In a view of improvement of bili-bili quality, a traditional fermented drink made from sorghum from the savannahs of Northern Cameroon, the optimization of malting conditions in order to obtain a malt with better technological potential was studied by the response surface method. A composite plan centered on three factors whose levels were chosen according to the traditional conditions of production of bili-bili, grain soaking time (24-48 hours), germination time (48-96 hours) and aging time (24–72 hours) allows to define the optimal conditions of improving α and β amylase activities, soluble proteins and free amino acids. It appears that the linear and quadratic contributions of the soaking time have a significant effect (P˂0.05) on the different responses, except for free amino acids and the germination duration significantly influences (P˂0.05) the α and β amylase activities as well as soluble proteins. The duration of aging has a significant influence (P˂0.05) on all responses. The desirability function shows that the optimal malting conditions are 36h, 72h and 48h for the soaking, germination and aging times respectively. At this point, the α and β amylase activities, soluble proteins and free amino acids are respectively 9.34±1.06 meqg/100gDM; 15.97±1.06 meqg/100gDM; 2.05±0.22% and 377.67±6.02 mg/L. Comparing these values ​​with predicted ones by the model does not show a significant difference, thus concluding that the models fit well. In a context of revival interest in promoting of local products and food systems, this work has had the merit of meeting some of the expectations of the main actors of this technical system.

The diagnosis of the technical production system of « bili-bili », a fermented drink made from sorghum, in the consumption space of the of Northern Cameroon savannah, was conducted by a survey in 365 production structures distributed in the cities of Maroua, Garoua and Ngaoundéré, with the aim of defining both the constraints of local practices and the innovations needs. The study shows that « bili-bili » production is an exclusively female and ethnic activity, carried mainly by the Toupouri (34%), Moundang (29%) and Laka (21%) tribes. The organized or spontaneous migrations of these tribes to the fertile lands of Adamawa have led to a diffusion of the technical production practices of the drink in a north-south trajectory with territorial adaptations of the process and related tools. Four variants of the production process have been identified with innovation needs that converge mainly on the need for optimization and control of the main unit operations involved.