Publications by authors named "Hoda S El-Sayed"

11 Publications

  • Page 1 of 1

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

Food Chem 2021 Dec 1;365:130513. Epub 2021 Jul 1.

Packaging Materials Department, National Research Centre, 33 El Bohouth St. (former El Tahrir st.), P.O. 12622, Dokki, Giza, Egypt. Electronic address:

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.
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http://dx.doi.org/10.1016/j.foodchem.2021.130513DOI Listing
December 2021

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

Carbohydr Polym 2020 Jul 8;239:116234. Epub 2020 Apr 8.

Packaging Materials Department, National Research Centre, 33 El Bohouth St. (former El Tahrir st.), Dokki, Giza, P.O. 12622, Egypt. Electronic address:

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.
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http://dx.doi.org/10.1016/j.carbpol.2020.116234DOI Listing
July 2020

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

Heliyon 2020 Mar 10;6(3):e03541. Epub 2020 Mar 10.

Dairy Department (Microbiology lab.), National Research Centre, Dokki, 12622, Cairo, Egypt.

A comparison between the most investigated alginate-based encapsulating agents was performed in the current study. Here, the survivability of 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 >10 cfu/g at the pasteurization temperature (65 °C for 30 min). Interestingly, storage under refrigeration conditions increased the viability of 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 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.
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http://dx.doi.org/10.1016/j.heliyon.2020.e03541DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7068628PMC
March 2020

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

Carbohydr Polym 2020 Apr 31;234:115941. Epub 2020 Jan 31.

Chemistry of Natural and Microbial Product, National Research Centre, Dokki, Cairo, 12622, Egypt; Sharjah Institute for Medical Research, University of Sharjah, P.O. Box 27272, Sharjah, United Arab Emirates. Electronic address:

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.
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http://dx.doi.org/10.1016/j.carbpol.2020.115941DOI Listing
April 2020

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

Pak J Biol Sci 2018 Jan;21(8):394-400

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.
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http://dx.doi.org/10.3923/pjbs.2018.394.400DOI Listing
January 2018

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

Contemp Clin Dent 2018 Jul-Sep;9(3):457-462

Restorative and Dental Materials Department, Oral and Dental Research Division, National Research Centre, Giza, Egypt.

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 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) ( = 18); G1: NanoCare, and G2: CHX. Each group was subdivided into two subgroups (C) ( = 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 ≤ 0.05, as well both groups had a significant decrease in bacterial colony count where ≤ 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 . 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.
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http://dx.doi.org/10.4103/ccd.ccd_308_18DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6104352PMC
September 2018

A synbiotic multiparticulate microcapsule for enhancing inulin intestinal release and Bifidobacterium gastro-intestinal survivability.

Carbohydr Polym 2018 Aug 20;193:137-143. Epub 2018 Mar 20.

Dairy Science Department, National Research Centre, Dokki, Cairo, Egypt. Electronic address:

A novel synbiotic multiparticulate microparticle was produced in the current study to expand the synbiotic industrial applications. Initially, the inulin was fabricated into PLGA nanoparticles. After the inulin entrapment efficiency was boosted to reach 92.9 ± 8.4% by adjusting the formulation parameters, the developed particles were characterized by different techniques such as particle size analyzer, TEM, and TLC. The obtained data showed that the particle size was 115.8 ± 82.7 nm, the particles had smooth surface and round shape, and the fabrication procedure did not affect the integrity of the inulin. Later, the inulin loaded nanoparticles together with selected Bifidobacterium species were double coated with gum arabic and alginate. The maximum survivability of the encapsulated Bifidobacterium in the simulated gastric solution reached 88.29% of the initial population, which was significantly higher than the survivability of the free bacteria. Finally, the inulin release from the multiparticulate microparticles was studied and found to be sustained over three days.
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http://dx.doi.org/10.1016/j.carbpol.2018.03.068DOI Listing
August 2018

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

Int J Biol Macromol 2018 Aug 1;115:1002-1011. Epub 2018 May 1.

Dairy Science Department, National Research Centre, 33 El Bohouth St. (former El Tahrir st.), Dokki, Giza 12622, Egypt.

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 (TiO-NPs) were prepared. Moreover, the prepared bionanocomposites (CS/PVA/Gy/TiO-NPs) were characterized using XRD, SEM, TEM, WVTR and mechanical strength. The developed CS/PVA/Gy/TiO-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% TiO-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% TiO-NPs ranked the highest acceptability at the end of storage period.
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http://dx.doi.org/10.1016/j.ijbiomac.2018.04.165DOI Listing
August 2018

Chemical composition and antimicrobial activity of garlic essential oils evaluated in organic solvent, emulsifying, and self-microemulsifying water based delivery systems.

