Leavened Dough Processing by Supercritical Fluid Extrusion (SCFX)

Abstract

Yeast-leavened dough processing is semicontinuous due to the requirement for fermentation at constant temperature and humidity. Also, new regulations on the emission of alcohols are becoming burdensome on the baking industry. Extrusion processing of dough with supercritical carbon dioxide (SC-CO(2)) is envisioned to alleviate emission problems and to decrease production time by eliminating fermentation. A bread dough formulation with 50% (w/w) moisture was leavened by injecting 1.5% (w/w) SC-CO(2) in a twin-screw extruder at 37 degrees C. Specific mechanical energy input was 260 kJ/kg. The operating apparent shear rate range was 60-260 s(-1). SCFX-leavened dough density (420-430 kg/m(3)) was in good agreement with values reported for similar doughs. The flow behavior index, obtained by an on-line slit rheometer, was 0.49 for the nonleavened control and 0.63 for the SCFX-leavened dough. Apparent viscosity of the SCFX-leavened dough varied from 37 to 23 Pa-s. This new continuous process offers attractive possibilities for industrial applications if further developed.

3D microstructure of supercritical fluid extrudates I: Melt rheology and microstructure formation

“…The consistency index decreased when the ratio of SC-CO 2 to feed was increased for all formulations possibly due to the dilution effect of SC-CO 2 . This trend of K value is wellsupported by , Winoto (2005), and Hicsasmaz, Dogan, Chu, and Rizvi (2003). The flow behavior index increased with the addition of SC-CO 2 (Table 1).…”

“…The flow behavior index increased with the addition of SC-CO 2 (Table 1). A higher flow behavior index was obtained for SCFX dough compared to the control without SC-CO 2 (Hicsasmaz et al, 2003). Lee, Tzoganakis, and Park (1998) also showed that the flow behavior index of polyethylene/polystyrene/ CO 2 blends increased from 0.29 to 0.34 when the CO 2 concentration was increased from 0% to 2%.…”

Properties of yeast free bread produced by supercritical fluid extrusion (SCFX) and vacuum baking

“…The average SME input was calculated as 18 kW h/ton. Hicsasmaz et al (2003) found that the SME input for SCFX dough leavening was higher than that of the dough leavened by conventional and CBP methods. This was due to the higher pressure development and the inconsistent pressure profile within the extruder barrel.…”

“…This is more desirable for leavening dough than the conventional means for chemically leavening dough. Hicsasmaz, Dogan, Chu, and Rizvi (2003) showed that SCFX technology could be used to continuously produce yeast-free dough using CO 2 as a blowing gas. The SCFX-leavened dough was found to have rheological properties comparable to the commercial dough.…”

Estudo da estrutura de massas de pães elaboradas a partir de diferentes processos fermentativos

“…Segundo Hicsasmaz et al, (2003) o processo industrial mais comum de fazer pão é pelo método esponja, envolvendo de 10-20 minutos para a mistura, 2-3 h de fermentação, 10-15 minutos de modelagem e fermentação da massa, seguida de 45-60 minutos de fermentação final no total de 4-5 h. Do-Maker e AMFLOW são modificações do processo de massa esponja que envolvem pré-fermentação (2-4 h) seguida de adição de ingredientes secos, mistura intensa, modelagem e fermentação final, levando à diminuição no tempo de processo.…”