http://irgu.unigoa.ac.in/drs/handle/unigoa/18 2026-04-07T11:45:25Z http://irgu.unigoa.ac.in/drs/handle/unigoa/7816 Biopolymeric chitosan/ZnO-nanocomposite films from pomegranate peels for sustainable and functional food packaging Sangodkar, V.; Vaidya, M.; Ayyanar, M.; Prabhu, S.; Nadaf, S.; Naik, A.V.; Gurav, N.; Kumbhar, P.; Kharkar, P.; Gurav, S. Chitosan (CS), a biopolymer derived from chitin, is well known for its biodegradability and significant antimicrobial, photocatalytic, and UV-protective properties, making it an intriguing candidate for sustainable and active food packaging solutions. In response to rising environmental concerns and the demand for sustainable food packaging, this study investigates the eco-friendly synthesis of CS-conjugated Punica granatum (PG)-derived zinc oxide nanocomposites (PG-ZnONCs) for use in food packaging applications. A quality-by-design approach was employed to identify optimal conditions that maximize the desired properties of the nanocomposite films, ensuring a robust and efficient formulation process. Nanoparticle and nanocomposite preparation was confirmed by monitoring colour change and validated by UV-visible spectroscopy. X-ray diffraction, SEM, and TEM analyses confirmed the crystallite structures of the particles, with particle sizes of 112.3 nm and 160.8 nm, polydispersity indices of 0.182 and 0.215, and zeta potentials of -21.98 mV and - 10.6 mV, indicating stability. The successful application of DOE (Design of Experiments) ensured a robust and efficient formulation process, contributing to the high-quality characteristics of the final product. PG-ZnONPs and PG-CS/ZnONCs demonstrated strong antioxidant activity, effectively scavenging radicals in DPPH and ABTS assays, and exhibited potent antibacterial effects against foodborne pathogens. The PG-CS/ZnONC films (2.5 percent, 5 percent, and 7.5 percent) exhibit excellent mechanical, thermal, and barrier properties, thereby extending the shelf life of fresh foods. Incorporating Alizarin (AZ) as a pH-responsive indicator enabled real-time freshness monitoring. The PG-7.5 percent NC film preserved Solanum lycopersicum (cherry tomatoes) for 16 days and Stolephorus indicus (Indian anchovy) for 9 days, compared to 4 days for uncoated samples. Overall, PG-CS/ZnONC films, particularly with AZ for smart monitoring, present a promising solution for sustainable food packaging, enhancing food preservation while reducing waste. 2026-01-01T00:00:00Z http://irgu.unigoa.ac.in/drs/handle/unigoa/7812 Bioremediation of chromium by Oscillatoria pseudogeminata: growth dynamics, metal uptake, and physiological responses Chahal, S.; Chanekar, T.; Bhandari, R. Hexavalent chromium, Cr(VI), is a highly toxic heavy metal that disrupts metabolic processes and threatens aquatic ecosystems. Cyanoremediation using metabolically active cyanobacteria for heavy-metal sequestration and detoxification is a sustainable, eco-friendly remediation approach. The present study evaluated the Cr(VI) removal efficiency and physiological responses of an indigenously isolated freshwater cyanobacterium, Oscillatoria pseudogeminata, under different Cr(VI) concentrations (2, 5, 7, and 10 ppm). Growth performance, photosynthetic pigments, oxidative stress markers, antioxidant responses, and chromium uptake were assessed to determine cellular responses to metal stress. Increasing Cr(VI) concentrations caused a concentration-dependent decline in growth, biomass accumulation, and pigment content, indicating impairment of photosynthetic and metabolic processes. In contrast, oxidative stress indicators and antioxidant defense responses, including malondialdehyde accumulation, superoxide dismutase activity, and proline content, were significantly elevated at lower Cr(VI) levels (2 and 5 ppm), reflecting activation of cellular defense mechanisms. These responses declined at higher concentrations, suggesting enzyme inhibition and severe metal-induced oxidative damage. Scanning electron microscopy revealed morphological alterations in treated filaments, while atomic absorption spectroscopy confirmed significant Cr(VI) absorption by the cyanobacteria, with removal efficiencies ranging from 48 to 60 percent. Overall, Oscillatoria pseudogeminata demonstrates notable chromium tolerance and biosorption capacity, highlighting its remediation potential for treating chromium-contaminated water. 