Molecular structure, rheological and thermal characteristics of ozone-oxidized starch

作者:Chan Hui Tin; Leh Chiu Peng; Bhat Rajeev; Senan Chandra; Williams Peter A; Karim Alias A*
来源:Food Chemistry, 2011, 126(3): 1019-1024.
DOI:10.1016/j.foodchem.2010.11.113

摘要

The effects of oxidation by ozone gas on the molecular structure, rheological and thermal properties of starch (corn, sago and tapioca) were investigated. Starch, in dry powder form, was exposed to ozone for 10 min at different ozone generation times (OGTs). Average molecular weight decreased in oxidized corn and sago starches but increased in oxidized tapioca starch. All oxidized starches exhibited non-Newtonian shear-thinning behaviour. Starch viscosity decreased drastically with increasing OGT. Young's modulus for all oxidized corn and sago starch gels stored for 1 and 7 days at 4 degrees C increased significantly compared to unmodified starch. No differences were noted in gelatinization temperatures and gelatinization enthalpies of all oxidized starches compared to unmodified starch. Retrogradation enthalpy increased markedly in corn starch after 1 min OGT. These results show that the extent of starch oxidation varies among starches of different botanical origins under similar ozone treatment conditions.

  • 出版日期2011-6-1