Potato starch is the main material for the preparation of culture medium. There are two ways to apply potato starch in production or experiment: one way is to wash the new potatoes (potatoes) and dig out the buds, peel off the skin after weighing, take 200 grams of potatoes, cut into julienne strips, boil in 1000 ml of water for 15 minutes to 30 minutes, a little bit cooled, and then filtered through four layers of gauze, take the filtrate and replenish the water with enough water for 1,000 milliliters! This method of utilizing potato starch should be made ready for use as needed in seed production.
Another method is to peel and remove the sprouting eyes of the potato into a fine pulp, held in a container with water and four layers of gauze filtration 2 to 3 times, the filtrate will naturally precipitate, after the end of the precipitation to remove the supernatant night, and then, the starch will be thinly spread on a glass plate to dry. Finally, the fully dried starch will be sealed in a container, so that it can be used at any time in the future when the need for seed production. For seed preparation, 20 g of starch is weighed and 1000 ml of water is added. The nutrient content of potato starch prepared in this way is virtually undamaged.
3, wort preparation method:
Take 1 kg of barley soaked in warm water for a day and night filtered out, flat in the tray, covered with layers of wet gauze moisturizing, insulation, and then, placed in 24 ℃ under the condition of culture, to be most of the malt out and up to the length of the wheat grain itself when cleaned, drained, mashed, filtered, precipitation, and then take the supernatant night. 1 kg of barley germination prepared by supernatant night. 1 kg of barley germination prepared supernatant night can be matched with 2000 ~ 3000 ml of culture medium. Fresh wort should be used now, and the excess should be kept in the refrigerator.
The germinated malt can be dried and stored in the sun, and when needed, 200 grams of malt can be crushed and added to 1000 milliliters of water.
The method of determining saccharification: take 0.5 ml of saccharification solution, add iodine drops, such as the absence of blue that is the completion of saccharification.
4, yeast juice preparation method:
Whether it is dry malt prepared wort or fresh malt prepared wort need to be at a temperature of 80 ℃ ~ 82 ℃ under the conditions of saccharification for 2 ~ 3 hours, and the determination of the saccharification is complete when the boiling and filtration standby.
Take dry yeast 7 to 10 grams, add 1000 ml of water, boil, leave to clarify, take the supernatant, after filtration, can be used instead of yeast paste. Add 10 ml of yeast juice per 1000 ml of medium.
Yeast can also be crushed dry yeast, add the right amount of water, at 53 ℃ conditions, insulation for two days and nights, the yeast dissolves on its own, yeast self-solution. Diluted with water to 1% (i.e., 100 ml of water containing 1 gram of dry yeast), and then boiled for 10 ~ 15 minutes, cooling, adjust the PH to 4.5 sedimentation, take the supernatant, and then adjust the PH to 7 ~ 7.4 after sterilization. Add 5 to 10 ml of yeast self-solution per liter or add as appropriate.
5, natural medium or semi-synthetic medium modulation:
Modulation of natural medium or semi-synthetic medium should be based on different materials and different processes. Generally speaking, the selected materials are grains, plant stems, tubers, roots and skins, etc., should be made first in the leaching solution. Cereals should be washed in water; potatoes, sweet potatoes, taro, fenugreek and other stems and tubers, should be washed first, peeled, and then weighed; woody materials should be selected young and tender branches or sapwood and crushed or cut into small pieces; berries should be mashed into a puree, weighed and replenished with the appropriate amount of water, and then boiled, change the fire to cook for 10 to 15 minutes (grains of the time should be extended to 1 to 2 hours), while still hot, with layers of gauze, filtered, replenished with water! Add agar, continue to heat until the agar is dissolved and then add the other ingredients, sugar in the cease-fire after adding and fully stirred to dissolve. At this point should be divided into test tubes or triangular bottles, petri dishes and other containers while hot.
Rice flour, cornstarch and other starch materials, after weighing, add a small amount of cold water to make a paste, and then add the rest of the water, and then boil and four layers of gauze filtration, take the juice and then heated and add the other ingredients according to the aforementioned method, until the various materials are fully melted and then hot test tubes or other containers.
Soluble starch, dextrin, potato starch in the weighing of a little cold water into a slurry, and then add the rest of the water, boil and add agar, and then add the other ingredients as described above, fully dissolved and divided into containers.
Humus, stable manure, compost leachate, according to the aforementioned method of boiling, the filtrate in a beaker, put 4 ℃ below the low temperature of standing overnight, and then suck the supernatant, make up the water, and then add agar, inorganic salts and sugars in turn. Production methods 1. washing and grinding: the washing process of potato is carried out in the washing machine. Remove the mud, stones, stems and leaves and the impurities such as mud and sand adhering to the surface of the potato, the amount of water is about 5 times the amount of raw materials, after washing, sent to the grinder for processing. The grinder used has two types: tooth plate type and hammer type.
2. Sieving: after grinding the potato paste should be sieved. The traditional method is to use flat shaking sieve, modern potato starch factory are used centrifugal sieve. In the sieving process to add water to wash, sieve under the starch milk, sieve on the slag for the second sieving, recovery of part of the starch, after cleaning the starch slag can be used as feed.
