masoud aman mohammadi

Nowadays the importance of vitamins is clear for everyone. However, many patients are suffering from insufficient intake of vitamins. Incomplete intake of different vitamins from food sources due to their destruction during food processing or decrease in their bioavailability when mixing with other food materials, are factors resulting in vitamin deficiency in the body. Therefore, various lipid based nanocarriers such as nanoliposomes were developed to increase the bioavailability of bioactive compounds. Since the function of nanoliposomes containing vitamins on the body has a direct relationship with the quality of produced nanoliposomes, this review study was planned to investigate the several aspects of liposomal characteristics such as size, polydispersity index, zeta potential, and encapsulation efficiency on the quality of synthesized vitamin-loaded nanoliposomes.

The human intestinal microbiota is a collection of microorganisms that reside in the gastrointestinal tract and there is a direct link between the presence of beneficial microbiota and the development of immune function, the nervous system and the host metabolic pathways.  Probiotics are known to be non-pathogenic microorganisms that, if taken in sufficient amounts, can have health effects. Therefore, consumption of foods or supplements containing post-biotic compounds is one of the most important strategies to balance the microbiota and to improve the health of the host. Evidence suggests that post-biotics do not require survival compared to their parent probiotic cells and can produce health-like effects similar to probiotics. Also, the production and use of post-biotics is safer, more stable and more cost-effective. Post-biotics have biological activity, including immune modulating, anti-inflammatory, antioxidant, and anti-cancer activity.  Clinical studies also confirm the efficacy of probiotics as an effective factor in improving the treatment of a wide range of diseases such as ulcerative colitis, acute infectious diarrhea, antibiotic resistant diarrhea, irritable bowel syndrome, necrotic enteritis, liver disorders, and gastrointestinal cancers. In this study, a review of the concept of post-biotics and classification of post-biotics has been done based on type and chemical composition and physiological activities and promising effects on prevention or improvement in treatment methods as well as delaying spoilage and increasing shelf life in food products.

In this research, electrospinning method was employed to fabricate food-grade nanofibers (NFs) from chitosan-gelatin combination for stigmasterol encapsulation. The spinnability of mixed chitosan and gelatin solutions was investigated at different polymer ratios, and the physicochemical properties of the NFs were evaluated.

The mixture solution of chitosan (1.5 % w/v) and gelatin (20 % w/v) in acetic acid indicated spinnability under the following conditions: the ratio of 25:75, voltage of 17 kV, and 15 cm capillary collector distance with a flow rate of 0.2 mL/min. Stigmasterol (0.04 % w/v) was incorporated into NFs of chitosan-gelatin at a respective ratio of 25:75.

Encapsulation efficiency (EE) of loaded stigmasterol was found to be 87 ± 5 %. The antioxidant ability of loaded stigmasterol was considerably higher than that observed for free stigmasterol. Scanning electron microscopy (SEM) results demonstrated the formation of the ultrathin fibers with no bead (with diameters of 217 ± 43 nm). The concentration of polymeric solution and viscosity had a notable effect on the electrospinning efficiency of the chitosan-gelatin-based nanofibers. The thermal stability of chitosan and gelatin fibers was more than that of native gelatin and chitosan. The in vitro stigmasterol release from these nanofibers followed a controlled-release pattern. The released phytosterol from chitosan formula was less than from those without chitosan formula (46 ± 3 % and 96 ± 4 % respectively).

The obtained results suggested that gelatin had a high potential for enhancing the spinnability of chitosan under acidic conditions at optimized concentrations.

  Utilization of essential oils instead of chemical preservatives has received significant attention in recent years. The present study aims to evaluate chemical composition and antibacterial and antioxidant properties of essential oils of Zataria multiflora, Artemisia deracunculus and Mentha piperita.              Chemical profile of the essential oils was analyzed by gas chromatography/mass spectrometry. The microwell dilution and agar disk diffusion methods were used to evaluate the antibacterial properties of the essential oils. Total phenolic content, β-carotene-linoleic acid bleaching test and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays were carried out to determine the antioxidant properties.              Menthol (39.18%) and mentone (21.64%) were the main components of the essential oil of M. piperita, while estragol (34.75%) and limonene (15.72%) were the major components of the essential oil of A. dracunculus. The main components of the essential oil of Z. multiflora were carvacrol (36.81%) and thymol (33.04%). The essential oils of M. piperita and Z. multiflora showed greater antimicrobial effects. Moreover, Z. multiflora showed the greatest antioxidant activity among the essential oils. The total phenolic content of Z. multiflora was 228.14±0.45 mg gallic acid equivalent/g.              Given their favorable antioxidant and antimicrobial properties, the essential oils of Z. multiflora, A. deracunculus and M. piperita can be used as natural food preservatives.              Keywords: Zataria multiflora, Artemisia deracunculus, Mentha piperita, antibacterial effect, antioxidant effect.

Preparation of nano-microfibers from biopolymers (e.g., proteins and polysaccharides) by using electrospinning technology has been considered by researchers due to the formation of fibers or particles at the nano and micrometer scales, high porosity level, adjustable dewatering behavior, and special mechanical behavior. These products can be used in the microencapsulation of bioactive compounds, stabilization of enzymes and smart packaging. In the electrospinning method, a high voltage is used to create a nanofibers-particles. When the electric field overcomes the surface tension of the droplet, a jet exits the polymeric solution and is formed along the collector surface as it stretches toward the collector panel of the nanofiber. Parameters including molecular weight and polymer microstructure characteristics such as electrical conductivity, viscosity, surface tension, and the electrical potential applied by the device, solution flow rate, distance between the tip of the needle and the collector plate and sometimes the material of the collector plate are effective in the formation of electrospun fibers and particles. In this review, we discussed and evaluated the production stages, the strengths and weaknesses of the fibers produced from proteins and polysaccharides, and their functional properties and potentials, especially in food and drug sciences.