Heat-induced structural changes of acid-hydrolysed and hypochlorite-oxidized barley starches

Karin Autio, Tapani Suortti, Antti Hamunen, Kaisa Poutanen

Research output: Contribution to journalArticleScientificpeer-review

14 Citations (Scopus)

Abstract

The effects of hydrolysis and oxidation on the heat-induced structural changes of barley starch dispersions were studied by dynamic viscoelastic methods and light microscopy. The effects of the modifications on the molecular weight of amylose and amylopectin were investigated by high-performance liquid chromatography (HPLC) with post-column iodine staining. Comparison of the molecular weights of oxidized and acid-hydrolysed barley starch dispersions with the same limiting viscosity values showed that the molecular weight of amylose was decreased more by oxidation than by hydrolysis, whereas the molecular weight of amylopectin was reduced to the same degree. Relative to acid hydrolysis, oxidation also reduced the temperature at which gel-formation occurred and weakened the gels. Irrespective of the type of modification, large amounts of granule residues were left after heating at 120 °C for 20 min. Microstructural studies of the gels showed that both hydrolysed and oxidized starches underwent phase separation into amylose- and amylopectin-rich phases.
Original languageEnglish
Pages (from-to)155-161
Number of pages7
JournalCarbohydrate Polymers
Volume29
Issue number2
DOIs
Publication statusPublished - 1996
MoE publication typeA1 Journal article-refereed

    Fingerprint

Cite this