This study investigated different amino acid-based surfactants (AASs), also known as biosurfactants, including sodium N-dodecyl asparagine (AS), sodium N-dodecyl tryptophan (TS), and sodium N-dodecyl histidine (HS) for their potential anticorrosion, antibacterial, and antidermatophyte properties. The chemical and electrochemical techniques were employed to examine the copper corrosion inhibition efficacy in H₂SO₄(1.0 M) solution at 298 K. The results indicated their promising corrosion inhibition efficiencies (% IEs), which varied with the biosurfactant structures and concentrations, and the concentrations of corrosive medium. Higher % IEs values were attributed to the surfactant adsorption on the copper surface and the production of a protective film. The adsorption was in agreement with Langmuir adsorption isotherm. The kinetics and mechanisms of copper corrosion and its inhibition by the examinedAASswere illuminated. The surfactants behaved as mixed-kind inhibitors with minor anodic priority. The values of % IEs gained from weight loss technique at a 500 ppm of the tested surfactants were set to be 81, 83 and 88 forAS, HSandTS, respectively. The values of % IEs acquired from all the applied techniques were almost consistent which were increased in the order:TS > HS ≥ AS, establishing the validity of this study. These surfactants also exhibited strong broad-spectrum activities against pathogenic Gram-negative and Gram-positive bacteria and dermatophytes.HSexhibited the highest antimicrobial activity followed byTS, andAS. The sensitivity of pathogenic bacteria varied against testedAASs.Shigella dysenteriaeandTrichophyton mantigrophyteswere found to be the most sensitive pathogens.HSexhibited the highest antibacterial activity againstShigella dysenteriae, Bacillus cereus, E. coli,K. pneumoniae,andS. aureusthrough the formation of clear zones of 70, 50, 40, 39, and 35 mm diameters, respectively.AASsalso exhibited strong antifungal activity against all the tested dermatophyte molds and fungi.HScaused the inhibition zones of 62, 57, 56, 48, and 36 mm diameters againstTrichophyton mantigrophytes,Trichophyton rubrum, Candida albicans, Trichosporon cataneum,andCryptococcus neoformans, respectively.AASsminimal lethal concentrations ranged between 16 to 128 µg/ml.HSpresented the lowest value (16 µg/ml) against tested pathogens followed byTS(64 µg/ml), andAS(128 µg/ml). Therefore,AASs, especiallyHS,could serve as an effective alternative antimicrobial agent against food-borne pathogenic bacteria and skin infections-associated dermatophyte fungi.

In this study processed cheese was supplemented with either fresh or dried edible mushroom (Pleurotus ostreatus Hk 35), to improve its nutritional value, functional and sensory properties, chemical composition, amino acids content, and microbiological quality. Fresh mushroom was added to cheese blend in pieces and smashed form at levels of 0, 5, 10 and 15%, while dried mushroom was added at levels of 0, 1, 1.5 and 2%. Among all processed cheese treatments obvious differences (P≤0.01) were noticed in the organoleptic scores; the highest flavor scores (37.4, 37.3) were recorded for processed cheese supplemented with 1% and 1.5% mushroom powder, respectively. Significant differences (P≤0.01) were also recorded among chemical composition of the resulted processed cheese spreads. Moisture, ash and protein recorded the highest values in processed cheese supplemented with mushrooms compared to control. Moisture content in processed cheese control was 46.26%, while ranged from 47.39 to 53.72% in cheese spread supplemented with mushrooms. There was a significant difference (P≤0.001) in ash content of processed cheese spreads; the highest ash content (5.4%) was for processed cheese spread supplemented with 2% dried mushroom. Cheese spreads that contain mushrooms was high in protein/DM (31.20-36.36%) comparing to the spread of control (30.88%). There was also a significant difference (P ≤ 0.001) in the contents of all tested minerals in processed cheeses. The highest mean values of Ca, P, Mg and Zn was observed in control and processed cheese that contain mushroom powder. Regarding the pH values; processed cheese spreads that contain mushrooms have pH values ranged from 5.39-5.78, while in control ranged from 5.47-5.63. Microbiological investigation showed that the total viable counts and spore former bacteria was lower in processed cheese supplemented with mushrooms than in cheese control. On the other hand, an increase in lipolytic and proteolytic bacteria was noticed during storage period. No yeast and molds were detected in the first month of storage for all processed cheese treatments.

