History of food conservation
Food plays a fundamental role in genetic configuration and the development of the brain of the current human being. For this reason, human evolution has a close relationship with food and, consequently, with its conservation. In this way, the development of conservation methods goes very hand with the great steps of humanity. Without a doubt, it is exciting to follow the track to the conservation methods of old foods:
How food retained in prehistory
– In the Paleolithic, the first hunters consumed food just after hunting them.
– Desiccation arises as a result of human needs. This technique uses air and sun as principles. It is still practiced today.
– At the end of the Paleolithic (superior) or beginning of the Mesolithic, the first mud vessel in Japan (Jomon Period), the first conservation container is created.
– In the Neolithic, humans leave their life nomadic, agriculture and livestock arises. At the same time, they build the first barns, to protect their animals from animals. Caves and graves excavated on the ground are used for this mission.
– During the iron age, to northern Europe, it is experienced with dehydration. The first furnaces arise to dry freshly harvested wheat.
Food conservation in the old age
– The first salting and smoked techniques arise, thanks to the Egyptians.
– The Greeks create two forms of fruit conservation, one with virgin wax and another with honey.
– The Romans retain wine for decades, packaging it at hermetically closed amphorae.
– The Visigoths prepare confitures with honey and apples, they keep them in odres.
– A revolutionary preservative arises in New Guinea: sugar. Then, travel to India, China, other parts of the East, Persia and, finally, it arrives in Europe in the fourth century.
Ice cream shops to conserve food in the Middle Ages
– Some time after the discovery of America, the Spaniards take the cane to Santo Domingo, Cuba and Mexico to cultivate and import it throughout Europe.
– To the north of Europe, deposits excavated in the stone are created, where they keep a large amount of snow and ice blocks, which they call ice cream makers.
Modern Age: New conservation techniques
– In the sixteenth and seventeenth centuries, recipes are recorded for different types of food conservation: brine vegetables and salt, meats preserved in lard (these techniques are still practiced today).
– In the seventeenth century, sugar production and consumption are extended all over the world.
– In 1795, Nicolás Appert, a French chef, discovers that boiling food inside a closed container (glass bottles with cork in this case), are preserved in perfect condition for a long time.
– The same year, in France the first artificial food dehydrator is invented, called the hot water room.
Food conservation methods of contemporary age
– In 1801 the first beet sugar factory emerged. However, it is not until 1811 that the confitures gain popularity, a culinary method that until then was reserved for the upper class.
– Peter Durand Patenta in 1810 the first canned, made with iron and vacuum fierro.
– In 1858, Charles Tellier created the first ice maker. Thus, food transport and conservation become much easier.
– Louis Pasteur discovers pasteurization in 1864, one of the most used conservation methods today.
– As of 1879, the refrigerator reaches many homes, becoming an artifact of domestic use.
– At the beginning of the 20th century, lyophilization or vacuum cryodly is created.
– Thanks to technological advances, in the twentieth century the machinery is every day more sophisticated and is designed to prevent pollution from microorganisms.
– In the second half of the twentieth century substances that retain food for decades are discovered: preservatives.
– At the end of the 20th century, more aseptic containers are designed, such as Tetrabrik, as well as biodegradable plastic polymers.
– At the end of the 20th century and principles, the revolutionary food irradiation techniques and biotechnological manipulation open the spectrum of food conservation to unimaginable limits.
Types of conservationVirtually everything we consume today has previously gone through a conservation process. For this reason, it is much that we can learn from the various forms of conservation that exist, as well as the advantages that provide each food. Food conservation techniques are divided into two main blocks: according to the performance of microorganisms and according to the applied technique class. The first block distinguishes conservation types as follows:
– Methods that destroy germs or inactivate them: sterilization, pasteurization, radiation, high pressures, among others.
– Methods that prevent the development and proliferation of microorganisms: cooling, freezing, dehydration, smoked, addition of chemical substances, among others.
