Techniques food preservation correspond to a set of techniques responsible for increasing the life and availability of food for human consumption and animal.
Drying or dehydration / Pasteurization:
This is one of the oldest methods used by humans to preserve food. The method is based on the fact that microorganisms that contaminate food can not grow in dry foods. Meats, fruits, vegetables, etc.., Were placed in the sunlight to evaporate the water are having, in this way, it was possible to last much longer than if they remain without such treatment.
For example, many foods and products are freeze-dried for preservation, which is a process used for removing water by vacuum drying and low temperatures. Mainly used in food and pharmaceutical industries, but also can be used to produce materials such as Aerogel. The
freeze-dried fruits (bananas, strawberries)
is a fairly expensive and slow when compared with traditional methods of drying, but it in products of higher quality, because when not using heat, largely avoids the nutritional and sensory loss. Instant coffee and instant soups are lyophilized, the high price of the freeze and its relatively low capacity, make this technique very attractive for treating large quantities of product.
As industrial process was developed in the 50's of XX century, but its principles were already known and used by the Incas. The procedure was to leave ancestral night that the food is frozen by the action of the cold of the Andes and through the first rays of morning sun and low atmospheric pressure of the high Andean highlands occurred sublimation of water that had been frozen. This process is known as natural freeze.
For example, many foods and products are freeze-dried for preservation, which is a process used for removing water by vacuum drying and low temperatures. Mainly used in food and pharmaceutical industries, but also can be used to produce materials such as Aerogel. The
Freeze drying is a process in which frozen food and frozen once introduced into a vacuum chamber so as to raise the water by sublimation. In this way water is removed from the solid state to the gaseous feed in the room without passing through the State líquido.Para used to accelerate the process repeated freezing and sublimation which can eliminate virtually all of the free water contained in the original product.
is a fairly expensive and slow when compared with traditional methods of drying, but it in products of higher quality, because when not using heat, largely avoids the nutritional and sensory loss. Instant coffee and instant soups are lyophilized, the high price of the freeze and its relatively low capacity, make this technique very attractive for treating large quantities of product.
As industrial process was developed in the 50's of XX century, but its principles were already known and used by the Incas. The procedure was to leave ancestral night that the food is frozen by the action of the cold of the Andes and through the first rays of morning sun and low atmospheric pressure of the high Andean highlands occurred sublimation of water that had been frozen. This process is known as natural freeze.
The liquid food pasteurization to a temperature rise of boiling and then lower the temperature abruptly near freezing point.
Add salt and smoking:
are two other food preservation methods widely used since ancient times. Meat and fish can be treated with common salt, which dehydrates and prevents germs attack, acting as an antiseptic, and protecting food.
Smoking is a cooking technique that involves subjecting food to smoke from wood fires to low level of resin. This process, in addition to serving as curator smoked flavors extending the life of food.
There are two types of smoked fish, hot and cold. In cold, the process takes approximately 24 to 48 hours (depending on the food) and must not exceed 30 ° C hot and the temperature must be above 60 º and not exceed the 75 ° C. It is recommended to first perform the cold-smoked and then hot.
This form of food preservation, comes from ancient times where it was discovered by chance that possibly hanging food above the stove is used for heating and cooking food lasted longer than that were not in contact with smoke. This preservation process could be compared with the salt to preserve food, which basically takes away moisture to foods and flavors is transferred.
Canned and bottled : Smoking is a cooking technique that involves subjecting food to smoke from wood fires to low level of resin. This process, in addition to serving as curator smoked flavors extending the life of food.
There are two types of smoked fish, hot and cold. In cold, the process takes approximately 24 to 48 hours (depending on the food) and must not exceed 30 ° C hot and the temperature must be above 60 º and not exceed the 75 ° C. It is recommended to first perform the cold-smoked and then hot.
This form of food preservation, comes from ancient times where it was discovered by chance that possibly hanging food above the stove is used for heating and cooking food lasted longer than that were not in contact with smoke. This preservation process could be compared with the salt to preserve food, which basically takes away moisture to foods and flavors is transferred.
Smoked Fish Smoked
Canned: is a food preservation technique widely used today, and practically useful any kind of food. When Canned food is sealed in its container after taking a vacuum and heated. Any organism present is removed by this procedure, and others can not get food that are insulated sealed tin. The entire process, including filling and sealing the cans or containers, is performed automatically in modern industries.
microorganisms and enzymes need a certain degree of temperature to alter the food, but excessive heat destroys them. That is used by heat sterilization to preserve food, especially canned. The cans filled and sealed, are subjected to high temperatures (between 100 º and 150 º C.) during a certain time. Once sterilized cans, and while they do not open and deterioration, these products remain unchanged for a long time. For this reason it is useless to keep the cans in the refrigerator before opening.
Bottling is usually used for fruit and vegetables. The process is similar to canning, but the food is placed in bottles instead of cans.
Freezing Freezing, ie the exposure of food at temperatures below zero degrees, can be used to preserve most foods such as meat, fish, fruits, vegetables, etc., including cooked foods and ready. When using this technique, the food is frozen quickly to avoid changes in the texture and flavor.
Cooling: 3 ° C and 8 º C the food is stored a few days.
Freezing: -5 º C and -18 º C foods can be stored up to 3 months.
The freezing, temperatures below -18 º C. Food can be kept for up to one year.
Cooling and vacuum:
The process in which meat is vacuum cooled aims to prolong the life of the flesh, that is, lengthen the time between production and consumption by human beings in a manner that is safe, without resorting to freezing or other preservation methods.
The period of extension of the quality of the product depends on the factors involved in the process of vacuum as we interact with each other during it.
The purpose of this process is that the meat is coated with a film that acts as both water vapor to oxygen, so as to achieve the proper microclimate between the film and cut to the proliferation of beneficial bacteria such as lactic acid (similar to those found in yogurt) as the acid lactic acid is a natural preservative for foods. At the same time, is obtained as a habitat not conducive to the development of unwanted bacteria that damage the meat or becomes dangerous for consumption by minimizing the development of them and preventing putrefaction.
