Cost has been the greatest obstacle for Landec Corp.'s IntelliPac packaging system in cracking the modified atmosphere packaging arena, and a successful program featuring iceless broccoli crowns with a 21-day shelf life for the Japanese market appears to have solved it.

The firm's Apio Inc. processing subsidiary began testing the iceless shipping system in April. Apio CEO Nick Tompkins recently pronounced the trans-Pacific program a success, noting the 33 percent reduction in freight expense and the elimination of waxed cartons more than offset the membrane's cost. Apio's shipping system also reduces contamination potential and eliminates the need for re-icing broccoli in coolers in Japan, resulting in additional savings of up to $3 per carton.

Highly respiring produce such as asparagus, strawberries and broccoli pose particular packaging challenges, and the permeability of 2 mil polyethylene films typically used for MAP is ill-suited to supply the additional oxygen these products need when temperatures increase. In the case of broccoli, an atmosphere of 2 percent oxygen and 5 to 10 percent carbon dioxide needs to be maintained, according to Raymond Clarke, Intellipac membrane products' director of product development, and keeping the produce cool is extremely critical to maintain that atmosphere.

The Intellipac membrane compensates for temperature fluctuations with the side chain crystallizable (SCC) polymers that coat its porous substrate. By varying the side chain lengths from 12 to 22 carbons, engineers can create copolymers with melting points between 32 and 154 F degrees. A spike in temperature turns SCC into an amorphous state, allowing greater gas exchange; when temperatures cool, they return to a crystalline state, creating an impermeable, non-adhesive solid.

About 100 million lbs. of U.S.-grown broccoli is exported annually to Japan, and Apio expects the new packaging system to significantly increase its 22 percent share of that market.

Systems engineering keys packaging productivity gains

Packaging efficiencies at food plants and other manufacturing sites increased sharply last year, and much of the credit goes to the systems engineering steps taken by four out of five plants, concludes "The 2001 Packaging Productivity & Profitability Trends Indicator Study" from the Packaging Machinery Manufacturers Institute (PMMI).

While the study focuses primarily on specific steps taken to improve productivity, such as retrofitting or buying new equipment or jawboning material suppliers for lower prices, the authors point out many changes are made in the context of an industrial engineering strategy. The most common step was a redesign of packaging line layouts, which almost three-quarters of the survey's 813 respondents undertook last year. Almost half effected a redesign or restructuring of line scheduling, and more than a third instituted a productivity measurement system last year. "By merely creating greater awareness of the productivity issue through systematic measurement," the study notes, "operators and other personnel are encouraged (if not prodded) to work from productivity benchmarks toward specific goals."

Fewer than one in five have attempted to integrate packaging in a centrally controlled system, but that engineering approach is "gaining advocates," the study states. "Tighter control attainable through systems integration...allows senior operating personnel to continually monitor and adjust the packaging process," according to the authors.

Despite efforts to dumb-down operator controls, the increasing complexity of packaging machinery is putting a premium on better educated operators, a need identified by 83.8 percent of respondents.

The complete study is available from PMMI for $75. Contact Paula Feldman at 888-275-7664 (ASK-PMMI).