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.

CFP may be a prebiotic due to its high resistance against α-amylase and acid. CFP provides two ways to adjust nitric oxide synthesis in macrophages. We show the use of CFP in the production of synbiotic yogurt with favorable physical and chemical characteristics.

The AgNPs were synthesized using water-soluble polysaccharides extracted from the Leucaena leucocephala seeds. The UV-visible spectrum of the AgNPs showed a sharp absorption peak at 448 nm. The XRD analysis showed four major peaks of the crystalline AgNPs with planes of a face-centered cubic lattice of silver. The EDS spectrum showed a strong signal peak at ~3 keV. TEM and SEM observations showed the spherical shape of AgNPs with no particle agglomeration, and the size ranged from 8 to 20 nm. AgNPs were highly stable at -14.2 mV by zeta potential measurement. AgNPs showed significant anticancer activity against the cell lines of breast cancer, liver carcinoma, and colon carcinoma with the I C 50 value of 22.5, 12.3, and 8.9 μg mL-1, respectively. AgNPs at 900 μg mL-1 exhibited considerable antifungal activity against ten fungal pathogens. Water-soluble polysaccharide has the ability to synthesize AgNPs keeping strong antitumor, antifungal activities. The AgNPs can slow down spoilage of composite milk samples at different temperatures. In addition, the accuracy of milk-IR-analyses was not affected by different concentrations of AgNPs.

No abstract

Postbiotics are functional bioactive substances manufactured during fermentation in a food matrix, which can be used to improve human health, but their influence on the adhesion potential and physicochemical cell surface of probiotics is still unclear. We examined the postbiotic influence produced by Escherichia coli Nissle 1917 in functional labneh on cell surface properties (auto-aggregation, hydrophobicity, and co-aggregation) and the adhesion capacities of three probiotic strains. The most commonly detected effects of probiotics, particularly Lsyn−7, were an increase in auto-aggregation, hydrophobicity, co-aggregation, and adhesion ability of the tested strains. Lactobacillus rhamnosus with Lsyn−7 (59%) presented the highest hydrophobicity, whereas the least adhesion to xylene was detected in L. rhamnosus with LHM. Lactobacillus casei with Lsyn−7 showed the highest auto-aggregation after 24 h (60.55%). Moreover, it also has a strong adhesion to Caco-2 cells and effectively prevents the binding of Salmonella Typhimurium to Caco-2 cells. Lactobacillus plantarum with Lsyn−7 presented the strongest co-aggregation with Staphylococcus aureus (85.1%), S. Typhimurium (85.02%) and Listeria monocytogenes (77.4%). The adherence potential of tested probiotic strains was highly correlated with auto-aggregation, hydrophobicity, co-aggregation, and competitive inhibition of L. monocytogenes and S. Typhimurium. The findings suggest that Lsyn−7 can be a candidate to promote the adhesion potential of selected probiotic strains. For the reason that the application of probiotic strains has been more interested in their positive influences in the gastrointestinal tract, it is essential to use some functional compounds, such as postbiotics, to improve adhesion abilities and cell surface properties in terms of bacterial binding.

The present study aimed to isolate and characterize strains of exopolysaccharide (EPS)-producing lactic acid bacteria (LAB) from traditional Egyptian dairy products. A total of 388 suspected LAB isolates were recovered from 100 samples of traditional Egyptian dairy products including Kariesh cheese, Zabady, Laban Rayeb and Ras cheese. Out of these suspected LAB cultures, 123 and 27 isolates were identified as potential LAB cocci and lactobacilli, respectively. These 150 LAB isolates were further examined for their ability to produce exopolysaccharides (EPS) in milk. Only 7 LAB isolates were found to produce EPS. These isolates were cultured form Laban Rayeb (3 isolates) and Zabady (4 isolates). A PCR identification procedure was carried out to identify these EPS-producing isolates to the species level. All the 7 isolates were found to belong to Streptococcus thermophilus. These results generally suggest the possibility of using Egyptian dairy products as a source of EPS-producing LAB.

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.

This study was carried out to evaluate the effect of the partial substitution of NaCl with different levels of KCl and MgCl 2 on the manufacture of Kareish cheese. Kariesh cheese was made by using vat set lyophilized starter cultures using different concentrations of salts namely: NaCl with KCl or MgCl2 (1:1, 2:1and 1:2 %). Kariesh cheese being made with only (3%) NaCl was considered as control, the salt added in all treatments after fermentation. All treatments analyzed when fresh, after one week and two weeks for chemical (Total protein (TP), non-protein nitrogen (NPN), soluble nitrogen (SN), total solid (TS), pH values and minerals of (Na, K, Mg)), as well as microbial analysis, organoleptic indices (flavor, body & texture and appearance & color) and rheological properties (Hardness, cohesiveness, springiness, Adhesiveness, Gumminess and chewiness).it could be notic that the total solid is inversely proportional to substitution percentage of NaCl with KCl or MgCl2. On the other hand, Cheese yield is directly proportional to substitution percentage of NaCl with KCl or MgCl 2. pH value of all treatments was lower than control. NPN and SN contents significantly increased during storage period (p<0.05), while TP content and pH value significantly decreased during storage period (p<0.05). The replacement of NaCl with MgCl2 by the ratio (1: 2) enhanced the organoleptic and texture properties of the cheese comparing with the control. NaCl retention percentage in Kareish cheese curd was the highest, compared with other salts, followed by KCl and then MgCl 2. Hardness, gumminess and chewiness were significantly lower (P> 0.05) in karish cheese made with the partial substitution of sodium chloride (KCl or MgCl 2) than cheese salted with sodium chloride alone (control). Cohesiveness, adhesiveness and springiness were significantly higher in cheese salted with NaCl/ KCl or NaCl/MgCl 2 mixtures. It could be concluded that the partial substitution of NaCl with KCl or MgCl 2 resulted a positive effect on Karish cheese textural characteristics. Instrumental and sensory properties showed indicated that Karish cheese being made using partial substitution of NaCl with KCl or MgCl 2 was softer and smother than control.