Effect of surfactant treatment on swelling behaviour of normal and waxy cereal starches

Starch swelling behaviour greatly affects its functionality in a food matrix. For some granular starches pre-treatment with the surfactant, sodium dodecyl sulphate, is known to dramatically affect swelling behaviour. The purpose of this study was to assess the effect of this surfactant treatment on the swelling behaviour of a variety of waxy and normal cereal starches. A concurrent mid-infrared spectroscopy study was carried out to investigate the chemical nature of variations in swelling behaviour. The native normal starches (amylose content 23-28%) showed significant variation in their pasting properties, which was largely eliminated by surfactant treatment. Surfactant treatment had less effect on the behaviour of the waxy starches (amylose contents 1-8%), which still exhibited some residual variation. Waxy durum appeared to be unique within the waxy starches, behaving more similarly to the normal starches. The spectroscopic data highlighted the carbohydrate fingerprint region as the main source of variation between samples.