Valorization of edible films based on chitosan/hydroxyethyl cellulose/olive leaf extract and TiO2-NPs for preserving sour cream.

Biodegradable edible films for sour cream packaging were developed based on chitosan (CS), hydroxyethyl cellulose (HEC), Olive leaf extract (OE), and titanium dioxide nanoparticles (TiO2-NPs). The prepared CS/HEC/TiO2-OE bionanocomposite films were evaluated for their antimicrobial and antioxidant activities as well as using FT-IR, mechanical, permeability, and contact angle. The effect of developed films on the lipid oxidation, microbiological load, and chemical properties of sour cream was investigated. The fabricated films had an antimicrobial impact against all tested strains. The film containing 8 % OE showed effective protection against fat oxidation, with a peroxide value of 3.21 meq O2/kg, a para-anisidine value 5.40, and free fatty acids of 0.82 mg KOH/kg. The films with OE 4 % and 8 % have a good effect on the microbiological load of sour cream for 90 days. These films did not influence the chemical composition of sour cream and therefore can be used in this sort of dairy product.

Laboratory evaluation of anti-plaque and remineralization efficacy of sugarless probiotic jelly candy supplemented with natural nano prebiotic additive.

We evaluated the anti-cariogenic effect of an experimental synbiotic compound containing probiotic Lacticaseibacillus rhamnosus (NRRL B-442)-based jelly candy supplemented with natural prebiotic grape seed extract (GSE) in a nanoemulsion formula on the colonization and establishment of Streptococcus mutans (ATCC 25175) and Actinomyces viscosus (ATTCC 19246) biofilms through counting colony forming units, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). We were then analysing the remineralizing effect of synbiotic jelly candy on human enamel surface lesions using Vickers microhardness testers, atomic force microscopy (AFM), SEM, energy-dispersive X-ray spectroscopy (EDAX), and confocal laser scanning microscopy (CLSM) at three stages (sound, after demineralization, and after pH cycling). We found after 21 days of treatment of the pH-cycled enamel discs with jelly candy for 10 min twice daily, a 68% decrease in S. mutans colony formation, reducing biofilm development, trapping S. mutans visualized in jelly candy under SEM examination, and significantly altering the morphological structure of these bacteria under TEM analysis. For remineralization measurements, statistically significant differences in microhardness integrated mineral loss, and lesion depth through CLSM between demineralization and treatment stages. These findings provide an effective anti-cariogenic synbiotic compound of grape seed extract and probiotic jelly candy with potential remineralizing activity.

Bigel formulations based on sesame oleogel with probiotics alginate hydrogel: A novel structure for nutritious spreadable butter.

As a replacement for saturated fats, bigel butter spread (BgBs) based on sesame oleogel and alginate hydrogel was developed. Morphology, oxidative stability, microbiological, chemical, and sensory analysis were assessed. The results demonstrated that unsaturated fatty acids were higher in cinnamon (73.87 %) than in plain (71.57 %) BgBs. The peroxide value was higher in plain (5.25 meqO2/kg) than in cinnamon BgBs (4.29 meqO2/kg). Cinnamon BgBs had 44.44 % more antioxidant activity compared to plain BgBs (40.20 %). Moreover, BgBs products kept their probiotic counts at >7 log cycles. The cinnamon BgBs had a lower microbial load than plain BgBs. The chemical composition of the BgBs products did not change significantly. But the pH values slightly dropped with the storage time. The sensory evaluation of plain and cinnamon BgBs did not significantly differ from one another. However, the period of storage and the addition of the cinnamon oil significantly affected the flavor ratings.

In vitro antibacterial effect of probiotics against Carbapenamase-producing multidrug-resistant Klebsiella pneumoniae clinical isolates, Cairo, Egypt.

