Nutritional quality and consumer acceptability of cowpea seeds (Vigna unguiculata L. Walp) treated with natural and synthetic insecticides against bruchid infestation

•Cowpea seeds stored with ten plant materials and Actellic® gave good organoleptic and sample analysis results after 6 months.•Stored uncooked seeds were mostly judged to have retained sensory properties as good as the control.•The test materials had no adverse effect on viability of the treated seeds.•We report that farmers could store their seeds with these plant products without fear of losing the quality parameters.

Sample analyses, organoleptic, sensory and viability tests were carried out in the laboratory to evaluate the effects of ten plant products with insecticidal properties on cowpea seeds stored for six months. Actellic 2% dust® (Pirimiphos-methyl) was used as a standard insecticide. Most of the plants are used for culinary or medicinal purposes in Nigeria. Sample analyses were conducted before and after six months of storage. Cowpea seeds were stored with either pulverized plant materials at the rates of 2.5, 5.0 and 10.0 g/100 g seeds or Actellic 2% dust at the rates of 1.0, 2.0 and 3.0 g/100 g seeds to determine the crude protein, crude fat, crude fibre, total ash and moisture content of the seeds. Organoleptic tests of cooked seeds for taste, odour, texture, appearance and overall acceptability and sensory tests for firmness and appearance of uncooked treated seeds relative to a control were evaluated at a single rate of 10.0 g plant powder or 3.0 g Actellic®/100 g seed. Viability tests on the seeds were carried out before commencement and six months after storage. All data were subjected to ANOVA and differences between means determined at 5% probability level. Sample analysis showed that all the plant products and Actellic® increased the moisture and crude fibre contents and decreased the crude protein content. The plant products and Actellic had no significant adverse effect on organoleptic characteristics and viability of the treated seeds. Sensory tests of uncooked seeds stored with most of the materials were also adjudged to be as good as the untreated control by a majority of the panelists.