FISH LIVER OIL

Korero (AEWS), Volume 2, Issue 22, 6 November 1944, Page 12

FISH LIVER OIL

A KORERO REPORT

It’s a fishy business. You can tell that by the smell. It meets you long before the factory manager shouts his greeting above the whirr of wheels. It’s a messy business, too. One look at the cream-cans crammed with grey, black, yellow, brown, and pink livers will convince you of that. Or a glance at the electric mincer dripping out a stream of liquid liver into pans streaked with dull colours— colours like those of the layers of sand in the little bottles on grandmother’s mantlepiece. But you will agree there are compensations when you watch the centrifuge pouring out rich, brown —oil which clears to redgold when held in a beaker against the light. It’s the fish liver oil industry, and you find it has more than visual compensations when you hear something of its history and the uses of its product. In fact, you begin -to wonder why nobody ever thought of it before. You learn that they did, but it was not until the war endangered our overseas supply of medicinal fish oils that New Zealand had to find a home-made substitute. We found something more than a substitute. We found the livers of many New Zealand fish produced an oil far more valuable than the cod-liver oil we had previously imported. ’ Livers which had always been wasted became highly prized. Fish that New-Zealanders normally shunned as a food became valuable for their livers. Once again it was a case of the war forcing us to find riches in our own back yard, but whereas

many of our wartime substitutes are only substitutes for the original, here we have found a product many times better than the overseas article The beneficial results, the manufacturers hope, will not be confined only to New Zealand. Why is fish oil so valuable ? What are its uses ? You can find answers to these questions in a factory at Newtown, Wellington. In this factory, set back in trees and shrubs on a terrace below the Karitane Home, there is a small but well-equipped laboratory. In charge is a woman doctor who is only too glad to tell you why the new industry is so vital to New Zealand’s national health. The factory produces baby foods : special mixtures which help both the ailing and the normal baby. But it is not a commercial concern. It is the outcome of the work of the late Sir Truby King, who devoted his life, his money, and his brilliant mind to improving the health of New Zealand babies. It is an adjunct of the Plunket Society, and it produces the special foods which form an integral part of the Plunket system. It makes the foods as well as possible, sells them as cheaply as possible, and uses any profits for the maintenance of its Karitane Homes both in New Zealand and overseas. New Zealand is still the only country to produce the emulsions and humanized milk used under the Plunket system. From this spick-and-span Melrose factory these products are consigned to Australia, England, Canada, South Africa, India, and many other countries as well.

We ask the doctor why fish oil is So valuable. Her answer is easy to understand. “ There are two reasons. It is a fat, and our bodies need fat. It also contains two valuable vitamins, A and D. An adequate supply of vitamin A keeps our mucous membrane healthy and guards ns against colds. Vitamin Dis the bone and teeth vitamin. For children it is the only safe protection against rickets.” “ But,” we ask, “ isn’t milk, with its calcium, as good a bone and teeth builder ? ” A simple analogy makes things plain. To build a wall you need bricks, mortar, and a bricklayer. Calcium (in milk) provides the bricks, phosphorus (in eggs) provides the mortar, and vitamin D is the bricklayer.” We learn, too, that, apart from sunshine, fish oil is the best source of vitamin D. There is little of this vital ingredient in our ordinary diet. Sunshine and codliver oil help build bonny babies, or at least provide them with bonny teeth and bones, and if children cannot get sunshine, then cod-liver oil will guard against rickets.

