Process optimization and characterization of ragi‐based probiotic camel milk drink for enhanced functionality

Abstract A ragi‐based probiotic camel milk drink (RPCD) had been developed employing two different probiotic bacteria, Lacticaseibacillus rhamnosus NCDC347 (RPCD‐LGG) and Limosilactobacillus fermentum NCDC141 (RPCD‐LF). The product was optimized using a two‐factor Central Composite Rotatable Design to enhance its sensory and antioxidant properties. The variables used for the optimization were ragi concentration and fermentation time, with antioxidant activity (as % 2‐diphenyl‐1‐picryl‐hydrazylhydrate inhibition potential) and sensory profile (as sensory evaluation scores) as responses. The final optimized formulation comprised 5% ragi and a fermentation duration of 21.2 h. The drinks were analyzed for their proximate and physicochemical properties. The fermented variants exhibited notably higher antioxidant activity, (49.88% and 54.95%, respectively), and Total Phenolic Content (12.73 mg GAE/100 mL and 13.34 mg GAE/100 mL, respectively) than the unfermented control. Fourier transform infrared analysis was conducted, identifying important functional groups in the probiotic product. Metabolomics profiling of the drink revealed key bioactive compounds, including alkaloids, flavonoids, polyphenols, etc. The storage stability of the product kept at 4°C was assessed over 21 days. The drinks exhibited acceptable sensory and microbiological quality, including probiotic viability, throughout the assessment period.