Food preservation has been used for centuries. Natural food preservation was done in oil, salt, and sugar from Egyptian times. It is an ancient technique from the prehistoric period owing to the scarcity of resources and other forces of external stimulus. Men also learned that storage and use of certain ingredients could stop food spoilage.  

Although synthetic chemicals are used in modern food preservation, food preservation is still practised in homes and industries. Synthetic food preservation is cost-effective and is developed in labs; hence it is widely used in the food industry. 

History of Food preservation 

Food preservation was invented in the year 1810 by Nicolas Appert. In the year 1795, various experiments were conducted by Nicolas to preserve different categories of food. Although techniques like drying are as old as 1200 BC. 

Hence, it is considered the oldest forms for preserving varied food types.  More than 100 years ago, salting was commonly used to preserve meat and fish. It helped to kill bacteria and other types of microorganisms.  Pickling is very common to preserve cut vegetables with dry salt. 

The population is becoming aware of opting for food products free from chemical preservation processes. Thus, the label “no artificial preservatives” does not indicate a reduction in shelf life. Instead, it indicates natural preservatives, herbs, spices, ingredients, and natural processes.  

Before 1200 BC, sun and wind are used to dry meats, vegetables and fruits in the Middle East. Oxidation has been the primary spoilage cause as the oxygen in the air reacts with molecular structure, due to which various substances of the molecules are broken down. 

 Food preservation techniques are also considered antioxidant functions. For this reason, investigations on wild and cultivated plants are being conducted for acquiring information on natural antioxidant features. 

In addition, techniques like fermentation, pickling, salting, smoking, oil packing are ancient technologies. Refrigeration was used by putting the food into caves, ice or cold water in 6000 B.C.

Mechanism of food preservation 

The protection for antioxidants extends food shelf life. On the other hand, there are high chances for microorganisms in many food products that threaten shelf life. Hence, natural methods are beneficial for a shelf-life extension. Natural preservation techniques include refrigeration, freezing, reduction in water- activity. 

Thus, it might be further extended by acidification, modified packaging, electric pulses, fermentation, restricting nutrients, irradiation, antimicrobial compounds. These methods usually help food production as an unfriendly environment for microorganism growth is created. 

Food preservation techniques are not healthy as nutritional value; fat-soluble, essential fats are reduced or destroyed. In addition, lipid oxidation reduces shelf life as it alters organoleptic qualities by modifying the final product’s colour, texture, or taste. 

Preservation was initiated in colder areas where hunters observed that food covered with snow and ice helped to retain it throughout the season. For this reason, ice houses were built for freezing food. 

Food Preservative List 

Natural food preservatives can be used as per the need and foods

1. Oils- Oils have been used in the natural food preservatives for food industry techniques for ages. It is a naturally occurring ingredient used in several foods for preservation. Owing to its capability of stopping the penetration of moisture within food products. Oxidation processes are also halted, leading to decay and fungus development. It is widely used in pickling as the layer is formed on the food surface, stopping oxidation processes. These further increase the shelf life of preserved food like pickles. 
2. Salt- Salt is another natural preservative that helps retain the water within the food. It is also used in pickled food for stopping food spoilage. Vegetables in dried form are stored for longer shelf life after adding salt. Adding salt to any cut vegetables helps stop them from turning brown due to their antioxidant ability. 
3. Sugar- Sugar also tops the list of natural food preservation techniques. It locks food moisture which reduces the chances of spoilage. In addition, sugar is heavily added to canned foods to preserve them for a longer time. 
4. Spices- natural food preservative examples include red chillies, thyme, rosemary, oregano which are used to preserve several types of food. The spices also help prevent food oxidation which preserves it for a longer time. 
5. Vinegar- Vinegar is a type of citric juice used as an antioxidant for preserving. The use of vinegar has been from a historical period. This type of antioxidant is generally created from fermentation techniques from apples, grapes, dates, and others. 
6. Garlic- Garlic contains anti- viral properties which helps to preserve food for longer time. Food that is coated in garlic permits lower bacterial growth than other preservatives.
7. Ascorbic Acid- Another name for Vitamin C which has crucial anti- oxidant properties. Lemon has been used for pickling and other preservative activities for more than a month. 
8. Celery- It contains sodium nitrite which prevents bacterial growth. 

Conclusion 

Preventing spoilage helps to elongate shelf -life. Natural food preservation techniques have been used since 12000 BC. Although, natural food preserving techniques have been altered with synthetic preservatives. Consumers have become aware of the health facts in recent years, while public health initiative has provided the impetus to use more natural preservatives. 

The most common examples of natural food preservatives include sugar, salt, spices and oils. Natural food preservation techniques are canning, drying, pickling and others. The primary purpose of food preservation is to stop the oxidation process, which increases the shelf- life of any food product.  Natural preservatives are less harmful than synthetic or chemical ones while they are easily available in seasons.