BACKGROUND: Searching for a non-antibiotic therapeutic option such as probiotics is gaining momentum nowadays. We aimed to evaluate the in vitro antibacterial ability of cell-free supernatant (CFS) of selected Lactobacillus strains (with probiotic properties) against clinical isolates of OXA-48-producing multidrug-resistant (MDR) Klebsiella pneumoniae separately and in combination with cefoperazone antibiotic. METHODS: Over a period of 8 months, a cross-sectional experimental study involving 590 Klebsiella pneumoniae isolates was done. Our study took place at The Specialized Pediatric Teaching Hospital of Cairo University. Of the 590 Klebsiella pneumoniae isolates collected from blood cultures, pus, endotracheal aspirates, and pleural fluid, only 50 unrepeated clinical isolates of MDR Klebsiella pneumoniae-producing OXA-48-like detected by CHROMID® OXA-48 (bioMérieux, France) were selected for our study. After determining the minimal inhibitory concentration of CFS of ten Lactobacillus strains and cefoperazone each, the synergistic effect of both was tested. RESULTS: Among ten tested Lactobacillus spp., a significant increase in the mean value of inhibition zone diameter with CFS of L. helveticus (14.32 mm) and L. rhamnosus (13.3 mm) was detected separately. On the contrary, an antagonistic activity against all tested isolates was detected upon combination of Lactobacilli with cefoperazone (512 µg/ml). The mean value of inhibition zone diameter of L. helveticus CFS+ cefoperazone was (11.0 mm) and for L. rhamnosus CFS+ cefoperazone was (10.88 mm) (p value <0.001). CONCLUSION: The antimicrobial efficiency of using CFS of Lactobacillus species separately indicates that these therapies may be a substitute treatment strategy against MDR Klebsiella pneumoniae.

Designated functional microcapsules loaded with green synthesis selenium nanorods and probiotics for enhancing stirred yogurt.

Green synthesis selenium nanorods (Se-NRs) were produced based on Aloe vera leaf extract. The size, morphology, antimicrobial, and activation of Se-NRs for probiotics were analyzed. The Se-NRS was stable with a diameter of 12 and 40 nm, had an antimicrobial effect, and improved probiotics counts. The microcapsules loaded with Green Se-NRS (0, 0.05 or 0.1 mg/100 ml) and probiotics (Bifidobacterium lactis and Lactobacillus rhamnosus) were designated with efficiency between 95.25 and 97.27% and irregular shapes. Microcapsules were saved probiotics against gastrointestinal juices. The microcapsules were showed a minor inhibition effect against the cell line. Also, microcapsules integrated into stirred yogurt and exanimated for microbiology, chemically, and sensory for 30 days. The probiotics counts, acidity, total solids, and ash values of samples were increased during storage periods without affecting fat and protein contents. The overall acceptability of yogurt with microcapsules containing probiotics and Se-NRs was high without change in body, odor, color, and appearance.

Stirred Yogurt as a Delivery Matrix for Freeze-Dried Microcapsules of Synbiotic EVOO Nanoemulsion and Nanocomposite.

Nowadays, dairy products are considered a good matrix to deliver many functional substances either vital oils or probiotic cells. Two models of microcapsules were produced from co-encapsulation of extra virgin olive oil (EVOO) nanoemulsion or nanocomposite and synbiotic bacteria (maltodextrin with Lactobacillus acidophilus and Bifidobacterium bifidum) using the freeze-drying technique. These models of microcapsules were added to stirred yogurt, and then its storage effect on microbiology, chemically, and sensory properties were evaluated for 21 days. The average droplet size and zeta potential distribution of EVOO nanoemulsion and nanocomposite were investigated. Also, oxidative stability, microencapsulation efficiency, release profile, and antioxidant activity were studied. The results showed that the average particle size of EVOO nanoemulsion and nanocomposite ranged between 416 and 475 nm, while zeta potential was -39.6 and -33.6 mV, respectively. The induction period of EVOO extracted from nanoemulsion and nanocomposite microcapsules models was 11.30 and 8 h. The microencapsulation efficiency of probiotic and EVOO was determined at 88.84 and 65.61% for the nanoemulsion microcapsules model, while the nanocomposite microcapsules model showed 98.49 and 72%. The two models of microcapsules have boosted the viability of probiotic bacteria inside stirred yogurt than free cells. Also, the presence of microcapsules did not affect the viability of stirred yogurt starter cultures, and high values for the total solid and protein were detected. Therefore, the results recommended that stirred yogurt is a good delivery carrier for highly antioxidant and healthy microcapsules of synbiotic EVOO nanoemulsion and nanocomposite.

Characterization of stirred yoghurt enriched with probiotics and beetroot and its therapeutic potential in experimental type 2 diabetes.

