16 research outputs found

    Development of simultaneous antioxidant and visual pH-sensing films based on guar gum loaded with Aronia melanocarpa extract

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    Anthocyanins have attracted increasing attention for different packaging systems due to having functional features such as biocompatibility, antioxidative activity, visible colour response at varying pH values. In this study, the extract of Aronia melanocarpa as anthocyanins source was incorporated into guar gum films to take advantage of both antioxidant and pH responsive attributes. Aronia addition did not affect the thermal stability of guar gum films. Radical scavenging activity of the films (%) was measured by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay, and aronia added films exhibited very strong antioxidant activity (up to 85%). The colour of aronia solution varied from pink to brown with pH ranging from 1 to 13. Similarly, when the films were immersed in buffer solutions at different pH values, the visual colour varied from pink to brownish yellow. ΔE values of GR_AR_3 (guar gum films having the highest aronia concentration) ranged between 23.31 and 40.62 at pH 1–13. This result proved colour change of the films can be even detected by untrained consumers. Furthermore, the films were found to be very sensitive to ammonia vapour. Aronia incorporated guar gum films could be suggested as both antioxidant films to prevent foods oxidation from oxidation and promising intelligent films to monitor the deterioration of foods

    Fabrication of gallic acid loaded Hydroxypropyl methylcellulose nanofibers by electrospinning technique as active packaging material

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    The objective of this study was to encapsulate gallic acid in Hydroxypropyl methylcellulose (HPMC)/poly-ethylene oxide (PEO) blend nanofiber by using electrospinning and examine the usage of nanofibers as active packaging materials. Gallic acid loaded nanofibers showed homogenous morphology. Gallic acid was loaded into nanofibers efficiently and nanofibers showed strong antioxidant activity. As the gallic acid amount increased, the TGA curves had shifted one stage to two stage degradation and degradation temperature (T-d) of gallic acid decreased from 275 degrees C to 250 degrees C due to the crystalline structure change. Interaction between gallic acid and HPMC/PEO nanofiber demonstrated that gallic acid successfully embedded into the nanofibers. Gallic acid loaded nanofibers decreased the oxidation of walnut during storage. Overall, electrospinning technique was proved to be an efficient method to encapsulate bioactive compounds and gallic acid loaded nanofibers showed promissory results that can be suggested as great potential to active packaging material

    Effects of Microwave-Infrared Combination Drying on Quality of Eggplants

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    The objective of this study was to investigate the effects of hot-air drying and microwave-infrared combination drying on drying characteristics and quality parameters of eggplants. Eggplant slices were dried by using microwave-infrared combination oven at different microwave powers (30, 40, and 50 %) and different infrared (IR) powers (10, 20, and 30 %). Hot-air drying was performed in a tray dryer at 50 A degrees C with an air velocity of 1.5 m/s. As quality parameters, color, rehydration ratio, shrinkage, microstructure, and pore size distribution of dried eggplants were chosen. Microwave-IR combination provided significantly shorter drying time than hot-air drying. Osmotic dehydration also reduced drying time in microwave-IR combination oven. Effective diffusivity of moisture in hot-air drying (5.070 x 10(-10) m(2)/s) was found to be lower than that observed in microwave-IR drying (7.100 x 10(-9)-1.445 x 10(-8) m(2)/s). Higher microwave and IR powers increased but osmotic pretreatment decreased effective diffusivity. Decrease in IR power and osmotic dehydration treatment increased L* but decreased a* values of dried eggplants. Microwave-IR-dried eggplants had more porous structure than hot-air-dried ones. Therefore, these eggplants had lower shrinkage and higher rehydration ratio than hot-air-dried ones. Osmotically dehydrated eggplants had higher shrinkage and lower rehydration ratio than untreated ones

    Enhancing oxidative stability of walnuts by using gallic acid loaded lentil flour based electrospun nanofibers as active packaging material

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    The objective of this study was to enhance oxidative stability of walnuts present in active packages produced by electrospinning technology. Gallic acid was encapsulated into lentil flour/polyethylene oxide (PEO) nanofibers. To promote the solubility of lentil proteins, pH of solutions was adjusted to pH 1 and pH 10 which were far away from isoelectric point of lentil proteins. While acidic solutions had lower viscosity values than alkaline solutions, their electrical conductivity values were significantly higher. When the scanning electron microscopy (SEM) images were examined, it should be noted that alkaline nanofibers showed homogenous structure. Although gallic acid was not so stable at alkaline conditions, gallic acid loaded nanofibers prepared at alkaline pH still showed antioxidant activity after electrospinning. The physical and thermal properties of encapsulated gallic acid and nanofibers were examined by Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA) and differential scanning calorimeter (DSC) analyses. FTIR results indicated the effect of pH on chemical properties of nanofibers and the interaction between gallic acid and lentil flour-based nanofibers. Gallic acid addition reduced onset temperature and thermal stability. Therefore, it could be taken as evidence of incorporation of gallic acid. Disappearance of enthalpic peak related to melting of crystalline structure of gallic acid in DSC thermal curves confirmed successful encapsulation of gallic acid. Fabricated gallic acid loaded nanofibers were used to pack walnuts and the reduction in oxidation of walnuts with lower peroxide, p-anisidine and Totox values was observed. This would make these packaging materials substantially preferable for packing of foods being highly susceptible to oxidation

    Nanostructured poly(lactic acid)/soy protein/HPMC films by electrospinning for potential applications in food industry

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    As an alternative to oil based materials, there is a demand for easily degradable packaging materials. With this regard, the objective of this study is to produce bilayer nanofiber sheets composed of Poly (lactic acid) (PLA) and soy protein, hydroxypropyl methylcellulose (HPMC) and combination of them by using electrospinning. In addition, it was aimed to analyze morphological, optical, thermal properties of films and investigate permeability characteristics. Homogenous nanofibers were successfully collected onto PLA sheets. The solution containing HPMC had the highest viscosity and the lowest electrical conductivity values. Therefore, HPMC based nanofibers had the highest the average diameter values. Combining nanofibers with PLA sheets decreased transparency as compared to the transparency of neat PLA, it also did not improve permeability values. When the thermal properties of PLA/nanofibers were examined it was observed that while PLA sheet showed one stage degradation, bilayer films had two stage degradation. Soy protein containing nanofibers showed higher thermal stability. The FTIR spectrum of PLA/nanofiber sheets displayed the chemical characteristics of both PLA and nanofibers. PLA/nanofiber sheets obtained by electrospinning can be suggested in packaging of light sensitive foods

    Primary immunodeficiencies: HSCT experiences of a single center in Turkey.

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    Background Primary immunodeficiency diseases (PID) are characterized by the occurrence of frequent infections and are caused by many genetic defects. Hematopoietic stem cell transplantation (HSCT) is the only curative treatment option for the majority of PID. As a Pediatric Hematology-Oncology-Immunology Transplantation Unit, we wanted to present our HSCT experience regarding treatment of primary immunodeficiency diseases
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