TINNED MEAT

Wairarapa Times-Age, 2 May 1939, Page 3

TINNED MEAT

FRESH AFTER 115 YEARS CARRIED on polar expedition. INSPECTION BY SCIENTISTS. The process of preserving food by cooking and sealing in airtight vessels, which are subsequently heated, was invented by a Frenchman named Appert at the end of the eighteenth century. He used glass jars. The introduction of tins was made in England by Hall and Donkin about 1813; they supplied 23,779 tins of 15 varieties of preserved meat and vegetables io the Admiralty in 1818, and in 1824 supplied a large number of this of meat and vegetables to Sir Edward Parry for the provisioning of his expeditions in search of the North-west Passage. Two tins which were taken to the Arctic on Parry’s third expedition in 1824 were brought back unused and taken again on the fourth expedition in 1826, and again returned to London unused. One tin contained four pounds of roast veal and the other two pounds of carrots and gravy, and they were kept in the museum of the Royal United Services Institution of the National Maritime Museum at Greenwich respectively. The condition of the food and the tins after 115 years is of considerable scientific and practical interest, and the museum authorities gave permission for them to be opened and their contents examined. This has been done by J. C. Drummond. W. R. Lewis, T. Macara, G. S. Wilson, and H. L. Shipp, and their reports have been delivered to the food group of the Society of Chemical Industry. IN PERFECT CONDITION.

When the tin of veal was perforated there was an outrush of gas, which suggested that the internal pressure in the tin had been at least 151 b per square inch. The gas was analysed and proved to bo 85 per cent hydrogen, with some nitrogen and carbon dioxide, find a trace of oxygen. The meat was bright pink, like salmon/ and rapidly lost its colour after exposure to the air. When a portion was re-sterilised the pink colour returned. The meat was in perfect condition, and the larger pieces looked quite like recently-cooked veal. Some of the veal fat was removed and analysed. The composition was very similar to that of fresh veal fat. The most surprising result was that the 115-year-old veal fat had still 60 per cent as much vitamin D (the vitamih which prevents rickets) as the fresh veal fat. It is evident that canned foods may keep some vitamin activity for a very long time. Portions of the meat were given to 12 adult rats for 10 days. They were consumed with avidity and without ill-effects. An adult cat ate two and a half ounces of the meat at one meal without harmful effect. BACILLI DISCOVERED. The 21b tin of carrots and gravy also contained a gas consisting largely of hydrogen. The evolution of the gas is due to a/ reaction between the metal Container and the slightly acidic contents. When the tin was opehed the carrots looked as if they had been freshly cooked and allowed to go cold. The bright orange colour became dull after a few minutes. Bacteriological examination of the veal appeared to show that it contained six strains of bacillus spores —that is, quiescent bacilli. .It is thought that these were derived from the flour used in making the veal gravy. If this is so, and the spores did not enter the meat until the can was opened, it is a unique fact, as the survival of the spores in the living condition far more than a hundred years is without parallel in bacteriological records. The tinned food supplied by Donkin and his partners to the Admiralty included a variety named “Soup and Bouilli.” The word bully-beef was coined by seamen in their efforts to pronounce Bouilli. OTHER ANCIENT FOODS. Some other ancient preserved foods have been examined by the same investigators. They have analysed a portion of a cake of “portable soup,” which was probably made in 1771, arid was carried by Captain Cook on his voyage of 1772-75 and has since been in the museum of the United Services Institution. This cake is a flat rectangular slab about 4in square and marked with a broad arrow. The material was very hard and fractured like a piece of glue. It dissolved easily in cold water, and made a clear, pale yellow solution without smell or taste. It contained 23 per cent, of protein, and appeared to be a desiccated clear broth prepared from meat and bones. It had remained virtually unchanged for 160 years. Sir John Pringle, the president of the Royal Society, who was dismissed from his office by George 111 after the outbreak of the War of Independence for supporting Franklin’s theory of lightning conductors, has recorded that portable soup was made by “long boiling the most putrescent parts of the meat” so that it “is reduced to the consistence of glue, which in effect it is, and will, like other glues, in a dry place keep sound for years together.” An examination of the inside of the can which contained Parry’s 1824 veal showed that one half of it was still bright and the other half was corroded in patches. It appeared that the can had been scoured with sharp sand before filling, and the corrosion followed many of the scratches.