Food is most often prepared by heat processes. Proper thermal treatment destroys most of the bacteria. This is where changes are taking place on foods. The food usually becomes softer, changing its color, smell and taste, and it is easier for a child to consume it. During heat treatment, undesirable changes may occur, such as loss of some useful nutrients or vitamin degradation, and changes in pigments may result in color that is unbearable to a child.
Hot food processing processes that take place in the damp environment are blanching, cooking and stewing while roasting and frying take place in a dry environment.
Blending is heat treatment with water or water vapor, suitable for vegetable and fruit processing. When blanching, microorganisms are destroyed, volume decreases and softens food. The blanching can be carried out with water at a temperature of between 80 and 100 ° C for 3 to 10 minutes or with water vapor at a temperature above 100 ° C for 25 to 180 seconds. When steaming, less water-soluble substances are lost. When processing the water, the loss of the dry matter of fruit and vegetables occurs. In this case, sugar, starch and vitamin C are lost, and color changes may occur.
Cooking is the most commonly used heat treatment in the damp environment. When cooking is lower than when frying or roasting.
This process is subjected to meat, fruits and vegetables, carbohydrates such as pasta and rice. By cooking, complex carbohydrates break down into simpler. Poorly cooked meat or poultry may still contain harmful microorganisms.
Cooking can be done in several ways; In water at a temperature of about 90 [deg.] C. or boiling temperature, peaks at ordinary or high pressure, in cooking pots under pressure of “espresso pots” at a temperature of about 105 [deg.
If the food is placed in a cold or slightly heated water, greater exposure to soluble substances occurs. Such a procedure is suitable for soups and buffaloes (meat extracts).
By placing the food in hot water, it creates a shrinkage that protects against the extraction and dissolution of certain ingredients. The cooked product is softer and delicious, but is of a lower quality. This is true for cooking meat. By cooking, the soluble food substances are lost. Celery, greens, rice and pasta are cooked in a larger amount of water, because it is preferable to extra extraction. In a smaller amount of water, peas, carrots and potatoes are cooked.
For vegetables containing sulfur compounds, such as cauliflower or kale, there is an optimum cooking time. For greens it is preferable to cook 5-8 min, and for cauliflower 8 min. For longer periods of cooking, sulfur compounds break down more intensively, with the appearance of undesirable taste and smell.
During the cooking of vegetables, especially green (spinach, peas, mahune) releases volatile components. If the vessel is closed, it results in an undesirable change in color in olive green. This phenomenon can be prevented by cooking in an open container at the same temperature and time conditions. The vegetables thus retain an intense green color.
In addition to changing colors, vegetables change and taste and hardness, and become softer.
The roasting is carried out by heat and mass transfer. The heat is transferred to food by contact with the heated surface and the air in the oven, and the moisture passes from the food to the surrounding air. On the surface of the food there is a “crust” because the surface of the food is dry. So prepared meat is not suitable for infant nutrition.
The cooking temperature can range from 120 ° C to 250 ° C. The choice of temperature and the duration of the cooking depends on the type, category of meat, the size of the pieces and the weight. A meat of gentle consistency, such as veal and pork of goat ‘s milk, chopsticks and bunnies, is recommended for the oven at a temperature of 150 ° C to 170 ° C.
When grilling, the temperature is between 150 ° C and 200 ° C, there is a crevice that prevents the release of soluble substances. So the processing of meat must be of high quality.
During the baking, changes in texture occur, depending on the type of food, temperature and warming time. During the baking of meat, fat is fried, spattered in the form of droplets and exits through the meat structure. The surface is dried up and the structure becomes harder and crunchy. The food gets a specific aroma, smell and taste.