Details

Autor(en) / Beteiligte

• Utrilla-Coello, R.G.
• Hernández-Jaimes, C.
• Carrillo-Navas, H.
• González, F.
• Rodríguez, E.
• Bello-Pérez, L.A.
• Vernon-Carter, E.J.
• Alvarez-Ramirez, J.

Titel

Acid hydrolysis of native corn starch: Morphology, crystallinity, rheological and thermal properties

Ist Teil von

• Carbohydrate polymers, 2014-03, Vol.103, p.596-602

Ort / Verlag

Kidlington: Elsevier Ltd

Erscheinungsjahr

2014

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •The acid hydrolysis of native corn starch was monitored for short and long times.•Amylose depletion of about 5% residual was obtained at the third day.•Maximum crystallinity was exhibited after 3 days.•Viscoelasticity was gradually reduced to achieve liquid-like behavior. The acid hydrolysis of native corn starch at 35°C was monitored during 15 days. After this time, the residual solids were about 37.0±3.0%. First-order kinetics described the hydrolysis data, giving a constant rate of kH=0.18±0.012days−1. Amylose content presented a sharp decrement of about 85% and X-ray diffraction results indicated a gradual increase in crystallinity during the first 3 days. SEM micrographs showed that hydrolysis disrupted granule morphology from an initial regular shape to increasingly irregular shapes. Fractal analysis of SEM images revealed an increase in surface roughness. Fast changes in the thermal effects were caused by molecular rearrangements after fast hydrolysis of amylose in the amorphous regions in the first day. Steady shear rate and oscillatory tests showed a sharp decrease of the apparent viscosity and an increase of the damping factor (tan(δ)) caused by amylose degradation.