– Methods that avoid re-contamination: aseptic processing, packaging, hygienic storage, among others.
On the other hand, the first type of conservation according to the applied technique class is the conservation by variation in the temperature of the food. This is divided into cold conservation and heat conservation or thermal conservation.
Cold conservation
This uses low temperatures (around 0 ºC) to extend food freshness. The cold reduces the speed of chemical reactions and decreases the activity of microorganisms. However, it does not kill them, so when the food is heated, they begin to multiply again. Cold conservation methods are divided into:- Refrigeration
– Freezing
– Ultracongelación
Heat conservation or thermal conservation
For its part, thermal conservation uses heat to slow down chemical reactions, as it inactive enzymes in a process called denaturation. In this technique, temperature and time variables play an essential role in product durability. At higher temperature, greater durability. The different methods that apply this technique are:- Pasteurization
– Sterilization
– Cooking (scalded), used to conserve and freeze foods such as broccoli
There are other conservation techniques that use variables other than temperature. Some of them are:
Moisture reduction conservation
This process is based on moisture control contained in food. Since microorganisms and bacteria reproduce by means of water, if moisture is controlled, the probability of pollution decreases. That is, less water, less capacity for reaction of enzymes and development of microorganisms. The methods that apply this technique are:- Desción
– Dehydration
– Evaporation
– Lyophilization
– Concentration
Chemical conservation or by addition of substances
Chemical conservation prolongs the resistance and life of food through the addition of substances that chemically modify the product. This method is widely used in the food industry, as it is a very effective method for industrial production, thanks to the fact that food durability increases considerably. Within chemical conservation, we can find organoleptic conservation, in which food sensory properties are modified, such as:- alcohol addition
– Addition of Fats
– Addition of sugars (jam, grajeado, grajeado)
– Sales addition (salting, curing)
– Acidification (marinated, various forms of marinade, pickles and pickled)
– fermentation (alcoholic, acetic, butyric)
On the other hand, we can also find various food conservation methods that use the addition of other chemicals or food additives of industrial origin, as is the case of:- dyes
– Preservatives
– Antioxidants
– Stabilizers
If you want to know what food additives are and what are their advantages and disadvantages for food production and health, do not hesitate to click the link and visit our article.
Non -thermal or emerging methods
The growing interest in organic food (without additives or preservatives) has drawn the attention of the technological industry. Currently, new forms of conservation are very sophisticated, considerably increased the quality of the products and their durability. The new most relevant food conservation methods are those that are achieved with:- High pressures
– Electric fields
– Light pulses
– Radiation
– Irradiation (ionizing)
– Non -ionizing method (microwave)
– Treatment of edible surfaces and coatings
– Controlled encapsulation and release
– Vacuum packaging
– Modified atmosphere
– Ultrafiltration
– Sterilizing filtration
Food conservation techniquesAlthough supplying us with food is as simple as visiting the supermarket and saving food at home, there is a great gear that depends a lot on the conservation of these products. In many cases, food does not use a single conservation method, but several combined to improve their quality and durability. It is interesting to mention that although the elementary principles of conservation are applicable for much of food, not all microorganisms react the same before a method (they can inhibit or die). Therefore there are better methods than others according to the characteristics of the food and the microorganisms that can be activated in it.
Refrigeration
Refrigeration or positive cold consists in preserving a food at a stable and cold temperature, close to 0 ° C, to avoid pile and hygrometric value. Consequently, the proliferation of microorganisms is controlled. The most appropriate domestic cooling temperature is 0-8 ° C, while the industrial one is between 0-5 ° C. In refrigeration, food can last a few days.
Freezing
The negative freezing or cold consists in conserving a long -term food, at temperatures below 0 ° C, so that food of the food freezes. Remember, the cold chain must be respected, otherwise microbes reproduce again.