BACKGROUND: Type-2 diabetes is the most prevalent metabolic disease, which calls for researchers to find many natural products that are effective in fighting diabetes and its complications. METHODS: Stirred yoghurt samples were prepared, enriched with probiotics, and fortified with either 1% or 2% of the fine powder of beetroots. The chemical, physical, sensorial, and microbial properties of the yoghurt samples were studied over a 15-day storage period. The total phenolic compounds, flavonoids, antioxidant activity as well as the reducing power of the dried beetroot and the yoghurt samples were assessed.The prepared yoghurt samples were evaluated in type 2 diabetic rats. RESULTS: Fortification with beetroot led to an increase of the total phenolic compounds, antioxidant activity, and the probiotic counts in the prepared yoghurt. The intervention with the prepared yoghurt samples resulted in an increase in the number of beneficial bacteria in diabetic rats’ feces, hypoglycemic effect, and suppression in the elevation of C-reactive protein (CRP) and thyroid stimulating hormone (TSH). CONCLUSIONS: This study suggests that stirred yoghurt enriched with probiotics and fortified with beetroot have therapeutic potential for type 2 diabetes.

Novel approach for biosynthesizing of zinc oxide nanoparticles using Lactobacillus gasseri and their influence on microbiological, chemical, sensory properties of integrated yogurt.

This research aimed to biosynthesizing zinc oxide nanoparticles (ZnO-NPs) using lactobacilli strains. All tested lactobacilli able to biosynthesis ZnO-NPs indicated by white precipitates. The characteristics of the biosynthesis ZnO-NPs from Lactobacillus gasseri were studied using UV-visible spectroscopy, TEM, SEM, DLS, FT-IR, XRD, and antimicrobial activity. The characteristic examination depicted cubic structures, pure and spherical ZnO-NPs with a diameter size of 22 nm. Antimicrobial study of ZnO-NPs displayed better higher antimicrobial activity on food pathogens in a dose-dependent manner. Moreover, integrated biosynthesis ZnO-NPs in yogurt positively affected the shelf life of yogurt during storage for four weeks without changes in the sensory evaluation. The microbiological population of fortified yogurt significantly reduced during storage than control. But chemically evaluation of fortified yogurt indicated an increase in dry matter, protein, and ash content than control. The achieved results suggested that the low amount of biosynthesized ZnO-NPs lead to the development of properties of integrated yogurt. Furthermore, the biosynthesized ZnO-NPs additive to yogurt could be a good food source for groups suffering from zinc deficiency such as the elderly groups or vegetarians who do not eat meat and at risk of zinc inadequacy.

Preparation and characterization of novel bionanocomposites based on garlic extract for preserving fresh Nile tilapia fish fillets.

In this paper we describe the preparation of a new bionanocomposite based on carboxymethyl cellulose (CMC), Arabic gum (AG) and gelatin (GL), incorporating garlic extract (GE) and TiO2 nanoparticles (TiO2-NPs). The prepared bionanocomposites were evaluated using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Energy Dispersive X-ray Analysis (EDX), and scanning electron microscopy (SEM), and were evaluated for their antimicrobial effect. The permeability and thermal and mechanical properties of the films were assessed. The water vapor transmission rate (WVTR), oxygen transmission rate (OTR), and mechanical, thermal and antimicrobial properties of the prepared bionanocomposite films were enhanced by the addition of GE and TiO2-NPs. The effects of GE and TiO2-NPs in combination incorporated into a CMC/AG/GL blend as an edible coating on the quality of fresh Nile tilapia fish fillets during refrigerated storage were evaluated. The microbiological status and weight loss of fresh Nile tilapia fish fillets were periodically tested for 21 days during storage at 4 °C. The results indicated that GE combined with TiO2-NPs has a synergistic influence on the enhancement of the preservation properties of CMC/AG/GL/GE-TiO2 bionanocomposites for refrigerated tilapia fish fillets, which could control microbial growth, and decrease weight loss during the storage of tilapia fish fillets.

Short term chronic toxicity of tributyltin on the testes of adult albino rats and the possible protective role of omega-3.

