The sound ranges employed can be divided into high frequency, low energy diagnostic ultrasound and low frequency, high energy power ultrasound. The former is usually used as a non-destructive analytical technique for quality assurance and process control with particular reference to physicochemical properties such as composition, structure and physical state of foods.
Nowadays, power ultrasound is considered to be an emerging and promising technology for industrial food processing. The use of ultrasound in processing creates novel and interesting methodologies which are often complementary to classical techniques. Various areas have been identified with great potential for future development: crystallisation, degassing, drying, extraction, filtration, freezing, homogenisation, meat tenderization, sterilization, etc.
There is a wide scope for further research into the use of ultrasound in food processing both from an industrial and academic viewpoint. APA Dolatowski Z. Ultrasonic treatment low-intensity and low-frequency and the use of vacuum caused favorable microstructural changes in pork loins marinated in sodium chloride [ 15 ] and these effects are highly dependent on the intensity of ultrasound treatment. Furthermore, cavitation generates shock waves, which contribute to this effect.
Factors that modulate the effects of ultrasound application include time of exposure, processing volume, and sample composition [ 12 , 14 ]. Bacteria are the most important microorganisms in food processing. While most are harmless and many are beneficial, some indicate the likely presence of contamination and deterioration and may cause diseases. While thousands of bacterial species have been identified, all are unicellular and fall under three basic forms: spherical, rod-shaped, and spiral.
Some rod-shaped bacteria can take two forms: latent spores and active vegetative cells. The vegetative cells form spores under adverse conditions to survive. Most sporulating bacteria that grow in the presence of air belong to the Bacillus genus, and most of those that grow only in the absence of air belong to the genus Clostridium.
Meat is susceptible to the growth of some pathogenic microorganisms such as E. Several methods are used to avoid microbial growth in meat. The most commonly used methods involve heating, dehydration, and addition of preservatives [ 64 ]. The most common types of mesophilic bacteria that are pathogenic to humans include Staphylococcus aureus , Salmonella , and Listeria. Although it may survive without damage in the intestinal tract of humans, salmonella is a common cause of food poisoning.
Another common mesophilic bacterium, Listeria monocytogenes , is more often distributed through contaminated foods such as raw meats or unpasteurized cheeses [ 64 ]. Animals, including humans, may transport Listeria , but it primarily threatens those with weakened immune systems.
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Some E. These are called enteropathogenic bacteria. Staphylococcus is nonsporulated bacteria without mobility, but because they are resistant to drying, they are easily dispersible by dust particles through air and surfaces [ 65 ]. It is almost always present in small quantities in raw meats and foods extensively handled by humans. Maintaining food that is completely free of contamination with Staphylococcus is often difficult or impossible.
Pasteurizing or cooking destroys the organism but not its toxin [ 66 ]. Meat is one of the most perishable foods consumed by humans—it is easily damaged by bacteria.
One of the most commonly used preservation methods is refrigeration, including freezing. This group includes some pathogens such as Yersinia enterocolitica , Listeria monocytogenes , nonproteolytic strains of C. Several other organisms that can cause foodborne diseases and grow at refrigeration temperatures include: Vibrio parahaemolyticus , Bacillus cereus , Staphylococcus aureus, and some Salmonella strains [ 64 ].
When refrigeration is extended, Pseudomonas , Acinetobacter , and Moraxella species may grow and damage fresh meat [ 67 ]. Gram-negative organisms are known to survive less frequently compared to their Gram-positive counterparts [ 68 , 69 , 70 ]. However, recent studies have shown higher survival rates among Gram-negative bacteria, especially Pseudomonas species, which account for the majority of bacteria responsible for refrigerated meat deterioration [ 67 ]. This fluctuation in temperature reduces the useful life of the products and can lead to major public health problems. The fresh meat industry must incorporate as many treatments as possible that reduce the microbial population and minimize reproduction.
Some of these treatments include heat, acidification, preservatives, reduced water activity, and packaging under modified atmospheres. Although modified atmospheres are included as a potential barrier, it should be noted that reduced oxygen atmospheres can actually favor anaerobic pathogens. For many products, the modified atmosphere actually helps improve product quality rather than safety. Yeast and molds grow on most foods, equipment, and building surfaces with small amounts of nutrients and moisture [ 71 ]. Because bacteria grow faster, they greatly outgrow yeasts and molds in most foods.
Fungi and yeasts grow well in low-pH, humid, and temperature environments with high concentrations of salt and sugar. Therefore, they can pose a problem in dry foods, such as dried meat and salted fish [ 72 ]. Effective microbial destruction is of paramount importance for food processing; a single report of microbial contamination could question the reputation of a manufacturer and jeopardize their future success.
To minimize the bacterial load of a product, the manufacturer must reduce the initial contamination, inactivate microorganisms present in the food, and implement procedures to prevent or slow the growth of microbial populations that have not been inactivated. Conventional methods of bacterial inactivation involve thermal treatments, such as pasteurization.
These treatments generally result in undesirable flavors and the loss of nutrients. Ultrasonic treatment has been used to inactivate bacterial populations [ 73 ]. This is due to cavitation effects: pressure changes produced by the ultrasonic waves cause microbiological inactivation [ 3 , 73 ]. The microbiological damage resulting from the application of various ultrasound wave amplitudes depends on factors such as contact time with the microorganism, microorganism type, food quantity, composition, and treatment temperature [ 74 ].
Microbial resistance varies among microorganisms, i.
