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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Healthy Processed Foods Research » Research » Publications at this Location » Publication #309760
Title: Physical characteristics of extrudates from corn flour and dehulled carioca bean flour blend

Author
item MOREIRA DA SILVA, ERIKA - Universidade Federal Do Espirito Santo (UFES)
item RAMIREZ-ASCHERI, JOSE - Embrapa
item PILAR DE CARALHO, CARLOS - Embrapa
item YOSHIE-TAKEITI, CRISTINA - Embrapa
item Berrios, Jose

Submitted to: Journal of Food Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/23/2014
Publication Date: 4/1/2014
Citation: Moreira Da Silva, E.M., Ramirez-Ascheri, J.L., Pilar De Caralho, C.W., Yoshie-Takeiti, C., Berrios, J.D. 2014. Physical characteristics of extrudates from corn flour and dehulled carioca bean flour blend. Journal of Food Science and Technology. 58:620-626.

Interpretive Summary: Extruded products were prepared from a corn flour and dehulled carioca bean flour blend using a single-screw extruder. The effects of extrusion process variables: screw speed (318.9 to 392.9 rpm), feed moisture (10.9 to 21.0 g/100 g) and bean flour level (4.8 to 55.2 g/100 g) on the energy (SME), sectional expansion (SEI), longitudinal expansion (LEI), volumetric expansion (VEI) and density (D) of the developed product. The texture of the product was also evaluated. The processing variables, previously indicated, had large effects on the physical properties (SEI, VEI and density) of the product, with the exception of SME and LEI. SEI increased with increasing screw speed, but a higher moisture and bean flour content resulted in decreasing SEI and VEI. The increase of moisture and bean flour increased the density of extrudates. According to texture analysis, some treatments with 30 and 45 g/100 g bean flour did not show significant differences when compared to commercial brand snacks. However, when combined with higher moisture content (greater than 19 g/100 g) and lower screw speed (lower than 333 rpm), the results of the expanded product were not satisfactory.

Technical Abstract: Extruded products were prepared from a corn flour and dehulled carioca bean (Phaseolus vulgaris, L.) flour blend using a single-screw extruder. A central composite rotate design was used to evaluate the effects of extrusion process variables: screw speed (318.9-392.9 rpm), feed moisture (10.9-21.0 g/100 g) and bean flour level (4.8-55.2 g/100 g) on the specific mechanical energy (SME), sectional expansion index (SEI), longitudinal expansion index (LEI), volumetric expansion index (VEI) and density (D) of the extrudates. The instrumental texture was also analyzed. The independent variables had significant effects on the physical properties (SEI, VEI and density) of extrudates, with the exception of SME and LEI. SEI increased with increasing screw speed, but a higher moisture and bean flour content resulted in decreasing SEI and VEI. The increase of moisture and bean flour increased the density of extrudates. According to texture analysis, some treatments with 30 and 45 g/100 g bean flour did not show significant differences when compared to commercial brand snacks. However, when combined with higher moisture content (=19 g/100 g) and lower screw speed (=333 rpm), the results of the expanded product were not satisfactory.