Changes in the activities of antimicrobial, antitumor, and antioxidant properties of postbiotics (YCG) are related to changes in the composition of phenolic compounds. Antimicrobial activity was found to be highest in postbiotic (YCG-7) against P. aeruginosa, S. aureus, and E. faecalis with an MIC of 3.1 µg/mL. YCG-7 revealed the most cytotoxicity against LS-174T and PC-3 cell lines with an IC50 of 5.78 and 6.56 µg/mL, respectively. YCG-7 was far more effective for scavenging free radicals in the NO• and DPPH assays with a scavenging activity of 70.73% and 85.6%, respectively. YCG-7’s total phenolic acid content is up to eightfold higher compared with control. Escherichia coli Nissle 1917 retained high viable counts during refrigerated storage, particularly in YCG (>108 cells g−1) revealing a potential prebiotic activity of Cape gooseberry juice. EcN affected the phenolic profile of the YCG. Pyrogallol, p-coumaric acid, ellagic acid, 4-hydroxybenzoic acid, salicylic acid, gallic acid, vanillic acid, o-coumaric acid, caffeic acid, catechol, syringic acid, and rutin were the predominant phenolic compounds in YCG-7 or YCG-15. Chlorogenic, rosmarinic, cinnamic acid, naringin, and kaempferol were degraded by EcN in YCG-7 and YCG-15. The YCG had significantly higher sensory scores for appearance, smoothness, sourness, mouthfeel, and overall acceptance. These results provide the basis to target the functional benefits of YCG for further human health applications.

Passion fruit peel powder (PFPP) was used to supplement the probiotic labneh to increase the activity of Escherichia coli Nissle 1917 (EcN) during production and storage. Labneh was manufactured with PFPP (0.5% and 1%) and analyzed at 0, 7, and 15 days of cold storage for postacidification and sensory properties and viability of EcN, survival of EcN to simulated gastrointestinal tract stress, and adhesion potential of EcN to Caco-2 cells. Acidification kinetics during fermentation showed that supplementation with PFPP reduced the time needed to decrease pH and reach the maximum acidification rate. PFPP addition contributed to postacidification of labneh during storage. PFPP had a beneficial effect (p < 0.05) on counts of EcN in labneh during different storage periods. Consumer preference expectations for labneh enriched with PFPP (0.5% and 1%) were higher than those for the control. PFPP provided a significant protective action for EcN during simulated gastrointestinal transit and had a positive effect on EcN adhesion to Caco-2 cells in vitro, although this decreased during storage with labneh. Labneh supplementation with PFPP can be recommended because of the positive effect on EcN viability and the high nutritional value, which may increase the appeal of the product to consumers.

India and Ethiopia employ Guizotia abyssinica (niger plant) as a source of edible vegetable oil. Previous studies have documented the niger plant’s antioxidant properties and dietary benefits. Here, G. abyssinica extract was obtained and ten known bioactive components (1–10) were isolated. The antioxidant, antidiabetic, and prebiotic properties of whole extract and isolated components of niger and the plant’s ability to cooperate symbiotically with probiotic strains were examined. Compound 10, myricetin-3-O-L-rhamnoside, had the highest antioxidant capacity measured in the 2,2-diphenylpicrylhydrazyl (DPPH, 4629.76 ± 6.02 µmol Trolox equivalent/g compound) and ferric-reducing antioxidant power (FRAP, 2667.62 ± 7.5 mol Trolox equivalent/g compound) assays. The lowest α-amylase and glycogen phosphorylase activities and glucose diffusion were obtained with whole G. abyssinica extracts, whereas compounds 8–10 had moderate inhibitory effects. G. abyssinica extract also induced the highest glucose absorption by yeast cells in the presence of 5 mM of glucose. Moreover, Lactobacillus plantarum and L. rhamnosus incubated with β-sitosterol 3-O-D-glucoside (compound 7) showed the highest prebiotic activity score. The levels of L-(+)-lactic acid isomer in the probiotic strains were the highest in presence of the whole extract and decreased progressively in the presence of flavonoid glycosides (compounds 8–10) and β-sitosterol 3-O-D-glucoside. The enzymatic profile of the probiotic strains was unaffected by the niger extract and compounds 7–10. The findings revealed that the biological activities of G. abyssinica extract are mediated by the compounds 1–10, and it may be considered as a promising plant for the treatment of diabetes mellitus.