Читать книгу Foods and Their Adulteration - Harvey Washington Wiley - Страница 147

—A distinction is made between a beef extract and a beef juice. The latter term applies solely to the liquid naturally remaining in the fresh meat after its proper preparation for consumption, that is, after the withdrawal of the blood and the proper cooling and storing of the flesh. The fresh meat is then subjected to strong pressure and the juices which are extracted are concentrated in vacuo to the proper consistence. The meat of old bulls is often used. A true beef juice must be extracted from the cold meat and not with the aid of heat, hot water or other solvents. It is difficult to preserve an extract of this kind without sterilization, and the heat required for sterilization is likely to coagulate some of the albuminous material which is expressed. It is a great temptation, therefore, in some cases to preserve the beef juice by a chemical preservative other than common salt. Boric acid and sulfite of soda may be used for this purpose, but these substances are objectionable on the score of possible injury to health. Glycerine is also used. Inasmuch as these juices are usually given to invalids or those whose digestive functions are impaired it is most important that injurious substances should be omitted. In case of pressure it is advisable, in some cases, to chop the meat very fine, and in this comminuted condition extract the juice with cold water. This does not produce any change in the character of the juice and the water is subsequently removed by evaporation at a low temperature in vacuo. Beef juices are usually prepared from heated meats.