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G. D. SADLER1, T. N. Koutchma1, and I. Setikaite2. (1) National Center for Food Safety and Technology, Illinois Institute of Technology, IIT Moffett Campus, 6502 S. Archer Rd., Summit-Argo, IL 60501, (2) NCFST, Illionois Institute of Technology, 6502 S. Archer Road, Summit-Argo, IL 60501 The behavior of polymers under high pressure has only recently become the subject of systematic study. Most existing studies have sought to determine whether packages remain highly functional following high-pressure treatment. In contrast, relatively few studies have examined the impact of high pressure on the fundamental properties of polymers. However, the interplay of polymer molecules and permeants molecules under high pressure produces an assortment of often-antagonistic actions which may result both in transient or permeant changes to the package. For example, atmospheric gases and organic vapors condense remarkably faster than packaging polymers, and ultimately change state during compression. A compound°Ēs solubility in a polymer may either increase or decrease depending on its compression relative to the compression of the polymer. When solubility is increased, decompression results in flashing of supersaturated compounds with subsequent blistering in laminate structures. Differential compressibility among various laminate layers may also result in delamination. Such delamination is facilitated by compression heating, especially when packages with aqueous contents enter the compression cycle at temperatures above 80°ėC. There is even evidence that a diesel-like ignition may occur inside packages which are preheated prior to compression. Selecting compatible polymers for laminated structures can minimize many of the packaging problems resulting from high pressure processing. Temperature control during the compression and decompression cycle may minimize other defects. In order to fully understand and accurately predict the impact of high pressure processing on laminate packages, the behavior of individual polymers under high pressure must be studied
Session 39, Advances in packaging technology required for implementation on novel food processes
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |