کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1387195 | 982555 | 2010 | 9 صفحه PDF | دانلود رایگان |
Molecular and crystal structures as well as morphology during debranching and crystallization of waxy maize starch at a high solid content (25%, w/w) were investigated, and the results were related to the digestibility of debranched products. The starch was cooked at 115–120 °C for 10 min, cooled to 50 °C and debranched by isoamylase. After 1 h of debranching, wormlike objects with 5–10 nm width and ca. 30 nm length were observed by transmission electron microscopy. Further release of linear chains and crystallization led to assembly of semi-crystalline structures in the form of nano-particles and subsequent growth of nano-particles into large aggregates. After 24 h at 50 °C, a debranched starch product with an A-type X-ray diffraction pattern, a high melting temperature (90–140 °C), and high resistant starch content (71.4%) was obtained. Small-angle X-ray scattering results indicated that all debranched products were surface fractal in a dry state (4% moisture) but had a mass fractal structure when hydrated (e.g. 45% moisture).
Journal: Carbohydrate Polymers - Volume 81, Issue 2, 11 June 2010, Pages 385–393