Effects of high intense pulsed light on optical and barrier performance of polypropylene packaging films

Flexible polypropylene (PP) packaging is widely used in the food industry due to its good processability, performance, and recycling potential, especially in applications that require moisture protection. At the same time, non-thermal food processing technologies have attracted great interest because they ensure microbial inactivation with minimal impact on final product quality. In this context, pulsed light (PL) emerges as a promising alternative for in-package applications, as it combines rapid and sustainable processing with reduced risk of recontamination. Thus, this study aimed to evaluate the effects of PL on the optical and barrier properties of PP and biaxially oriented polypropylene (BOPP) films, in order to verify possible changes in the functional performance of these materials. For this purpose, the samples were subjected to different PL conditions, varying the number of pulses applied, covering a dose of 12.48 J/cm², as well as one condition below (6.24 J/cm²) and one above that value (18.72 J/cm²). After film processing, the PP and BOPP samples were analyzed for light transmission in the UV-Vis region, color analysis, water vapor transmission rate (WVTR), and oxygen transmission rate (OTR). Overall, the light transmission and color analyses did not show significant differences between the treated samples and the controls, indicating maintenance of the films’ optical properties after processing. Regarding barrier properties, no statistical differences were observed in WVTR and OTR values between the treatments and the control sample, suggesting that PL did not cause relevant changes nor compromise the material’s barrier performance. Thus, under the conditions evaluated, PL proved compatible with maintaining optical functionality and had limited influence on the barrier properties of PP and BOPP films.