Food processors are using advanced thermal heating technologies to create natural colour and other qualities in ready-to-eat products
When it comes to ready-to-serve meals, deli products, frozen and even fast-food items, consumers are looking for products that feature authentic colour as well as appealing textures and delicious taste. Food processors are now able to meet those preferences through advances in thermal heat technologies designed for the best yields to a variety of quality standards.
Today, there are four principle methods for developing natural colour with thermal heat: impinged air, flame, sear and radiant infrared heat. With advancements in modern cooking technologies and natural browning agents, a whole range of authentic colours and surface effects can be achieved faster, more efficiently and more consistently. This enables processors to create foods with subtle differences in appearance, ranging from products traditionally made at home to those prepared by top chefs.
“Regarding quality RTE (ready-to-eat) products, consumers are placing a higher demand on our industry to develop products that appear to be naturally processed,” says Adam Cowherd, vice-president of International Sales at Unitherm Food Systems in Bristow, Okla. “In the case of a grill-marked chicken breast, customers are beginning to ‘read between the lines’ of the traditional bar marks, and want to see the same naturally occurring flamed highlights and colours they see on chicken prepared on their barbecue grills at home.”
Unitherm has been developing its Flame Grill System for over 15 years and offers current models with multiple independently controlled ribbon burners, adjustable bar-markers, and relative temperature controls. “Everything characteristic of the flame can be adjusted from the angle to the length,” Cowherd says.
Advanced flame grills are just one example of how equipment suppliers are meeting the demand with more flexible technology to provide a wider range of finished colour and texture. Here’s a breakdown of the four most common thermal heat technologies used by leading food companies:
1. Impinged Air
With this thermal technique, high-velocity air is forced directly to the product surface. For product surfaces that are less uniform, this technology can be used to develop uniform colour on top, bottom and all sides of the product. High-temperature air, combined with steam (to create super-heated vapour), can be used in combination with impinged air to speed up the browning process. This thermal heat method is appropriate for meat, poultry, pasta dishes and a variety of baked foods like pastries and pizza bases.
“The effect we see from products that are processed with impinged air is more uniform colour without the shadowing that you see with radiant heat such as gas infrared,” explains Cowherd.
New impinging oven designs, such as Unitherm’s versatile RapidFlow Oven, offer touchscreen controls that allow processors to alter multiple parameters, including the velocity of the impinged air, temperature, and humidity control. If they choose, these parameters may be used to create new recipes that are stored for future use. Such features enable processors to better control the appearance of the finished product. Most recently this impinged air technology is being adapted for use in a spiral oven.
2. Flame
Perhaps one of the oldest thermal heat methods for colouring products is flame. Currently, the term “flame grilled” is used to market everything from chicken wings to fire-roasted tomatoes for spaghetti sauce. Today’s flame-grill machines can be used for an array of products, ranging from burgers to veggies, chicken and fish.
The affect that flame has on any product depends partly on the fat to protein breakdown of the product. The colour result is anything but uniform; however, the taste of a truly flame-grilled product is unmistakable.
