50 research outputs found

    Biodegradable Polymers

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    Development of a novel low-calorie lime juice based prebiotic/ high-antioxidant beverage using combined design optimization methodology

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    A novel lime-juice based low-calorie functional beverage was developed by using D- optimal combined design optimization. For the preparation of the beverage, the following functional ingredients were used; lime juice, lime peel essential oil (LEO) as a flavoring agent and bioactive component, sucralose as a low-calorie sweetener, inulin/polydextrose (I/P) mixture as prebiotics fibers, pectin as a thickening agent and soluble dietary fiber, lutein as a carotenoid colorant and antioxidant, and peppermint extract (ME) as a flavoring agent and bioactive component. A combined design consisting of one mixture factor (LEO/ME ratio), one numeric factor (lutein concentration), and one categoric factor (presence or absence of prebiotics) was used for optimizing the functional beverage based on the sensory quality. Regression models were adequately fitted to the data of sensory acceptance with a determination coefficient >90%. The sample containing a mixture of prebiotics, 2:3 (v/v) ratio of LEO: ME, and 3 mg/100 ml lutein was selected as the best formulation among the six optimal beverages which was suggested by design expert software. This final optimum sample showed the highest total phenolic (44.22 mg gallic acid equivalents/L) and flavonoid (25.49 mg quercetin equivalents/L) contents, as well as its antioxidant activity (as DPPH• scavenging), was 38.30

    Physicochemical and rheological characterization of a novel hydrocolloid extracted from Althaea officinalis root

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    Althaea officinalis L. root polysaccharide (AOP) was extracted, and its physicochemical and rheological properties were investigated. Gel permeation chromatography results showed that the molecular weight was 1560 kDa. High-performance liquid chromatography indicated that it was an acidic heteropolysaccharide consisting of five types of monosaccharides including galacturonic acid (40.2%), rhamnose (31.7%), glucose (13.68%), galactose (9.07%), and arabinose (5.35%). The intrinsic viscosity value for AOP in deionized water was 9.4 dl g−1. The AOP solutions at different concentrations (0.5%, 1%, 2%, and 3% w/v), showed shear-thinning behavior, and the apparent viscosity decreased in the presence of different concentrations of NaCl and at different pHs. The frequency sweep test showed the AOP solutions at concentrations less than 0.5% and above 1% exhibited viscous and weak gel behavior, respectively. Since the hysteresis phenomenon was observed in the temperature sweep test of 2% AOP solution, it can be considered as a thermal irreversible gel during the heating and cooling proces

    Comparison of the Chemical Compositions and Antibacterial Activities of Two Iranian Mustard Essential Oils and Use of these Oils in Turkey Meats as Preservatives

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    Background and objective: Iranian mustard is cultivated in southern areas of Iran and used traditionally as natural preservative. Aims of the current study were identification and comparison of the chemical compositions and antibacterial activities of two Iranian mustard essential oils and assessment of these oils use for increasing the shelf life of turkey meats.Material and methods: Chemical compositions of two Iranian mustard essential oils were identified using gas chromatography-mass spectrometry and antibacterial activities of these oils were assessed against Salmonella typhimurium, Escherichia coli, Citrobacter freundii, Pseudomonas aeruginosa, Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus and Enterococcus faecalis using disc diffusion and broth macrodilution assays. Inhibitory effects of the essential oils were assessed on growth of mesophilic psychrotrophic bacteria, yeasts and molds and sensory evaluation was carried out for the turkey meats.Results and conclusion: Results of GC-MS showed presence of bioactive constituents, especially allyl isothiocyanate (75.87-80.07%). All the bacterial growth, especially for Escherichia coli, was inhibited with inhibition zones of greater than 20 mm and minimum inhibitory and bactericidal concentrations of 0.156 mg ml-1. Treatment of turkey meat samples with the mustard essential oils significantly decreased the count of mesophilic psychrotrophic bacteria, yeasts and molds during 20 days of storage at 4°C ±1, compared to controls (P≤0.05). Over the time, the sensory score of the treated samples increased, compared to controls. Based on these findings, the Iranian mustard essential oils can be used as natural preservatives in foods.Conflict of interest: The authors declare no conflict of interest

