Effect of food characteristics, storage conditions, and electron beam irradiation on active agent release from polyamide-coated LDPE films.
We investigated the effect of electron beam irradiation, storage conditions, and model food pH on the release characteristics of trans-cinnamaldehyde incorporated into polyamide-coated low-density polyethylene (LDPE) films. Active agent release rate on irradiated films (up to 20.0 kGy) decreased by 69% compared with the nonirradiated controls, from 0.252 to 0.086 microg/mL/h. Storage temperature (4, 21, and 35 degrees C) and pH (4, 7, and 10) of the food simulant solutions (10% aqueous ethanol) affected the release rate of trans-cinnamaldehyde. As expected, antimicrobial release rate decreased to 0.013 microg/mL/h at the refrigerated temperature (4 degrees C) compared to the higher temperatures (0.029 and 0.035 microg/mL/h at 21 and 35 degrees C). The fastest release rate occurred when exposed to the acidic food simulant solution (pH 4). In aqueous solution, trans-cinnamaldehyde was highly unstable to ionizing radiation, with loss in concentration from 24.50 to 1.36 microg/mL after exposure to 2.0 kGy. Fourier transform infrared (FTIR) analysis revealed that exposure to ionizing radiation up to 10.0 kGy did not affect the structural conformation of LDPE/polyamide films and the trans-cinnamaldehyde in the films, though it induced changes in the functional group of trans-cinnamaldehyde when dose increased up to 20.0 kGy. Studies with a radiation-stable compound (naphthalene) showed that ionizing radiation induced the crosslinking in polymer networks of LDPE/polyamide film and caused slow and gradual release of the compound. This study demonstrated that irradiation serves as a controlling factor for release of active compounds, with potential applications in the development of antimicrobial packaging systems.
Han
J
J
Research Laboratories in Sciences Applied to Food, Canadian Irradiation Center, INRS Inst. Armand-Frappier, 531 Boulevard des Prairies, Laval, Québec, Canada.
Castell-Perez
M E
ME
Moreira
R G
RG
D000171:Acrolein / Q000031:analogs & derivatives / Q000494:pharmacology; D004307:Dose-Response Relationship, Radiation; D005506:Food Contamination / Q000517:prevention & control*; D005514:Food Irradiation; D018857:Food Packaging; D005519:Food Preservation / Q000379:methods*; D005720:Gamma Rays; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009757:Nylons; D020959:Polyethylene / Q000737:chemistry / Q000528:radiation effects*; D011829:Radiation Dosage; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013696:Temperature
D009757:Nylons; D000171:Acrolein; D020959:Polyethylene; C012843:cinnamaldehyde