Caratterizzazione comparativa di contenitori per il latte fresco. Studi di trasmissione ottica (nota1)

The survey was carried out to characterize the optic properties of material used for milk packaging. The authors tested the luminance and the spectral light (UV – VIS – NIR = 350-1,050 nm) filtering capability of the following commercial milk packages: clear PET bottles, blue cobalt PET bottles, multilayer pigmented paperboard bottles with plastic screw cap on plastic flat top, and Gable Top multilayer pigmented paperboard brick boxes. The measurements were carried out in different luminotechnique conditions (incandescent lamp at different power and fluorescent lamp), analyzing the print ink effect on the paperboard light filtering capability also. Results showed the paperboards package presented the best performances, with a light filtering capability over the 99% for all the spectral field. The clear PET bottles did not present any light filtering power. The blue cobalt PET bottles filtered around the 85% of the total incident light. With respect to spectral filtering it was not able to cut UV and IR critical frequencies that are mainly responsible of the photooxidative damage.