Going continuous triples output

The largest producer of cooked pasta in Sweden, Mixum AB, tripled output and cut clean-up and changeover times by 85% when it moved from batch cooking and cooling pasta to continuous production.

Mixum supplies pasta-based salads to 3000 Picadeli salad bars chain in Sweden, Scandinavia and much of northern and western Europe. The company’s success is due largely to its attention to product quality, food safety and streamlined manufacturing initiatives. Mixum operates in compliance with HACCP (Hazard Analysis and Critical Control Points) and is certified through FSSC (Food Safety System Certification) 22000 and ISO 14001.

In 2012, Mixum rebuilt its entire production facility into a model food processing plant, with some emphasis on energy efficiency. One of the key systems installed was a line of continuous-process blanching and cooling equipment for pasta, which replaced a batch processing system being used for more than a decade.

“We were cooking our pasta in batch vessels,” explained Magnus Franzen, CEO of Mixum. “This did not give us much control of our cooking and cooling times. We were looking for a solution that could both cook and cool the pasta, maintain better control over the entire process and get more consistent product quality.”

Mixum also needed to increase its production throughput to keep pace with growing demand for its pasta products. It needed shorter runs of a wider selection of pasta to be processed, with increasing need for quick changeovers and faster clean-up and turnaround times.

“After reviewing many process options, we decided on a continuous-process Clean-Flow XT blancher, from Lyco Manufacturing, and a continuous-process Easy-Flow cooler, also from Lyco,” Franzen said.

The Clean-Flow XT blancher addresses Mixum’s need for more consistent pasta quality and faster clean-up and changeovers. The blancher has a 1 m diameter auger with flights to move the pasta through water, fully submerged, from input to output. It is equipped with Hydro-Flow agitation, a Lyco development, which enables more uniform cooking and cooling. Hydro-Flow uses water flow to create turbulence, so it keeps the pasta moving to achieve a more even cook — eliminating under- and over-cooking of the pasta and losses from sticking and clumping.

Faster sanitary clean-up time is key. What would normally take several hours for a thorough sanitary cleaning can now be done in 30 minutes, reducing labour hours and increasing flexibility for more frequent changeovers to accommodate shorter production runs. A clean-in-place system, using spray manifolds, cleans 98% of the auger and tank by itself.

The pasta exiting the blancher is gently deposited into the Easy-Flow cooler via a flume, where it is quickly and evenly cooled to bring it down to the required 4.5°C final temperature.

Traditionally, pasta products take 12 minutes to cook and another 5-10 minutes to cool to 4°C. Mixum’s Easy-Flow cooler receives the 82–93°C pasta and chills it to 4°C or less in under 30 seconds.

When the pasta enters the cooler, it is pulled into a damage-free, Venturi-action water plenum and mixed with cold water where the heat begins to be removed. The cooler consists of four zones, or chambers, for cooling the pasta. Each zone submerges and mixes the pasta in chilled 0.5°C water where it rapidly discharges heat. The first stage cools the pasta to below 21°C in under 10 seconds. The second stage cools the pasta to 13°C, the third and fourth stages bring the pasta temperature down to 4.5°C or less.

Automatically controlling the pasta cooking and cooling, with consistent parameters for temperatures, process times and recipes, has completely outperformed the batch method used formerly by Mixum.

“With the batch method, we were running about 300 kg of pasta per hour,” Franzen explained. “With the new blancher/cooler, we are processing about 1000 kg/h and still not running at full capacity. We can achieve more exact process temperatures and times, and the pasta quality is much better.”