Department of Food Processing Technology and Management
Permanent URI for this communityhttps://dspace.psgrkcw.com/handle/123456789/159
Browse
10 results
Search Results
Item TOWARDS MIMICKING THE FETAL LIVER NICHE: THE INFLUENCE OF ELASTICITY AND OXYGEN TENSION ON HEMATOPOIETIC STEM/PROGENITOR CELLS CULTURED IN 3D FIBRIN HYDROGELS(MDPI, 2020-09-02) Christian, Garcia-Abrego; Samantha, Zaunz; Burak, Toprakhisar; Ramesh, Subramani; Olivier, Deschaume; Stijn, Jooken; Manmohan, Bajaj; Herman, Ramon; Catherine, Verfaillie; Carmen, Bartic; Jennifer, PattersonHematopoietic stem/progenitor cells (HSPCs) are responsible for the generation of blood cells throughout life. It is believed that, in addition to soluble cytokines and niche cells, biophysical cues like elasticity and oxygen tension are responsible for the orchestration of stem cell fate. Although several studies have examined the effects of bone marrow (BM) niche elasticity on HSPC behavior, no study has yet investigated the effects of the elasticity of other niche sites like the fetal liver (FL), where HSPCs expand more extensively. In this study, we evaluated the effect of matrix stiffness values similar to those of the FL on BM-derived HSPC expansion. We first characterized the elastic modulus of murine FL tissue at embryonic day E14.5. Fibrin hydrogels with similar stiffness values as the FL (soft hydrogels) were compared with stiffer fibrin hydrogels (hard hydrogels) and with suspension culture. We evaluated the expansion of total nucleated cells (TNCs), Lin−/cKit+cells, HSPCs (Lin−/Sca+/cKit+ (LSK) cells), and hematopoietic stem cells (HSCs: LSK- Signaling Lymphocyte Activated Molecule (LSK-SLAM) cells) when cultured in 5% O2 (hypoxia) or in normoxia. After 10 days, there was a significant expansion of TNCs and LSK cells in all culture conditions at both levels of oxygen tension. LSK cells expanded more in suspension culture than in both fibrin hydrogels, whereas TNCs expanded more in suspension culture and in soft hydrogels than in hard hydrogels, particularly in normoxia. The number of LSK-SLAM cells was maintained in suspension culture and in the soft hydrogels but not in the hard hydrogels. Our results indicate that both suspension culture and fibrin hydrogels allow for the expansion of HSPCs and more differentiated progeny whereas stiff environments may compromise LSK-SLAM cell expansion. This suggests that further research using softer hydrogels with stiffness values closer to the FL niche is warranted.Item ASSESSING POLLUTANT SORPTION EFFICIENCY OF MODIFIED AND UNMODIFIED BIOCHAR WITH BACILLUS CEREUS ON CONTAMINATED LAKE WATER: IMPLICATIONS FOR ORYZA SATIVA SEEDLING AND ARTEMIA FRANCISCANA LARVAE VIABILITY(Springer Link, 2023-10-02) Mathiyazhagan, Narayanan; Ramesh, Subramani; Sabariswaran, KandasamyThis study evaluated the efficacy of biochar in removing pollutants from a polluted lake. Biochar, both with and without Bacillus cereus, was assessed for its sorption potential. The treated water samples were analyzed for toxicity using Oryza sativa and Artemia franciscana larvae. The lake water exceeded permissible limits for pH, turbidity, dissolved oxygen (DO), chemical oxygen demand (COD), biological oxygen demand (BOD), and various metals. The 10-day biosorption study with different treatment groups (MB, UMB, MBB, UMBB, and BC) revealed that the MBB group exhibited remarkable pollutant sorption potential. It achieved pollutant removal percentages of 33.35% for Cd, 15.73% for As, 26.21% for Cr, 32.72% for Pb, 32.81% for Zn, 23.58% for Cu, 5.44% for Cl, 22.01% for Ni, 28.2% for Hg, and 4.19% for SO42−. MBB-treated lake water showed no toxicity, confirming pollutant removal by metal-tolerant Bacillus cereus in modified biochar.Item THE INFLUENCE OF SWELLING ON ELASTIC PROPERTIES OF POLYACRYLAMIDE HYDROGELS(Frontiers in Materials, 2020-07-23) Ramesh, Subramani; Alicia, Izquierdo-Alvarez; Pinaki, Bhattacharya; Mathieu, Meerts; Paula, Moldenaers; Herman, Ramon; Hans, Van OosterwyckPolyacrylamide (PAM) hydrogels are commonly used as substrates for cell mechanical and mechanobiological studies because of their tunable stiffness and ease of handling. The dependence of bulk rheological and local elastic properties (assessed by Atomic Force