Jilebi: 1. Effect of moisture content, curd addition and fermentation time on the rheological properties of dispersions

Jilebi is a popular traditional confectionery product of South-East Asian countries. The rheological characteristics of
jilebi batter made out of wheat flour were determined using the plate-cone geometry of a controlled stress rheometer. The
effects of moisture content, curd addition and fermentation time on flow characteristics including yield stress, flow behaviour
index, consistency index and the apparent viscosity were investigated using a second order central composite rotatable
experimental design. Shear-thinning characteristics with yield stress were observed for all samples. The moisture content of
batter has the most dominating effect on the rheological parameters. Yield stress, consistency index and apparent viscosity
increased markedly with decrease in moisture content of batter but the flow behaviour index decreased. The experimental yield
stress varied between 0.31 and 15.76 Pa. The Herschel-Bulkley model, along with experimental yield stress, is suitable to
correlate well (r > 0.967, p < 0.01) the shear-stress/shear-rate data. The sensory observations on flowability of batters indicated
that moisture content of 53 to 57% needed additional force to push the batter through an orifice while gravity flow was possible
when moisture content was between 57 and 61%.