ADULTERATION - PRESERVATIVES IN FOOD While from time immemorial certain articles of food have been preserved by salting, smoking, drying, the addition of sugar or of saltpetre, during the last quarter of the i9th century the use of chemicals acting as antiseptics or preservatives extended enor mously. Refrigeration and cold-storage have enabled meat and other highly perishable foods to be imported, but it is necessary to prevent decomposition prior to such goods coming into cold store. This difficulty—apart from the use of preservatives—can only be overcome by improvement in transport facilities or con striction of the area from which supplies can be obtained. The legality or otherwise of the use of chemical preservatives hinges upon the difficult question of their innocuousness. Hence in 1899 a committee of the Local Government Board was appointed to inquire into the use of preservatives and colouring matters in food. In 1901 this committee recommended that the use of formalde hyde or formalin, or preparations thereof, in food or drinks, be ab solutely prohibited, and that salicylic acid be not used in a greater proportion than one grain per pint in liquid food and one grain per pound in solid food, its presence in all cases to be .declared ; that the use of any preservatives or colouring matter whatever in milk offered for sale in the United Kingdom be constituted an offence under the Sale of Food and Drugs Act; that the only preservative which it shall be lawful to use in cream be boric acid, or mixtures of boric acid and borax, and in amount not exceeding o.25% ex pressed as boric acid, the amount of such preservative to be notified by a label upon the vessel; that the only preservative per mitted to be used in butter and margarine be boric acid, or mix tures of boric acid and borax, to be used in proportions not exceed ing o•5% expressed as boric acid; that in the case of all dietetic preparations intended for the use of invalids or infants, chemical preservatives of all kinds be prohibited.
As the most commonly used chemical preserva tive is boric acid, free or in the form of borax, which is extensively employed in butter, cream, ham, sausages, potted meats, cured fish, and sometimes in jams and preserved fruit, the arguments for and against its employment deserve more detailed attention. It cannot be looked upon in the light of common adulteration be cause, in any case, the quantity used is but an inconsiderable frac tion, and the cost of it is generally greater than that of the food itself. It is not used to hide any traces of decomposition that may have taken place or to efface its effects. It enables food to be kept from decomposition, but it also lessens the need for clean liness and encourages neglect and slovenliness in factories. It has little taste and hence cannot be perceived by the consumer or. avoided by him should he desire to do so. Its preservative action is very slight in comparison with most other preservatives; its potential injuriousness to man must be proportionately small. It is practically without interference upon salivary, peptic or tryptic digestion, unless given in large quantities. An exhaustive investi gation was carried out by Dr. H. W. Wiley, chief chemist to the United States Department of Agriculture. Dr. Wiley concludes his report : "It appears, therefore, that both boric acid and borax, when continuously administered in small doses for a long period or when given in large quantities for a short period, create dis turbance of appetite, of digestion and of health." This report was adversely criticized, but on the whole the balance of evidence seems to be that while no acute injury is likely to result from boron compounds in food, they are liable to produce slighter digestive interferences. Its use as a preservative for food was prohibited in England in 1925.
Other chemical substances used to preserve food may be treated more shortly. Formaldehyde, coming into commerce in the form of a 4o% solution under the name of formalin, was for a time largely used in milk. It is now generally recognized as admirably adapted for disinfecting a sick-room, but unsuitable for food preservation.
Salicylic acid or orthohydroxybenzoic acid is either obtained from oil of winter-green or is made synthetically. When pure, salicylic acid employed as a food preservative has never produced decided injurious effects, although it is a powerful drug in larger doses and requires careful administration, especially as about 6o% of the persons to whom it is administered show symptoms known as "salicylism," namely, deafness, headache, de lirium, vomiting, sometimes haemorrhage or heart-failure. When present in proportion of i to i,000 it inhibits the growth of moulds and yeasts. In jams two grains per pound and in beverages seven grains to a gallon are considered by manufacturers to be sufficient for preservative purposes. It is used mainly in articles of food or drink containing sugar. Its use in butter, potted meat, milk or cream, is now quite exceptional. To some extent benzoic acid and benzoates have taken the place of salicylic acid and salicylates, partly because salicylic acid can readily be detected analytically, while benzoic acid is not quite easily discoverable.
For the preservation of meat and beer, lime juice and dried fruit, sulphur dioxide (sulphurous acid) and some of the sulphites have long been employed. About 1 part in 4,000 or 5,000 of beer is the usual amount. By the Public Health (Preservatives, etc., in Food) Regulations, 1925, in England, the amount of sulphur dioxide (by weight) in beer must not exceed 7o parts per million. While in larger quantities the sulphites pro duce nephritis, there is no evidence that they have ever caused injurious effects in alcoholic liquors.
Sodium fluoride, a salt possessing powerfully antiseptic properties but interfering with salivary and peptic digestion, has been found in butter, imported mainly from Brittany, in quantities quite inadmissible in food under any circum stances. A few other chemical preservatives are occasionally used. Hydrogen peroxide has been found effective in milk sterilization. and if the substance is pure no serious objection can be raised against it. Saccharine and other artificial sweetening agents having antiseptic properties are taking the place of sugar in beverages like ginger-beer and lemonade, but the substitution of a trace of a substance that provides sweetness without at the same time giving the substance and food value of sugar is strongly to be deprecated.
The employment of chemical preservative matters in articles intended for human consumption threatens to become a grave danger to health or well-being. Each dealer in food contributes but a little ; each one claims that his particular article of food cannot be brought into commerce without a preservative, and each condemns the use of these substances by others. There is doubtless something to be said for the practice, but infinitely more against it. It cheapens food by allowing its collection in districts far away, but the chief gainer is not the public as a whole but the manufacturer and the wholesale merchant. It is clearly the duty of the state to see that the evil is checked.