Microscopy, or AFM) of PAM hydrogels on its composition and polymerization temperature has been extensively studied. PAM hydrogels swell when immersed in media, but the influence of swelling on local elastic properties is poorly characterized. Direct measurements of the effect of swelling on PAM elastic properties are scarce. We report here, for the first time, the direct measurements of volumetric swelling and local elastic properties of PAM gels throughout the post-polymerization swelling process until equilibrium. First, local and global elastic properties (measured by rheology), were obtained during polymerization in the absence of swelling, and showed good agreement with each other. Four PAM hydrogel compositions were characterized thus, with corresponding storage shear moduli (as measured immediately after polymerization) of 4,530 Pa (termed stiffest), 2,900 Pa (stiff), 538 Pa (soft), and 260 Pa (softest). Next, all compositions were subjected to swelling in phosphate buffered saline. Swelling ratios and local elastic moduli were measured at 0, 3, 6, 9, 12, and 24 h post-polymerization for the soft and softest compositions, and once daily till 6 days post-polymerization for all four compositions. For the stiffest and stiff gels, swelling ratio, and local elastic modulus changed negligibly with time, while for the soft and softest gels, substantial changes between Day 0 and Day 1 were found for both swelling ratio (increased by 21.6 and 133%, respectively), and local elastic modulus decreased (by 33.7 and 33.3%, respectively), substantially. Experimental data were analyzed by a model that combined ideal elastomer mechanics and poroelastic swelling kinetics model. Model predictions confirmed the validity of present measurements with respect to past studies where swelling and elastic properties were not measured simultaneously. The present study underlines the important effect swelling can have on PAM elastic properties and provides detailed quantitative data to guide the duration taken to reach equilibrium—a useful information for cell mechanics experiments. In addition, the simultaneous measurements of swelling and local elastic moduli provide novel data for the validation of theoretical models.Item PREPARATION AND CHEMICAL PHYSICAL CHARACTERIZATION OF INDIVIDUAL NANOSCALED FIBRILS(Bentham Science Publishers, 2022-04-26) Praveetha, Senthilkumar; Sharmila, Chandran; Alexey, Kartsev; Vladimir, Shavrov; Petr, Lega; Ramesh, SubramaniPolymer-based nanofibril finds its application in various fields including tissue engineering, environmental monitoring, food packaging, and micro/nanoelectromechanical systems. These nanofibrils are subjected to chemical treatment and constant stress, which may cause permanent deformation to the fibrils when it is used. Therefore, the synthesis of well-defined nanofibrils and characterization techniques are key elements in identifying desired chemical and physical properties for suitable applications. Many methods have been developed to prepare individual nanofibrils, including electrospinning, phase separation, template synthesis, and self-assembly. Among all, self-assembly offers simple, efficient, and lowcost strategies that produce high-ordered nanofibrils using noncovalent interactions including hydrogen bonding, electrostatic interactions, π-π interactions, and hydrophobic interactions. The first part of the review provides detailed molecular interactions and simulations that can be controlled to achieve the formation of well-defined individual nanofibrils. The second part of the review describes the various existing tools to characterize the chemical and physical properties of single nanofibrils including atomic force microscopy. In the final part of the review, recently developed novel nanotools that measure the mechanical properties of nanofibrils are described. By bridging the gap between molecular interactions and resulting nanoscale fibirls, physical and chemical properties may lead to the construction of novel nanomaterials in the area of nanoscience and nanotechnology.Item RESVERATROL-LOADED Β-LACTOGLOBULIN NANOFIBRILS TO PREVENT ENZYMATIC BROWNING ON SLICED APPLE(Applied Food Biotechnology, 2022) Praveetha, Senthilkumar; Vladimir, Shavrov; Petr, Lega; Ramesh, Subramani: Resveratrol is a polyphenol with nutraceutical health benefits used as anticancer, antioxidant and anti-inflammatory with cardio protective effects. However, resveratrol lacks solubility and bioavailability and is affected by UV light, which decrease its use in food industries. It is possible to overcome these problems by loading resveratrol with appropriate biomaterials. Beta-lactoglobulin is known to form well-defined nanofibrils with various uses. The objective of this study was to use β-lg nanoscaled fibrils to increase bioavailability of resveratrol as well as preserving freshness and preventing enzymatic browning of sliced applesItem SYNTHESIS OF NOVEL LUMINESCENT CYCLOMETALLATED PLATINUM (IV) COMPLEXES WITH A QUINOLINE SCHIFF BASES LIGAND AND THEIR PHOTOPHYSICAL PROPERTIES(Taylor and Francis Group, 2023) Sathya Priyadarshini G; Ramesh, Subramani; Elakkiya S; Selvi, GopalThe synthesis, characterization, electro and photophysical properties of eight cyclometallated platinum (IV) complexes 6a–6d and 7a–7d derived from quinoline Schiff base ligands are reported. Spectral studies revealed that nonparticipation of nitrogen atom and participation of carbon atom of the quinoline ring in the bond formation through [NN′C] mode of coordination for complex 6, whereas [N S O] mode of coordination with octahedral geometry for complex 7. The absorption and emission spectra studied in acetonitrile medium at room temperature showed that the ligand charge transitions within the quinoline Schiff base ligands with Metal Ligand Charge Transfer (MLCT) character. The broad band appeared in the range of 460–502 nm is attributed to the higher emission intensities of cyclometallated platinum (IV) compounds. The HOMO, LUMO and energy gap of the synthesized complexes was found to be − 2.60 eV, −4.75 eV and 2.15 eV through Density Functional Theory (DFT).Item KINETIC MODELLING OF OKRA AND GRACILARIACORTICATAHYDROCOLLOID MUCILAGE POLYSACCHARIDES(Research and Innovation in Food Science and Technology, 2023) Ramesh, Subramani; Charumathi, Pushparaj; Archana, GanesanThe biopolymer has become essential component in the recent years to overcome the environmental issues raised from the synthetic polymer. In this aspect we attempt to make such valuable and economical important biopolymer from the natural sources such as Abelmoscus esculentus and Gracilaria corticata in an eco friendly approach with thermally stable biopolymer. Thermal analysis of Okra and Gracilaria corticata mucilage polysaccharide has been carried out to ascertain their thermal degradation behavior and thermal stability. Thermal analysis of Okra and Gracilaria corticata mucilage polysaccharide weighed in the range of 5-10mg was carried out with TGA (Thermal Gravimetric Analyzer) and DSC (Differential Scanning Calorimeter). Activation energy of the biopolymers for degradation studies was predicted and compared with Ozawa-Flynn-Wall (O-F-W). The activation energy obtained showed high R-square value of 0.9999, 0.9951, 0.9997 for Okra and 0.9992, 0.9998, 0.9999 for Gracilaria corticata. The results obtained in this study established the thermal characteristics of Okra and Gracilaria corticata mucilage polysaccharide and suggest their potential application in the food, cosmetic and pharmaceutical sectors.Item GUM ACACIA/PECTIN/PULLULAN-BASED EDIBLE FILM FOR FOOD PACKAGING APPLICATION TO IMPROVE THE SHELF-LIFE OF IVY GOURD(INSTITUTE OF FOOD SCIENCE TECHNOLOGY, 2022-06-15) Siva, Nandhini Suresh; Charumathi, Puspharaj; Arunadevi, Natarajan; Ramesh, SubramaniTernary blend of gum acacia/pectin/pullulan (GPPL) polysaccharide composite film was prepared using solution casting technique with the addition of different ratios of glycerol and sorbitol to increase plasticiser—polysaccharide interactions. The results showed that the film thickness, water contact angle, moisture content, solubility, tensile strength, elongation and anti-microbial properties were in good agreement with already reported films in the literature. Composite film solution was used as a coating solution to improve the shelf-life of ivy gourd (Coccinia indica). Weight loss, titrable acidity (TA), total soluble solids (TSS), anti-oxidant, total phenolic content (TPC) and storage time were