Physico-Chemical Properties of Traditional Rajmudi Rice: A Comprehensive Evaluation

Abstract

Rajmudi rice, a traditional brown rice variety native to Mysore, Karnataka, was historically favoured by the kings of Mysore for its nutritional characteristics. This study evaluated the physicochemical properties of Rajmudi rice using AOAC and other standard methods. The physical properties analysed included grain dimensions, sphericity, aspect ratio, bulk and true density, porosity, thousand-grain weight, and angle of repose. The mean length, width, and thickness were 6.51 ± 0.098, 3.48 ± 0.200, and 2.25 ± 0.057 mm, respectively. The geometric mean diameter, equivalent mean diameter, and arithmetic mean diameter were 3.71 ± 0.039, 3.74 ± 0.042, and 4.08 ± 0.042 mm, respectively. Sphericity and aspect ratio were 57.0 ± 1.030% and 0.536 ± 0.037, respectively. True density and bulk density were 1440 ± 3.240 and 776 ± 8.900 kg/m-3, respectively. Porosity was 46.2 ± 0.601%, the angle of repose was 33.6° ± 0.133, and the thousand-grain weight was 17.9 ± 0.030 g. Proximate analysis showed moisture, crude protein, dietary fibre, crude fat, carbohydrate, and ash contents of 11.8 ± 0.112%, 9.96 ± 0.049%, 4.16 ± 0.024%, 2.01 ± 0.019%, 75.1 ± 0.172%, and 1.17 ± 0.011%, respectively, with an energy value of 355 ± 3.81 kcal/100 g. These findings provide baseline information on the physical and proximate characteristics of Rajmudi rice and may support its evaluation for household use, value-added product development, and food-processing applications.