Thermal Heating Technologies Create Natural Color in Ready-to-Eat Products

Searing: Using the latest searing technologies, a product can pick up additional color from the equipment belt at high temperature and/or be marked with searing hot branding irons. Unitherm Food Systems utilizes custom-made branding irons for fancy patterns such as diamonds and crosses. Simply making the marks is not enough, however; the ability to develop color and texture between the marks is what sets the new technology apart. The result is a handcrafted product that looks as though it were prepared by a chef or cooked on the grill at home.

Infrared: Infrared is one of the hottest thermal heat technologies in the industry and is usually either gas or electric heated. Gas infrared units commonly consist of a flat-surface burner head, which allows processors to develop colors with highlights, achieving a high-note/low-note appearance, where the higher points of the food surface brown more quickly because of their proximity to the infrared head. This fixed-head technology provides continuous in-line cooking and produces the golden-brown color and unmatched yields required by a major fast food chain in the preparation of foods such as breakfast sausage patties. One downside to this technology is that it cannot be used to color the underside of the product. If coloring both sides of the product is important, the product must be uniform in size, shape, and weight so it will flip on a transfer conveyor mechanism.

Like gas infrared, electric infrared is a radiant heat. Perhaps the most common example is your toaster. Advances in electric infrared systems have resulted in higher temperature black-bar emitters that allow rapid browning on all surfaces of the product. Used in combination with liquid smoke, a fully cooked deli product, for example, can be post-process pasteurized and smoked in 60 seconds with less than 2% yield loss. Cooking with this method can also obtain a greater than 3.0 log reduction in Listeria monocytogenes, according to studies conducted by Dr. Peter Muriana of Oklahoma State University.

Cowherd added that the majority of smoked deli meat manufacturers in the U.S. are using electric infrared technology. By smoking and browning in-line with Unitherm’s Infrared Pasteurizer, processors can control color and also make a safer product for consumers.

Ed Sullivan is a Hermosa Beach, Calif.-based writer. He has researched and written about advanced technologies, health care, finance, and real estate for more than 25 years.