In Africa, the cotton industry is one of the most important agricultural sectors. In Benin, a record 730,000 tonnes will be produced in 2020-2021, making the country the leading producer of the white gold in Africa. Although essential to the economy, fourteen types of residue from cotton processing remain unexploited. This waste is generally burnt by producers, which contributes to environmental pollution through the emission of greenhouse gases. To overcome this problem, we focused our work on recycling cotton fiber waste into a cotton fiber-starch composite material for use as false ceiling panels in the building industry, in place of the plywood generally used. To achieve this, we manufactured sheets from our composite material to determine mechanical properties such as modulus of elasticity and flexural modulus of rupture in accordance with NF EN 310. Three-point bending loading-unloading cycles were performed. The plates manufactured have dimensions of 300x300x100mm3. The plates are manufactured with «starch/water» and «starch/cotton fiber» mass ratios respectfully equal to 0.25 and 1. We obtained a modulus of elasticity equal to 2830 MPa and a modulus of rupture equal to 11.53 MPa.

This research work aims to transform and study the physico-chemical properties of leaf-based agro-materials of Musa sapientum and Tectona grands species. Indeed, the latter are traditionally used as a food packaging medium in West Africa and Benin in particular. The analysis by phytochemical screening of the main chemical groups present at the level of the leaves reveals the presence of molecules of interest, namely: flavonoids; catechol tannins and anthocyanins. The latter are indeed recognized for their pharmacological benefits. In addition, leuco anthocyanins and gallic tannins are only present in Tectona grandma leaves. To produce biofilms based on the leaf species studied, a Box-Doehlert experimental design was carried out. Fifteen (15) formulations were thus made, varying the leaf, starch, and glycerin contents of the mixture. It has been observed that, for low water sensitivity (0.1471) and low thickness (0.0573mm) of bioplastics, 1g of leaves are required; 6g of starch and 4.23mL of glycerin for the leaf of Tectona grandis while for that of Musa sapientum (low thickness: 0.0617mm, low sensitivity to water: 0.3466), it takes: 1.74g of leaf; 6g of starch and 2.5mL of glycerin.

Gari is a flour obtained by frying cassava pulp. This operation is not mechanized today in Benin. Gari processors are working under difficult conditions that exposed them to smoke and heat resulting in serious health hazard. Manual gari frying process and physico-mechanical characteristics of the obtained gari from three different localities were evaluated. The achieved results showed that, cassava greater throughput is of 390 kg/h whereas that of frying of 18 kg/h. The yield of gari production is of 26.9% and cassava pulp moisture decreases from 42.27% to 5.9% during the dry-frying step when temperature increases from 27 °C to 90 °C. The values for moisture, bulk density, coefficient of uniformity of obtained respective gari are for Savalou 6.28%, 602.02 kg/m3, 2.12, Comé 6.12%, 596.08 kg/m3, 2.40 and Ikpinlè 8.11%, 609.78 kg/m3, 2.21. Their coefficients of friction are respectively for Savalou 0.68, Comé 0.65 and Ikpinlè 0.62, on the black iron sheet surface. Those results give us a useful data basis for the design of a performing frying gari machine.