Physical characteristics of extruded cassava starch

Abstract

Considering the importance of cassava starch for Brazilian industries, the current work aimed at evaluating the effects of extrusion parameters on the physical characteristics, mainly viscosity properties of extruded cassava starch. A factorial central composite design (2 3 ) with three independent variables and the response surface methodology were used to evaluate the results of expansion index, specific volume, water absorption index, water solubility index, color and paste properties, according to the variations in the moisture content, barrel temperature and screw speed. Results indicated that barrel temperature influenced the expansion index, specific volume, water absorption index, all the color parameters, the initial viscosity, peak and final viscosity. Feed moisture influenced the specific volume, color parameters, final viscosity and retrogradation. The screw speed had effects on water absorption index, color components as well as on the final viscosity and retrogradation of extruded starch. High moisture, low screw speed and intermediate temperature provided lower starch degradation, which is desirable for pre-cooked starch.

Effects of processing on physical properties of extruded snacks with blends of sour cassava starch and flaxseed flour

“…Similar results for the effect of temperature were cited by Leonel, Freitas and Mischan (2009) who observed that under high moisture and high barrel temperature conditions, there was less darkening of the extruded cassava starch, i.e. greater L*.…”

Physical characteristics of potato flour from 'Ibituaçú' cv. under different extrusion parameters

“…Larger ratios were obtained in less moisture content and higher extrusion temperature conditions, as shown in figure 1a. LEONEL et al (2009) observed similar behavior in extrudates from cassava starch. EI is a quality indicator; the more expanded products tend to be the more crisp they will be, which increases consumer market acceptability (FERRARI et al, 2014).…”

Thermal and pasting properties of cassava starch-dehydrated orange pulp blends

“…Figure 2 shows the viscoamylography profile of cassava starch-dehydrated orange pulp blend extruded in condition of 19.5% of moisture, 65ºC of extrusion temperature and 218 rpm. Leonel et al (2009) observed for extruded cassava starch: 5.3 to 14.7 RVU for initial viscosity, 6.3 to 14.6 RVU for viscosity peak, 2.8 to 12.8 RVU for breakdown, 7.2 to 13.1 RVU for final viscosity and 2.5 to 12.5 RVU for setback. Therefore, the differences observed in pasting properties of extruded mixtures of cassava starch and citrus pulp can be due the fiber content.…”