High-solid systems of partially hydrolysed waxy maize starch: Rheological and structural characterisations

• Type: Article in International Scientific Journal
• Date: 2007

Authors

Lopes, GK (Author) Other; Azero, EG (Author) Other; M. Vázquez da Silva (Author) FEUP; Maria do Pilar Gonçalves (Author) FEUP; Andrade, CT (Author) Other

Journal

Title: Journal of the Brazilian Chemical Society

Vol. 18

Pages: 65-73

ISSN: 0103-5053

Publisher: Sociedade Brasileira de Quimica

Indexing

ISI Web of Knowledge - 1 Citation

Scopus - 1 Citation

Other information

Authenticus ID: P-004-DRT

DOI: 10.1590/s0103-50532007000100007

Abstract (EN): The rheological behaviour of some high-solid mixed dispersions of partially hydrolysed waxy maize starch (HWS), in the presence of whey protein concentrate (WPC) and urea, was followed by small-amplitude oscillatory measurements in the linear domain, under heating to 80 C and cooling to 25 degrees C, at pH 7.5. The non-gelling HWS sample was obtained by sonication of previously gelatinised waxy maize starch. Steady-shear flow and microstructure were investigated after cooling to 25 C. Dispersions were prepared at 1: 1 (m/m) WPC/urea ratio, with increasing HWS concentrations. Typical solid-and liquid-like rheological behaviours were observed after quenching the mixtures to low temperature, depending on HWS/WPC ratio. At the lowest HWS/WPC ratio, a thixotropic structure was characterised under steady-shear flow, and visualised by light microscopy at low magnification as a continuous network. With increasing HWS/WPC ratio within a certain range, gelling and non-gelling mixtures resulted in phase-separated structures, which hindered viscous flow. At the highest HWS/WPC ratio, a shear-thinning dispersion was formed, consistent with the liquid-like small deformation properties and the homogeneous image obtained by light microscopy.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9