Effect of maize weevil (Sitophilus zeamais Motschulsky 1855) infestation on the quality of three commercial pastas

Abstract

The effect of maize weevil (Sitophilus zeamais Motschulsky 1855) infestation was evaluated on three pastas under laboratory conditions of 32±2^°C temperature and 67±3% relative humidity. Macaroni suffered the highest quantitative loss with the highest number (62) of emerged adults at 2 months after infestation (MAI). However, the highest number (90) of insect at 4 MAI seen in spaghetti was significantly (P< 0.05) higher than 29 observed in noodles. Macaroni had the significantly (P<0.05) lowest final weight (13 g) at 4 MAI. Proximate analysis at 4 MAI revealed that noodles had the highest carbohydrate, dry matter, fibre, crude fat and ash which were significantly higher (P<0.0001) than spaghetti and macaroni. Spaghetti had the highest crude protein which was significantly higher (P<0.0001) than noodles and macaroni. The population of S. zeamais at 2 MAI was negatively correlated (r=-0.999, P=0.022) with the final crude fat and positively correlated (r=1.00, P=0.018) with final fibre contents of the pastas. The final weight of pastas at 4 MAI was negatively correlated (r=-0.998, P=0.037) with initial crude protein content of the pastas. The final dry matter of the pasta was positively correlated with the thickness (r=0.998, P=0.044).

Key words: Spaghetti; macaroni; noodles; Sitophilus zeamais; infestation; pasta