Food Chem 2017 Apr 12;221:196-204. Epub 2016 Oct 12.

Aroma & Flavor Chemistry Department, National Research Centre, Cairo, Egypt. Electronic address:

The chemical composition of garlic essential oils (GEOs) extracted from two different cultivars has been characterized using GC-MS analysis. GEO that was extracted from the white-skin cultivar (WGO) had a lower percentage of the major constituents diallyl trisulfide and diallyl disulfide (45.76 and 15.63%) than purple-skin cultivar (PGO) which contained higher percentages (58.53 and 22.38%) of the same components, respectively. Evaluation of the antimicrobial activity of WGO and PGO delivered in organic solvent (isopropanol) showed dose-dependent antimicrobial activity against the tested pathogenic bacteria and fungi, especially with WGO. On the other hand, formulation of both GEOs in water-based emulsions totally suppressed the antimicrobial activity of GEO. Re-formulation of GEOs in water-based microemulsion (particle size 10.1nm) showed better antimicrobial activity than emulsions at the same concentration of GEOs. This study can assist in designing the proper water-based delivery system of GEO for application in food preservation.
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http://dx.doi.org/10.1016/j.foodchem.2016.10.052DOI Listing
April 2017

Enhancement of Egyptian soft white cheese shelf life using a novel chitosan/carboxymethyl cellulose/zinc oxide bionanocomposite film.

Carbohydr Polym 2016 Oct 17;151:9-19. Epub 2016 May 17.

Univ. Grenoble Alpes, LGP2, F-38000 Grenoble, France; CNRS, LGP2, F-38000 Grenoble, France.

A novel bionanocomposites packaging material prepared using chitosan (CH), carboxymethyl cellulose (CMC), and zinc oxide nanoparticles (ZnO-NPs), namely CH/CMC/ZnO bionanocomposites, was prepared by casting method. The CH/CMC/ZnO bionanocomposites were investigated using FT-IR, TEM, SEM, XRD, and TGA. The acquired bionanocomposites exhibited improved mechanical and thermal properties compare with the biocomposites (CH/CMC) blend. The soft white cheese were manufactured, packaged within the prepared bionanocomposites films and stored at 7°C for 30days. The influence of packaging material on packaged cheese (rheological properties, colour measurements, moisture, pH and titratable acidity) were assessed. Furthermore, the effect of packaging material on the total bacterial counts, mold & yeast and coliform in cheese was evaluated. The prepared bionanocomposites displayed good antibacterial activity against gram positive (Staphylococcus aureus), gram negative (Pseudomonas aeruginosa, Escherichia coli) bacteria and fungi (Candidia albicans). Moreover, the packaging films assisted in increasing the shelf life of white soft cheese. Therefore, it can be used in food packaging applications.
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http://dx.doi.org/10.1016/j.carbpol.2016.05.023DOI Listing
October 2016

Evaluation of bionanocomposites as packaging material on properties of soft white cheese during storage period.

Carbohydr Polym 2015 Nov 25;132:274-85. Epub 2015 Jun 25.

Univ. Grenoble Alpes, LGP2, F-38000 Grenoble, France; CNRS, LGP2, F-38000 Grenoble, France.

Novel bionanocomposites based on chitosan/poly(vinyl alcohol)/titanium nanoparticles (CS/PVA/TiO2 nanocomposite) were prepared and used as packaging materials for soft white cheese. The prepared bionanocomposites were characterized using XRD, SEM, TEM and FT-IR. The CS/PVA/TiO2 bionanocomposites exhibited good mechanical properties. Furthermore, the obtained bionanocomposites exhibited superior antibacterial activity against gram positive (Staphylococcus aureus), gram negative (Pseudomonas aeruginosa, Escherichia coli) bacteria and fungi (Candidia albicans). The soft white cheese was manufactured and packaged within the CS/PVA/TiO2 nanocomposite films and stored at 7 °C for 30 days. The color, rheological and chemical properties of cheese were evaluated, also the influence of CS/PVA/TiO2 bionanocomposites on microbiological analysis of soft white cheese was assessed, the results indicated that the total bacterial counts, mold & yeast and coliform decreased with the increasing storage period and disappeared at the end of storage period compared with control. Consequently, CS/PVA/TiO2 bionanocomposite can be used in food packaging applications.
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http://dx.doi.org/10.1016/j.carbpol.2015.06.075DOI Listing
November 2015
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