boiling is not continued for any length of time the amount of sugar inverted is less than in the manufacture of jams and preserves where the boiling is continued for a greater length of time.
The quantity of non-crystallizing material in the juices from which the jellies are made, namely, the pectose bodies in fruits, is sufficient in most cases to prevent the crystallization of the cane sugar in the jelly. The jelly is formed by these pectose bodies being present in the juice in sufficient quantities to become semi-solid on cooling after manufacture. The solidifying may take place in a short time or only after several hours. The juice at the time of completion of the boiling is thoroughly sterilized, and in this hot condition should be placed in sterilized vessels and covered before setting away with sterilized parchment paper or a thin film of sterilized paraffine. The covering of the surface will prevent the deposition of the seed of moulds and bacteria which often infect the top layer of jellies or other fruit products prepared in a similar manner whose surface is not properly protected.
Preservatives.—Since the care which is necessary to prepare a jelly in a thoroughly sterilized condition and to protect the exposed surface so that infection thereof cannot take place is a matter of expense and requires great attention to details, it has been sought to avoid these by the use of chemical preservatives. Salicylic acid and benzoic acid or benzoate of soda have been the principal preservatives employed, and until state and municipal laws introduced a proper inspection or analysis of these products the use of these chemical preservatives was very common. In later years their use has been gradually diminished, owing to the objections on the part of the laws and the public to the presence of these bodies in the finished products. There are, however, still on the market many products which are preserved by salicylic acid, benzoic acid, or benzoate of soda or some similar active agent.
From the above résumé it is seen that the consumer who buys in the open market is not quite certain that he is getting the product for which he pays. This condition of affairs will doubtless pass away with the advent of the proper inspection of fruits which are used in manufacturing on a large scale and a proper supervision of the manufacturing establishments, together with a rigid execution of the national and state food laws. Under such conditions the adulterations will either disappear from the market or be so labeled as to practically inform the purchaser of their character.
Marmalade.—The term "marmalade" is applied to a special character of fruit product prepared in the same manner as jam in which the fruit is not so thoroughly pulped. The orange is a fruit which is used very extensively for making marmalade,—an orange marmalade, in other words, is only a fruit product of the character of jam and made after the same manner. This class of fruit products is so nearly the same as jam as not to need any special description.
