Abstract

Clausena anisata (Rutaceae) and Plectranthus glandulosus (Lamiaceae) is applied on the corn grains during conservation limit insect’s attacks. In addition to this first use, the present work aims to evaluate the potential of these oils to preserve technological and nutritional qualities of treated grains during 5 months of storage. Investigations carried on grains treated three times consecutively with the effective concentration which kills 80% of experimental population (LC80) of Sitophilus zeamais (Coleoptera: Curculionidae) compared to an industrial molecule imidacloprid, taken as reference. Results show that C. anisata and P. glandulosus essential oils limit grains perforation by S. zeamais during 150 days of storage. In the control sample, S. zeamais bores 83.13% of grains and produces 9.11 g of boring flour after 5 months storage. During the first 50 days, the variation of damages is 19.45, 24.43 and 9.05%, respectively on sample treated with imidacloprid, C. anisata and P. glandulosus. Concerning nutritional parameters following these attacks and treatments, no variation is observed (P>0.05) between samples treated with essential oils and imidacloprid. Principal Component Analysis (PCA) applied on technological and nutritional parameters of food treated with these essential oils shows that, grains treated by P. glandulosus, C. anisata (50 and 100 days) and imidacloprid (50 and 100 days) have a similar level of protection than grains resulting from the control sample stored during 5 months. 

Key words: Clausena anisata, Plectranthus glandulosus, nutritional qualities, technological qualities, Sitophilus zeamais.