    Phytosome and Liposome: The Beneficial Encapsulation Systems in Drug Delivery and Food Application

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    Due to poor solubility in lipids, many of bioactive components (Nutraceutical materials) show less bioactivity than optimal state in water solution. Phytosomes improve absorption and bioavailability of biomaterials. Liposomes, spherical shaped nanocarriers, were discovered in the 1960s by bangham. Due to their composition, variability and structural properties, liposomes and phytosomes are extremely versatile, leading to a large number of applications including pharmaceutical, cosmetics and food industrial fields. They are advanced forms of herbal formulations containing the bioactive phytoconstituents of herb extracts such as flavonoids, glycosides and terpenoids, which have good ability to transit from a hydrophilic environment into the lipid friendly environment of the outer cell membrane. They have better bioavailability and actions than the conventional herbal extracts containing dosage. Phytosome technology has increasing effect on the bioavailability of herbal extracts including ginkgo biloba, grape seed, green tea, milk thistle, ginseng, etc., and can be developed for various therapeutic uses or dietary supplements. Liposomes are composed of bilayer membranes, which are made of lipid molecules. They form when phospholipids are dispersed in aqueous media and exposed to high shear rates by using micro-fluidization or colloid mill. The mechanism for formation of liposomes is mainly the hydrophilic-hydrophobic interactions between phospholipids and water molecules. Here, we attempt to review the features of phytosomes and liposomes as well as their preparation methods and capacity in food and drug applications. Generally, it is believed that phytosomes and liposomes are suitable delivery systems for nutraceuticals, and can be widely used in food industry

    Effect of Surface Modification by Oleic Acid on Physical Properties of Cellulose Nanofibers

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    Oleic acid was used as a hydrophobic agent to modify cellulose nanofiber (CNF) and the reaction time and fatty acid content were tested in relation to the hydrophilic properties of the products as well as the physicochemical properties of CNF. It was found that the degree of substitution (DS) increased by extending the reaction time though the fatty acid content had no effect on hydrophobicity of CNF. The success of the esterification reaction was confirmed by Fourier transform infrared spectroscopy. Higher degree of substitution led to increased contact angle of CNF surfaces with water, which indicated the increased surface hydrophobicity of modified CNF. The X-ray diffraction analyses showed a lowering trend in crystallinity index and crystallite size with increases in DS value. Surface modification changed the thermal stability of CNF by lowering the degradation temperature from 290.8°C for unmodified cellulose to 195.4°C for highly esterified cellulose. Scanning electron microscopy micrographs revealed that after esterification of CNF with oleic acid, its filamentous shape was preserved. As a result, although the surface modification of CNF by fatty acid increased its hydrophobicity and its ability to mix with non-polar polymers, but it changed CNF physicochemical characteristics and weakened its functional properties

    Potato Starch/Montmorillonite-Based Nanocomposites: Water Sensitivity, Mechanical and Thermal Properties and XRD Profile Study

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    Studies were carried out on the effect of adding different percentages of montmorillonite (3, 5, 7 and 9% of starch weight) on the physical properties of potato starch-MMT nanocomposites. Heat resistance and mechanical properties of films were measured by differential scanning calorimetry (DSC) and tensile test. Nanoparticles distribution in polymer matrix was investigated using X-ray diffraction test (XRD). For investigation of water vapor resistance of film samples, moisture sorption and water vapor permeability (WVP) were measured. The results showed that the distribution of nanoparticles in the polymer matrix was exfoliated. WVP in pure starch films was 2.62×10-7 g/mhPa and with the addition of 9% MMT it was reduced to 1.43×10-7 g/mhPa. With the addition of nanoclay from zero to 9%, the ultimate tensile strength of nanocomposite samples was increased from 5.9 to 6.63 MPa and strain-to-break was decreased from 34.82 to 26.83%. But the rising trend was not significant for nanocomposite samples containing low concentrations of nanoclay (0-7%). The main reasons for the enhancement of mechanical properties due to the addition of nanoclay were to establish hydrogen bonding between polymer chains and clay layers, filling the empty spaces and increase the crystalline domains. Investigation of thermal resistance of nanocomposite samples showed that they have higher thermal resistance and melting point in comparison with pure starch films. With the addition of nanoclay from zero to 9%, the melting point of film samples was increased from 218 to 232.1°C. With the addition of nanoclay, probably the mobility of amylopectin chains decreased and crystalline domains increased. Also, with increasing nanoclay content, the glass transition temperature of nanocomposite samples was increased. This result corresponded to shrinkage in free volume and thus reduction in the polymer chains mobility in amorphous regions

