Microbial Safety in Low-temperature Meat Products: Integrating Non-thermal Sterilization and Natural Antimicrobials

Teixeira Chan^*
*Correspondence: Teixeira Chan, Department of Food Science and Bioengineering, Tianjin Agricultural University, Tianjin 300380, China, Email:

Introduction

The global demand for low-temperature meat products, including cold cuts, sausages, and ready-to-eat meats, has risen substantially due to their convenience, extended shelf life, and rich flavor profiles. However, these products are highly susceptible to microbial contamination, which can lead to foodborne illnesses. The primary challenge in ensuring the safety and longevity of low-temperature meat products lies in effectively controlling microbial growth without compromising product quality, nutritional value, or flavor.

Traditionally, thermal sterilization techniques have been employed in meat processing to kill or inhibit microbial growth, but the high temperatures involved can lead to undesirable changes in the texture, color, and taste of the meat. In response, there has been increasing interest in non-thermal sterilization methods and the use of natural antimicrobials. These approaches offer promising alternatives to traditional methods by allowing for the preservation of meat products without compromising their sensory properties. This article will explore the microbial safety of low-temperature meat products through the integration of non-thermal sterilization and natural antimicrobials.

Description

Low-temperature meat products are particularly vulnerable to microbial contamination due to the conditions under which they are stored and processed. The relatively low temperatures, typically between 0°C and 5°C, help slow down bacterial growth but do not eliminate it. As such, bacteria such as Salmonella, Listeria monocytogenes, Escherichia coli, and Staphylococcus aureus can still proliferate, albeit at a slower rate, potentially leading to foodborne illnesses if these pathogens are present. In addition to bacterial pathogens, lowtemperature meat products may also be contaminated with molds and yeasts, which can cause spoilage, off-flavors, and discoloration. As these products are often consumed without further cooking, ensuring their microbial safety is a top priority. Therefore, effective microbial control during both production and storage is necessary to minimize health risks and maintain the quality of the meat. Non-thermal sterilization techniques involve methods of microbial control that do not require high temperatures. These methods are becoming increasingly popular in the food industry due to their ability to preserve the nutritional quality, texture, and flavor of the meat while still ensuring microbial safety. Some key non-thermal sterilization techniques include High-Pressure Processing (HPP), Pulsed Electric Field (PEF) treatment, cold plasma, and ultraviolet (UV) light [1].

High-pressure processing involves subjecting food products to intense pressure, typically between 300 and 600 MPa, for a specified period. This pressure disrupts the cell membranes of microorganisms, leading to their inactivation. HPP is particularly effective at inactivating pathogenic bacteria such as Listeria monocytogenes, Salmonella, and E. coli, while minimally affecting the texture, flavor, and nutritional content of meat products. HPP is widely used in the meat industry to extend the shelf life of cold cuts, ready-toeat meats, and other low-temperature meat products. Since it does not require heat, HPP helps preserve the sensory qualities of meat, making it a favorable option for consumers seeking minimally processed foods. Furthermore, HPP can enhance the safety of these products by providing an additional barrier against microbial contamination.

Pulsed Electric Field (PEF) treatment is another non-thermal method that uses short bursts of high-voltage electrical fields to disrupt the cell membranes of microorganisms. PEF treatment can be applied to liquid and solid foods, including meat, to reduce microbial load without significantly affecting the sensory properties of the product. PEF treatment is particularly effective in killing or inactivating bacteria, yeasts, and molds that are present in low-temperature meat products. It works by creating pores in the microbial cell membrane, allowing for leakage of intracellular contents and ultimately leading to cell death. PEF has been shown to be effective against a variety of pathogens, including Listeria monocytogenes, Salmonella, and E. coli, which are common contaminants in meat products [2].

