Food preservation methods play a dominant role in food safety and security. These methods have enabled humans to form communities, store foods for additional times while maintaining a leisure attitude. Besides food safety and security, food preservation methods allowed the availability of healthy and nutritious food.
Food Preservation. Image Credit: monticello/Shutterstock.com
Food is vital for survival, an important factor of growth and development. Across the globe, food is the source of sustenance for all kinds of life on planet earth. Food wastage occurred at all stages, from harvesting to consumers. However, much of food wastage occurred due to moisture, improper handling of crop production, and microbial organisms.
So, the food losses to such factors contribute to a food shortage or unequal distribution. In such circumstances, food preservation methods play a vital role in food prevention from spoilage due to microbial spores and moisture.
The microbial contaminations not only reduce food quality but also impact the quantity. And, these contaminations appear in the form of symptoms, thus impacting the economic value of crop production (fruits and vegetables). To counteract food spoilage, food preservation is the best and sustainable solution. These methods maintain food nutrition, health, and its edibility.
In addition to maintaining food nutrients, these methods also ensure the availability of enough food. Because with the ever-increasing global population, there is demand for more fresh and healthy food.
In ancient times, food preservation methods were also employed. The methods were sun drying, salting, and freezing based on climacteric conditions. These methods enabled humans to form communities and keep food for additional times.
With advancements in food science and technology, the food preservation idea gets new insights into food safety and security with an extended shelf life for the ever-rising human population. The objective of food preservation is to inhibit biochemical reactions and restrict the entry of bacteria and fungi. This idea aims to provide food to all with no losses to microbial contaminations.
The food preservation method includes ozone treatment, freezing, ultrasound, thermal treatment, pulse electric field, and nanotechnology. All these methods play a key role in the food preservation industry. The foods that are preserved by these methods are fruits, vegetables, liquid food, and spices.
A breakdown of various food preservation methods
Ultrasound
The ultrasound food preservation method involves the use of high-intensity and frequency sound waves. These waves passed into the food material. In this process, the ultrasound waves passed through the targeted solution. The high-intensity waves cause disturbance in the solid particles (particle-particle bond) of the solution leading to particles breakdown and release into solution. The ultrasound technology has a promising potential in the wine industry and dairy production.
In dairy production, this technology is utilized to kill microbial spores. It also improves the texture and homogenization of yogurt, skimmed milk, and cheese. In the winemaking industry, the use of high-frequency sound waves replaces the use of chemicals (sulfur oxide) as food preservations material.
A study by (Gracin et al., 2016) confirmed the 85 to 90% reduction in lactic acid bacteria in wine when treated with high force ultrasound waves for 20 minutes. The caution in this is proper and careful handling to maintain the flavor and texture.
Freezing
The freezing food preservation method is used for leafy vegetables, spices, and milk productions to maintain their nutritional value. The freezing techniques involved cryogenic, air blast, dehydration freezing, and high-pressure freezing. These techniques are based on the principle of heat transfer.
Thermal treatment
The use of heat in food preservation serves as a novel approach with wide applications in the food industry. For example, this technique has applications in the bakery, fresh fruits & vegetables, and dairy. The heat treatment process involves heating food materials at higher temperatures between 75 and 90 C with a holding time of 25–30 seconds.
Ozone treatment
This technique is used in the food industry because of its diverse properties. The ozone is formed when oxygen is split in the presence of ultraviolet rays. Later, this compound is quickly broken down into oxygen which has high oxidation potential. And these molecules as functions as an antimicrobial and antiviral agent.
Nanotechnology
Nanotechnology has great potential in food preservation and holds the potential of sustainability in food processing, packaging, and storage for the long run. This technology has greater potential compared to other methods because of its distinctive properties. These properties include precision action, no pollutants, energy efficiency (sustainable), and high surface area.
This technology involves the manufacturing of nanoparticles on the scale of atoms or a small group of atoms. These nanomaterials classified as organic and inorganic based on their material and functionalities.
Not only nanotechnology has a breakthrough role in food preservation, but it also has a promising role in precision agriculture. For example, the use of nano fertilizers allowed sustainable farming with less or no use of chemical pesticides. These nano fertilizers maintained plant growth and nutritional qualities by controlling weeds.
Nanomaterials have great electrochemical and optical properties in sauces, oils, juice, and beverages. These nanomaterials are used as supplements, sensors, and ingredients in food processing. Examples of such ingredients are magnesium oxide and silicon dioxide and are used as a food flavor and baking agent.
The titanium oxide is used in gums, sauces, and cakes as an additive. Examples of other supplements are zinc oxide, copper oxide, and iron oxide. These are used as an additive in food products to enhance their shelf life.
Fresh fruits and vegetables are sensitive to higher moisture contents and oxygen that leads to deterioration of food quality. In food packaging, nanotechnology also plays a crucial role in food preservation from spoilage. To circumvent this spoilage, the coating of food materials with nanoparticles and polymer-based materials has proved their potential in food preservation.
The cellulose films and chitosan are used as food packaging material with nanoparticles (zinc oxide, etc). Chitosan- and cellulose-based films possess antifungal, antioxidants, and antimicrobial properties.
Sources:
- Sridhar, A., Ponnuchamy, M., Kumar, P.S. and Kapoor, A., 2020. Food preservation techniques and nanotechnology for increased shelf life of fruits, vegetables, beverages, and spices: a review. Environmental Chemistry Letters, pp.1-21. DOI: 10.1007/s10311-020-01126-2
- Gracin, L., Jambrak, A.R., Juretić, H., Dobrović, S., Barukčić, I., Grozdanović, M. and Smoljanić, G., 2016. Influence of high-power ultrasound on Brettanomyces and lactic acid bacteria in wine in continuous flow treatment. Applied Acoustics, 103, pp.143-147. DOI:10.1016/j.apacoust.2015.05.005
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