The future in film technology: a tunable packaging system for fresh produce.
Clarke, R. and Moor, C. P. de
Postharvest Horticulture Series - Department of Pomology, University of California Year: 1997 Issue: No. 19 Pages: 68-75 Ref: 2 ref.
1997
บทคัดย่อ
A primary objective for modified atmosphere packaging of fresh produce is to provide a package atmosphere which preserves freshness and taste by matching film permeability to respiration rates. Some of the challenges to further development of modified atmosphere systems are identified; these include development of films with higher permeability, films that are more responsive to increases in temperature, and films in which the relative permeability of CO2 to O2 can be altered. By using a membrane consisting of a unique and proprietary polymeric coating on a porous substrate, it is possible to create and maintain target atmospheres even for products with high respiration rates or during exposure to elevated temperatures. Increased permeability of up to 100 times that of polyethylene can be achieved by changing the properties of the polymer used to coat the membrane. The membrane can also be adjusted to alter the CO2:O2 permeability ratio from 1.5 to 18.0. The ability to adjust this ratio is parti
cularly useful for products which are CO2-sensitive. Maintaining a specific atmosphere within a given temperature range has been achieved by making a membrane coating from a side chain crystallizable polymer having a specific melting point. By utilizing such a polymer, it is possible to have permeability increase substantially as the temperature rises. The increase in permeability reduces the chance of the package becoming anaerobic during incidents of temperature abuse as when the cold chain is broken. Examples of broccoli florets, coleslaw and strawberry packages in which the design atmosphere is maintained if the temperature is varied are provided.