Physicochemical and Functional Characterization of Dried Distiller’s Rice Spent Grain as a Function of Particle Size
Charu Bisht *
Department of Food Science and Technology, College of Agriculture, Govind Ballabh Pant University of Agriculture & Technology, Pantnagar, Uttarakhand, India.
Satish Kumar Sharma
Department of Food Science and Technology, College of Agriculture, Govind Ballabh Pant University of Agriculture & Technology, Pantnagar, Uttarakhand, India.
Anil Kumar
Department of Food Science and Technology, College of Agriculture, Govind Ballabh Pant University of Agriculture & Technology, Pantnagar, Uttarakhand, India.
Ashutosh Dubey
Department of Biochemistry, College of Basic Sciences and Humanities, Govind Ballabh Pant University of Agriculture & Technology, Pantnagar, Uttarakhand, India.
Umesh C. Lohani
Department of Post Harvest Process and Food Engineering, College of Technology, Govind Ballabh Pant University of Agriculture & Technology, Pantnagar, Uttarakhand, India.
Neha Rawat
Department of Food Technology, School of Allied Sciences, Dev Bhoomi Uttarakhand University, Dehradun, Uttarakhand, India.
Archana Gangwar
Department of Food Science and Technology, College of Agriculture, Govind Ballabh Pant University of Agriculture & Technology, Pantnagar, Uttarakhand, India.
*Author to whom correspondence should be addressed.
Abstract
Dried distiller’s rice spent grain (DDRSG), a protein-rich by-product of the rice-based ethanol industry, has considerable potential as a sustainable food ingredient; however, its physicochemical and functional characteristics can vary with particle size. The present study investigated the influence of particle-size fractionation on the physico-chemical, and functional properties of DDRSG. Dried DDRSG was fractionated using a mechanical sieve shaker into seven particle-size ranges: < 125, 125 - 212, 212 - 300, 300 - 500, 500 - 850, 850 - 1000, and 1000 - 2000 μm. The fractions were evaluated for particle-size distribution, proximate composition, colour characteristics, bulk and tapped bulk densities, compressibility, Hausner ratio, wettability, water-holding capacity (WHC), and oil-holding capacity (OHC). The highest yields were recorded for the 1000-2000 μm (27.09 %), 300-500 μm (26.82 %), and 212–300 μm (24.17 %) fractions. Particle size significantly affected most evaluated properties. Crude protein decreased from 53.23 % in the < 125 μm fraction to 47.25% in the 1000-2000 μm fraction, whereas moisture increased from 9.92 to 12.40 %. Increasing particle size decreased L* value from 51.50 to 37.13, while a* and b* values increased. Bulk and tapped bulk densities decreased with increasing particle size. In contrast, WHC and OHC increased from 2.35 to 4.03 g/g and 1.36 to 2.45 g/g, respectively. Wetting time decreased from 30.00 to 11.37 s, indicating improved wettability in coarser fractions. Crude fat and ash were not significantly affected by particle size. Overall, particle-size fractionation effectively modified the physico-chemical and functional attributes of DDRSG, demonstrating its potential for tailoring this protein-rich by-product to specific food-processing and formulation requirements.
Keywords: Dried distiller’s rice spent grain, particle size fractionation, physicochemical characteristics, functional properties.