In this study, ultrasonication, a physical, relatively cheap, and environmentally benign technology, was investigated to characterize its effect on functional properties of rice starch and rice starch-based sauces. Temperature-assisted ultrasound treatment improved the granular swelling power, fat and water absorption capacities, and thermal properties of rice starch, signifying its suitability in the formulation of starch-based sauces. Rheological characterization of the formulated sauces revealed a shear-thinning flow behavior, well described by the Ostwald de Waele model, while viscoelastic properties showed the existence of a weak gel. Results indicated that ultrasonication significantly enhanced the pseudoplastic behavior of starch-based sauces. Additionally, textural analysis showed that textural attributes (stickiness, stringiness, and work of adhesion) were also improved with ultrasonication. Moreover, enhanced freeze/thaw stability was also achieved with ultrasound-treated starch-based sauces. Overall, the results from this study show that ultrasound-treated starches can be used in the formulation of sauces and potentially other food products, which meets the requirements for clean label and minimally processed foods.
Keywords: Freeze/thaw cycle; Rheology; Rice starch; Texture; Ultrasound; White sauce.
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