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Rice flour was thermomechanically modified by steam‐jet cooking and the physicochemical, rheological and oil‐resistant properties of the resulting product were characterized. Compared with native rice flour, the steam jet‐cooked rice flour exhibited significantly increased hydration properties. Its pasting properties were also characterized by cold initial viscosity, decreased setback and the lack of peak viscosity. The shear‐thinning behaviors of the steam jet‐cooked rice flour were satisfactorily fitted into the Carreau equation. In addition, dynamic viscoelastic measurements showed that the liquid‐like nature was more dominant over the solid‐like properties. When incorporated into frying batter formulations, the steam jet‐cooked rice flour increased the batter viscosity and pickup. The use of steam jet‐cooked rice flour also enabled fried batters to control the moisture loss effectively. Furthermore, the wheat flour replacement with 20% steam jet‐cooked rice flour in batters led to dramatic reduction of oil uptake by around 40%. PRACTICAL APPLICATIONS This study introduces a hydrothermal treatment (steam‐jet cooking) as a new technique to impart better functional properties to rice flour. Specially, the steam jet‐cooked rice flour exhibited oil‐resisting properties when incorporated into frying batters, consequently producing fried foods with reduced content of oil and calorie.

Potato strips were coated with xanthan gum solutions (0.3, 0.6, 0.9%, w/v) which exhibited shear‐thinning and weak gel‐like characteristics. Then, the effects of the surface coating on heat transfer during deep‐fat frying of the potato strips were investigated as a function of concentration of xanthan gum solutions. Deep‐fat frying of surface‐coated potato strips exhibited sigmoidal temperature profiles which were shown to be dependent on the concentration of xanthan gum solutions. Heat transfer coefficients were also determined to be between 215 and 254 W/m2 K. The use of higher concentration of xanthan gum led to a distinct decrease in heat transfer coefficients during frying of potato strips, which were shown to be highly correlated to the viscosity of xanthan gum solution (R2 = 0.99). It thus suggested that the surface coating of potato strips with xanthan gum might create an insulating layer, consequently reducing the rate of heat transfer during frying. PRACTICAL APPLICATIONS Coating and batters in the frying industry are the common methods to reduce the oil uptake of fried foods. However, few experiments have been carried out to investigate the changes in the heat transfer during frying when a food matrix is coated or battered. In this study, a food matrix coated with hydrocolloid solutions was subjected to deep‐fat frying during which heat transfer coefficients were investigated. Our results obtained in this study can provide a fundamental understanding for the mechanisms of heat transport in coated (or battered) fried food systems, consequently helping optimization and control of a frying process.