Influence of variety, concentration, and temperature on the steady shear flow behavior and thixotropy of canary seed (Phalaris canariensis) starch gels

Abstract

In this study, the rheological properties of starch gels from two varieties of canary seeds (CDC Maria and CO5041) were investigated. The experimental conditions were different concentrations (4, 6, and 8% w/w at constant temperature of 25°C) and temperatures (25, 40, 55, and 70°C at constant concentration of 6%). All samples showed shear‐thinning and thixotropy behavior at studied conditions. The power‐law model (R2 = 0.940–0.987; RMSE = 1.297–15.325) and Casson models (R2 = 0.861–0.975; RMSE = 0.211–0.917) were selected to describe time‐independent behavior of the samples. In addition, the first‐order stress‐decay model (R2 = 0.89–0.98 and RMSE = 2.84–20.79) described the time‐dependent behavior of canary seed starch samples in the study well. The CO5041 starch gel had higher pseudoplasticity at different concentrations than CDC Maria. Both starches exhibited the same shear‐thinning behavior with increasing temperature. With increasing concentration, the canary seed starch samples showed more shear‐sensitive thixotropic nature and faster rupture rate. The CO5041 starch gel exhibited higher extent of thixotropy than CDC Maria starch gel at different concentrations.

Steady Shear Rheological Properties of Native and Hydrothermally Modified Persian Acorn (Quercus brantii Lindle.) Starches

“…Generally, the amounts of η c and τ 0c decreased as temperature increased. The same results were observed by Irani et al…”

“…At the temperature of 25 °C, the flow behavior index decreased with increasing in concentration, showing a more pseudoplastic behavior at higher concentrations. The same behavior has been reported on canary seed starch and wheat starch . However, at higher temperatures, the flow behavior index values first increased and then decreased as concentration increased.…”

“…The increase in the amounts of these parameters were more noticeable at higher concentration (3%). These results were inconsistent with those of canary seed, chestnut, and acorn starches, probably due to different concentration range studied. Since a threshold starch content produces complete interactions between polymers and higher amylose content would limit the increase in viscosity; however, in this study (concentration range of 1–3%) that threshold was not reached.…”

“…The η c values ranged from 2.117 (for 1% concentration at 70 °C) to 41.167 mPa s (for 3% concentration at 25 °C) and the τ 0c values were between 0.333 (for 1% concentration at 70 °C) to 506.667 mPa (for 3% concentration at 55 °C) (Table ). The maximum η c of native acorn starch at the concentration of 3% was comparable with that of canary seed starch (CO5041 variety) at the concentration of 4% at 25 °C . The values of τ 0c (at 5% of concentration and 25 °C) were 34.9 Pa for sweet potato starch, 19.2 Pa for rice starch, and 10.7 Pa for tapioca starch .…”

Effects of pH and storage time on the adhesive and rheological properties of cottonseed meal‐based products

“…The observation on the increase in viscosity of WCSM slurries with storage may be due to the build‐up of internal aggregation structure under rest conditions which probably is destroyed under shear . This thixotropy behavior (decreasing viscosity during time of shearing at constant shear rate) is more extensively in hydrocolloidal starch and protein than in biobased adhesives with higher solid contents . In this work, we observed that storage time affected the viscosity of CSPI slurries less than that of WCSM slurries.…”