Preparation and characterization of gelatinized granular starches from aqueous ethanol treatments

Benshan Zhang, Sushil Dhital, Enamul Haque, Michael J. Gidley

Research output: Contribution to journalArticleResearchpeer-review

48 Citations (Scopus)


In order to modify the properties of native starch granules, the formation of gelatinized granular forms (GGS) from normal, waxy, and high amylose maize, as well as potato and tapioca starches was investigated by treating granules with aqueous ethanol at varying starch:water:ethanol ratios and then heating in a rotary evaporator to remove ethanol. The modified starches were characterized using bright field, polarized and electron microscopy. Short/long range molecular order and enthalpic transitions on heating were also studied using infrared spectroscopy, X-ray diffractometry and differential scanning calorimetry respectively. A diffuse birefringence pattern without Maltese cross was observed for most GGS samples. Treatment with aqueous ethanol resulted in starch-specific changes in the surface of granules, most noticeably swelling and disintegration in waxy maize, surface wrinkling in normal maize and tapioca, swelling and opening-up in potato starches, and swelling and bursting in high amylose maize. The ratio of ethanol to water at which original granular order was disrupted also varied with starch type. GGS had less short range molecular order than native granules as inferred by comparing 1047/1022 wave number ratio from infrared spectroscopy. Similarly, A- and B-type diffraction reflections were either reduced or completely lost with evolution of V-type patterns in GGS.

Original languageEnglish
Pages (from-to)1587-1594
Number of pages8
JournalCarbohydrate Polymers
Issue number4
Publication statusPublished - 6 Nov 2012
Externally publishedYes


  • Aqueous ethanol treatment
  • Cold water solubility
  • Gelatinized granular starches
  • V-type crystallinity

Cite this