Cold plasma is a relatively new non-thermal sterilization technique that involves ionized gas at low temperatures. The plasma generates reactive species, such as ions, electrons, and free radicals, which can interact with microbial cells, leading to cell damage and inactivation. Cold plasma has been shown to be effective against a wide range of microorganisms, including bacteria, molds, and viruses, and is increasingly being used in food processing. Cold plasma is advantageous because it can be applied to both solid and liquid food products, including meat. In addition to its antimicrobial properties, cold plasma also has potential applications in extending the shelf life of meat products by slowing down the growth of spoilage microorganisms. Furthermore, since cold plasma is a dry sterilization method, it does not introduce any moisture, which can be a concern in some traditional thermal methods.

Ultraviolet (UV) light is another non-thermal technique used for microbial control. UV-C light, in particular, has a germicidal effect, as it damages the DNA of microorganisms, preventing them from replicating. UV light is effective in inactivating a wide range of microorganisms, including bacteria and molds, and has been used in various food applications, including meat products. UV light is commonly used in the post-processing stage for surface sterilization of low-temperature meat products. It is particularly useful in reducing surface contamination and preventing the growth of spoilage microorganisms. One of the key advantages of UV light is its ability to treat meat products without the need for chemical additives, making it a clean and environmentally friendly option [3].

In addition to non-thermal sterilization techniques, the use of natural antimicrobials has gained significant interest as a way to enhance the microbial safety of low-temperature meat products. Natural antimicrobials, derived from plants, herbs, and spices, offer a safe and sustainable alternative to synthetic preservatives, which can be a concern for health-conscious consumers.

Essential oils: Essential oils, derived from plants such as thyme, oregano, clove, and rosemary, possess potent antibacterial and antifungal properties. These oils contain compounds like phenols, terpenes, and aldehydes, which can disrupt the cell membranes of microorganisms and inhibit their growth. Essential oils have been widely studied for their antimicrobial effects and are increasingly used in food preservation. For example, thyme oil has shown efficacy in controlling Listeria monocytogenes and E. coli in low-temperature meat products, while oregano oil has demonstrated activity against Salmonella spp. and other foodborne pathogens. The application of essential oils in meat products not only provides antimicrobial protection but also imparts desirable flavors and aromas, which can enhance the overall sensory experience of the product.

Plant extracts and natural antioxidants: In addition to essential oils, plant extracts such as rosemary extract, green tea extract, and garlic extract have been shown to possess antimicrobial and antioxidant properties. These extracts can help preserve the freshness and quality of low-temperature meat products by inhibiting microbial growth and reducing oxidative rancidity. The inclusion of natural antioxidants like tocopherols (vitamin E) and ascorbic acid (vitamin C) can further enhance the shelf life of meat products by preventing lipid oxidation.

Organic acids: Organic acids, such as lactic acid, citric acid, and acetic acid, are commonly used as natural preservatives in meat products. These acids lower the pH of the meat, creating an unfavorable environment for microbial growth. Lactic acid, in particular, has been shown to be effective in inhibiting the growth of Listeria monocytogenes and other pathogens in refrigerated meat products. The use of organic acids as part of a natural antimicrobial strategy can help ensure the safety and quality of low-temperature meat products. The combination of non-thermal sterilization methods and natural antimicrobials offers a synergistic approach to microbial control in lowtemperature meat products. By integrating both strategies, meat processors can enhance the safety and shelf life of their products while maintaining the quality and sensory attributes that consumers expect. For example, combining high-pressure processing with the addition of essential oils or plant extracts can provide a comprehensive solution that addresses both pathogenic and spoilage microorganisms [4,5].

Conclusion

Ensuring the microbial safety of low-temperature meat products is essential for protecting public health and maintaining product quality. The integration of non-thermal sterilization techniques such as high-pressure processing, pulsed electric field treatment, cold plasma, and ultraviolet light with natural antimicrobials such as essential oils, plant extracts, and organic acids offers an innovative and sustainable solution for achieving this goal. These technologies can work synergistically to provide effective microbial control, prolong shelf life, and preserve the sensory attributes of meat products. As consumer demand for cleaner, healthier, and more natural food products continues to rise, the combination of non-thermal sterilization and natural antimicrobials represents a promising strategy for the future of meat processing.

Acknowledgment

None.

Conflict of Interest

There is no conflict of interest by author.

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