Bioactivity of flours of seeds of leguminous crops Pisum sativum, Phaseolus vulgaris and Glycine max used as botanical insecticides against Sitophilus oryzae Linnaeus (Coleoptera: Curculionidae) on sorghum grains

Cereals occupy an important place in the solving of food insecurity problems in the northern Cameroon. Chemicals continue to be the main tools to protect cereals during storage in spite of the deleterious effects due to their current usage. Nowadays, entomotoxic proteins of seeds of leguminous are more and more considered as alternative insecticides. Efficacy of crude flours of four legumes seeds, applied to the sorghum grains, was evaluated against Sitophilus oryzae L. (Coleoptrea: Curculionidae) by contact-ingestion. This research revealed that flours of bean and pea are very active on S. oryzae. The lethal dose 100 (LD100) and the lethal times 100 (LT100) are respectively 5 g and 20 days for pea’s flour and 10 g and 50 days for bean’s flour. The toxicity of flours’ seeds increased with the dose and the duration of application (F=169.734***, Df =6; 28). During a period of 90 days, the flours of P. sativum and P. vulgaris keep their insecticidal activities, showing constant mortality rates for bean (F= 2.325ns, Df =6; 28) and for pea (F=1,91ns, df= 34). The flours of seeds of P. sativum and P. vulgaris at the weight ratio of 5 % and 10 % respectively can provide protection of sorghum grains against the attack of S. oryzae. The legumes seeds are the alternative active ingredients to hazardous conventional insecticides.Keywords: Cereals; leguminous plants; entomotoxic proteins; persistence; Sitophilus oryzae

Diversity of processes for transformation of fresh fish in Northern Cameroon

Fish as a foodstuff of high nutritional value is considerably perishable. It must be transformed in order to improve the duration of its conservation. Drying and smoking are the most popular processes to transform fish in northern Cameroon. These steps usually affect the quality of the finished products. In order to improve the quality of locally transformed fish in a handmade manner and to typify such activity, an survey was conducted in three fishing ponds in the Northern part of Cameroon with 160 fishermen and fish transformers. It appears that the technique of transforming fish in those main fishing ponds in Northern Cameroon vary at the level of preprocessing and dehydration phases of fresh fish. Smoking is done in a traditional oven followed by cleaning (4.1% in the Adamawa Region and 33.0% in the North and Far North Region) or flaking of the fish (95.9% in Adamawa and 61.1% in the North and the Far North Region). Then, come emptying (95.9% in Adamawa and 61.1% in the North and Far North), cutting into small pieces (11.1% in the Far North) or cracking (82.6% in the Adamawa Region). At the end, washing (95.9% in the Adamawa and 72.2% in the North and Far North), spinning (100%), smoking (100%) and then packaging of the fish (100%) complete the process. All these operations are conducted without equipment for protection, on uncleaned surfaces and with irregularly washed materials with clean water. The drying process is done on bare ground on top of a drying stall is a constant step in the Far North (54.9%) and North (28.6%) regions and scarce in the Adamawa region (9.3%). A particular emphasis should be laid on hygienic measures to ensure a sanitary quality of dry fish at the end of both smoking and drying processes. Keywords: Processing, smoking, drying, Northern Cameroon, Transformatio

Susceptibility of three varieties of Bambara groundnut (Vigna subterranea L.) towards Callosobruchus maculatus according to their nutritional and antinutrient contents

The leguminous seeds of voandzou (Vigna subterranea L.) are an important source of protein and anti-nutrients. The present study analyses nutritional and antinutrients content of 3 varieties of voandzou during storage under attacked by Callosobruchus maculatus. Three varieties of voandzou seeds with distinct colors: white cream (CM/EN/DW/14), red (CM/EN/DW/07) and black (CM/EN/DW/28) were collected from local markets and stored in flasks for 3 months. Thereafter, these seeds were sieved and weighted per batch. Chemical analysis of nutritional potential according AOAC methods and Phytic acid, Tannin, Oxalate and the trypsin inhibition activity were conducted both on clean and infested voandzou seed samples. The results showed that the CM/EN/DW/14 seed variety was the most attacked (75.4%) followed by CM/EN/DW/07 (42.6%). Nutritional properties indicate that CM/EN/DW/14 had the highest nutrient contents, highest ash and moisture content, while CM/EN/DW/28 recorded the lowest nutritional content compared to the other two samples. Concentrations of studied anti-nutritional factors were significantly different according to the color. The black color has the highest concentration of anti-nutrients content compared to the red and the white cream color. Seeds with higher anti-nutrients content had less attack rates compared to the others. Keywords: Voandzou, Callosobruchus maculatus, Antinutient contents, Storage abilit

Variation of some chemical and functional properties of Bambara groundnut (Voandzeia Subterranean L. Thouars) during sort time storage

Abstract The storage susceptibility of Bambara groundnut (B. G.) (Voandzeia Subterranean (L.) Thouars) to Callosobruchus maculatus and chemical and functional properties of 11 varieties form Far-North of Cameroon were investigate using standard analytical methods. Storage susceptibility shown that, after five months within treatment, C. maculatus destroy 10 to 50% of grains. The chemical characteristics of none attack grains of 11 varieties were range to 18.64 at 21.08%, 6.85 at 7.44%, 49.75 at 52.68% and to 6.05 at 7.55% respectively for protein, fat, starch and free carbohydrate. These chemical characteristics significantly (p < 0.05) decreases form attacks varieties. For the functional parameters, the none attacks grains was range of 130 at 135%, 19.15 at 20.91%, 18.20 at 21.13%, 2.76 at 3.21% and of 8.54 at 10.14% respectively for water capacity absorption, solubility index, gel length, ash and humidity. The results of this study indicated that storage susceptibility, chemical and functional properties of B. G. be dependant to the varieties

Functional response of Xylocoris falvipes, a biological control agent of the flour beetle Tribolium castaneum

The warehouse pirate bug Xylocoris flavipes is an opportunist predator of many stored product insect pests. Its functional response in relationship with variable densities of prey appears as the Holling’s type II model. The predator X. flavipes, collected within small holder granaries in Mayo Danay division in the far North province of Cameroon, feeds on Tribolium castaneum (Herbst) and could perform a good biological control of this pest