3. Separation and cleaning in the flow tank: the starch milk from the sieving section is first separated from the protein and other impurities in the flow tank, and then cleaned in the cleaning tank. The yellow slurry water with starch from the flow tank is sent to the flow tank to recover starch, and then the secondary starch is obtained through the cleaning tank.
4. Dehydration and drying: after starch cleaning, the moisture content is very high, it must be dewatered by centrifuge to get wet starch with moisture content of 45%, and dried to dry starch with equilibrium moisture of 20% by air dryer. Production method The production process of large potato starch is basically similar to that of small-scale production, and its process flow: Potato - hydraulic conveying - cleaning and conveying - secondary cleaning - cleaning and de-stoning elevation - crushing, separating -Desanding - Concentration and refining - Vacuum dehydration - Air drying - Finished product packaging.
1, cleaning process and equipment
Mainly to remove the material appearance of the skin layer of the sand, and wash to remove the material tuber skin, to remove the stone cleaning machine is to remove the hard impurities in the material. Cleaning of raw materials for starch production is the basis for ensuring the quality of starch, the cleaner the cleaning, the better the quality of starch. Conveying is to pass the material to the next process, often conveying also has the function of cleaning. Commonly used conveying, cleaning, de-stoning equipment are: hydraulic flow tank, screw cleaner, inclined squirrel cage cleaner, slurry leaf cleaner, de-stoning on the cleaning machine, (flat) squirrel cage cleaner, rotary cleaner, scraper conveyor and so on. According to the soil and material characteristics can choose some of these combinations, to achieve the high degree of cleaning and conveying convenient requirements.
2, raw material crushing and equipment
The purpose of crushing is to destroy the organizational structure of the material, so that tiny starch particles can be successfully disintegrated from the tuber to separate. Crushing requirements are:
1. As far as possible to make the material cell rupture, release more free starch particles;
2. Easy to separate. Do not want the skin residue is too fine, the skin residue is too fine is not conducive to the separation of starch and other ingredients, and increase the difficulty of separating the fine residue.
3, screening process and equipment
Starch extraction, also known as slurry residue separation or separation, is a key link in starch processing, directly affecting the starch extraction rate and starch quality. Crushed materials are fine fibers, the volume is larger than the starch particles, the expansion coefficient is also larger than the starch particles, the specific gravity is lighter than the starch particles, will be crushed materials, water as a medium, so that the starch and fibers are separated from each other.
4, washing process and equipment
Starch washing and concentration is dependent on the starch cyclone to complete, the cyclone is divided into the concentration cyclone and washing and refining cyclone. The starch slurry after passing through the sieve firstly passes through the thickening cyclone, and the underflow enters into the washing and refining cyclone, and finally reaches the product quality requirement. The equipment is equipped with a full set of automatic control system, using high-quality cyclone tube and optimized discharge scheme, can make the last cyclone excluded starch milk concentration of 23Be', is the ideal choice for starch washing equipment.
5, starch dewatering
Potato starch is often used vacuum suction dewatering machine. It can realize automatic feeding, automatic dehydration and automatic cleaning.
6, starch drying
Air dryer is the use of high-speed flow of hot air so that the wet starch suspended in it, drying in the air flow process. It is characterized by high heat transfer coefficient, large heat transfer area and short drying time.
7, starch cooling and sieving packaging
The temperature of starch is high after drying, in order to ensure the viscosity of starch, it is necessary to cool down the starch rapidly after drying. The cooled starch enters into the finished product sieve, and enters into the last packing process under the premise of ensuring the fineness and yield of the product.
The starch residue produced in small factories is directly used as feed without drying, while most of the starch residue in large factories is dried. In order to save thermal energy consumption, it can be first dewatered by the press, and then dried by air dryer. The crushing of potato is divided into primary and secondary crushing, and the purpose of crushing is to rupture the cells of the tubers as much as possible and release starch granules from them. Primary crushing is to crush the washed potato pieces directly, and the crushed slurry is a kind of mixture, which is composed of ruptured and unbroken plant cells. The starch released from the cells is free starch, the starch remaining in the unbroken cells is bound starch, and the bound starch is discharged with the residue. The degree of potato cell disruption can indicate the extent to which starch granules are taken from the cells.
Crushed potato tuber equipment have tracing machine and pounding crusher. In the potato starch processing is often used in the first crushed paste extraction of free starch, the extraction of free starch after the crude residue for additional grinding for the second grinding. The second grinding can improve the potato grinding efficiency of 2-4%, in order to improve the effect of the second grinding, should try to make the residue dewatering, and make the residue in the dry matter of not less than 10-20%. In the crushing operation, if the potato rot is not sufficient, the cellular tissue destruction is complete, the starch is not easy to take the net, starch separation can not be carried out quickly, if the grinding is too fine, will also cause separation of starch difficulties. Potato tubers after grinding, the production of starch water is required to be colorless and transparent, soft water without calcium, otherwise, the water impurities and color will be infiltrated into the starch, affecting the quality and color of starch.