Synthesis of active packaging films from Lepidium sativum gum/polyvinyl alcohol composites and their application in preserving cheddar cheese.

The interest in active packaging for extending food shelf life has increased lately. Moreover, the negative impact of synthetic plastic wastes on the environmental motivated the researchers to seek for bio-based alternatives. In this context, active packaging film made of a composite composed of Lepidium sativum extract (LSE), polyvinyl alcohol (PVA), and a fixed amount of hyperbranched polyamide amine (PAMAM) were prepared. The chemical, thermal, and mechanical properties of the film were investigated. Moreover, we examined the extract's constituents and antioxidant properties. Cheddar cheese samples were coated with films of different compositions. The samples coated with active packaging films showed a longer preservation time of up to 4 weeks compared to other samples, which noticeably deteriorated. The films showed potent antimicrobial activity against five food-borne bacteria: three gram-negative bacteria including Escherichia coli O157.H7, Pseudomonas aeruginosa, and Salmonella Typhimurium, and two gram-positive bacteria, Listeria monocytogenes, and Staphylococcus aureus. Applying PVA films containing LSE improved the microbiological quality and delayed the visible decay of cheddar cheese. The oxidizability of the fat extracted from different cheese samples was 0.40-0.98, confirming oxidation resistance. Finally, cheese samples coated with treated films were protected from forming trans fats compared to other samples, demonstrating the effectiveness of modified films as antioxidant, antimicrobial, and food-preserving packaging.

Role of Bifidobacterium spp. intake in improving depressive mood and well-being and its link to kynurenine blood level: an interventional study.

OBJECTIVES: Evidence for the contribution of the brain-gut-microbiota axis to the depression pathophysiology is increasing nowadays. Disturbed gut microbiota equilibrium along with bad dietary habits both lead to kynurenine pathway abnormalities contributing to the depression pathophysiology. In this respect, many studies are found but the interventional clinical trials are limited. The present interventional study aims to evaluate the impact of Bifidobacterium spp. supplementation together with improving dietary intake on depressive mood and well-being and their correlation with kynurenine blood level in adult Egyptian healthy volunteers. METHODS: A number of 98 healthy female volunteers with a mean age of 46.96 ± 1.82 years were selected and enrolled in this study. They were given yogurt enriched with Bifidobacterium spp. daily for eight weeks. Clinical examination as well as questionnaires for the evaluation of psychological well-being and depression were done at base line and after eight weeks of intervention. Fasting blood samples and stool samples were collected from all subjects at baseline and eight weeks after the intervention for the investigation of serum kynurenine concentration, blood hemoglobin, serum transaminases (ALT & AST) serum urea and creatinine as well as fecal Bifidobacterium count. RESULTS: Data revealed that both depression and well-being showed highly significant improvement combined with significant drop in kynurenine blood level after intervention. Also, a significant rise in fecal Bifidobacterium count and a significant improvement in hemoglobin level and activity of liver enzymes were recorded. After intervention, a significant negative correlation was recorded between depression and fecal Bifidobacterium count as well as between serum kynurenine level, and well-being. CONCLUSION: Bifidobacterium spp. supplementation combined with improvement in dietary intake resulted in improvement of depressive mood and well-being and reduced kynurenine blood level.

Self-stick membrane based on grafted gum Arabic as active food packaging for cheese using cinnamon extract.

Encapsulation of volatile essential oils has been investigated to provide an active food packaging (AFP) material with more control over their fast release and pungent smell. In this work, Gum Arabic-based adhesive membrane was developed as a self-stick AFP material, delivering cinnamon essential oil (CEO) in vapor phase. Gum Arabic (GA) was grafted with butyl acrylate (BA) and hydroxyethyl methacrylate [GA-g-poly(BA-HEMA)]. Adhesive membrane was characterized by means of spectral, physicochemical and rheological analysis. GA-adhesive membrane made of 5% wt/v GA, 3.5 m mol HEMA, and 87 m mol BA with 21 N/m tack are loaded with 4, 8 and 10% v/v of CEO and used for antimicrobial bioassays. GA-g-poly(BA-HEMA) membrane prolonged CEO release up to 2 days. 8%v/v CEO showed superior activities against both Gram negative and positive bacteria. Shelf-life of cheese samples, packed with the self-stick membranes loaded with cinnamon extract, has extended from 3 to 8 weeks. Cheese samples that inoculated with shiga toxin producing E. coli O157:H7 and packed in plastic boxes with the self-stick AFP (4, 8 and 10 % CEO), showed significant reduction in the total bacteria counts.

Fabrication of cellulose-based adhesive composite as an active packaging material to extend the shelf life of cheese.