The declining rate of male fertility is a growing concern. Tributyltin (TBT) is a well-known endocrine disruptor (ED), that induces imposex in female gastropods and is widely used in various industrial applications. The aim of this study was to evaluate the toxic effects of TBT on the testes of adult albino rats and the possible role of omega-3. Forty two adult male albino rats were divided into five groups; control group (Group I) and four experimental groups: omega-3 treated group, TBT treated group, TBT & omega-3 treated group and follow up group. At the end of the study, the rats were subjected to biochemical, histological, immunohistochemical staining for Ki-67 and seminal examinations. Our results clarfied that TBT induced a significant decrease in testosterone, FSH, LH and serum glutathione peroxidase levels and a significant increase in the serum Malondialdehyde as compared to the control group. Tributyltin induced disorganization and shrinkage of seminiferous tubules, apoptosis, cellular damage and marked reduction in the germinal epithelium. A significant decrease in the cell proliferation and arrested spermatogenesis were also detected. Seminal analysis of TBT group showed a significant affection of all parameters as compared to other groups. Omega-3 ameliorated all of these hazardous effects. Follow up group still showed toxic effects. In conclusion, TBT has a toxic effect on the testis. Increased testicular oxidative stress, cellular damage and arrest of spermatogenesis with attenuation in antioxidant defenses are all contributing factors. Omega-3 can protect against TBT induced reproductive toxicity.

Rational design of chitosan/guar gum/zinc oxide bionanocomposites based on Roselle calyx extract for Ras cheese coating.

Roselle calyx extract (RE) was used to prepare zinc oxide nanoparticles (ZnO-NPs) as a green technique. In the current work, chitosan/guar gum/zinc oxide bionanocomposites based on Roselle calyx extract, namely (CS/GG/RE-ZnO) bionanocomposite were prepared. The synthetic ZnO-NPs and the prepared bionanocomposites were characterized by Fourier transforms infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Moreover, the addition of RE-ZnO nanocomposites was improved mechanical, permeability, antimicrobial and antioxidant properties of bionanocomposite films. The influence of coating Ras cheese with the fabricated CS/GG/RE-ZnO bionanocomposites on chemical, microbiological, and sensorial properties of Ras cheese was evaluated during ripening in comparing with uncoated cheese. Ras cheese coating with bionanocomposite film containing 3% RE-ZnO nanocomposites protects their surface for around three months from yeasts, molds and other bacteria growth. The prepared CS/GG/RE-ZnO bionanocomposite films can be used as a promising candidate for food packaging applications.

Survivability of alginate-microencapsulated Lactobacillus plantarum during storage, simulated food processing and gastrointestinal conditions.

A comparison between the most investigated alginate-based encapsulating agents was performed in the current study. Here, the survivability of Lactobacillus plantarum microencapsulated with alginate (Alg) combined with skim milk (Sm), dextrin (Dex), denatured whey protein (DWP) or coated with chitosan (Ch) was evaluated after exposure to different heat treatments and in presence of some food additives, during storage and under simulated gastrointestinal condition. In addition, the encapsulated cells were evaluated for production of different bioactive compounds such as exopolysacchar. ides and antimicrobial substances compared with the unencapsulated cells. The results showed that only Alg-Sm maintained the viability of the cells >106 cfu/g at the pasteurization temperature (65 °C for 30 min). Interestingly, storage under refrigeration conditions increased the viability of L. plantarum entrapped within all the tested encapsulating agents for 4 weeks. However, under freezing condition, only Alg-DWP and Alg-Sm enhanced the survival of the entrapped cells for 3 months. All the microencapsulated cells were capable of growing at the different NaCl concentrations (1%-5%) except for cells encapsulated with Alg-Dex, showed viability loss at 3% and 5% NaCl concentrations. Tolerance of the microencapsulated cells toward organic acids was varied depending on the type of organic acid. Alg-Ch and Alg-Sm provide better survival for the cells under simulated gastric juice; however, all offer a good survival for the cells under simulated intestinal condition. Our findings indicated that Alg-Sm proved to be the most promising encapsulating combination that maintains the survivability of L. plantarum to the recommended dose level under almost all the stress conditions adopted in the current study. Interestingly, the results also revealed that microencapsulation does not affect the metabolic activity of the entrapped cells and there was no significant difference in production of bioactive compounds between the encapsulated and the unencapsulated cells.

Production of prebiotic chitooligosaccharide and its nano/microencapsulation for the production of functional yoghurt.

