Fish is an essential food in the human diet, rich in proteins, omega-3 fatty acids, vitamins, and minerals. However, its rapid deterioration due to microbial activity poses a significant challenge for the food processing industry. Traditionally, methods such as cooling, freezing, and canning have been used to preserve fish, but they have limitations. Nevertheless, a new technological frontier is revolutionizing the fishing industry.
A study published by researchers from the University of Aveiro (Portugal) and the University of Porto (Portugal) examines the current state of research on electricity and pressure-based technologies that have the potential to extend the shelf life of fresh fish. The study also analyzes the advantages and disadvantages of each technology, their possible applications, and the challenges that arise with their integration into the fish processing industry.
Factors Influencing Microbial Decomposition of Fish
The growth of microorganisms in fish after capture is influenced by various factors such as temperature, pH, water activity, and the presence of nutrients. Fish, having high water activity and low acidity levels (pH > 6), creates an ideal environment for microbial development. Additionally, it contains numerous non-protein nitrogenous compounds, such as free amino acids, peptides, and amines, that promote the growth of these microorganisms.
Among the most common bacteria found in fish are Pseudomonas, Aeromonas, Serratia, Bacillus, Lactobacillus, and Micrococcus. Under refrigeration conditions, psychrotolerant gram-negative bacteria such as Shewanella and Photobacterium are responsible for spoilage. During this process, bacteria produce compounds such as volatile amines, organic acids, and ketones, which generate unpleasant odors and flavors in the fish.
The Electricity and Pressure Revolution
Traditional fish preservation methods such as refrigeration, freezing, and canning have been used for centuries. However, they have limitations in terms of energy consumption, nutrient reduction, and alteration of fish quality.
To overcome these challenges, new technologies have emerged that promise to revolutionize the fish processing industry.
Recently, two innovative technologies have emerged that are revolutionizing fish preservation: electrical and pressure-based techniques. These methods stand out for their ability to eliminate microorganisms without significantly compromising fish quality.
- Electricity to the Rescue: Methods such as pulsed electric fields (PEF) and high-voltage electrical discharges (HVED) use electric pulses to perforate bacterial cell walls, causing their death. These treatments are highly effective in eliminating microorganisms without significantly affecting the taste, texture, and aroma of the fish.
- Pressure as an Ally: On the other hand, techniques such as high-pressure processing (HPP) and hyperbaric storage (HS) use pressure to inactivate microorganisms. Like electrical techniques, these largely preserve the sensory and nutritional qualities of the fish.
These advanced technologies offer a promising alternative to traditional methods, which often involve high temperatures or chemicals. In addition to ensuring food safety, they extend the shelf life of fish, reducing waste and benefiting the environment.
The Future of the Fish Processing Industry
Although the results are promising, there is still a long way to go. It is necessary to investigate the optimal conditions for applying these techniques, understand how they inactivate microorganisms, and assess their long-term impact on fish quality.
Likewise, economic, scalability, and regulatory factors must be considered for the successful implementation of these technologies in the fish processing industry, which will benefit both the fishing and aquaculture industries.
Conclusion
The need to improve fish preservation to extend its shelf life, maintain its quality, and reduce economic losses is increasingly urgent in a world where the demand for healthy food continues to grow. Emerging technologies such as pulsed electric fields, high-voltage electrical discharges, high-pressure processing, and hyperbaric storage represent promising solutions. However, their implementation in the fishing industry must be approached with care, considering both their benefits and the challenges they present.
Ongoing research and the adaptation of these technologies could significantly transform the way fresh fish is preserved, ensuring safer and higher-quality products for consumers. The results of this research will enhance the technologies being studied to improve fish processing and increase shelf life.
Contact
Jorge A. Saraiva
LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193, Aveiro, Portugal
Email: jorgesaraiva@ua.pt
Reference
Mousakhani Ganjeh, A., Pinto, C. A., Casal, S., & Saraiva, J. A. (2024). Potential of electric and pressure-based techniques for the inactivation of microorganisms in fresh fish. Food Bioscience, 61, 104537. https://doi.org/10.1016/j.fbio.2024.104537