    Formulation of Nanoliposomal Vitamin D3 for Potential Application in Beverage Fortification

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    Purpose: Vitamin D, a liposoluble vitamin has many benefits on health. Encapsulation of bioactives in lipid-based carrier systems like nanoliposomes preserves their native properties against oxidation over time along with providing its stable aqueous dispersion. Methods: In the current study, vitamin D3 nanoliposomes were prepared using thin-film hydration­- sonication method and fully characterized by different instrumental techniques. Results: According to FTIR and DSC results, no interaction was observed between encapsulated nutraceutical and liposome constituents. The particle size and size distribution (Span value) were calculated 82–90 nm and 0.70–0.85, respectively. TEM analysis showed nano sized globular and bilayer vesicles. In all formations, the encapsulation efficiency of vitamin D3 was calculated more than 93%.­ Addition of cholesterol to lecithin bilayer increased the negative zeta potential from -29 to -43mV. Conclusion: The results of this study concluded that the liposomal nanoparticles may be introduced as a suitable carrier for fortification of beverages with vitamin D3

    Application of Response Surface Methodology in the Preparation of Pectin-Caseinate Nanocomplexes for Potential Use as Nutraceutical Formulation: A Statistical Experimental Design Analysis

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    Background: The formation of electrostatic complexes between two types of biopolymers, sodium Caseinate (a derivative from most abundant milk protein) and Pectin (a natural hetro polysaccharide), was studied as a function of biopolymers concentrations and pH of solutions (3.9- 4.3). Method: The size and morphology of the resulted complexes were investigated by using of laser light scattering and transmission electron microscopy, respectively. Response surface methodology (A three-factor, three levels Box-Behnken design) was used for the optimization procedure with pH, pectin and sodium Caseinate concentrations as independent variables. Particle size and polydispersity index of nanocomplexes were considered as dependent variables. Results: Negatively charged nanocomplexes were produced below the isoelectric point of protein (5.4), at pH 4.1 with a suitable colloidal stability and average particle size of about 100 nm. It was found that the particle size of nanocomplexes could be controlled by changing in variables. Conclusion: In conclusion response surface methodology are simple, rapid and beneficial approach for preparation, optimization and investigation of the effect of independent variables on the properties of products

    Properties of Poly(lactic acid) Nanocomposite Film Containing Modified Cellulose Nanofibers

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    ICellulose nanofibers (CNF)-reinforced poly(lactic acid) (PLA) nanocomposite was prepared by casting method. In order to improve the compatibility and miscibility of the whole system with respect to PLA matrix, CNFs were treated with oleic acid. The resulting modified nanofibers (MCNF) exhibited reduced polarity and crystalline structure as compared with unmodified CNF. These MCNF were subsequently introduced into a PLA polymeric matrix and the effect of nanofiller on physicochemical properties of the nanocomposites was studied. Surface morphologies of PLA films studied by atomic force microscopy and it was revealed that the surface roughness of nanocomposites increased by increasing the nanofiber content. The morphology of fracture surface, evaluated by scanning electron microscopy, confirmed the uniform dispersion of MCNF at low levels. However, a higher level of MCNF (12 wt%) led to less dispersion uniformity and more agglomeration of the nanofibers. The thermal analysis by differential scanning calorimetry showed that the melting temperature of the PLA-MCNF nanocomposites was significantly higher than that of pure PLA film. Also, the degree of crystallinity increased with an increase in MCNF content. X ray diffraction patterns confirmed that the addition of MCNF resulted in increased crystalline structure in PLA matrix. At MCNF content of 12 wt%, the tensile strength and Young’s modulus of the nanocomposites increased by 2.5 and 2 folds than those of pure PLA films, respectively. These improvements were primarily attributed to the effect of surface modification and uniform dispersion of the MCNF in the PLA matrix. However, the MCNF formed aggregates in the higher loading levels (12 wt %)
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