In this study the effect of using ultrafiltration (UF) processes, incorporating Oats (Avena sativa L.) powder (0, 1, 2%) and probiotic bacteria on the properties and nutritional value of synbiotic functional UF-low and full-fat Labneh was investigated. Mixed starter of Lactobacillus casei and Lactobacillus paracasei (1:1) was added (2%) and used as probiotic bacteria. The samples of both controls and all resultant synbiotic Labneh treatments were analyzed for gross chemical composition, microbiological and sensory attributes during 35 and 21 days, respectively at 5 °C. Also nutritional values were determined and calculated in all fresh samples. Lactose content and pH values were decreased during the storage period in all Labneh samples. Results showed that all low-fat Labneh treatments can provide human with high protein amount daily value (20% DV or more) while, low-fat UF-Labneh supplemented with 2% Oats recorded the highest daily values of protein (24.52%). Moreover, the results indicated that adding 2% of Oats to the UF-low fat Labneh, improve sensory parameters, motivate the numbers of probiotic bacteria and extended the shelf life. Moreover, all Labneh treatments were free from coliform group through all storage periods. The highest sensory total score was observed for UF-low fat Labneh at 7 days of storage and UF-low fat Labneh supplemented with 1% Oats at 28 days of storage. Finally, in this study using UF-technique and adding Oats powder in making Labneh, improved the nutritional value as it increased protein, %DV and fiber contents and decreasing lactose content which will be suitable for people who suffering from lactose intolerance. Also using the probiotic bacteria which produce bacteriocins; minimize the fungi and psychrophilic bacterial counts.

Camembert cheese is a surface white mould ripened cheese; when full ripe the casein becomes liquefy as the intensive degradation occurs by proteinases from surface flora and results over-ripening and off flavor. To control this, partial purified bacteriocin like substances (PPBLS) from newly lactic acid bacterial isolate (LAB100) exhibited antifungal activity against Penicillium candidum (in vitro) were used. Inhibition (%) of P. candidum by PPBLS at concentrations of 2, 4, 8, 16 and 32 mg/ml was 34, 50, 79, 80 and 85%, respectively. Based on their superior antifungal potential activity; isolate LAB100 was phenotypically and genotypically characterized as newly Lactobacillus sp. For delaying the Camembert cheese over-ripening (in vivo), bacteriocin producing isolate LAB100 and its PPBLS were incorporated and applied in different camembert cheese treatments. Three treatments beside control were conducted; after brining all cheese treatments stored at 12±2°C to ripen for 12 days and then at 5±2°C for more 30 days to complete ripening. Organoleptic properties, pH values and nitrogen distribution were determined during ripening period. In addition, the proteolysis of treated Camembert cheese was monitored by gel electrophoresis. The cheese treatment (T2) made with bacteriocin producer isolate LAB 100 added as co-culture to main starter recorded the highest total score, followed by T3 and the lowest one was recorded for control (T1). The highest WSN/TN% was in T1; 5.4, 22.87, 34.41 and 57.65% at 3, 10, 20, and 40 days after brining, respectively, while the lowest WSN/TN% was recorded for treatment that made with both bacteriocin producer strain LAB100 and sprayed by PPBLS solution after 3 days of brining (T3), where it was 5.05, 9.85, 13.82, and 31.74% at the same previous ages, respectively. These results were confirmed by gel electrophoresis, indicating that bacteriocin producer LAB100 and or its bacteriocin controlled the protein degradation. These results suggest that both bacteriocin producer strain and its PPBLS minimize the growth of P. candidum as a consequence the rate of proteolysis was controlled and hence extending the shelf life of Camembert cheese is occurred.

Exopolysaccharides (EPSs) are novel functional additives for low-fat yogurt. Pharmaceutical, medical, and food industries are using more LAB-based EPSs. In this study, Leuconostoc spp. was used to produce ninth bacterial EPSs in a modified molasses medium. Production of EPSs was concentration-dependent on all stains and the highest yield was obtained from the S3 strain (55.23 g/l), followed by S6 (49.95 g/l), S8 (45.68 g/l), and S7 (44.23), respectively. HPLC and FTIR analysis showed that all purified EPSs from Leuconostoc citreum (S3) and Leuconstoc holzaapfelii (S8) were related to exopolysaccharide glucan. Anticancer activity of all EPSs samples (EPSs1-9) against Caco-2 cells and normal MCR-5 cells were investigated using MTT assay. The results revealed that Caco-2 cells were more sensitive than the normal MCR-5 cells. The highest anticancer activity against Caco-2 cancer cells was recorded for EPS8 (IC50 = 22.94 µg/ml, SI=3.73), followed by EPS3 (IC50 = 36.15 µg/ml, SI=8.72), EPS1 (IC50 = 50.01 µg/ml, SI=3.73), and EPS4 (IC50 = 94.90 µg/ml, SI=3.26), respectively. The lowest cytotoxicity was recorded for EPS5 (IC50 = 130.5 µg/ml). The most active EPSs (EPS3 and EPS8) were used as fat replacements and stabilizers in low-fat set yogurt at non-toxic concentrations (0.4, 0.8, and 1.2%). EPS3 and EPS8 improved the low-fat yogurt’s organoleptic and rheological properties. EPS8 had the highest water holding capacity (77.26%), viscosity (3660 CP), and lowest syneresis (22.95%) and whey off (0.6 ml). Low-fat set yogurt enhanced with EPS3 and EPS8 recorded the highest sensory evaluation values with overall acceptability, especially EPS3b, EPS3c, EPS8c, and EPS8b; the total score point of 97.50, 97.43, 96.51, and 96.36, respectively in fresh age compared to control yogurt (92.64). In conclusion, Leuconostoc EPSs, especially EPS8, can be explored for anti-cancer effects on Caco-2 colorectal cancer cells. It could also improve the rheological and organoleptic qualities of low-fat set yogurt.