Food is an ideal medium for the growth of microorganisms. Therefore, by inhibiting the development of these, we can increase the shelf life of food.
Many causes negatively influence the quality of food, either by intrinsic factors, such as nutrient content, water availability, pH, etc., or by extrinsic factors, such as temperature of storage, relative humidity, exposure to sunlight and air, handling and processing of raw materials, etc.
The main objective of food preservation is to maintain a product in perfect hygienic conditions and to protect its rheological and organoleptic qualities [1].
The processes of food preservation allow us to obtain safe products of high quality at a reasonable price. The permanent increase in the demands of consumers in terms of quality and prolongation of the useful life of the food causes continuous changes in the way in which the food is produced, distributed, stored and sold. The food industry is constantly searching for new methods that are less aggressive with food, with lower energy consumption and more effective against pathogenic microorganisms.
Types and methods of food preservation
Food preservation methods are essential to delay spoilage and ensure safety and quality throughout the product’s shelf life. These methods include physical techniques such as refrigeration, freezing, dehydration, smoking, pasteurization, and sterilization, as well as chemical and biological approaches like fermentation or the use of preservatives. Food preservation with salt or sugar is also considered a chemical technique that improves food shelf life. The selection of the appropriate technique depends on the nature of the food, its composition, and the desired storage duration. In modern food systems, preservation strategies are increasingly combined with innovative packaging solutions to enhance effectiveness and minimize environmental impact.
Nowadays, packaging is vital in the marketing of food, since in addition to providing better conservation, longer life of the food and information for the consumer, they must produce a visual impact that makes them differentiate themselves from similar products to be chosen by the final consumer.
Packaging is a conservation method that protects food from light, moisture and other environmental contaminants. For a correct packaging process, the following factors must be taken into account:
- Storage: capacity to be stacked and transported, control of quantity produced, conservation of small products.
- Protection: against deterioration, leakage, breakage, dehydration, contamination, theft and alteration. Physical protection against shock, vibration, compression, temperature, etc. Barrier protection against oxygen, water vapor, dust, bacteria, etc.
- Information: identification of the product, description of use or preparation, warning about risks derived from improper use, list of ingredients, nutritional data and price, etc.
- Promotion: marketing tool to differentiate the product from similar ones and attract attention in shops and supermarkets using, for example, brands, colors, illustrations and forms.
- Transport: greater ease and safety to move products from the manufacturer to the warehouse and the vendors (tertiary containers) and even the consumer (primary packaging).
Types of food packaging for preservation
Packaging materials
A suitable container should avoid contamination of the food by preventing the passage of outside substances. In some cases, the packaging can cause alterations to the taste, smell or texture of food and be harmful to health, so it is necessary to control the materials with which it has been manufactured.
Currently we can find a variety of materials for the manufacture of containers, with different gas permeabilities, with variable resistances and permissiveness to light (transparent, translucent, opaque), but also some elements allow us to know if temperature has been constant during storage, or if there have been breakages of the cold chain, as well as the concentration and composition of the gas inside [2].
Due to its versatility in shape and size, being light and hygienic, the most used packaging materials are synthetic plastics. However, because they are products that do not decompose, they are a cause of environmental pollution. Therefore, in recent years, new types of less polluting or easy-to-recycle materials have been developed, which are called biodegradable packaging.
The biodegradable containers come from renewable sources and many of them are characterized as being edible. They are applied as a barrier for microorganisms and to improve sensory properties such as appearance, color, brightness and transparency.
Why choose active packaging?
Currently, the container, in addition to fulfilling its basic functions of containment, protection and information, is becoming a medium that performs sophisticated interactions with its content and in a registry of important information for both the consumer and the intermediaries of the chain of value, thus creating the concept of active packaging.
It is considered to be an active element when there is another function other than providing an inert barrier against external conditions. They belong to this group of products when food components or some material are used as an indicator of the history and quality of the product. There are two mechanisms of action to create this type of packaging: introducing the active element inside the container together with the food or introducing it into the food itself.
A way to achieve active packaging by incorporating natural antioxidants, such as tocopherols, which allows to increase the shelf life of foods by inhibiting or delaying the oxidation of lipids or other compounds [3].
It may interest you: What is a natural antioxidant and why is it useful in food?
Among the active packaging, the concept of intelligent packaging stands out. It is a packaging system capable of collecting and processing information from the environment to transmit it to the consumer [4]. Its objective is to ensure the quality of the product by monitoring the processes that alter the food.
Packaging in a modified atmosphere
Another method of food preservation that has stood out in recent years is packaging in a modified atmosphere. It consists of the alteration of the environmental gases to reduce microbial growth and the speed of the internal chemical reactions.
In commercial practice, oxygen reduction and an increase of carbon dioxide and/or nitrogen are usually used. Carbon dioxide acts as a destructive agent of bacteria and fungi and reduces the multiplication of pathogenic microorganisms. In the process of packaging in modified atmospheres, it is not necessary, in general, to maintain the composition of the gas throughout the storage, so it is more practical and economical.
When calculating the amount of modified gases, it must be kept in mind that the effect is not the same for all products and working conditions. It varies according to the composition, characteristics and sanitary status of the food to be conserved, the composition of the atmosphere and the storage temperature, as well as the packaging materials and packaging technology [5].
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Sources
- Casp A, Abril J. Procesos de conservación de alimentos. Madrid: Mundi-Prensa; 2003.
- Rodríguez AM Cabrera. Envasado de alimentos. Nuevos materiales [Internet]. 2021 [cited 2025 Oct 15]. Available from: https://riull.ull.es/xmlui/bitstream/handle/915/22777/ENVASADO%20DE%20ALIMENTOS.%20NUEVOS%20MATERIALES.pdf?sequence=1
- Quezada-Gallo, JA. (2009). Delivery of Food Additives and Antimicrobials Using Edible Films and Coatings. In: Huber, K., Embuscado, M. (eds) Edible Films and Coatings for Food Applications. Springer, New York, NY. doi:10.1007/978-0-387-92824-1_11
- Rodríguez-Sauceda R, Rojo-Martínez GE, Martínez-Ruiz R, Piña-Ruiz HH, Ramírez-Valverde B, Vaquera-Huerta H, Cong-Hermida MC. Envases inteligentes para la conservación de alimentos. Ra Ximhai. 2014;10(6 Especial):151-73. doi:10.35197/rx.10.03.e2.2014.12.rr
- Catalá R, Almenar E, Gavara R. Nuevos envases: de la protección pasiva a la defensa activa de los alimentos envasados. [Internet]. 2001 [cited 2025 Oct 15]. Available from: https://repositorio.upct.es/bitstreams/0b94a240-7d71-41ee-923f-0a464c030676/download