Читать книгу Foods and Their Adulteration - Harvey Washington Wiley - Страница 68
Composition of the Fresh and Canned Meat.
Оглавление—Below is found a table similar to that already given for the other sample, showing the composition of fresh beef and the resulting canned beef.
| Constituents. | Fresh Beef. | Extracted by Boiling. | Added in Canning. | Composition of Canned Beef as Determined by Analysis. |
|---|---|---|---|---|
| Lbs. | Lbs. | Lbs. | Lbs. | |
| Water, | 414.6 | 243.2 | 12.9 | 184.3 |
| Proteins, | 100.5 | 1.3 | .... | 101 |
| Meat bases, | 6.7 | 3.4 | .... | 4.6 |
| Fat, | 63.9 | 39.2 | .... | 24.7 |
| Ash, | 6.8 | 4.2 | .... | 2.6 |
| Undetermined, | 5.5 | .... | .... | 2.8 |
| Total, | 598 | .... | .... | 320 |
From the above table it is seen that the shrinkage during parboiling amounts to 46.49 percent of the weight of the fresh meat. Of this shrinkage 82.85 percent is water, 14.11 percent is fat, 1.51 percent ash, and 0.82 percent meat bases. It is noticed that more than half of the water originally found in the meat is extracted by parboiling.
It seems rather anomalous that boiling a substance with water would extract water from it, but in the case of meats it is seen that half the water, or even more, which a meat contains is extracted from it by boiling in water.
The two samples given are extreme cases in the method of preparing meats for canning. In the first instance the meat is placed at once into hot water just below the boiling point and kept there for only a short time. In the second case the meat is placed in cold water and is brought to the boiling point and maintained there for one hour. In the last case the low temperature of the water in which the meat was originally placed favors the extraction of a portion of the soluble protein matter, namely, albumins, globulins, etc., while, on the other hand, the long-continued boiling to which it was subjected tends to decompose the connective tissues of the meat and causes the loss of small particles of the insoluble protein thus separated by disintegration. Although in the last case the shrinkage was much greater than in the preceding experiment, practically no insoluble protein matter was extracted, mechanically or otherwise.