2026-01-01T00:00:00Z http://irgu.unigoa.ac.in/drs/handle/unigoa/7789 What determines the host preferences of hemiepiphytic Ficus species? A study from Western Ghats, Goa, India Fernandes, A.P.; Janarthanam, M.K.; Krishnan, S. The Ficus species play a vital role as keystone species in the tropical forest ecosystem. They are also referred to as figs and are classified as "free-standing" and "hemiepiphytic" based on their dependencies on host plants in the initial phase of their lifecycle. Despite their importance, the host association with hemiepiphytic Ficus species remain understudied. This study aims to understand their diversity, spatial distribution and factors that determine their interaction with the host. The study was conducted in the Cotigao Wildlife Sanctuary of Western Ghats, India. We recorded 262 Ficus individuals across the natural trails. 89 plots of 30 m diameter were established around selected individuals (as focal plant) in semi-evergreen and moist deciduous forests. Further, each plot was defined as hemiepiphytic or non-hemiepiphytic based on the focal plant. Statistical analyses, including PARMANOVA and NMDS highlighted significant differences in species composition between plot types based on the forest types. The hemiepiphytic species were observed more on rough and fissured bark, notably preferring Terminalia paniculata, T. elliptica, Schleichera oleosa, and T. bellirica. 2026-01-01T00:00:00Z http://irgu.unigoa.ac.in/drs/handle/unigoa/7788 Sustainable production of Syzygium laetum-engineered ZnO nanoparticles: From physicochemical properties to in vitro bioactivities and in vivo ecotoxicity assessment Nadar, A.P.; Krishnan, S. This study reports the green synthesis of zinc oxide nanoparticles (SL-ZnONPs) using an aqueous leaf extract of Syzygium laetum (Buch.-Ham.) Gandhi, a riverine endemic from the Western Ghats, via a solution combustion method. The synthesised SL-ZnONPs displayed a surface plasmon resonance peak at 371 nm and exhibited a direct band-gap energy of 2.6 eV. Dynamic light scattering analysis revealed an average hydrodynamic diameter of 54.3 nm, with a polydispersity index of 0.448 and a zeta potential of -15.04 mV, indicating moderate colloidal stability. Fourier transform infrared (FT-IR) spectroscopy confirmed the role of phenolic and carbonyl groups in reducing and stabilising SL-ZnONPs. X-ray diffraction (XRD), field emission gun scanning electron microscopy (FEG-SEM), and transmission electron microscopy (FEG-TEM) confirmed a hexagonal Wurtzite structure with an average crystallite size of 26.952 nm and particle size of 17.92 plus-minus 0.6 nm. The SL-ZnONPs showed strong antioxidant activity, with IC sub(50) values of 89.96 Mu g/mL in the DPPH and 68.1 Mu g/mL in the ABTS assay. SL-ZnONPs showed notable cytotoxic effects on MCF-7 cells (IC sub(50) = 7.02 Mu g/mL) and HeLa cells (IC sub(50) = 81.19 Mu g/mL), while remaining less toxic towards HEK-293 cells (IC50 = 224.9 Mu g/mL). Enzyme inhibition studies indicated inhibition of Alpha-amylase and Alpha-glucosidase, with IC sub(50) values of 77.10 and 86.80 Mu g/mL, respectively. Furthermore, SL-ZnONPs decreased intracellular lipid accumulation in 3T3-L1 cells, confirming its antidiabetic potential. Anti-inflammatory studies showed significant membrane stabilisation and reduced protein denaturation, reflected in IC sub(50) values of 37.09 and 40.29 Mu g/mL respectively. An ecotoxicity assessment with Danio rerio embryos indicated no significant developmental toxicity at doses up to 200 Mu g/mL. Overall, these findings underscore the potential of SL-ZnONPs as an eco-friendly nanoplatform with promising biomedical and therapeutic uses. 2025-01-01T00:00:00Z