Making the best of potatoes
The proportion of starch extracted from potatoes is relatively low compared with other plant materials. To maximise the output of potato starch, a special, industrial-purpose potato is often used. With an unpleasant taste due to the high starch content, this industrial potato is cultivated and processed during the European ‘potato starch season’ from August to April.
Potato starch production involves a well-defined process starting with the delivery, sorting, washing and grinding of potatoes to produce a potato juice. Starch and fibre solids are then extracted from the juice.
The potato juice obtained in the starch extraction process contains proteins, salts, sugars and amino acids. Potato protein has good nutritious qualities, similar to egg and soy protein, and offers attractive commercial potential for ingredients manufacturers.
The protein is separated in a liquid process involving heat treatment, pH adjustment and separation. For industrial and feed applications, the separated wet protein fraction, consisting of approximately 40 percent solids, is dried in a gentle process.
We offer several types of spray dryers, including our Zeta Dryer, which are ideal for the extraction of potato proteins.
Potato fibres are used as a food additive to improve texture and stability of food products, contributing to dietary enrichment, calorie and carbohydrate reduction. These fibres are processed to obtain a high–quality, high–nutritional value product. Around 90 percent of the fibre fraction can be used for human consumption, with the remaining suitable for animal feed or bio-gas production.
We offer a unique process for separation and drying of fibres from potatoes. This includes the Zeta Dryer, which is the optimal drying solution for this process.
Potato juice concentrate
The processing of potato starch produces large quantities of potato juice. Although potato juice is often used as a crop fertiliser, costs are very high and large storage units are required outside of the fertilising season. Furthermore, the fertilising effect can be poor and the liquid can emit strong, unpleasant odours.
These issues can be mitigated by concentrating the juice water to above 40 percent. This increases the commercial value of the potato juice considerably. The concentrate can be stored in smaller covered facilities until it is next required.
We can assist in designing and implementing an effective process for concentrating potato juice for excellent commercial returns. This includes recovering most of the energy required for the evaporation process, which can then be used in the starch plant.
We design and supply evaporators with mechanical vapour recompression (MVR) at production capacities exceeding 100 tons/hour, if required.