Читать книгу Foods and Their Adulteration - Harvey Washington Wiley - Страница 70

—The liquid in the can was examined with the following result: Weight of liquor, 10 ounces.

Solids,	6.93	percent
Protein and gelatin,	1.94	„
Meat bases,	1.84	„
Ash,	1.22	„
Salt,	1.15	„

The above data show that the beef lost 32.06 percent of its weight in the canning, a little over half of which is water.

It appears that less protein matter is extracted when the meat is parboiled by being plunged into boiling water than when it is packed in a can without parboiling and subsequently subjected to the temperature of sterilization. In the former case the soluble proteins in meat near the surface are coagulated before they can diffuse into the surrounding water. In the other case, owing to the low conductivity of meat, the temperature at the surface of the can penetrates slowly to the interior and the juices which are extracted from the meat carry with them protein matter in solution which is afterwards precipitated by heat and remains in the liquid as matter coagulated at the temperature of sterilization.

It is seen that parboiling has many advantages. It extracts less of the valuable matter from the meat, it shrinks the meat before packing so that the tins contain more nutrient matter, and it improves the appearance of the meat to the consumer when opened.