Résumé
Plant lipoproteic assemblies, such as oil bodies (OB), are very interesting vectors of PUFAs. To extract them, classical processes starts with hydration steps and subsequent aqueous crushing possibly followed by a high pressure homogenization step to help breaking up plant tissue and release OB efficiently.Besides this efficient wet integrated process, one can wonder whether some dry fractionation steps (dehulling, grinding, cryogrinding) can help reducing water and energy consumption while allowing acceptable OB extraction. To answer this question, selected dry fractionation operations were applied on two oleoproteagineous seeds (high oleic sunflower, and rapeseed),followed by an aqueous extraction of OB. Seeds and OB emulsions were characterized in terms of microbial load, lipid content, fatty acid profile, lipid classes, peroxide value and tocopherol content. In addition, the particle size distribution and morphology of the OB emulsions were assessed.Seed dehulling by abrasion or by impact is an interesting operation to lower phenolic compounds and fibers in the co-products obtained besides OB. Cryo- or ambient grinding with a ball mill induced efficient particle size reduction even for short treatments (≤30 s) and did not trigger lipolysis, increase of microbial load nor tocopherol oxidation in the seed crush. Such an upstream dry fractionation operation however induced coalescence of part of the OB, yet lead to acceptable recovery of OB (40 % to 60 % of initial lipid content) with preserved fatty acid and tocopherol profiles.This result is part of the OBEINN project which aims at efficient extraction OB for food innovation and should help consolidating sustainable processes of extraction of OB