Diet plays a fundamental role in the genetic configuration and development of the brain of today’s human being. For this reason, human evolution has a close relationship with water filters,food and, consequently, with its preservation. In this way, the development of conservation methods goes hand in hand with the great strides of humanity. Without a doubt, it’s exciting to keep track of old food preservation methods :

How they preserved food in Prehistory

• In the Paleolithic, the first hunters consumed food just after hunting it.
• 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 (upper) or beginning of the Mesolithic, the first clay pot was created in Japan (Jomon period), the first container for conservation.
• In the Neolithic, humans leave their nomadic life, agriculture and livestock arises. At the same time, they build the first barns, to protect their food from animals. Caves and trenches dug into the ground are used for this mission.
• During the Iron Age, in northern Europe, dehydration was experienced. The first ovens to dry freshly harvested wheat appear .

Food preservation in the Ancient Age

• The first salting and smoking techniques emerge , thanks to the Egyptians.
• The Greeks create two forms of fruit preservation, one with virgin wax and the other with honey.
• The Romans preserved wine for decades, packing it in hermetically sealed amphorae.
• The Visigoths prepare jams with honey and apples, preserving them in wineskins.
• A revolutionary preservative appears in New Guinea : sugar . Then it travels to India, China, other parts of the East, Persia, and finally reaches Europe in the 4th century.

Refrigerators to preserve food in the Middle Ages

• Some time after the discovery of America, the Spanish brought cane to Santo Domingo, Cuba and Mexico to grow it and import it to all of Europe.
• In northern Europe, deposits are created excavated in the stone, where they keep large amounts of snow and blocks of ice, which they call refrigerators.

Modern Age: new conservation techniques

• In the 16th and 17th centuries, recipes for different types of food preservation were recorded : vegetables in brine and salted meats, preserved in lard (these techniques are still practiced today).
• In the 17th century, the production and consumption of sugar were spread throughout the world.
• In 1795, Nicolas Appert, a French chef, discovered that by boiling food inside a closed container (glass bottles with cork in this case), they are kept in perfect condition for a long time.
• The same year, in France , the first artificial food dehydrator was invented , called the hot water room.

Food preservation methods of the Contemporary Age

• In 1801 the first sugar beet factory was created. However, it was not until 1811 that jams gained popularity, a culinary method that until then was reserved for the upper class.
• Peter Durand patented the first canned in 1810, made with forged iron and vacuum sealed.
• In 1858, Charles Tellier created the first ice-making machine. Thus, the transportation and preservation of food becomes much easier.
• Louis Pasteur discovered pasteurization in 1864, one of the most widely used preservation methods today.
• From 1879, the refrigerator reaches many homes , becoming an appliance for domestic use.
• At the beginning of the 20th century, lyophilization or vacuum cryodesiccation was created.
• Thanks to technological advances, machinery in the 20th century is becoming more sophisticated and is designed to prevent contamination by microorganisms.
• In the second half of the 20th century, substances that preserve food for decades were discovered: preservatives.
• At the end of the 20th century, more aseptic containers were designed, such as tetra brik, as well as biodegradable plastic polymers.
• In the late 20th and early 21st centuries, revolutionary food irradiation techniques and biotechnological manipulation opened the spectrum of food preservation to unimaginable limits.

Conservation types

Virtually everything we consume today has previously gone through a conservation process. For this reason, there is much that we can learn from the various forms of preservation that exist, as well as from the advantages that they bring to each food. Food preservation techniques are divided into two main blocks: according to the performance of the microorganisms and according to the type of technique applied. The first block distinguishes the types of conservation as follows:

• Methods that destroy germs or inactivate them : sterilization, pasteurization, radiation, high pressure, among others.
• Methods that prevent the development and proliferation of microorganisms : refrigeration, freezing, dehydration, smoking, addition of chemical substances, among others.
• Methods that avoid re-contamination : aseptic processing, packaging, hygienic storage, among others.

For its part, the first type of preservation according to the class of technique applied is preservation due to variation in food temperatures . This is divided into cold storage and heat storage or thermal storage.

Cold preservation

It uses low temperatures (around 0 ºC) to extend the freshness of the food. 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. The methods of preservation by cold are divided into:

• Refrigeration
• Freezing
• Deep freezing

Conservation by heat or thermal preservation

For its part, thermal conservation uses heat to slow down chemical reactions, since it inactivates enzymes in a process called denaturation. In this technique, temperature and time variables play an essential role in the durability of the product. At higher temperatures, greater durability. The different methods that apply this technique are:

• Pasteurization
• Sterilization
• Cooking (blanched), used to preserve and freeze foods such as broccoli

There are other conservation techniques that use variables other than temperature. Some of them are:

Conservation by reducing humidity

This process is based on the control of the humidity contained in the food. Since microorganisms and bacteria reproduce through water, if humidity is controlled, the probability of contamination decreases. In other words, less water, less ability for enzymes to react and the growth of microorganisms. The methods that apply this technique are:

• Desiccation
• Dehydration
• Evaporation
• Lyophilization
• Concentration

Chemical preservation or by addition of substances

Chemical preservation prolongs the resistance and shelf 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, as it considerably increases the durability of food. Within chemical preservation, we can find organoleptic preservation, in which the sensory properties of food are modified, such as:

• Adding alcohol
• Adding fats
• Adding sugars (jam, grated, grajeado)
• Adding salts (salting, curing)
• Acidification (marinade, various forms of marinade, pickles and pickles)
• Fermentation (alcoholic, acetic, butyric)

On the other hand, we can also find various food preservation methods that use the addition of other chemical substances or food additives of industrial origin, such as:

• 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 on the link and visit our article.

Non-thermal or emerging methods

The growing interest in organic food (without additives or preservatives) has caught the attention of the technology industry. Currently, the new forms of conservation are very sophisticated, considerably increasing the quality of the products and their durability. The most relevant new food preservation methods are those that are achieved with:

• High pressures
• Electric fields
• Light pulses
• Radiation
• Irradiation (ionizing)
• Non-ionizing method (microwave)
• Edible surface treatment and coatings
• Encapsulation and controlled release
• Vacuum packed
• Modified atmosphere
• Ultrafiltration
• Sterilizing filtration