This research aimed to investigate the effects of the inoculation method and diverse ingredients on the quality properties and probiotics viability of pudding with milk and/or soymilk. The probiotic strain (Lactobacillus acidophilus, LA-5) was inoculated into the yogurt base and fermented until the pH is 5.10 ± 0.05. The fermented yogurt was added into pudding base (yogurt inoculation), or LA-5 was directly inoculated (direct inoculation). During the storage of the puddings at 4±1oC for 4 wks, the quality characteristics (pH, acidity, texture) and the probiotics viability of pudding were measured and compared. As a result, the puddings with yogurt inoculation showed significantly lower pH and higher acidity than those with direct inoculation. In texture properties, including hardness, chewiness, and gumminess, the addition of rice powder increased those in milk pudding more but the addition of inulin in the milk-soymilk pudding more. The addition of rice powder increased probiotics viability more than inulin in milk and milk-soymilk puddings. Therefore, adding rice and/or inulin can potentially improve the probiotics viability and quality characteristics of pudding.
Bacteria get stressed and damaged during freeze-drying process for commercialization and this result in loss of its effect. Viability is important for its efficacy, but this drying process can deteriorate viability by damaging the integrity of the cell membrane as well. In this study, we propose 0.03 M histidine for rehydration of freeze-dried probiotics to improve their viability. The freeze-dried bacteria mixture with 0.03 M histidine showed augmented survivability during in vitro simulated gastric and duodenum stress conditions and increased viability during 60 min rehydration. It exhibited a significantly increased adherence ability of lyophilized bacteria to the HT-29 cell-line. Therefore, this shows possibility of probiotics commercialization with damage of lyophilization restored and survivability ameliorated.