People will say, dry sweet potato starch process and fresh sweet potato is not the same, anyway is the sweet potato starch, what difference will there be?Kaifeng sweet potato starch production equipment company tells you, the difference is not a point.Today, we are going to talk about the process of producing starch from sweet potatoes. What's the difference?
Pretreatment of raw materials: fresh sweet potato harvest, usually cut it into sheets or filaments, after the sun or fire drying, made of sweet potato.The dried sweet potato is inevitably mixed with various impurities in the process of processing and transportation, so it must be pre-treated.There are dry and wet pretreatment.Dry method is the use of screening equipment and air separation equipment.Wet treatment is using a washing machine or bucket.
(2) soaking: in order to improve the yield of starch can be soaked in alkaline water.Generally with saturated lime milk or 1% dilute alkali solution to add soak water, make the ph value of 10-11.Soak for about 12 hours at a temperature of 35-40 degrees Celsius.After soaking, the water content of sweet potato chips is 60%.
3, crushing and grinding: soaked sweet potato chips with water into the hammer chip crusher for crushing, reach a certain fineness, through the sieve out of the machine.
(4) screening: dry sweet potato after crushing the sweet potato paste is also known as liquid, must be screened, separation of residue, that is, fiber.Usually use the flat shake sieve, feed liquid into the sieve surface, the requirements of uniform screening, constantly dripping water, starch with water through the sieve hole into the slurry pool, and residue retained on the sieve surface from the end of the sieve.Screen cloth is 120 mesh nylon cloth.In the screening process, because the material contains pectin and other viscous substances in the screen, affecting the screen separation effect, therefore, the screen cloth should be often washed, in order to ensure the screen hole unimpeded.
5] flow tank separation: after the starch after fine screening, generally use flow tank to separate protein.Its advantages are that it is easy to build, USES less steel, saves energy and is more stable to operate.Disadvantages are large footprint, intermittent operation, low separation efficiency, starch loss, poor working conditions.
6, alkali, acid treatment and cleaning: in order to further improve the starch purity, in the process of cleaning starch, but also through the alkali, acid treatment.Starch alkali, acid treatment and cleaning are all carried out in cement pool with mixing device. The size of cement pool is determined according to the production capacity, and the speed of agitator is about 60 RPM.The starch was treated by alkali, sodium hypochlorite and acid.Its purpose is to dissolve acid-soluble proteins, neutralize the alkalinity left by alkali treatment, and inhibit the activity and reproduction of microorganisms.
· centrifuge separation and drying: the starch obtained after cleaning has high moisture content, which must be dehydrated by centrifuge first to reduce the starch moisture content to below 45%.Some factories produce or use wet starch directly.In order to facilitate storage and transportation, the dehydrated wet starch needs to be dried to reach the required moisture content.Starch drying can use airflow drying, because it has the advantages of fast drying speed, high efficiency, high production capacity and low equipment cost.
As can be seen from the above, the process of producing starch from dry sweet potatoes is different from that of fresh sweet potatoes. However, no matter you are dry sweet potatoes or fresh sweet potatoes, our company has equipment for producing starch. We can customize it for you.