Active LDPE films loaded with biopesticides by supercritical CO2-assisted impregnation for stored grain protection

Abstract

The aim of this contribution was to obtain bioactive materials for stored grain protection and food preservation, by incorporating a biopesticide (1-octen-3-ol) in polyethylene (LDPE) films using supercritical CO2–assisted impregnation. The influence of different pressures and depressurization rates on impregnation yield was investigated. Results revealed that the best impregnation yield of biopesticide in the films (Y = 3.39 ± 0.27%) is associated with low depressurization rate (0.5 MPa min-1) and mild pressure conditions (~9 MPa). The release kinetics of 1-octen-3-ol from the impregnated films was also investigated. In addition, the biocidal activity of impregnated films obtained at the best operational conditions was tested towards two of the main pests of stored grains. Films showed insecticidal activity against Sitophilus zeamais (100% mortality after 24 h) and also produced a decrease of the fungal growth rate of Fusarium verticillioides (55% inhibition).