Production and potential application of chitooligosaccharide is reported in this study. Chitooligosaccharide was produced by enzymatic hydrolysis of chitosan using Bacillus cereus chitosanase. The chitooligosaccharide was characterized, and its prebiotic activity together with the antioxidant activity were evaluated and compared to marketed standard and chitosan. Additionally, its stability in yoghurt was monitored. The produced chitooligosaccharide was water soluble with molecular weight of 2.005 kDa and higher degree of acetylation. Bioactivity results cleared the chitooligosaccharide has potent prebiotic plus antioxidant activity with poor stability in yoghurt. Subsequently, encapsulation of chitooligosaccharide into nanoparticles and microparticle were assessed to enhance its stability. Our results indicated that nanoparticles with size 100 nm maintained 96.83 + 1.2 % of chitooligosaccharide in yoghurt during shelf life compared to 45.09 ± 2.5 % for microparticle (850 µm). Finally, the sensory evaluation favored the yoghurt containing chitooligosaccharide nanoparticles over free chitooligosaccharide or chitooligosaccharide microparticle, which suggest nanoparticles as potential formula to boost the chitooligosaccharide stability in yoghurt.

Synthesis and evaluation of eco-friendly carboxymethyl cellulose/polyvinyl alcohol/CuO bionanocomposites and their use in coating processed cheese.

In the present study, we formulated and characterized CMC/PVA/CuO bionanocomposites to evaluate their use in coating processed cheese. Copper oxide nanoparticles (CuO-NPs) were prepared and added to a mixed solution of carboxymethyl cellulose (CMC)/polyvinyl alcohol (PVA) using compositions of 0.3, 0.6 and 0.9% (w/v). The CMC/PVA/CuO bionanocomposites were prepared by a solution casting method and used for coating processed cheese. The fabricated bionanocomposite films and CuO-NPs were characterized by TEM, SEM, EDEX, XRD, DLS, and FT-IR analysis. Inclusion of CuO-NPs decreased the gas transmission rate (GTR) and water vapor transmission rate (WVTR) of the prepared film. Also, the bionanocomposite suspensions exhibited high but variable inhibitory effects against several pathogenic bacteria and fungi. The impact of coating of processed cheese surfaces with the prepared bionanocomposite films on microbiological, physicochemical, textural and sensory properties of the processed cheese were assessed during 6 months of cold storage. Coating cheese with film containing CuO-NPs eliminated mould growth on the cheese surface and decreased significantly (P < 0.05) the total bacterial count of the cheese. Furthermore, coating of cheese decreased the moisture losses and retarded the increase in the cheese hardness during storage. The highest acceptability at the end of the storage period was given for processed cheese coated with the bionanocomposite containing 0.9% CuO-NPs. Thus, the obtained CMC/PVA/CuO bionanocomposite films could be a promising candidate for cheese packaging applications.

Antibacterial and Remineralization Efficacy of Casein Phosphopeptide, Glycomacropeptide Nanocomplex, and Probiotics in Experimental Toothpastes: An In Vitro Comparative Study.

OBJECTIVE: This article evaluates the antibacterial and remineralization potential of experimentally prepared toothpastes containing different mixtures of nano casein phosphopeptides (nCPP), nano amorphous calcium phosphate (nACP), probiotic - Lactobacillus rhamnosus B-445 (L. rhamnosus), and nano glycomacropeptide (nGMP). MATERIALS AND METHODS: Five experimental toothpaste samples were prepared and grouped, such that group (A0) was the experimental toothpaste base formula. Groups (A1), (A2), (A3), and (A4) were the experimental toothpastes containing: nCPP; nCPP and nACP; nCPP, nACP, and L. rhamnosus, and nCPP, nACP, and nGMP, -respectively. Group (A5) was the commercial group (GC MI Paste Plus). The five groups were screened against Streptococcus mutans (ATCC 25175) growth, and investigated for their remineralizing potentials on demineralized bovine enamel using Vickers -microhardness test (Vickers hardness number [VHN]). Scanning electron microscope (SEM) images were obtained for the demineralized and remineralized enamel of the two most effective toothpastes against in vitro bacterial induced enamel demineralization. Statistical analysis was performed using one-way analysis of variance (ANOVA) as well as repeated measures ANOVA followed by Tukey's post hoc test. RESULTS: Both (A3) and (A4) were significantly higher in mean inhibition zone -diameters than group (A1) and (A2). Group (A4) showed the highest statistical -significance in the mean difference between VHN values of demineralization and 15 days remineralization period. SEM images showed the deposition of nano-sized particles fill the -microrough surface pattern of the etched enamel. CONCLUSION: All these findings suggest the use of probiotic, nCPP-nACP, and nGMP as a dental anticariogenic and remineralizing active agents.

