the yield of alcohol
Today, manufacturers are increasingly using proteolytic enzymes and the effect of their use is obvious.
Thus, based on the given data on the composition of the grain and the enzyme preparations used with wide range actions of our company, we have developed tables for optimizing the introduction of enzyme preparations for various schemes water-heat treatment.
