Document Type : Original Article


1 Food Technol. Res. Inst., Agric. Res. Cent., Giza, Egypt

2 Pl. Prot. Res. Inst., Agric. Res. Cent., Giza, Egypt


Most packaged food products are subject to attack and penetration by insects. In addition reducing food quality, insects annihilate quantity, too. Since, different ways are designed for controlling stored-product pests without application of chemical methods. So, the present study included laboratory methods to evaluate the effectiveness of three packaging materials, namely high density polyethylene (HDPE), polyamide/polyethylene (PA/PE) and polyester/aluminum/polyethylene (PET/AL/PE) to prevent or minimize the insect infestation and grain wastage resulting in the attack of wheat grain and their products by two notorious insect species, the lesser grain borer Rhyzopertha dominica as primary infestation insect and red flour beetle, Tribolium castanium as secondary one. Two laboratory experiments were conducted to determine the protecting capacity of the three package materials through assessing some parameters, number of adults emerged (progeny), infestation (%), weight loss (%) germination (%) and moisture content. The first experiment contained cleaned and correct wheat grain in each bag with numbers of insects released external around the bags in glass container supplied with a lid to determine the penetration levels of both insects separately. The second experiment comprised infested wheat grain by the two tested insects packaging in each of the three materials separately with three replicates and stored for ten months. The same replicates without insect infestation were carried out to serve as control. In the first experiment, the results revealed that high density polyethylene was the susceptible packaging material because it had maximum number of holes and penetrations by insects into them. In the second experiment, results showed that all tested parameters significantly influenced by the type of packing materials and storage periods. Increasing storage periods of wheat seed up to 10 months significantly affected grain quality. Effect of time period showed significantly more number of adults emerged, increased insect infestation and weight loss percentages in wheat grains after 10 months than after 8, 6, 4 and 2 months. Oppositely, germination (%) and moisture content were decreased gradually through the periods of experiments. Packaged wheat grains in polyester/Aluminum/ polyethylene (PET/AL/PE) significantly recorded the most excellent results for all tested parameters, followed by polyamide/polyethylene (PA/PE) and lastly in high density polyethylene (HDPE).In addition that, Rhyzopertha dominica had penetration ability greater than Tribolium castaneum. Except Rhyzopertha dominica with (HDPE) material, the two insect species cannot penetrate any of the tested packing materials with no perforations. Eventually, the triple layer bag (PET/AL/PE) can be used in storing wheat grain against the attack of both Rhyzopertha dominica and Tribolium castanium.