کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
226595 | 464553 | 2006 | 10 صفحه PDF | دانلود رایگان |

Effects of xyloglucan (XG) on rheological properties and thermal stability of tapioca starch (TS) were investigated. Mechanical spectra of 5% w/w TS/XG mixtures changed from gel behavior to concentrated solution and showed higher loss tangent (G″/G′) with increasing XG concentration. Rapid visco-analysis profiles of 5% TS/XG mixtures at different mixing ratios revealed that peak and final viscosities increased with increasing XG content. From steady shear measurements at 25 °C, viscosities of gelatinized TS/XG mixtures were higher than those of TS pastes, while flow curves of both TS and TS/XG pastes showed shear thinning behavior. Apparent viscosities at 50 s−1 of TS and TS/XG pastes decreased with increasing temperature but the activation energy of TS/XG mixtures was lower than that of TS alone according to the Arrhenius plot, indicating improved heat stability of TS. Water separation of TS/XG pastes was also lower compared with that of TS alone from freeze–thaw cycle experiments. The results suggest that XG imparted more viscous, liquid-like rheological properties and heat stability to the gelatinized TS/XG mixtures.
Journal: Journal of Food Engineering - Volume 77, Issue 1, November 2006, Pages 41–50