Impact of annealing and incorporation of vegetable oils on physicochemical and rheological properties of wheat starch.

This study investigated the impact of annealing treatment and lipids (vegetable oils, such as palm, olive, and grapeseed oils) on the physicochemical and rheological properties of wheat starch. Annealing of wheat starch (WS, WS) under different temperatures (45 °C and 55 °C) and with added vegetable oil (WS-Oil, WS-Oil) were compared with untreated wheat starch (WS). Annealing at 45 °C resulted in slight changes in the physicochemical properties of starch. However, annealing at 55 °C significantly decreased the relative crystallinity, pasting viscosity, and swelling power. WS-Oil showed a higher ΔH (dissociation peak) than WS, indicating successful lipid incorporation, whereas WS-Oil showed no significant difference from WS, suggesting that lipid integration was not achieved. Rheological tests showed that WS-Oil slightly reduced the shear-thinning behavior and viscoelastic properties of starch. The introduction of oils affected the swelling and pasting properties, weakened the gel network, and significantly reduced the gel hardness. This approach offers a potential method that uses food-grade oils and annealing to modify starch and alter its rheological and physical properties while retaining its native granular characteristics.