A Promising Probiotic Irrigant: An In Vitro Study.

AIM: The present study aimed to investigate the inhibitory effect of Lactobacillus rhamnosus (B-445) as a probiotics irrigant on the growth of Enterococcus faecalis. METHODS: Forty-two extracted single human canal anterior teeth were prepared with rotary instrumentation and sterilised. Teeth were divided into 3 groups according to the type of irrigant, N = 14. Three experimental groups were inoculated with E. faecalis and cultured for 21 days before use; Group 1 was 2.5% NaOCl (positive control), Group 2 was saline (negative control), Group 3 was the experimental probiotic irrigant. Paper point sampling of the canals of each group was obtained before irrigation (S1), immediately after irrigation (S2) and after 24 hours (post irrigation samples) (S3) to determine remaining colony forming units for E. faecalis. Also, Colony counts for L. rhamnosus in Group 3 after immediate irrigation, as well as 24 hours post irrigation, was performed to determine the survival profile of these bacteria in infected root canal with E. faecalis. RESULTS: The NaOCl irrigant group had the lowest mean value of (log 10 CFU/mL) of E. faecalis after immediate irrigation and after 24 hrs post irrigation followed by the probiotic group, while the highest mean value was the saline group (P ≤ 0.001). The survival profile for L. rhamnosus in Group 3 after immediate irrigation and post-irrigation were slightly higher than for E. faecalis (P ≤ 0.001). CONCLUSION: Lactobacillus rhamnosus which revealed a potential inhibitory effect on the growth of Enterococcus faecalis, could be used as a new natural, safe probiotic irrigant agent.

Production of Healthy Functional Soft White Cheese Using Moringa oleifera Oil.

BACKGROUND AND OBJECTIVE: Moringa oleifera oil is composed of highly unsaturated fatty acids containing 80.4% polyunsaturated, mainly oleic acids 67.9% and had a low acid value and low free fatty acids composition, so it is acceptable for edible application. The objective of study was the feasibility of using Moringa oleifera oil in manufacture of cheese compared with other oils (olive, sun flower) and the effect of using Moringa oleifera oil in chemically; organoleptically and microbial content in cheese. MATERIALS AND METHODS: Fat was mechanically separated from buffalo's milk to reach 3% fat. Then the resultant milk divided into four portions. First let as control, then, the rest milk divided into three portions and fat substituted with 1, 1.5 and 3% of olive, moringa and sunflower oils. The resultant milk manufactured to soft white cheese and the resultant cheese was analyzed chemically, microbiologically and organoleptically. RESULTS: Findings showed that 1.5% of different oils are best ratio and had gained highest scores for appearance, body and texture and flavor. The soft white cheese manufactured by Moringa oleifera oil was a best treatment than control and other treatments and has antimicrobial properties. Acidity, fat, total nitrogen, soluble nitrogen, total volatile fatty acids (TVFA) and thiobarbituric acid (TBA) increased during cold storage at 5°C+1 for 3 weeks cheese with Moringa oleifera oil had lower (PV) peroxide value than other treatments and pH took an opposite trend. CONCLUSION: It was concluded that Moringa oleifera oil in soft cheese improved body and texture, flavor, than olive and sunflower oils and also increased the shelf life of cheese.

Assessment the viability properties of Lactobacillus casei strain using labneh as a carrier.

