EFFECTS OF SIZE AND FORM OF SPIRULINA (ARTHROSPIRA SP.)BIOMASS ON THE SHRINKAGE AND POROSITY DURING DRYING
Spirulina is a photosynthetic micro organism constituted by filaments.The filtrated biomass is used after drying.The dried aspect depends on the used drying process and on the initial biomass form and size.The aims of this study are to understand how and why the dried aspects change in function of the initial form and size,to characterise the physical evolution during drying and to calculate the porosity to permit a control of the final form and aspect.The drying kinetics,the form and dimension evolution,the shrinkage are measured for convective drying at 45°.Shrinkage of 1 to 6 mm initial diameter cylinders and 1 to 4 mm thick thin layers of biomass were characterized.Porosity models are proposed.Anisotropic coefficient showed that the cylinders shrinkage was more significant in the perpendicular direction to the support than in the parallel one,up to a 4 factor time more.Several shrinkage periods with transitions were pointed out.The shrinkage is similar for all cylinders down to relative moisture content of 0.8 and for layers down to 0.6,depending also on the initial dimensions.Initial biomass porosity is measured around 20%,final dry cylinder porosity lead between 53 and 78%.SEM photos completed porosity formation explanation.Dry layers don’t show porosity.Those physical changes have a significant implication on taste criteria and explain why Spirulina in layer form is not developed although layer drying energetic efficiency is higher.
Arthrospira Spirulina shrinkage convective drying size isotropicity SEM
H.Desmorieux J.Madiouli C.Herraud
LAGEP,UMR CNRS 5007,Université Claude Bernard Lyonl-bat.308G,43,Bd du 1+novembre 1918,69622 Villeurb LETTM,Faculté des sciences de Tunis,Université El Manar,1060 Tunis,Tunisia LAGEP,UMR CNRS 5007,Université Claude Bernard Lyon1 - bat.308G,43,Bd du 1+novembre 1918,69622 Villeu
国际会议
The 18th International Drying Symposium Conference(第十八届国际干燥学术大会(IDS2012))
厦门
英文
1-8
2012-01-11（万方平台首次上网日期，不代表论文的发表时间）