Analytical Applications of Ultrasound, Volume 26
Studies have shown that larger or longer cells are more susceptible to ultrasound because they have more a larger contact surface and are therefore more exposed to the pressure produced by cavitation [ 75 ]. Gram-positive bacteria are less susceptible to ultrasound compared to Gram-negative bacteria, although results have shown that rod-shaped bacillus microorganisms tend to be more susceptible than cocci [ 76 ]. Gram-positive bacteria are likely less susceptible to ultrasound because of their thicker cell walls, which contain an adhesive peptidoglycan layer [ 77 , 78 ].
In general, microorganisms that produce spores exhibit a greater resistance to heat and ultrasound [ 74 , 75 ].
Enhancement of Cerium exchange with Ultrasound
A considerable amount of data on the impact of ultrasound on microbial inactivation is available. For this reason, a new method for antimicrobial treatment could feature the combined effects of pressure and ultrasound manosonication , ultrasound and heat thermosonication , or ultrasound, heat, and pressure manothermosonication [ 79 ].
These are likely the best microbial inactivation methods because they are more energy-efficient and effective in inhibiting microorganisms than conventional methods. The effectiveness of ultrasonic treatments requires prolonged exposure to high temperatures, which may deteriorate functional properties, sensory characteristics, and the nutritional content of foods [ 73 ].
In combination with heat, ultrasound can accelerate the rate of food sterilization, thereby decreasing the necessary duration and intensity of heat treatment and the resulting damage. The inactivation of Salmonella typhimurium, Salmonella derby, Salmonella infantis, Yersinia enterocolitica, and a pathogenic strain of Escherichia coli was studied in inoculated samples treated for 0.
The total viable bacterial counts decreased by 1. The reduction of the population in the skin was significantly greater than that in the meat, although no significant differences were observed between the types of bacteria. However, the study by Smith et al. They reported no effect after ultrasound on Salmonella or on E.
Analytical applications of ultrasound | Open Library
Some authors [ 82 ] have studied the elimination of Gram-negative bacteria Salmonella anatum, Escherichia coli, Proteus sp. Other reports show that treating chicken carcasses in the process line with steam and ultrasonic treatments significantly reduces the population of Campylobacter in contaminated poultry.
The total viable content decreased by approximately three logarithmic units when steam and ultrasound were applied immediately after slaughter [ 83 ]. Ultrasound treatments combined with lactic acid may be a suitable method for decontaminating poultry carcass skins. Ultrasound effects depend on frequency, amplitude, time, and temperature [ 84 ] as it was demonstrated on the inactivation of suspensions containing Escherichia coli, Staphylococcus aureus, Salmonella sp. These three parameters affected the inactivation of bacteria in pure cultures. The results showed increased microbial inactivation for longer treatment periods, particularly when they were combined with high temperature and amplitude.
Meat treated for the longer period showed the largest reduction of microorganisms during storage [ 21 ]. Selected and potential applications of ultrasound mainly in the field of food preservation and product modification were discussed. High-intensity ultrasound generates acoustic cavitation in a liquid medium, developing physical forces that are considered the main mechanism responsible for the observed changes in exposed materials.
These forces include acoustic streaming, cavitation, shear, micro-jet, and shockwaves. The quantity of energy released by the cavitation depends on many factors such as treatment medium and ultrasound frequency.
Ultrasound has a wide range of applications in the food industry. It can be used as a processing aid in extraction, crystallization, freezing, emulsification, filtration, and drying. Applications of ultrasound in meat have been reported with interesting advantages in freezing, thawing, meat brining, and tenderizing.
Ultrasound has also been shown to improve physicochemical characteristics, preparation processes for meat products, microbiological content, and sensory characteristics in fresh and processed meat. Acoustic cavitation may induce the mechanical rupture of the myofibrillar protein structure with significant effect on collagen characteristics and meat textural properties.
- Analytical applications of ultrasound.
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High-intensity ultrasound reduces microbial loads in meat, resulting in the destruction of living cells and this effect remains during cold storage. Like most innovative food processing technologies, high-power ultrasonics needs to be developed and scaled up for each application.
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The authors declare that they have no interest or benefit arising from the direct applications of this chapter. Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution 3. Help us write another book on this subject and reach those readers. Login to your personal dashboard for more detailed statistics on your publications.
By Niamh Burke, Krzysztof A. Ryan and Catherine C. Edited by Dongpo Li. We are IntechOpen, the world's leading publisher of Open Access books. Built by scientists, for scientists. Our readership spans scientists, professors, researchers, librarians, and students, as well as business professionals. Downloaded: Abstract High-intensity ultrasound offers an alternative to traditional methods of food preservation and is regarded as a green, versatile, popular, and promising emerging technology.
Keywords ultrasound cavitation emerging technology minimal processing meat quality. Introduction Evolution of food processes is driven by changes in consumer preferences and the need to produce safe and high-quality foods. Power ultrasound Power or high-intensity ultrasound has emerged as a new and complementary technology with a high number of potential applications. Applications in food Ultrasound has potentially a wide range of applications in the food industry.
Applications in meat The use of ultrasound in the meat industry, which began with the evaluation of live cattle fat and muscle, has been conducted since the s. No effect on collagen. No effect on pH. Higher water holding capacity. Increased free calcium. Would you like to change to the United States site? Undetected location. NO YES. Home Subjects Chemistry Analytical Chemistry. Ultrasound in Chemistry: Analytical Applications. Selected type: Hardcover.