Ultra freezing
Ultra freezing is based on decreasing the temperature of a food to -40 ºC. This can be achieved through several processes that can use the use of plates, immersion in liquids, cold air, among others. This type of fast freezing occurs in a time less than 2 hours.
Lyophilization
Lyophilization consists in freezing a food (at a temperature of less than -30 ºC) with the purpose of extracting its vacuum water, transforming ice into water vapor. This method retains almost the entire nutritional value of food. However, its use is expensive, so it is applied to products such as coffee (normal or decaffeinated soluble), childrens milks and some other foods.
Pasteurization
Through this technique, heat is applied to food for a certain time (time varies depending on it), at temperatures between 80-100 ºC. Immediately afterwards, food must cool quickly. This treatment regulates and destroys the pathogenic microorganisms of food, but not inactive its spores. For this reason, the product must be cold after open.
Sterilization
It is the process that applies to a food or object in order to eliminate germs and spores. By sterilizing a product, it is exposed to temperatures surrounding the 115 ºC. This treatment affects the organoleptic qualities of food and causes some nutrients to lose. In the dairy industry, one of the most used sterilization treatments is pasteurization.
Dehydration
Dehydration is a procedure by which food loses water, thus inhibiting the development of bacteria. This practice can be carried out by exposing the food to the sun or using a dehydrating oven. It applies to many food products such as grains, cereals, fruits, vegetables, among others. With dehydrated foods, dehydrated soups, powdered coffee, dehydrated eggs, cereals, among other products can be obtained.
Desiccation (or drying)
This thermal technique is used prior to the freezing of food, with the intention of destroying the enzymes that affect the color, flavor and vitamin content of the product. Also, soften the food.
Salation
This conservation technique is to dehydrate a food by adding common salt (sodium chloride), either by immersion of the product in a saline solution or by direct diffusion of the salt on its surface. This procedure inhibits the growth of microorganisms, the degradation of enzymatic systems and, consequently, slows chemical reactions.
Cured
It is the process prior to the smoked and has several objectives: to provide more flavor, better texture and prolong the duration of the food. Simple cure can be done with homemade ingredients, however, the industrialist is done with common salt, healing salts, nitrites and nitrates (potassium and sodium).
Smoked
This procedure is a combination of desiccation and salting. In the smoked, the smoke obtained from the combustion of certain substances is used with the intention of giving food a sterilizing and antioxidant effect. In addition, it gives the product a peculiar aroma and an excellent texture. In general, beef meats, fish and pork meats are dripped. Some recipes with smoked meats include smoked salmon, smoked chicken and smoked chops.
Acidification
This technique is based on the decrease in food pH through the addition of acidic substances (such as vinegar). In this way, the development of microorganisms is avoided.
Pickled
This procedure uses a mixture of salt and vinegar to conserve food. Vinegar contributes its qualities as a preservative, while salt dehydrates food. In the beginning, this technique was used as a conservation method, but today it is used in gastronomy to highlight food texture and provide them with a very characteristic flavor. Some escabeche recipes include mussel mussels or pickled chicken.
Fermentation
This conservation technique takes advantage of the microorganisms present in food to enhance their organoleptic qualities and optimize their nutritional quality. This process is usually applied to dairy products.
Irradiation
This method consists in exposing food to controlled radiation, with the main intention of preventing the reproduction of microorganisms (bacteria or fungi). The irradiation of food (cold pasteurization or ionization) retains the organoleptic properties of the product and much of its nutrients.
Vacuum packaging
The vacuum packaging system is based on the extraction of much of the oxygen that surrounds the food (cooked or in its natural state) to subsequently pack it in plastic bags. This method slows the oxidation of food and its rot, extending its expiration date for more than 30 days and even up to a year.
Food additives of industrial origin
Additives are substances that are added to food in order to recover, maintain, enhance their organoleptic qualities (flavor, color, texture and volume) or prolong their conservation times (braking the proliferation of microorganisms).
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