Potato starch production is very lucrative and moderately challenging. Starch production involves the isolation of starch from plant based sources. The product is used in food processing industry including production of dextrin, starch derivatives and hydrolysates.
Use of potato starch
Potato starch has many applications in non-food products and food manufacturing. Modified starch is used to change material properties and found in plastics, drilling fluids, adhesives and emulsion stabilizers. More are wallpaper adhesives, paper coating, textile finishing and gummed tape. Starch derivatives in culinary applications are found in bakery creams, instant soups, potato chips, wines and noodles.
Non-food products
- food manufacturing
- change material properties
- found in plastics
- drilling fluids
- adhesives
- emulsion stabilizers
- wallpaper adhesives
- paper coating
- textile finishing
- gummed tape
Starch derivatives in culinary applications
- bakery creams
- instant soups
- potato chips
- wines
- noodles
Sourcing Potatoes
Some countries specifically cultivate potato for starch production. Top cultivators are India, China, Poland, Japan, Germany, Ukraine, Austria and Sweden. There are two ways starch producers source raw materials. They are bought for starch production or sourced as bye products. Most potatoes are ideal for starch production however the best variety are those with high starchy content.
Potato Starch Processing Equipment
Potato starch processing equipment are either locally fabricated or imported. Machinery are potato starch separating equipment (rasper). Others are starch concentration and rafining equipment and cleaning/washing equipment. More are the starch dewatering equipment, starch drying (flash dryer), packaging equipment and silo.
Starch Processing Equipment
- potato starch separating equipment (rasper)
- starch concentration and refining equipment
- cleaning/washing equipment
- starch dewatering equipment
- starch drying (flash dryer)
- packaging equipment
- silo
- vacuum filter
- starch vacuum filter
- starch hydrocyclone washing machine
- hydrocyclone separator for starch
- starch centrifugal screen
- drum washer
Potato Starch Production Process
The production process starts from the harvesting on the various farms. The potatoes are transported, unloaded and cleaned. Next is the rasping process then the potato juice separation. The starch is then extracted and starch milk rafintion before dewatering of refined starch milk and finally starch drying.
Raw Materials in Preparation of Starch
There are many starchy plants used as raw material in the production of starch. In China, Europe and America starch is isolated from maize. South Africa and south East Asia produce starch from tapioca while many countries isolate the material from sorghum or rice. Australia and Europe use wheat or potatoes to isolate the material.
Raw materials used in preparation of starch
- Wheat
- Tapioca
- Sorghum
- Maize
- Potatoes
- Rice
Potato starch production
Potato delivery
First in the value chain is delivery of the tuber by road or rail. The starchy plant is unloaded depending on the state of the plant. Wet are unloaded using strong jets of water while tippers or elevator system is used for dry ones.
Cleaning process
Before cleaning stones, straw and dirt is removed from the potatoes. Then coarse cleaning is done with scrubber by channel during transportation. Next any stones, sludge or dirt that escapes is removed before washing is done. The potatoes are washed with water, purified and recycled to go through the cleaning process again.
Tuber rasping
To release starch the cell walls of the potato tubers goes through a rotary grater. This extracts about 85% of the starch while the remaining starch is in the mesh. The mesh is processes to remove the remaining starch before oxidization takes place.
Potato juice and starch extraction
Potato juice is extracted and pulp is moved to the washing station. A strong stream of water is then applied to the pulp diluted with water. This flushes out the milk starch (raw starch milk) which is basically potato juice and small fiber contaminants. The dewatered pulp becomes a waste product.
Starch milk raffination
The raw starch milk is then sent through a purification process to remove the contaminants. Parallel hydrocyclones and screens including condensation are used to remove the fibers and juice in raw starch milk. Desending bihydrocyclones and sulfurous acid is applied to refine the starch.
Dewatering and drying
Dewatering of refined starch is needed to reduce moisture by 20%. Two stages of dewatering are use of rotary vacuum filter then drying of moist starch. A drying process is applied with the aid of a pneumatic dryer then the starch is separated from hot air in a cyclone system.
The intensive water separation alongside the high temperature drying heats the surface about 40 degrees centigrade while water content in dried starch is about 21%. The resultant starch is stored in silos while packaging is done in paper bags or jute bags.
Waste Products
There are three waste products derived from the starch extraction process. The waste products are juicy water, potato juice, potato pulp. Potato pulp is the resultant mash from the washing process, juicy water is a liquid product from refined starch milk while potato juice is the product after separation of potato pulp. Potato protein is extracted from juice through a coagulation process and used in animal feed and fertilizer.
