Simply Sophisticated Extruders
Dec. 1, 2011
by Dan Malovany
Same-old just doesn’t cut it anymore when it comes to producing bars, crackers or any other baked snacks. That’s because consumers want a little more complexity than the conventional cookie offers. From a production perspective, adding a twist to traditional treats has become quite commonplace because of the recent advances in extrusion technology.
“The trend clearly shows that extruded products must be more and more sophisticated,” noted Jane Solby, marketing coordinator for Haas-Meincke, Tonsbakken, Denmark. “This means, for example, producing triple-extruded bars with dough, cheese and jam or wire-cutting products in three colors with funny shapes.”
Even better-for-you products need not be bland or boring. In many cases, bakers and snack producers now push the boundaries of multiple-extrusion technology to develop products with more healthful attributes. For example, snack producers can incorporate functional ingredients including soy and root vegetables as well as quinoa, amaranth, spelt and other so-called ancient grains to add nutrition, flavor and texture to their products, noted Bill Butler, sales manager, Clextral Inc., Tampa, FL.
Overall, extrusion involves a continuous process inside a closed barrel, unlike the batch process used for many products. Clextral’s twin-screw extruder allows snack producers to create multiple products on a single system by changing formulas or production parameters, Mr. Butler said.
“New flavor and texture combinations are hot, and [companies are] developing multi-layer snacks that combine new and exciting flavors, colors and textures — for example, fruit with savory tones, chocolate and chili pepper, or spicy sweet potato,” he explained. “We extrude co-expanded products that meld two texture and flavor combinations [or create] co-extruded products with a soft center with a hard outer shell.”
BETTER BAKED SNACKS.
From a health-and-wellness perspective, the fight against obesity also prompts an upsurge in demand for baked snacks machinery both in the US and internationally, according to John Eshelman, director, pretzel and snack machinery sales, Reading Bakery Systems, Robesonia, PA. The push comes not only from consumers but from global government initiatives as well.
Creating more healthful alternatives often requires a number of extrusion processes, Mr. Eshelman noted. Medium- and high-pressure extrusion systems rely on heat, shear and pressure to develop certain types of formed and expanded snacks, while low-pressure technology takes a completely different approach. “When you’re dealing with yeast-raised doughs, the No. 1 priority is to do as little damage to the dough as possible,” he said. “You want to minimize heat, shear and pressure so that the characteristics of the dough coming out of the extruder are pretty much the same as what’s going in.”
Low-pressure extrusion systems can produce gluten-free snacks that often have difficult-to-handle formulas. “With the absence of gluten in the formula, the dough being made has very little to no extensibility or elasticity, which results in poor flow characteristics,” Mr. Eshelman explained.
To solve this challenge, he said, Reading Bakery Systems introduced its dough pre-feed system several years ago. The system consists of counter-rotating forcing rolls that positively push the dough from the fill hopper into the main extrusion augers resulting in even and consistent dough flow through the extrusion process.
Extruders come in many styles, including single-screw, double-screw, cooker extruders, roll extruders and co-extruders, observed Don Setsma, vice-president, sales and marketing, Hi-Tech/FPA, Grand Rapids, MI.
“Which method to use depends on the end product the manufacturer wishes to produce,” he said. “FPA looks at the customer’s objective and the yield per hour needed. Through lab testing, [the company] can recommend the appropriate equipment. If we do not manufacture the type needed, we will recommend the company that manufactures the best [system] for the application.”
To meet the demand for better-for-you snacks, many bakeries and snack manufacturers are developing a greater number of products that include nuts and seeds to enhance their nutritional profiles, according to John McIsaac, vice-president, strategic business development, Reiser, Canton, MA.
“In recent years, I cannot recall any customer coming to us to produce a bar that did not have beneficial health effects,” he said. “Flaxseed, sunflower seeds, gluten-free and fruits have all been factors in the range of cookies and bars we have run recently.”
Consumers want to see larger, more identifiable particulates to reinforce the more wholesome nature of today’s products. Reiser’s Vemag has a positive displacement, double-screw pump that can transport delicate inclusions without smearing or crushing them.
To provide production versatility, Mr. McIsaac said, Reiser has developed attachments that allow bakers and snack producers to switch from extruding and sheeting to filling, dividing or depositing. Operators can swap out these attachments for quick changeovers. They can also use the attachments on the single-lane Vemag 500 or its HP E series machines to create small bars, pan-sized sheets and multiple-outlet portioning, Mr. McIsaac noted.
According to Mr. Eshelman, Reading Bakery Systems can upgrade many of its existing extruders with co-extrusion capabilities to produce more elaborate products such as filled snack sticks. “The extruder forms continuous dough tubes while, at the same time, injecting a filling into the dough jacket,” he said.
EVERY SHAPE AND SIZE.
In addition to chips, crackers and health bars, extruded snacks include whole-grain nuggets, thin and crispy chips and even dipping-strength chips, Mr. Butler explained. Extruded multigrain wavy chips came first, and now snack producers are adding a greater level of sophistication with high-fiber, low-fat, nutrient-enriched formulas, he said.
In some cases, food producers are literally changing the shape of snacks to come. “We’re creating innovative shapes such as cartoon characters, animals, logotypes and more — made possible with recent advances in die and cutter technology,” Mr. Butler said.
To increase throughput while maintaining product quality, Reading Bakery Systems upgraded its cutting systems over the years, Mr. Eshelman said. Back in the early 1960s, its first pneumatically operated cutters could make 40 to 50 cuts per minute. Ten years ago, a more advanced mechanism achieved 175 cuts per minute. In 2008, the company introduced a system capable of 265 cuts per minute. “Improved extrusion efficiency, automation and higher-capacity ovens are the driving forces,” he said.
To provide better controls at a time when ingredient costs can be so volatile, companies are developing more accurate systems. Reiser offers enhanced pumping technology for dispensing butters and margarines, an approach that can help reduce fat and calorie counts on the Nutrition Facts Panel, Mr. McIsaac said.
Additionally, the company offers multi-outlet systems for precise dispensing of fruit fillings for extremely thin, low-calorie snacks where fruit is sandwiched between dough products.
Meanwhile, Haas-Meincke’s new V60 machine — the company’s third generation of depositing, extruding and wire-cutting equipment — can accurately process a range of ingredients and particulates. When developing the V60, Ms. Solby said, the company bundled a combination of technologies that allows bakers to create custom-designed products.
A few years ago, she said, bakers began adding filling to the classic European Spritz cookie. In 2011, producers combined nougat filling into chocolate chip cookies, providing a fresh alternative to that
Extrusion technology, Ms. Solby noted, has advanced in a way in which product developers can manufacture even those creatively challenging concepts that the marketing team often dreams up. “Only the imagination sets the limit for the unique products that we will see in the future,” she said.