Though an extreme dramatization, retailers cannot discount the fact that the mantra of today’s consumers is “the fresher, the better.” They are shopping store perimeters and seeking out minimally processed foods. Butcher counter services are booming and sliced-to-order deli meat sales continue to grow.
Raw and cooked meat and poultry, with the latter including ready-to-eat (RTE) meats, sausages, hot bar foods and heat-and-eat products, however, are highly perishable. This is not only because of their biological composition, which includes active enzymes and oxidation-prone compounds, but also the omnipresence of aerobic psychrothropic strains of bacteria, many of which may be pathogenic.
Delivering farm-to-fork freshness to most growing urban populations requires technologies that manage these attributes. This includes the use of shelf-life extending ingredients, with the goal being to preserve the quality of meat and poultry while also ensuring safety.
Desirable color and flavor
To ensure visual integrity, processors often incorporate ingredients with antioxidant functionality. These ingredients slow oxidative changes that may take place in myoglobin, the protein in meat responsible for desirable red and pink color. When myoglobin oxidizes in fresh meat, it becomes discolored. This is not a food safety issue, yet consumers often associate off color with old product.
Oxidation of fat content may also occur. Such fatty acid breakdown is more prevalent in cooked meats, as heat initiates the breakdown of polyunsaturated fatty acids (PUFA) present in such products. These fats are highly susceptible to oxidation, which produces unwanted flavor changes in the final product. This includes the production of warmed-over flavor (WOF), which are odors and flavors commonly described as stale, cardboard-like, painty or rancid. WOF has long been recognized as one of the primary causes of quality deterioration in cooked, refrigerated and pre-cooked frozen meat products.
The most common solution is the addition of antioxidants, which protect PUFA from oxidation by sacrificing themselves to the oxidation process. Artificial preservatives such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and tertiary butylhydroquinone (TBHQ) function as antioxidants and have long been the standard to ensure an economically sensible shelf-life for fully cooked and packaged meat products.
These ingredients are still widely used, but many processors are exploring the growing number of more label-friendly options, such as tocopherols, a class of vitamin E with powerful antioxidative properties. Tocopherols have long been used as a natural shelf-life extender in many products and have application in raw meat. Inclusion can be cleanly identified on ingredient statements as vitamin E or mixed tocopherols, usually with a parenthetical explanation of being added to maintain freshness, so as not to be confused with inclusion for fortification or nutrition profile enhancement.
There are also a number of plant-based extracts that function as antioxidants. Many are identified simply as “natural flavors” on ingredient statements. Rosemary and green tea extracts, for example, may assist with conserving the appearance, taste and quality of raw and cooked meat products, both refrigerated and frozen. Carefully selected plant breeds enable production of the most potent extracts. Suppliers blend the extracts into the most effective combination for a specific application and desired shelf life.
At the molecular level, rosemary extract and green tea extract have similar functionality. Their active components exhibit chain-breaking antioxidant activity. The main difference is that green tea extract has a lower negative flavor contribution to the final product. Thus, using a lower level of rosemary extract in combination with green tea extract allows the manufacturer to increase the natural plant extract usage rate, often resulting in an extract blend that performs better than using rosemary alone.
There are fruit-based extracts that exert antioxidative function in meat and poultry. Acerola extract (cherry powder), for example, boasts high levels of antioxidant vitamin C. Select plum ingredients contain antioxidants along with concentrated levels of organic acids that have been shown to assist with reducing WOF.