The Influence of Electron Beam Irradiation on the Effectiveness of Trans‐cinnamaldehyde‐coated LDPE/Polyamide Films

Abstract

ABSTRACT: We have evaluated the effect of electron beam irradiation (up to 20 kGy) on the functional and barrier properties of trans‐cinnamaldehyde‐coated low‐density polyethylene (LDPE)/polyamide films. Irradiation did not affect the tensile strength and toughness of the films, but the 20 kGy treatment increased the percent elongation‐at‐break significantly. The barrier properties were also enhanced (approximately 18.8%) when the films were exposed to 20 kGy. Addition of trans‐cinnamaldehyde with 3% of polyamide coating solution (w/w) did not affect the tensile strength and barrier properties of the films, but significantly decreased the percent elongation‐at‐break and toughness. Films with 3% and 10% coating were used to wrap fresh‐cut romaine lettuce samples to determine their antimicrobial activity. Total aerobic plate count (APC) and yeast and mold growth were determined as a function of dose (0, 0.5, and 1.0 kGy) for 14 d of storage at 4 °C. Irradiation reduced the total APC and yeast and mold counts (YMC) as dose increased. The 0.5‐ and 1.0‐kGy treatments decreased initial APCs by 1.2‐ and 1.5‐logs, and no YMCs were observed in the 1.0‐kGy treated samples at day 0. Irradiation exposure significantly lowered APCs of lettuce samples by almost 1‐log colony‐forming unit (CFU)/g compared to the nonirradiated controls, though it only slightly reduced YMCs. The effectiveness of using irradiation with antimicrobial films was enhanced with increased radiation dose and trans‐cinnamaldehyde concentration (3% to 10%).