POTATO STARCH

Ashburton Guardian, Volume 61, Issue 44, 2 December 1940, Page 3

POTATO STARCH

NEW INDUSTRY IN THE COUNTY.

THE FACTORY ALMOST READY.

THE METHOD OF EXTRACTION

The extraction of starch from potatoes, an industry not previously known to either New Zealand or Australia, is expected to commence in the Ashburton County toward the end of the present week. An old iron shed 60 feet long on the property of Mr T. C. McLachlan, “Corwar,” Barrhill, has in less than a month been adapted for use as a factory, and almost all of the machinery is installed. A good quantity of potatoes is available, for immediate processing.

The shed being used is admirably suited for the purpose as a large waterrace flows nearby, while under the building, which is on piles, is a large well about 12 feet deep. There is thus ail adequate supply of water. Further, the Rakaia River, about 170 yards distant, is conveniently situated for the dumping of refuse. The drainage system appears to be satisfactory.. The shed has been strengthened and some new flooring has been put down. The Glassworks building, near Ashburton, was considered unsuitable as there' was scarcely an adequate water supply, the building was larger than was required, and, being close to the town, the dumping of refuse might have proved a difficulty. The installation and provision of the necessary equipment has been undertaken by the Dunedin firm, Messrs A. L. S. Cassie, Ltd, the director of which (Mr F. Edmonds) has been one of the brains behind the work. The whole task of making and installing the equipment has presented some difficulties, as there is no similar factory in either Australia or New Zealand from which to copy, and the firm, with a rough idea of European factories, has had to devise its own equipment.

Mr Edmonds stated that all difficulties had been overcome, and expressed confidence that everything would work well after the few first adjustments had been made.

Practically all of the equipment has been made in Dunedin. A few brushes imported from Australia have arrived in New Zealand and are expected in a day or two. An Interesting Process. The process by which the potatoes are converted into starch is an interesting one. Almost all potatoes can be used. They are first piled into a grader, which is used mainly for the purpose of shooting them into the next piece of machinery, the “washer.” This, a round barrel-like object, with four brushes on the inside, as it revolves at 15 or 16 times a minute, washes the dirt from the tubers. They are automatically shot out of the washer and carried toward the , roof by an elevator into a hopper, from which they fall into the “rasper,” where they are torn asunder and the pulpy remains fall into a tank below. The contents of the tank are pumped into, an narrow, shallow oval tank known as the “sieve.” A gauze is placed in the sieve so that liquid may pass through into the bottom. By playing a high pressure of water on the pulp from pipes along the side of the vessel, the unpurified starch settles to the bottom, leaving the pulp, tvliich moves up to one end and is disposed of. The impure starch is' conveyed by pipe, on the principle of gravitation, to six long, narrow and shallow tin troughs, in which the starch settles after about 10 minutes, leaving the water and impurities on the top. By means of a suction pump attached to a flexible hose these impurities and the water are removed. An advantage of the building is that it has floors at two heights, allowing liquids to be easily conveyed by pipe from the top to the bottom floor. The starch is shovelled into rewash tanks, where it is mixed with water and agitated before again settling down, the water being removed as before. The final stage is when the starch passes into a vacuum diying pan. It passes from this in, a semi-dry state. It is proposed to dry out this material in a nearby wool shed before bagging. The mechanical part of the equipment is run completely by electricity there being two motors, of ten and three horse-power. § The pulpy potato material left over from the manufacture will probably be dumped into the river. I.t is stated, however, to be excellent for pigs, as a part of their diet. The Starch in Potatoes. The normal starch content of potatoes is stated to be 15 per cent., although it is known to have reached as high as 22 per cent. It, therefore takes about seven tons of potatoes to give a ton of starch. The scientific part of the organisation has been in the hands of Dr. R. G. Gardner, an analytical and consulting chemist and industrial bacteriologist. The cost of the plant is stated to be between £IBOO and £2OOO. Once in operation the co t st of running should not be very high. It is estimated that somewhere about five men will be required to control and supervise the equipment: It is intended to run the factory 24 hours a day. About 50 tons of potatoes will be handled daily.

Potato starch was formerly bought from Holland, Denmark and! Poland hut as a. result of the war these supplies have bepn cut off. The demand for the starch is for making dextrine for practically all pastes. Dextrine is also adhesive, being used for many industrial purposes. Glucose also can be manufactured from starch. Potato starch is not quite as good for laundering as that made from rice. A ready market for potato starch is stated to exist in New Zealand and recent quotations gave the price at £3B per ton for first grade, and £32 per ten second grade. The Government is allowing a. subsidy of £6 on every ton of starch produced at the Barrhili factory.

Potatoes are so short in Australia,

the warm climate being not favourable to their grotfth, and the nrices always on so high a level that the Commonwealth can never be a rival in the potato starch industry, but always a market.

The industry possesses a great possibility of expansion, for the manufacture of dextrine and glucose are natural sequences of starch-making. It should also stabalise the potato industry and be a valuable asset to the country in extending industrial activ-. ities.

The factory has aroused considerable interest in the district and there have been many visitors to “Corwar.”