Healthy snack alternatives: a new challenge for processors

The trend towards healthy snack alternatives continues to influence the extruded snack category. However, these new products also present new challenges for processors. The mainstay of the extruded snack industry for many years has been the single-ingredient puffed snack, which is then coated with oil and a savory flavoring. These are often made using rice grits or cornmeal and are easily processed on relatively simple extruders. While lower caloric content can be achieved through water or gum-based coatings, there is a growing trend in the use of unique ingredients to enhance their appeal as better snack choices for the consumer. These ingredients range from vegetables such as peas and pumpkin, dried fruit powders and kale, to ancient grains such as quinoa and sorghum. When these ingredients are added to the raw material mix they bring with them a number of challenges to the snack processors, which are associated with sugar content, protein level, and particle size. As the recipe of a snack product grows to include multiple ingredients, it is important to consider the impact on hardware selection and operating parameters.

During the development of new extruded snack recipes there are many things to be considered. For example, when choosing ingredients it is important to match the particle size of each component. Ingredients with smaller particle sizes will typically absorb water more quickly than larger particle sizes and the non-uniform hydration can lead to limited expansion. An example is making a protein-enhanced snack by blending bean flour with corn meal. Bean flour, due to the smaller particle size and the fact that the protein easily hydrates, soaks up all the added moisture leaving the corn meal dry. The resulting product not only has a hard, glassy texture but it can also contain non-hydrated particles of corn meal. One method to effectively process these blends is to reduce the particle size of the corn meal so that it hydrates at a similar rate to the bean flour.

New ingredients trends of course then impact the selection of process equipment; ingredients such as dehydrated carrots or peppers have relatively high levels of sugar present which melt during extrusion resulting in dense, hard products. Still others, such quinoa and other ancient grains, contain blends of fibre, starch, and protein which do not expand as easily as corn. Simply controlling the particle sizes of these ingredients is not enough to allow them to be uniformly processed via the traditional single screw snack extruder. The addition of a preconditioner provides a combination of aggressive mixing and residence time, which allows the water to be adequately absorbed into the dry blend. These preconditioners can be mounted on rails so that they can be moved out of the way when not required. Modern twin screw snack extruders give additional advantages. Not only can they be fitted with preconditioning technology but they also offer a wider range of screw elements, screw speed control, and their design allows for better control of the mechanical shear added to the product during processing. This gives processors added flexibility in controlling texture, density, shape and mouth feel, and provides the best possible product to the end consumer.

To learn more about Wenger Manufacturing’s line of expanded snack food equipment, including single and twin screw extruders, dryers, and enrobers, contact Doug: [email protected]