Comparative analysis of physicochemical and functional characteristics of rice flour produced in the Ampara district and commercial brands

Abstract

Rice flour is an integral part of Sri Lanka’s culinary tradition, yet small-scale production in the Ampara District faces challenges in standardization and competitiveness. This study compared the physicochemical, functional and sensory properties of locally produced (LPRF) and commercial rice flour (CRF). Thirty local samples were collected from major paddy-cultivation areas in the Ampara – Akkaraipattu (n=10), Nintavur (n=10) and Sammanthurai (n=10), alongside 10 commercial samples. String hoppers were prepared to assess physical properties. Sensory evaluation was performed by 30 semi-trained panelists (aged 20-50 years; 17 female and 13 male) using a 9-point hedonic scale. Data were analyzed by one-way ANOVA (SPSS Ver.25, p= 0.05). LPRF, processed by semi-milling and traditional roasting, had larger particle size (>180 µm) and higher acid insoluble ash content (0.35–0.47%), exceeding SLS 913:2020 limits due to contamination. CRF had finer particles (70.58% <180 µm), higher moisture content (8.71% vs 6.15–7.05%) and superior hydration properties: water absorption index (WAI) (3.02 vs 1.81 2.02), swelling power (SP) (8.60 g/g vs 7.29–7.57 g/g) and solubility (2.94% vs 1.04–1.19%). CRF exhibited has lower gelatinization temperatures (70.66°C vs 73.64–74.08°C). All samples complied with pH (5.44–5.66) and total ash (<1%) standards. String hoppers made from CRF showed higher moisture content (66.88%) and lower evaporation (17.33%). Moisture content positively correlated with finer particles (r=0.341) and hydration properties: WAI (r=0.385), SP (r=0.376) and solubility (r=0.381). Moisture evaporation negatively correlated with particle size (r= –0.486), solubility (r= –0.435), WAI (r = –0.576), and SP (r= –0.235). Sensory evaluation favored CRF for softness and smoothness, with no significant differences in color, odor, taste or overall acceptability. Improving the marketability and quality of locally produced rice flour requires improved processing, including particle size, controlled roasting and optimized drying.