And are all fish oils equally valuable ? Not by any means. Before the war Karitane Products imported 10,000 gallons of -liver oil a year. It came mainly from England and Norway. But 200 gallons of hapuka-liver oil has as much vitamin A and 400 gallons as much vitamin D. This means that our own groper, plentiful in New Zealand waters, contain an oil with fifty times more vitamin A and twentyfive times more vitamin D than the cod-liver oil we previously imported. Ling is next in value, and then comes the previously despised shark, which produces an oil high in vitamin A and, because of its size, a lot of it. Kingfish and barracouta also have valuable livers, and though the factory processes cod livers, it prefers the others because of their better quality. How long have we known the health-giving properties

of fish liver oil ? For centuries ; ’ but up till twenty years ago the usual method of extracting it was to rot the liver in the sun and collect the oil that remained. A high time must have been had by both manufacturer and patient. This knowledge that the smell is better is small comfort when you get your first whiff of the Island Bay factory. Even though the livers arrive frozen hard, and are salted down and kept in a freezer, there is a fruity flavour to the air both inside the factory and out. But you get used to it, and in no time are interestedly watching the manager show you the difference between the liver of a shark and a hapuka. You notice, though, that he hurries to wash his hands. The manager explains that when the war began Karitane Products had good stocks of imported oil and it was not until 1943 that the factory was started. In eighteen months it has produced more than 10,000 gallons of oil and has exported 5,000 gallons to the Ministry of Food in the United Kingdom. The manager tells you New Zealand will never again import fish liver oils. In fact, she will be able to help less fortunate countries if the supply of our raw material remains plentiful. The factory was built at Island Bay, the harbour of Wellington’s fishing fleet. More livers were needed than Wellington could supply, so a drive was organized

among fishermen from as far south as the Bluff to the northern boundaries of Wellington Province. They were offered is. a pound for what they had previously dumped in the sea. Now the creamcans come in from all parts of New Zealand, their contents frozen hard, for it is essential to keep the livers fresh for the best-quality oil. An Auckland factory handles the northern trade, but the Island Bay concern gets enough to keep it busy, and hopes for more than enough when the war releases both trawlers and fishermen for the fishing fleets. Half a ton of livers a day is their present maximum, but additions now in progress will treble the weight the factory can handle. The size of fish livers varies. Hapuka, dogfish, kingfish, and barracouta average from £ lb. to 1 lb. The ling liver weighs from 2 lb. to 3 lb., but the shark varies from 5 lb. to 50 lb. One yielded an 84 lb. liver, which is an all-time record and likely to remain so. Other’fish livers are accepted, mainly to keep the good will of fisherman ; they are treated to produce an oil of high value as a stock or poultry food. The livers are first sorted, washed, and finally minced into a large pan. Because they contain only 10 per cent, solids, the livers come from the mincer with the consistency of a thick cream. These pans are emptied into vats

holding 100 gallons and the heat, direct steam, is turned on. Ling, shark, and the others are heated for two hours at 200 degrees F. Some livers need longer and more specialized treatment, and they are digested by a special process for forty-eight hours at a temperature which must remain between no degrees and 120 degrees. All this time an agitator keeps the stew continually moving. After heating, the contents of the vats are pumped up to an agitator pan where they

are thoroughly mixed and from which they gravitate to a super-centrifuge. This machine is like a super-separator and, retaining the solids in its core, throws out the water through one spout and the oil through another. The core revolves at 16,000 revolutions a minute. To see the small amount of solids that are left in the centrifuge makes you realize the livers are largely liquid. Only a quarter of a kerosene tin from a day’s workingit makes good garden manure ! The quantity of oil in a liver varies with different fish. Hapuka contains about 10 per cent. ; half a ton of liver produces about 10 gallons of oil, Ling contains 25 per cent. ; and shark, as well as having the largest liver, provides the highest proportion of oil 50 per cent. The oils vary also in colour and consistency. Hapuka gives a red-gold oil, the same colour as that of the mixed inferior livers but heavier in consistency. Shark oil is free flowing and a light gold. Ling oil is a pale yellow. But light or heavy, yellow or brown, they are run off into 44-gallon drums and sent to the factory at Melrose to wait for shipment or to be included in little Johnny’s “ Karil ” emulsion. The factory uses plenty of this liver about 600 lb. of oil to every 2,000 lb. of emulsion.