How is ultrasound used in the food industry?
In line with increasing consumer demand for minimally processed food and the tightening of food and environmental regulations, food manufacturers are turning more to new technologies that have the power and capabilities to meet their needs. Ultrasound technologies in the food industry are one of the fast, versatile, emerging, and promising non-destructive green technology used in the last few years.
It helps to minimise processing, retain nutrient, non-nutrient (bioactive), and sensory characteristics and ensure the safety of food products. Ultrasound is used in various applications across the food industry, which we will be exploring in this article.
First, what is ultrasound?
Ultrasound is mechanical sound waves that come from molecular movements that oscillate in a propagation medium. These waves have a frequency that goes beyond the capacity of human hearing. When the ultrasound propagates through a material it creates compressions and decompressions in the particles of the medium and as a result a high level of energy is produced.
The main principle behind ultrasound is that it relies on interactions between high-frequency sound waves and matter to gather information about the composition, structure, and dimensions of materials through which it propagates.
Ultrasound has varying effects on different systems, on solids for instance, it effects through vibrational energy for cutting and melting. In liquids it effects by creating intense cavitation, and in gases it affects by forming strong acoustic fields.
Applications of ultrasounds in the food industry
Acoustic drying
Typically, food products are dehydrated using hot air, but higher temperatures during the drying process results in product damage and induces unwanted changes to its colour, taste, and nutritional value. Whereas ultrasonic osmotic dehydration technology includes lower solution temperature leading to higher water loss and solute gain rates.
Sonic assisted drying is done at lower temperatures, so the likelihood of oxidation or degradation is reduced in the material. Acoustic drying is especially useful for heat-sensitive material because the application of low temperatures and short exposure time for dehydration causes less alterations in the parental attributes of the food.
Acoustic filtration
Also called ultrasonically assisted filtration which is used to increase the flux by deconstructing the concentration polarisation and cake layer formed on the surface of the membrane without effecting the permeability of the membrane. This approach is mostly used for extracting the fruit juice and drinks from the pulp.
Defoaming
Foam is characterised as the dispersion of gas in a liquid. Intensive foaming or persistent foams are unwanted in many processes as they can lead to problems like loss of products, reduced productivity and more. The food industry equipment that is normally used to control foams are mechanical breakers, which lower the temperature by adding chemical antifoams.
High-intensity ultrasonic waves have become a distinctive method of breaking foam as they don’t require airflow, prevent chemical contamination, and is performed under sterile conditions or within a contained environment. This makes it a suitable choice for implementation in both pharmaceutical and food industries.
Meat tenderisation
Several applications of ultrasonic treatment are in meat technology such as the reduction of meat toughness because of a large amount of connective tissue. Using sonication to tumble the meat pieces or adding salt helps with tenderising the meat. The samples that are treated with these are often superior in quality. So, ultrasound is useful in improving the physical properties of meat products including tenderness, water-binding capacity, and cohesiveness.
Acoustic extraction
Another food industry process that uses ultrasound is the extraction of enzymes and proteins that are kept in cells and sub-cellular particles. Ultrasound is applied in a unique and effective way and carries the possible benefits in extraction and isolation of novel potentially bioactive elements.
For example, lipids are extracted from plant seeds including soybeans (e.g., flour or defatted soybeans) or other oil seeds. The destruction of cell walls allows the pressing (hot or cold) and minimises residual oil or fat in the pressing cake. This technique also applies to citrus oil from fruits, oil extraction from ground mustard, peanut, herb, oil, canola, soy, corn, etc.
Conclusion
These are just a few examples of the many ways ultrasound is used effectively in the food industry. It’s a useful and modern technology that many businesses can take advantage of. At FESS Group, our team of experienced food factory design consultants are on hand to help you ensure your operations are working as efficiently, safely, and cost effectively as possible. Contact us today or book a free site survey online to see how we can help you optimise your factory processes.