Traditional solutions of food packing are limited for antimicrobial packaging materials that interact with the product to inhibit the growth of microorganisms. In this work, adhesive composite was developed as an active packaging material using allyl isothiocyanate (AIC) in vapor phase. Such adhesive composite was made of gelatin electrospun fibers loaded by AIC and supportive adhesive sheet. Gelatin electrospun fibers loaded by AIC (2-10% v/v) into 24% wt/v gelatin solutions was produced using electrospinning apparatus at 15 kV, 15 cm air gap and 0.2 mL/h flow rate. This mat was supported by pressure-sensitive adhesive (PSA) made of hydroxyethyl cellulose backbone grafted by acrylic acid and methylbutyl acrylate [HEC-g-poly(AA-MBA)]. PSA was characterized in means of spectral, physicochemical and rheological analysis. Final product with AIC (2% v/v) showed significant antimicrobial activities against two food born bacteria including Staphylococcus aureus ATCC 25923 and Escherichia coli O157:H7. Antimicrobial activities on cheese showed that gelatin nanofibers loaded by AIC (10% v/v), applied in the headspace, extended the shelf life of cheese from 4 weeks to 8 weeks.

Pyrazole-based compounds in chitosan liposomal emulsion for antimicrobial cotton fabrics.

The chemistry of pyrazoles has gained increasing attention due to its diverse pharmacological properties such as antiviral, antagonist, antimicrobial, anticancer, anti-inflammatory, analgesic, anti-prostate cancer, herbicidal, acaricidal and insecticidal activities. 1-Phenyl pyrazole-3, 5-diamine, 4-[2-(4-methylphenyl) diazenyl] and 1H- pyrazole-3 (1), 5-diamine, 4-[2-(4-methylphenyl) diazenyl] (2) were synthesized, characterized and encapsulated into liposomal chitosan emulsions for textile finishing. The chemical modifications of cotton fabrics were demonstrated by infrared analysis. Retention of the fabric mechanical properties was investigated by reporting the tensile strength values. Synthesized pyrazole-based compounds were screened for cytotoxicity against skin fibroblast cell line and showed very limited toxicity for both compounds. Antimicrobial potentials of the treated cotton fabrics were tested against bacterial strains E. coli ATCC 8379 and Staphylococcus aureus ATCC 25923.

Microbiological Assessment of Moringa Oleifera Extracts and Its Incorporation in Novel Dental Remedies against Some Oral Pathogens.

AIM: To assess the antibacterial and antifungal potentials of different parts of Moringa oleifera plant using different extraction methods in attempts to formulate natural dental remedies from this plant. MATERIAL AND METHODS: Three solvents extracts (Ethanol, acetone, and ethyl acetate) of different parts of Egyptian Moringa tree were prepared and tested against oral pathogens: Staphylococcus aureus, Streptococcus mutans, and Candida albicans using disc diffusion method; As well as to incorporate the plant extract to formulate experimental toothpaste and mouthwash. The two dental remedies were assessed against the same microbial strains. Statistical analysis was performed using One-Way ANOVA test to compare the inhibition zone diameter and t-test. RESULTS: Ethanol extracts as well as leaves extracts demonstrated the highest significant mean inhibition zone values (P ≤ 0.05) against Staphylococcus aureus and Streptococcus mutans growth. However, all extracts revealed no inhibition zone against Candida albicans. For dental remedies, experimental toothpaste exhibited higher mean inhibition than the mouthwash against Staphylococcus aureus, Streptococcus mutans and only the toothpaste revealed antifungal effect against Candida albicans. CONCLUSION: The different extracts of different parts of Moringa showed an antibacterial effect against Staphylococcus aureus and Streptococcus mutans growth. The novel toothpaste of ethanolic leaves extract has antimicrobial and antifungal potential effects all selected strains.

Poly(vinyl alcohol)-based film potentially suitable for antimicrobial packaging applications.

This work aimed at developing a thin and water-resistant food-grade poly(vinyl alcohol) (PVOH)-based matrix able to swell when in contact with high moisture content food products without rupturing to release antimicrobial agents onto the food surface. This film was prepared by blending PVOH and 7.20% (wt/wt of PVOH) of poly(ethylene glycol) (PEG) with citric acid as crosslinking agent. The film-forming solution was then casted onto a flat surface and the obtained film was 60 µm in thickness and showed a good transparency (close to T = 100%) in the visible region (400 to 700 nm). After immersion in water for 72 h at room temperature, the crosslinked matrix loses only 19.2% of its original weight (the percentage includes the amount of unreacted crosslinking agent, antimicrobial in itself). Water content, degree of swelling, and crosslinking density of the film prove that the presence of PEG diminishes the hydrophilic behavior of the material. Also the mechanical properties of the wet and dry film were assessed. Alongside this, 2.5% (wt/wt of dry film) of grapefruit seed extract (GSE), an antimicrobial agent, was added to the film-forming solution just before casting and the ability of the plastic matrix to release the additive was then evaluated in vitro against 2 GSE-susceptible microorganisms, Salmonella enteritidis and Listeria innocua. The results indicate that the developed matrix may be a promising food-grade material for the incorporation of active substances.