Baking&Snack - May 2011 - 84

CONTINUOUS MIXERS

▲ Design of the new generation of continuous mixers emphasizes gentle blending and mixing of ingredients to produce well-developed doughs for breads, buns, English muffins, tortillas, hamburger buns and more.
READING BAKERY SYSTEMS

can result in reduced preventive maintenance, fewer spare parts, better sanitation and lower labor costs. Additionally, he said, there is almost zero temperature increase during the mixing process, resulting in better control of fermentation and the reduced need for cooling of the dough with ice. In some cases, international bakeries are using continuous mix technology to make American-style hamburger buns. In 2008, Wback, a German baking company, opened one of the world’s first continuous-mix bun production operations in Leipheim, Germany, where it bakes 50,000 buns per hour on two shifts a day. The line features automatic ingredient handling and a mix-

ing process using Codos continuous mixing technology developed by Reimelt (now known as Zeppelin Systems). The bun process relies on a continuous liquidsponge-and-dough production process that includes two separate stages for blending ingredients and mixing the dough, noted Stephen Marquardt, sales and product manager, Zeppelin Systems USA, Odessa, FL. “In the first stage for lump-free blending, we mix all of the ingredients together in a very short period of time, which hydrates the flour and provides an instantaneous start of the biochemical process,” Mr. Marquardt said. “The highly efficient mixing process results in an increased absorption of water up to 5%, which, in turn, delays the aging process of the products and extends shelf life.” Before entering the second stage, the system uses a conveying belt to transfer homogenized raw materials to the kneader. The belt also provides dough resting time, during which the raw materials can bulk-ferment and support dough development. CONTINUOUS IMPROVEMENT. Continuous mixing is an uninterrupted process where measured streams of dry and liquid ingredients are delivered to a twin-screw pre-mixer before entering the mixing chamber, according to Chuck Copenhaver, principal, Miranda Automation North America, Cypress, TX. Recipe-driven dough development takes place as the dough moves along the mixing cylinder through predefined mixing shaft speed and design. At discharge, the developed dough rope is cut and delivered to makeup equipment.

Keep Baking in Balance
Pretzel and extruded snack manufacturers face a special challenge because they are producing thin products that depend on volumetric sizing, meaning the individual pieces are sized by dough volume and not dough weight, according to Jim Warren, director, Exact Mixing, Reading Bakery Systems, Robesonia, PA. This means changes in product density due to batch mixing variations or mixing cycle time will result in changes in piece weights. This also alters the amount of moisture in the oven. Lighter products often burn in the oven, while pieces that are too heavy are not dried properly. This effect is made worse when varying piece weights change the moisture in the oven,” Mr. Warren said. “The oven is continually attempting to adjust to the new moisture level but never seems to catch the moving target.” With continuous mixing, he added, all dough is the same age when reaching the extruders, and that allows the volumetric extruding process to consistently produce pieces of the same weight. “This keeps the oven moisture in balance and results in much more consistent finished product. Improvements can be seen in both bake consistency and appearance,” Mr. Warren said.

BAKING & SNACK / May 2011

www.bakingbusiness.com

http://www.bakingbusiness.com

Baking&Snack - May 2011

Table of Contents for the Digital Edition of Baking&Snack - May 2011