Physicochemical, Morphological, and Microbial Characterization of Spray‐Dried Dairy–Cereal Grain‐Based Probiotic Beverage ( <i>Raabadi</i> ) Powder

ABSTRACT There is gaining interest in innovative instant probiotic food powders with the benefits of dairy and plant food matrices to meet the growing demand for sustainable and healthy probiotic food options. A dairy–cereal grain‐based probiotic Raabadi beverage powder (DCBPRP) was produced through spray‐drying and contains maize flour, skimmed milk powder, and probiotic culture. The physicochemical (water activity, density, hygroscopicity, porosity, wettability, flowability, rehydration, degree of caking, and solubility) and morphological (XRD, TGA, and FTIR) characterization were done using the standard methodology. The measured values for DCBPRP were as follows: water activity (0.268 ± 0.01), bulk density (0.32 ± 0.01 g/cm 3 ), tapped density (0.39 ± 0.0 g/cm 3 ), true density (1.007 ± 0.003 g/cm 3 ), porosity (68.23 ± 0.9%), Carr's compressibility index (18.521 ± 5.09), Hausner ratio (1.231 ± 0.08), solubility index (76.33 ± 1.53%), wettability time (311.67 ± 9.07 s), rehydration time (54.33 ± 2.52 s), hygroscopicity (16.64 ± 0.82 [g H 2 O/100 g dry weight]), and degree of caking (23.05 ± 0.85%). The ultrastructure images showed the particles with a spherical shape, whereas FTIR spectra revealed the presence of fat, protein, and carbohydrates. The XRD curve showed the amorphous state of the product, while thermogravimetric analysis showed good thermal stability. The probiotic survivability count and microbial contaminants were also analyzed. The probiotic count in DCBPRP was 7.81 ± 0.03 log 10 CFU/g, more than the recommended dose of 6 log 10 CFU/g.