"In the past, the most important sorting was done just after the freezer, which indicates that you also freeze your defect," adds Frank De Brauwer, market manager at Tomra Sorting Solutions, a unit of Odenberg, West Sacramento, Calif. "Removing these defects earlier and before freezing gives energy savings, more storage capacity for good product."
Cold and clean
The emphasis on hygiene has led to changes in equipment, processes and construction.
"Food safety has become a big concern all over the world," says GEA's Osterstrom. "Freezing equipment has to be easy to clean and must include CIP capabilities. We have emphasized this over the last 15-20 years, and that has helped us become one of the leaders in innovative hygiene freezing equipment."
An easy-to-clean in-line freezer must be built based on stainless steel welded construction rather than bolted, Osterstrom adds. The construction needs to be open to ensure accessibility for easy cleaning and inspection, and there should be no hidden areas, no horizontal surfaces, etc., that will make the freezer difficult to clean.
Much of the attention now is paid to the design of floors and enclosures. Previously, in-line freezers were built with enclosure panels that had caulked joints. These joints were found to harbor bacteria and were very difficult to clean. In-line freezers available from GEA Refrigeration Canada have stainless steel enclosures with welded seams, which is the most hygienic approach.
"Bacteria can more easily grow in the caulked joints of the enclosures of floors and in crevasses created in a bolted design, since it is difficult to clean," Osterstrom points out.
"Previously, welded designs were often an expense that was difficult for the food processor to justify. Now, they cannot afford not to have food-safe freezing equipment."
Observations on the trends toward hygienic equipment and environments are echoed by Kurt Warzynski, process engineering manager at Stellar, Jacksonville, Fla. Stellar is a design-build firm that works extensively with food manufacturers, and its capabilities include freezing rooms and equipment integration.
One technology adaptation Warzynski sees more of lately from food manufacturers is clean-in-place. Entire spiral freezer enclosures are now fitted with CIP, he says.
"Without CIP you would have to shut down the spiral freezer, maintenance crews would have to walk into the freezer with hoses and scrub brushes and foaming units and spray everything down," Warzynski says. "And when they are done, they get out and let it dry before you could start it back up."
Automated CIP systems on the other hand are faster and leave less room for human error. A maintenance team can work on other tasks while the equipment runs and then do a quick inspection and touch-up if needed once the rinse cycle completes. The movement toward CIP dovetails with trends toward hygienic design in equipment.
Warzynski says clients who are building new plants and expanding them are more likely than ever to go with top tier freezing and refrigeration solutions.
Not so long ago, the most exotic item in the frozen food aisle at the supermarket might have been something vaguely Chinese. Today's consumer can choose from items that are co-branded with celebrity chefs (example), or serious ethnic food (Saffron Road Crispy Samosas) or complete meals that cater to common dietary concerns, or organic offerings (Amy's Mushroom Risotto Bowls).
Here is how American Halal Co., Stamford, Conn., describes those samosas on the company website:
"We fill each pastry with a savory mélange of farm fresh vegetables, lentils and mashed red potatoes. Add a touch of garlic and a dash of aromatic fennel and this is a vegan appetizer that will titillate every palate, and bring joyful delight to your guests."
Today's frozen foods are a far cry from the functional TV dinner that once offered little beyond convenience. The sea-change in product diversity has definite implications on the plant floor. As noted previously, the need to minimize waste became elevated when rare spices or organic vegetables are included.
GEA's Osterstrom says the complexity of frozen foods makes for interesting challenges. "I really do like working in this field because each product has its own attributes and characteristics," he notes.
"We have the means to match the right equipment to a specific food application, and that is key. It is easy to simplify the characteristics of a food product. For example a blueberry is not just a blueberry – it can be a cultured blueberry or wild grown and can have differences in size and sugar content. All of these details are important when designing freezers. As a freezer manufacturer, we know the requirements in freezing different foods and take this into consideration during the selection, design and manufacturing process."