Beer wheat residue as a probiotic carrier: physicochemical properties via fluid bed granulation (Beer wheat residue for lactic acid bacteria encapsulation)

In recent years, consumer preference for symbiotics containing live bacteria has surged, driven by the acknowledged health benefits. Wheat residue from beer brewing, rich in dietary fiber, remains an unexplored prebiotic raw material for developing vegan probiotic powdered products. Concerns about ambient conditions, dehydration and drying affecting bacterial cell viability prompt the investigation of protective agents (maltodextrin, l-arabinose, casein, whey protein, skimmed milk) and fluidized bed granulation microencapsulation for enhancing the survival rate of Lactiplantibacillus plantarum NKUST 817. The results of the study show that wheat residue, when utilized as the carrier with 10% indigestible dextrin FB06, served as the optimal protective agent. Optimal air inlet temperature (45, 55 and 65 °C) for fluidized bed granulation was investigated along with cell survival rate and probiotic powder characteristics such as moisture, water activity, hygroscopicity, solubility, bulk density and flowability. Bacteria without protective agents showed a survival rate of only 82.63-86.96%. However, the addition of 10% indigestible dextrin FB06 significantly increased in the survival rate of bacteria (granulated at 45-65 °C) to 93.52-95.18%. The microencapsulated bacteria powder exhibited low moisture (2.38-4.36%) and water activity (0.06-0.22). Powder fluidity, indicated by Carr's index (10.87-13.62) and the Hausner ratio (1.13-1.16%), demonstrated good flowability. Furthermore, the powder remained stable for 45 days, with a viable bacteria count of 7.29 log colony-forming units g and a survival rate of 88.69%. This study pioneers vegan probiotic product development at the same time as addressing processing challenges to optimize strain resilience. This research stablishes wheat residue as a suitable candidate for a probiotics carrier. © 2024 Society of Chemical Industry.