Enhancement of physicochemical properties and baking quality of broken rice flour through superheated steam

Abstract

This study investigated the effects of superheated steam (SS) treatment at different temperatures (120 °C, 150 °C, 180 °C) on the physicochemical properties of broken rice flour and the quality of broken rice cakes. SS treatment at 120 °C significantly enhanced the moisture content of broken rice flour (P < 0.05). In contrast, treatments at 150 °C and 180 °C caused decrease of moisture content, amylose leaching, and reduction of damaged starch content. After SS treatment, the pasting properties of broken rice flour increased, along with the rising of storage modulus and loss modulus. The proportion of short chains (DP 6-12) in amylopectin increased from 29.42% to 34.80% (P < 0.05), which could delay starch retrogradation. Compared with untreated ones, the SS-150 broken rice cakes showed a significantly higher specific volume (2.96 mL/g, P < 0.05), more uniform cell structure, and lower hardness (1.66 N) and chewiness (10.22 mJ). After 7 days of storage, cakes from SS-treated rice flour (150 °C and 180 °C) had significantly reduced hardness and chewiness. The study demonstrated that SS treatment could improve the properties of broken rice flour and enhance the quality of broken rice cakes, especially at 150 °C and 180 °C. This study presents a method for improving the quality of broken rice flour and rice cakes using superheated steam treatment, addressing challenges related to poor flour characteristics and suboptimal cake quality. The findings offer technical and theoretical support for enhancing rice cake production, contributing to the comprehensive utilization of rice resources.