Regarding the RS gruels fermented by co-cultures, the addition of passion fruit fiber increased ηapp of gruels fermented by an amylolytic strain in co-culture with L. casei and had no effect on apparent viscosity of the others RSPF fermented gruels. In general, passion fruit fiber decreased the area of thixotropic loop, but significantly only in the RSPF gruel fermented by L. fermentum in co-culture with L. acidophilus ( Table 2). Surprisingly, in spite of the presence of pectin in passion fruit fiber – about 10–20% (Yapo & Koffi, 2008) – , the addition of this ingredient had smaller influence on ηapp than it could be expected for a thickener agent. Such a result can be due to the partial structure breaking promoted by the blade-shaped total dietary fiber from passion fruit rinds during the time of exposure to the shear rate (Fig. 5C).