Résumé
Sorghum (Sorghum bicolor, L) is the 5th most cultivated cereal in the world for its grain. Sorghum is gluten-freeand has interesting nutritional properties. In Europe, its cultivation is increasing rapidly, and has benefited fromEU funds for its promotion throughout the continent in recent years [1]. Sorghum can provide farmers withdiversification and an agronomic response to global warming due to its high photosynthetic and drought tolerance,its reduced and fertilizer requirements, and its resistance to pests [2]. With these agro-environmental qualities,sorghum grain could become an important component of global food security. The milling process is used totransform cereals, by combining different unitary milling operations and sorting of particles according to their sizeor aerodynamic properties. While this process has been widely optimized for wheat in order to separate thestarchy albumen with low contamination of peripheral tissues and germ and produce flour or semolina in the caseof durum wheat [3], this milling process has been scarcely studied for sorghum. The main challenge for sorghumis the location of the germ within the grain [4] that affects negatively the stability of flour. The aim of this study is toinvestigate the influence of pre-treatments (hydric, mechanical dehulling) to remove the peripheral envelopes; thedifferent milling steps and settings associated with different granulometries to diversify the end products usages(semolina and flour). An experimental design was conducted considering these factors to optimize the extractionyield of flour/semolina and the quality of end product. Specific conditions combing pretreatments and millingconditions were identified to produce high extraction yields of semolina and flour. These conditions were testedfor hard (white) and soft (red) sorghum varieties to better rely the impact of intrinsic physical and biochemicalproperties of grain on extraction yield, granulometry and functionality of end products. A focus was then made ongerm distribution in the flour and its impact through accelerated aging experiments in controlled temperatures.Biochemical and spectroscopic (FTIR) analyses were used to better assess these changes. A link with the secondtransformation will be highlighted through some tests in bread and pasta production.