Clean machines - enhancing hygiene in food processing

Prepared Foods, Oct, 1996 by Judy Rice

Clean-fill, ultra-clean-fill, aseptic -- What's the difference? And which mode most efficiently satisfies your product and shelf-life needs?

Enhanced hygienics in product filling can translate to extended shelf life (ESL) and higher quality for packaged foods. While we certainly expect that all products are filled under hygienic conditions, there are different degrees of cleanliness in packaging technology from a microbiological standpoint.

And, given the trend toward ever better quality, food and beverage processors are constantly re-evaluating their options as the technologies advance and the cost/benefit ratios improve.

HOW TO CHOOSE

In selecting a processing and packaging system, the essentials are microbial safety (in which the filling procedure plays a critical role), payback, line speed, versatility for product and package changeovers, and the ability to fill and assemble variety packs, according to George Arndt, supervising packaging equipment engineer for Nabisco Refrigerated Foods.

"Microbial safety is established by challenge-testing the processing, filling, and sealing systems using microorganisms, followed by incubation of filled packages," explains Arndt. "Reliable machine manufacturers will provide performance guarantees for their machines and technical assistance during start-up. Challenge testing following installation of machinery and prior to beginning commercial production is recommended."

When comparing the performance and application differences among clean-fill, ultra-clean-fill, and aseptic packaging machinery, Arndt says, "The differences center around the level of sterilization inside the package at the time of sealing. There's a progression in the stringency of critical control factors, depending upon which filling mode you use. Package and product sterilization levels and the means to maintain these conditions increase in sophistication with each level of the technology."

Arndt points out that food and beverage processors also may opt for some cross-breeding of technologies. "Aseptic systems may be used to package ultra-clean-fill and clean-fill products manufactured for refrigerated distribution. This is the premise behind extended-shelf-life packaging -- using high standards for processing and packaging of refrigerated foods. Aseptic processing and pure aseptic filling systems to produce shelf-stable foods are very expensive, and they are not engineered to stop and start to produce small quantities of product. Extended-shelf-life packaging offers a cost break over aseptic, and ESL products represent a growing market in the refrigerated foods category.

"Using todays high-tech, extended-shelf-life methods, processors can achieve refrigerated product shelf lives of 60, 90, even 120 days. And for many products, that's plenty. Shelf-life requirements for U.S. food products, established by the retail market, have steadily decreased over the last 10 years. Retailers and marketing managers pay close attention to the rate at which products move through the marketplace -- and that rate is accelerating. So, in essence, while the technologies for extending shelf life have advanced the marketplace demand for longer product life has, in many cases, (lessened. What we're seeing is a convergence of the two trends, with technology and market needs meeting in the middle.

"Consumers have demonstrated their interest in fresh, refrigerated foods, especially those marketed in single-serving, convenient packaging. So certainly, as the refrigerated foods segment continues to grow, clean-fill and ultra-clean-fill technologies, sometimes partnered with aseptic processing and/or packaging approaches, will continue to thrive," concludes Arndt.

FILLING A NEED

Among techniques to heighten hygienic packaging conditions are controlled environments for filling and sealing, including HEPA and sterile air environments; UV light exposure or hydrogen peroxide rinses for containers to be filled; steam sterilization of unfilled containers, inert gas flushing of filled container headspace; and built-in clean-in-place/sterilize-in-place functions for the fillers themselves.

"Advanced hygienic filling technologies require more complicated machine design -- more structural materials, more parts, and longer assembly times," says Tom Zopf, technical spokesman for the Jagenberg Group of Packaging Companies. "So these systems are going to cost more, and the engineers are constantly seeking to refine and simplify the design of systems and parts."

"For example," explains zopf, "Jagenberg's Erca has introduced a new series of form/fill/seal systems which offer a range of hygienic filling standards, including aseptic. Jagenberg's Gasti has engineered a new Servotherm preformed cup filling system which also offers standard clean-fill, ultra-clean, and aseptic filling. And Autoprod has worked extensively on development of top-notch clean-in-place technology."

Dairy products such as yogurt, cottage cheese, sour cream, and dips, says Zopf, often can be the best beneficiaries of enhanced hygienic standards and controls. He notes, for example, that studies suggest shelf life of cottage cheese can be extended significantly using techniques such as sterile air filling enclosures and inert gas Rushing. For more information, visit Autoprod and Jagenberg's family of machines at Booth E-2281.)