HEALTH NOTES

Nelson Evening Mail, Volume LXIV, 21 February 1931, Page 12

HEALTH NOTES

PURITY OF FOODSTUFFS SOME COMMON ERRORS EXPLAINED (Contributed by the Department of Health.) The real meaning of the word “purity’ is frequently misunderstood insofar as it is governed by the law. Many food substances in their natural condition which ordinarily might be considered the acme of purity could be quite unsuitable for consumption as food. A vegetable oil extracted by ordinary pressure from natural materials, and not further treated might be rancid in odour or bitter-tasting, or might bo cloudy or otherwise objectionable in colour. Such a state of “natural purity” would in many eases preclude the use as food of an otherwise wholesome article. On the other hand substances such as butter.and cheese may contain salt and added colour or a fruit juice contain a small amount of harmless preservative and yet be described as “pure” within the limits of tho Regulations, under the Sale of Foods and Drugs 'Act. In a somewhat similar, manner the word “adulterated” in its legal sense is rather wider than would be ordinarily supposed. Milk, for instance, can be described as adulterated for any of the following reasons: (a) If water is added; (b) if some of the cream has been taken off; or (c) if it is stale.

FOOD STANDARDS u ’ '”.*** ;• *' \V -• . A great ‘ foature of -the New Zealand regulations is -tho provision of standards for all the common foodstuffs, which haS' the effect, of keeping Ihe quality at a norhial level and prevents the use of extraneous substances as fillers or makeweights. Milk must contain not less than 3.25 per cent, of milk fat (cream), butter must not contain more than 16 per cent; 6f water, bread not more than 45 per cent, of water in any part of the loaf, baking powder must produce nob less than 10 per cent, by weight of carbon dioxide gas, vinegar has a specified acidity strength, ice cream must contain not less than 10 per cent, of milk fat, essence of (lemon must have at least 10 per cent, oil of lemon.

LABELLING, SAFEGUARDS . Then there are safeguards for the ( public in the matter of labelling. No 1 statement is permitted which is likely •to mislead the purchaser as to the nature or quality of the goods describ--1 ed, and in some cases certain statements are specifically prohibited, as, for in- . stance, in the labelling of custard powd- : er which, is merely a farinaceous or i- starchy base with added colour and flavour. There must be-no mention of . eggs or any suggestion of “creami- . ness”; and in the labelling of “flavoured” cordials with a fruit. name but 1 which are not made entirely from the 1 -juice- and--containing added colouring, the word “pure” must not bo used; in artificial .cordials and beverages pic- • tores.of fruit or any device suggesting fruit must not be used in the labelling. There are son:o terms loosely qsed in ordering foodstuffs: The average housewife and probably tho majority of grocers in-referring to rice probably mean polished rico. The regulations ' describe rice as the ' hulled grain of Oryza Saliva. It shall not contain any added substance. After the rice grain has been hulled and most of the husk : removed by winnowing the grain is passed into a-polishing apparatus where it is : deprived of the pericarp, subpericarp, and the germ. The subpericarpal layers are yellow so that rice which ,is . not highly'’polished is of that colour. But rice sent to the European markets is. usually, rendered white by the removal of the sub-pericarpal layer, and the subsequent facing or glazing of the grain with, talc. ' It is, strictly, an offence therefore to sell polished rice when rice is asked for. In order to provide for a reasonable standard _of purity in polished rice the regulation limits the amount of talc to one-half of one per cent-. This can be expressed as an amount of talc present equal' in quantity to. one grain of rice in every two' hundred grains. Talc is silicate of magnesia., Quite - a number of., the-’ articles sold by grocers as' foodstuffs and otherwise come within tho - definition, of drugs. Drugs must/'."comply With tfie standard of the British 'Pharmacopoeia, that is, they must be of the quality used by chemists in dispensing ' medicines. Tartaric acid,- citric acid and bicarbonate of Soda are used in food. Bicarbonate. of soda commonly? knowp. as baking soda is sometimes confused with carbonate of soda, which is called .washing Soda. Tartaric acid end citric acid are very similar in taste, but the former is derived from grapes, while the latter is derived from the citrus fruits, principally lemons. There is a great. difference between borax and boracic acid. Both are in the British Pharmacopoeia, but- although borax. is usually bought by tlm housewife for washing purposes, it is used in the purified form by the chemist for making such preparations as borax eye lotion, borax gargle and glycerin, of borax. . ,Its chemical name is biborate of sodium. Boracic acid is also called boric acid and is more commonly used in making pharmaceutical preparations. . The use of the powder externally on raw surfaces is dangerous, although wet boric bandages are harmless. ,The acid is also used in the form of lint, gauze, and wool. Solutions are of service as mouth washes, eye lotions and such. like.,, ... ..Boric acid has been, used as. a food preservative, but-such .is now prohibited. It is well known that a number of natural or simply prepared food substances supply, their own preservatives. Fruits such as cranberries and . bilberries contain benzoic acid; boiled, sugar sweets, caramel, and smoked fish, formaldehyde. Samples of fresh herring have; been found to contain traces of formaldehyde which can also be found as a natural constituent egg yolk, wheat bran, butter, codliver oil. spinach, and various fruits.Cases, are recorded of deaths from oxalic acid poisoning due to eating rhubarb leaves cooked with. soda. Arse'iiic has been discovered in shell fish and also in both smoking atod chewing tobacco in amounts reaching over i grain 1 per pound, though the cost of tobacco would appear to .make this form of arsenical'poisoning impossible for any but the wealthy. It will be seen, then, that the term “purity” may not always mean what it appears to indicate. In the case of refined sugar we have, perhaps, a common foodstuff which is as near “chemically pure as possible. It contains 99g per cent, of sucrose.