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JAMS AND JELLIES
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JAMS AND JELLIES . In the See also:article See also:Foot) PRESERVATION it is pointed out that concentrated See also:sugar See also:solution inhibits the growth of organisms and has, therefore, a preservative See also:action. The preparation of jams and jellies is based upon that fact. All fresh and succulent See also:fruit contains a large percentage of See also:water, amounting to at least four-fifths of the whole, and a comparatively small proportion of sugar, not exceeding as a See also:rule from 10 to 15%. Such fruit is naturally liable to decomposition unless the greater proportion of the water is removed or the percentage of sugar is greatly increased. The jams and jellies of See also:commerce are fruit preserves containing so much added sugar that the See also:total amount of sugar forms about two-thirds of the See also:weight of the articles. All See also:ordinary edible fruit can be and is made into jam. The fruit is sometimes pulped and stoned, sometimes used whole and unbroken; oranges are sliced or shredded. For the preparation of jellies only certain fruit is suitable, namely such as contains a See also:peculiar material which on boiling becomes dissolved and on cooling solidifies with the formation of a gelatinous See also:mass. This material, often called pectin, occurs mainly in comparatively See also:acid fruit like See also:goose-berries, currants and apples, and is almost absent from See also:straw-berries and raspberries. It is chemically a member of the See also:group of carbohydrates, is closely allied with See also:vegetable gums abundantly formed by certain See also:sea-weeds and mosses (agar-agar and See also:Iceland See also:moss), and is probably a mixture of various pentoses. Pentoses are devoid of See also:food-value, but, like See also:animal gelatine, with which they are in no way related, can See also:form vehicles for food material. Some degree of gelatinization is aimed at also in jams; hence to such fruits as have no gelatinizing See also:power an addition of See also:apple or See also:gooseberry juice, or even of Iceland moss or agar-agar, is made. Animal See also:gelatin is very rarely used. The See also:art of jam and jelly making was formerly domestic, but has become a very large See also:branch of manufacture. For the See also:production of a thoroughly satisfactory conserve the boiling-down must he carried out very rapidly, so that the natural See also:colour of the fruit shall be little affected. Considerable experience is required to stop at the right point; too See also:short boiling leaves an excess of water, leading to See also:fermentation, while over-concentration promotes See also:crystallization of the sugar. The manufactured product is on that See also:account, as a rule,more See also:uniform and See also:bright than the domestic article. The finish of the boiling is mostly judged by rule of thumb, but in some scientifically conducted factories careful thermometric observation is employed. Formerly jams and jellies consisted of nothing but fruit and sugar; now See also:starch-See also:glucose is frequently used by manufacturers as an ingredient. This permits of the production of a slightly more aqueous and gelatinous product, alleged also to be devoid of crystallizing power, as compared with the See also:home-made article. The addition of starch-glucose is not held to be an See also:adulteration. See also:Aniline See also:colours are very frequently used by manufacturers to enhance the colour, and the effect of an excess of water is sought to be counteracted by the addition of some salicylic acid or other preservative. There has See also:long been, and still exists to some extent, a popular See also:prejudice in favour of sugar obtained from the sugar-See also:cane as compared with that of the sugar-See also:beet. This prejudice is absolutely baseless, and enormous quantities of, beet-sugar are used in the boiling of jam. Adulteration in the See also:gross sense, such as a substantial addition of coarse pulp, like that of turnips or mangolds,very rarely occurs; but the pulp of apple and other cheap fruit is often admixed without See also:notice to the purchaser. Additional information and CommentsThere are no comments yet for this article.
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