Evaluation of a novel oxidative stress-adaptation method on membrane integrity, intracellular oxidation states, and survival of Bifidobacterium spp. during yoghurt fermentation and storage

This dataset describes the research conducted in the study, “Survival of Oxidative Stress-Adapted Bifidobacterium spp. in Yoghurt,” which consisted of three research phases. During phase 1, cultures of B. bifidum, B. breve, and B. animalis subsp. animalis were subjected to a sublethal (0.4 mM) H₂O₂ treatment followed by exposure to lethal (1 mM) H₂O₂ treatments for three successive generations. Phase 2 tested the H₂O₂-treated Bifidobacterium cells against previously lethal oxidative stress conditions. Finally, phase 3 evaluated the survival of the stress-adapted Bifidobacterium spp. during yoghurt fermentation and storage (28 days; analysis on days 0, 7, 14, 21, and 28).

The dataset files are organised by chapters: Chapters 2, 4, 5, and 6. The fluorescent histograms show the effects of the H₂O₂ treatments on the membrane integrity and intracellular oxidation states of the Bifidobacterium cells. SEM and TEM images indicate morphological and ultrastructural adaptations resulting from the H₂O₂ treatments. Furthermore, the fluorescent biplots illustrate both the membrane integrity and intracellular oxidation responses of the H₂O₂-treated Bifidobacterium cells following a lethal oxidative stress challenge. The tables display growth kinetics and maximum population density, along with the statistical analysis of the stress-adapted Bifidobacterium spp. under varying conditions of oxidative stress (0, 0.1, and 1 mM H₂O₂). Scanning and transmission electron microscopy (SEM and TEM) images also reflect the morphological and ultrastructural adaptations of stress-adapted Bifidobacterium spp. in response to lethal oxidative stress.

The analyses conducted during the yoghurt shelf-life study are presented in various figures and tables within the dataset. The figures show pH measurements (at 0, 1, 2, 3, and 3.4 hours) and Bifidobacterium spp. viability levels (before and after fermentation), along with the statistical analyses in the relevant tables. Physicochemical analyses, including pH, titratable acidity (TA), oxidation-reduction potential (ORP), and % syneresis, are shown during refrigerated storage on days 0, 7, 14, 21, and 28. Bacteriological analyses, such as standard plate counts and viability proportion index (VPI₂₈), are also presented, along with the respective statistical analyses for each yoghurt. Principal component analysis (PCA) was conducted on data collected during the shelf-life stage.