Development of insect-proof starch adhesive containing encapsulated cinnamon oil for paper box adhesion to inhibit Plodia interpunctella larvae infestation

Development of a multilayer insect-repelling film with trans-anethole for the storage of almond flake cereal

Trans-anethole (AN), which exhibits strong insect-repellent activity against Plodia interpunctella larvae, was applied on a polyethylene terephthalate (PET) film as an active packaging coating layer. All developed films at different concentrations (25%, 30%, 40%, and 50%) exhibited significant insect repellent activities. However, these films did not significantly differ from the control film in terms of color and transparency. In addition, the developed polypropylene (PP) and PET laminated films containing 25% AN (PP/AN25/PET) exhibited strong and continuous insect-repellent activity for up to 42 days. Finally, the developed film showed 2.86-fold stronger repellent activity than that of the control film when applied to the almond flake cereals packaging. These results suggest that PP/AN25/PET could be used as a potent insect-repelling packaging film in a realistic grain-packaging system. PRACTICAL APPLICATION: A PP/trans-anethole/PET film that exhibited good insect-repellent activity for 42 days was newly developed in this study. As it showed strong insect repellency, especially in almond flake cereals packaging, it is expected to have high potential as an insect-repelling grain-packaging film.

Analysis of the insect-repelling mechanism of star anise extract and its major active compounds against Plodia interpunctella

One of the major stored product pests, Indian meal moth causes the loss on the agriculture and food industries. This study was conducted to screen the insecticidal activity of ethanolic extracts and fractions partitioned by four different solvents [(1) n-hexane; (2) ether; (3) ethyl acetate; (4) water] from star anise (Illicium verum Hook. f.) against Plodia interpunctella larvae. Among all solvent-partitioned fractions, the strongest repellency was found for the n-hexane fraction of star anise extract. Solvent-solvent partitioning and chromatographic methods were further used to isolate and identify major anti-insect compounds from star anise extract. The results showed that trans-anethole (94.24%) was the major active compound showing an insect-repelling activity against P. interpunctella. Consequently, trans-anethole can be utilized as a main natural insect-repelling agent for controlling the P. interpunctella infestation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-022-01053-8.