measured to check the efficiency of the coating solution. The obtained data shows a 35% increase in the shelf-life of the ivy gourd during the storage period of 23 days. The anti-microbial test showed that the prepared film/coating is more resistant against Pseudomonas aeruginosa due to the presence of pullulan. Therefore, our coating shows a significant increase in shelf-life of ivy gourd up to 23 days of storage time. Thus, the prepared polysaccharide composite films in this study may be suitable for food packaging applications whereas the composite film solution can be used to improve the shelf-life of various food products in the food industry.Item SYNTHESIS OF ECO-FRIENDLY NANOCOMPOSITE WITH SILVER NANOPARTICLE TO INCREASE THE ANTIMICROBIAL ACTIVITY(2022) Sheeba, Maxwalt; Kumutha, Rahupathy; Siva Nandhini, Suresh; Ramesh, Subramani; Charumathi, PushparajNanomaterials are widely used as antifungal/antibacterial agents in numerous fields including cosmetics, therapeutics, diagnostics, food and other chemical industries. These nanomaterials are synthesized using various approaches; however, the use of chemical methods is leading to toxic and non-eco-friendly products, hence, there is an urge to prepare the nanomaterials free of toxicity. In this study, we synthesized and characterized the plant mediated silver nanoparticles-based composites using Cissus quandrangularis and Ocimum tenuiflorum. These eco-friendly nanoparticles were encapsulated with natural polymers and characterized by UV–Vis spectrophotometer, FT-IR and Scanning Electron Microscopy. In addition, synthesized nanocomposites were evaluated for antibacterial activity by disc diffusion method against Gram-negative (Escherichia coli, Staphylococcus aureus and Pseudomonas sps) bacteria showed higher antibacterial activity. These eco-friendly nanocomposites may be used as antimicrobial packaging materials, wound dressings and grafting applications.Item TOWARDS MIMICKING THE FETAL LIVER NICHE: THE INFLUENCE OF ELASTICITY AND OXYGEN TENSION ON HEMATOPOIETIC STEM/PROGENITOR CELLS CULTURED IN 3D FIBRIN HYDROGELS(2020-09-02) Christian, Garcia-Abrego; Samantha, Zaunz; Burak, Toprakhisar; Ramesh, Subramani; Olivier, Deschaume; Stijn, Jooken; Manmohan, Baja; Herman, Ramon; Catherine, Verfaillie; Carmen, Bartic; Jennifer, PattersonHematopoietic stem/progenitor cells (HSPCs) are responsible for the generation of blood cells throughout life. It is believed that, in addition to soluble cytokines and niche cells, biophysical cues like elasticity and oxygen tension are responsible for the orchestration of stem cell fate. Although several studies have examined the effects of bone marrow (BM) niche elasticity on HSPC behavior, no study has yet investigated the effects of the elasticity of other niche sites like the fetal liver (FL), where HSPCs expand more extensively. In this study, we evaluated the effect of matrix stiffness values similar to those of the FL on BM-derived HSPC expansion. We first characterized the elastic modulus of murine FL tissue at embryonic day E14.5. Fibrin hydrogels with similar stiffness values as the FL (soft hydrogels) were compared with stiffer fibrin hydrogels (hard hydrogels) and with suspension culture. We evaluated the expansion of total nucleated cells (TNCs), Lin−/cKit+ cells, HSPCs (Lin−/Sca+/cKit+ (LSK) cells), and hematopoietic stem cells (HSCs: LSK- Signaling Lymphocyte Activated Molecule (LSK-SLAM) cells) when cultured in 5% O2 (hypoxia) or in normoxia. After 10 days, there was a significant expansion of TNCs and LSK cells in all culture conditions at both levels of oxygen tension. LSK cells expanded more in suspension culture than in both fibrin hydrogels, whereas TNCs expanded more in suspension culture and in soft hydrogels than in hard hydrogels, particularly in normoxia. The number of LSK-SLAM cells was maintained in suspension culture and in the soft hydrogels but not in the hard hydrogels. Our results indicate that both suspension culture and fibrin hydrogels allow for the expansion of HSPCs and more differentiated progeny whereas stiff environments may compromise LSK-SLAM cell expansion. This suggests that further research using softer hydrogels with stiffness values closer to the FL niche is warranted.