BACKGROUND: Our study was conducted in two stages; the first stage was to examine the fructose fermentation profile by Lactobacillus (Lb.) casei FEGY9973. The second stage was to investigate the viability properties of Lb. casei either during cold storage of labneh or under simulated gastrointestinal tract (GIT) conditions. METHODS: Labneh as a carrier medium was classified into four treatments; the first one con- tained 2% free cells of Lb. casei as a control. The second, third and fourth treatments used 2% of encapsulated cells of Lb. casei with different capsule materials, including alginate-milk, sodium alginate and κ-carrageenan served as T1, T2 and T3 respectively. The physiochemical, microbiological and sensory properties of labneh during 15 days of cold storage were shown. Moreover, the viability of free and encapsulated Lb. casei sub- jected to some manufacturing and simulated GIT conditions was tested. RESULTS: It was revealed that lactate was the major metabolite in the medium for colonic fermentation, where- as no amounts of ethanol could be detected. Moreover, labneh samples including free cells of Lb. casei had lower pH values than treatments containing microcapsules of Lb. casei. The levels of moisture, acetaldehyde and diacetyle in treatments with different encapsulated materials were increased during the cold storage period. Accordingly, labneh samples with encapsulated Lb. casei had higher sensory scores than the control. In addition, labneh samples with Lb. casei in milk-alginate microcapsules showed a high viability during cold storage and under simulated GIT conditions. A significant decrease in the viability of free or encapsulated Lb. casei was observed at 15 days of cold storage. CONCLUSIONS: Encapsulated Lb. casei by alginate-milk was more resistant during the cold storage period and under simulated gastric conditions than the other two treatments.

The Antibacterial Effect of Two Cavity Disinfectants against One of Cariogenic Pathogen: An In vitro Comparative Study.

INTRODUCTION: Bacteria residing in the oral cavity penetrate freely through the resultant fissures under the fillings, which might lead to the development of secondary caries. Nowadays dentistry, different nanotechnological materials with antibacterial activity are being developed for oral cavity disinfection. AIM: This study aims to investigate the antibacterial activity of a new cavity disinfectant NanoCare Plus Silver Gold® (NanoCare) in comparison to (0.2%) chlorhexidine (CHX) gluconate disinfectant against Streptococcus mutans growth and colony count using Agar well diffusion method and contact test, respectively, and also, to assess the nanoparticles (NPs) size distribution and Zeta potential of a NanoCare disinfectant. MATERIALS AND METHODS: A total of 36 samples of cavity disinfectants were divided into two main groups (G) (n = 18); G1: NanoCare, and G2: CHX. Each group was subdivided into two subgroups (C) (n = 9) according to the antimicrobial test that the samples were subjected to. RESULTS: A chlorohexidine group demonstrated the higher mean inhibition zone values than NanoCare group where P ≤ 0.05, as well both groups had a significant decrease in bacterial colony count where P ≤ 0.001. The particles size distribution in NanoCare sample was found that 99% of particles number with an average size of 29.07 nm and 1% was 136.7 nm, while the Zeta potential value was -6.5 mV. CONCLUSIONS: NanoCare cavity disinfectant displayed good antibacterial property against S. mutans. The innovative incorporation of NPs into this cavity disinfectant could be used to improve the antimicrobial capacity of the material and help to decrease secondary caries risk.

Novel bionanocomposite materials used for packaging skimmed milk acid coagulated cheese (Karish).

Bionanocomposites have attracted a tremendous level of consideration as alternatives for a broad group of commercial materials based on petroleum-derived compounds and used for coating cheese. Sustainable, economical and environmentally compatible materials based on chitosan (CS), poly vinyl alcohol (PVA), glycerol (Gy) and titanium dioxide nanoparticles (TiO2-NPs) were prepared. Moreover, the prepared bionanocomposites (CS/PVA/Gy/TiO2-NPs) were characterized using XRD, SEM, TEM, WVTR and mechanical strength. The developed CS/PVA/Gy/TiO2-NPs bionanocomposites exhibited homogeneous, compact morphological features and enhanced mechanical and barrier properties. Also, the prepared bionanocomposite exhibited variable inhibitory effects against several pathogenic bacteria and fungi. Karish was made and coated with the prepared bionanocomposite containing 1, 2 and 3% TiO2-NPs, and cold stored. Changes in the weight losses, cheese composition, microbiological quality, textural parameters, and sensory properties were followed during storage for 25 days. Coated Karish cheese retained acceptable quality until the end of the storage period, while uncoated developed surface fungi growth and deteriorated quality after 15 days. Karish cheese coated with the bionanocomposite containing 3% TiO2-NPs ranked the highest acceptability at the end of storage period.