الفهرس | Only 14 pages are availabe for public view |
Abstract Stored grains and their products were infested during storage by many insects such as the rice weevil, Sitophilus oryzae (L.), the lesser grain borer, Rhizopertha dominica (F.) and the Mediterranean flour moth, Ephestia kuehniella (Zell.). The study was conducted in Plant Protection Department, Faculty of Agriculture, Zagazig University during three successive years 2012, 2013 and 2014 to study the effect of different storage periods on insect infestation of wheat grains and flour as well the effect on quality properties during storage period which reached to eight months under laboratory conditions, these quality properties included chemical constituents and rheological properties. The present results indicate that insect infestation reduced some chemical constituents such as total carbohydrates, starch, total sugars, reducing sugars, total lipids and pH. With regard to rheological properties, it was found that increasing insect infestation caused reduction in arrival time, dough development, stability, elasticity, extensibility and energy. To study the penetration ability of R. dominica for three types of common food packages at different thicknesses ranged from 20-60 µm during a storage period of 45 days under constant conditions of 28±1˚C. and 70±5 % R.H., the results showed that polyethyelene high dense package was the most resistant to penetration by the insect. To evaluate the efficacy of three types of botanical materials including Neemazal T/S (1% Azadirachtin) formulation, clove oil and mint oil which used on two types of packages (polypropylene + metalize and refrigerator polyethylene) to reduce the penetration rate of R. dominica to these packages, the results cleared that the highest percentage of adult mortality and the lowest mean number of holes in the package were recorded in case of the packages treated with Neemazal T/S. |