The Challenges Of Meat Preservation And Shelf-Life Management In Today’s Asian Market
Monday, March 18th, 2019
Around the world, consumers today demand authentic taste experiences that are more nutritious, convenient and safe—all at an affordable price. However, creating better-for-you foods that meet these consumer needs, while maintaining shelf-life, remains challenging. By Nutsuda Preechathammawong, Senior Scientist (RD&A, Functional Meat) at Kerry.
Meat products, fresh or cooked, have always been expensive and highly perishable. To keep them and other foods fresher for longer, traditional practices such as salting, fermenting and smoking have been used for centuries as natural methods of preservation. Later on, the development of chemical-based additives and preservatives paved the way for further enhancement of colour, flavour and texture of meat and meat products, subsequently improving their quality, shelf-life and consumption safety. With these three parameters inherently linked to one another, it is important to understand the relationship between them.
While the use of chemical-based additives and preservatives such as lactates, acetates, nitrites and phosphates, has been repeatedly proven to improve the colour, flavour and texture of meat products—in addition to being safe to consume—most consumers still view them as “harmful” chemicals and therefore deem them undesirable in natural foods, even when added in low quantities. As consumers today demand less processed food products containing fewer additives and preservatives, these products can become more susceptible to spoilage, compromising product quality by negatively affecting its organoleptic properties, safety and ultimately, shelf-life.
Shelf-life management is affected by three different factors: Intrinsic Factors (factors relating to the food itself, including water activity, pH level and redox potential); Extrinsic Factors (factors relating to the environment in which the food is stored, including temperature control and process hygiene as well as environment quality, including effective management and packaging systems involving materials, equipment and gases); and Implicit Factors (factors relating to the micro-organisms such as the initial starting microbial load as well as interactions between the micro-organisms and the food). Processing factors such as heating, cooling and drying can also affect the types and numbers of micro-organisms that remain in the food after treatment.
To maximise the shelf-life of any meat product, producers employ a combination of several of these factors or “hurdles”, including the use of preservatives to improve the safety and quality of a product, to make it shelf-stable. This is known as Hurdle Technology.
Some hurdles are critical in maintaining the safety and quality of meat products over their intended shelf-life, and involve the Implicit Factor or the initial bacteria load—the lower the starting load, the longer the shelf-life. Generally, a total count of 1×106 is considered the end of a product’s shelf-life, but this can vary between fresh and cooked meats, with cooked meats inclined to have slightly higher counts at the end of their shelf-life.
There is no legal requirement with regard to the total count of a product’s shelf-life as it relates to quality, not safety. A number of other factors bear a significant impact on this hurdle, most notably temperature control, process hygiene as well as the amount of processing involved.
Temperature control throughout the cold chain—from slaughter through processing to distribution, retail and consumption—is the most important parameter that affects the spoilage and, consequently, the shelf-life of meat and meat products. The Food and Agriculture Organisation of the United Nations guidelines for post-slaughter indicates that a deep muscle temperature of 6 deg C to 7 deg C should be achieved within 28 to 36 hours for beef, 12 to 16 hours for pork and two to three hours for chicken. Failure to reduce the internal temperature quickly will encourage the rapid multiplication of bacteria deep inside the meat, resulting in off odours and bone taint.
In meat processing facilities, temperatures of 6 deg C to 8 deg C are considered best practice. However, implementing these standards in countries with hot and humid climates is not only technically challenging, but also extremely costly. Maintaining refrigeration temperatures throughout the remaining cold chain of distribution, retail and consumption in such conditions is all the more important, although underdeveloped infrastructure in some of these countries can pose additional challenges as a result.
Water activity (aw) in meat products is one of the few Intrinsic Factors that can be altered to extend their shelf-life. The addition of salt or other chemicals as well as cooking reduces the amount of free water available to microbes, thereby reducing microbial growth. While it is a cost-effective option for controlling spoilage, the drive for reduced salt levels has weakened the effectiveness of this particular hurdle.
In Asian markets, highly processed meats are a mainstay, although these products present a separate set of challenges when it comes to shelf-life. The more processing involved, the greater the opportunity for micro-organism contamination and growth in such products. To remedy this, Mechanically Deboned Meat—a highly processed form of protein used widely in inexpensive meat products—is employed. However, this poses a much higher chance of contamination than with whole muscle products due to the process involved.
Today, one of the biggest challenges in the market is replacing the functionality of chemical preservatives to create cleaner labels. This typically requires a complex combination of natural ingredients. While many of these changes are designed to lead to the creation of healthier, cleaner foods in order to meet consumer needs, they also create additional challenges.
In cases where longer shelf-life is needed and increasing the dosage of chemical preservative is not possible due to regulations or an adverse impact on taste, clean label solutions can work in conjunction with chemical ones. Some solutions, such as anti-microbial smoke fractions, have shown strong synergy and significantly increased the shelf-life of food products when used with conventional shelf-life extenders.
Meeting current consumer demands for delicious, “cleaner” foods while maintaining high levels of food quality, safety and shelf-life is a delicate balancing act, particularly when producing ready-to-eat cooked meat products. Only by understanding the science of food and processing expertise can producers be able to deliver both, effectively.
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