Identification et prévention des moisissures sur milieu de culture malt extract Agar (MEA) et quelques aliments couramment consommés dans la Region du Centre

Abstract

This study aimed at three different objectives including a contribution to the identification of food fungi on some currently consumed foodstuff in the center région with particular attention to some bakery product such as bread and cakes on the hand, and cassava “bâton” (popularly known as “bobolo”) on the other hand. The influence of température on the time of conservation of these food items as well as the time of incubation before occurrence of spontaneous molds on freshly prepared MEA culture medium were also assessed. Température of conservation included room température (averagely 25°C) and conservation in the refrigerator (4°C to 8°C). After isolation of molds on these food items and their cultivation on MEA and thereafter as slide cultures; microscopie and macroscopie descriptions were done on structures observed in order to identify the fungal flora that grows in both types of conservation as well as for spontaneous molds growth on MEA. The experiment conducted at room température led to the identification on the above mentioned foot items of molds belonging to three généra including Aspergillus, Rhizopus and Tricoderma and only Aspergillus was isolated from some of these items conserved in the refrigerator. Aspergillus sp and Ulocladium sp were recorded as spontaneous molds growing on MEA culture medium with major différences in the time of occurrence at room température and in the refrigerator. Ail the food items including bread, cakes, and cassava “bâton” never showed mouldy contaminations. The time of incubation at room température for appearance of the first signs of molds was 3 to 4 days on bakery products including bread and cakes and 6 to 8 days for cassava “bâton”. In the refrigerator this time was extended to 26 to 30 days for bakery products and far over 30 days for cassava “bâton”. Ail in ail, this work led to several key remarks, the first being that without fully preventing the growth of molds on the food items tested, low température (4°C to 8°C) of réfrigération enables to reduce the diversity of the contaminating microfungi on these food items. Also this range of réfrigération (4°C to 8°C) température enables to extend by more than 3 weeks the time of conservation of bakery products (bread and cake) compared to room température and by more than 30 days the conservation of cassava “bâton”. Also the incubation period before appearance of spontaneous molds on MEA culture medium is also extended by more than 3 weeks in refrigerator compared to conservation at room température.