Faculty Publications

Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736

Publications by NITK Faculty

Browse

Author: search.filters.author.Zhuo, G.-Y.

Search Results

Now showing 1 - 7 of 7
  • No Thumbnail Available
    Item
    Physicochemical characterization of microcrystalline cellulose extracted by sequential dual acid hydrolysis
    (Elsevier, 2024) Kalita, R.D.; Chakraborty, I.; Singh, P.; Banik, S.; Mal, S.S.; Zhuo, G.-Y.; Mazumder, N.
    Properties and applications of microcrystalline cellulose (MCC) differ based on its source and method of extraction. In this article, MCC was extracted from Saccharum spontaneum using single acid hydrolysis (MCC1) and sequential dual acid hydrolysis (MCC2). Scanning electron microscope (SEM) images exhibited that the dimension of MCC2 is much smaller compared to MCC1. X-ray diffraction (XRD) indicated that sequential dual acid hydrolysis results in decrease the crystallinity index (CI%) in case of MCC2 (34.45%). Fourier transform infrared spectroscopy (FTIR) spectra indicates the presence of characteristic bonds such as O–H stretching, C–H stretching, OH bending, and C–O–C stretching in both MCC1 and MCC2. Based on thermal analysis conducted using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), it was confirmed that MCC2 (275.0°C) melts at much lower temperature compared to MCC1 (342.04°C). MCC2 is also less thermally stable compared to MCC1 in terms of mass loss (%). In all, both MCC1 and MCC2 have different physicochemical properties based on the process of extraction and may have different applications. Based on their physicochemical characteristics, smaller MCC particles are known to be favored for wide variety of applications such as pharmaceutical excipients and impact factors such as tablet hardness, friability, and disintegration. © 2024 Elsevier Inc. All rights are reserved including those for text and data mining AI training and similar technologies.
  • No Thumbnail Available
    Item
    Advanced Microscopic Visualization for Structural Characterization of Cellulose Extracted from Saccharum Spontaneum (Kohua Bon) of Assam, India
    (Optica Publishing Group (formerly OSA), 2021) Chakraborty, I.; Kalita, R.D.; Singh, P.; Banik, S.; Govindaraju, I.; Mal, S.S.; Zhuo, G.-Y.; Mahato, K.K.; Mazumder, N.
    Alpha, microcrystalline and nanocrystalline cellulose were sequentially extracted from stems and leaves of Saccharum spontaneum and were subjected to morphological and structural characterization using advanced microscopy techniques, including Scanning electron microscopy and nonlinear optical microscopy. © Optica Publishing Group 2021, © 2021 The Author (s)
  • No Thumbnail Available
    Item
    Microscopic and spectroscopic characterization of rice and corn starch
    (Wiley-Liss Inc., 2020) Govindaraju, I.; Pallen, S.; Umashankar, S.; Mal, S.S.; Kaniyala Melanthota, S.; Mahato, D.R.; Zhuo, G.-Y.; Mahato, K.K.; Mazumder, N.
    Starch granules from rice and corn were isolated, and their molecular mechanism on interaction with ?-amylase was characterized through biochemical test, microscopic imaging, and spectroscopic measurements. The micro-scale structure of starch granules were observed under an optical microscope and their average size was in the range 1–100 ?m. The surface topological structures of starch with micro-holes due to the effect of ?- amylase were also visualized under scanning electron microscope. The crystallinity was confirmed by X-ray diffraction patterns as well as second-harmonic generation microscopy. The change in chemical bonds before and after hydrolysis of the starch granules by ?- amylase was determined by Fourier transform infrared spectroscopy. Combination of microscopy and spectroscopy techniques relates structural and chemical features that explain starch enzymatic hydrolysis which will provide a valid basis for future studies in food science and insights into the energy transformation dynamics. © 2020 Wiley Periodicals, Inc.
  • No Thumbnail Available
    Item
    Investigation of structural and physico-chemical properties of rice starch with varied amylose content: A combined microscopy, spectroscopy, and thermal study
    (Elsevier B.V., 2022) Govindaraju, I.; Zhuo, G.-Y.; Chakraborty, I.; Melanthota, S.K.; Mal, S.; Sarmah, B.; Baruah, V.J.; Mahato, K.K.; Mazumder, N.
    Starch from a given botanical source can vary considerably in terms of physicochemical properties in its native and hydrolyzed forms. The current study investigated the structural and functional characteristics of starch from ten indigenous rice varieties endemic to Northeast India. In vitro enzymatic hydrolysis was used to reveal the dextrose equivalent profile of each type of starch. Gezep Sali and Betguti Sali respectively exhibited the highest and lowest starch hydrolysis. Among the ten rice varieties, amylose content varied between 7.50 and 28.58%. Optical and scanning electron microscopy (SEM) revealed the polyhedral shape of the native starch granules and deformation of the shape upon enzymatic hydrolysis. Second harmonic generation (SHG) microscopy and X-ray diffraction (XRD) analysis confirmed the presence of and variations in starch crystallinity. XRD revealed spectral peaks characteristic of A-type starch crystals in the native form. The elevated intensity of XRD peaks in hydrolyzed starch granules confirmed the occurrence of amylose hydrolysis rather than hydrolysis in amylopectin regions. Fourier transform infrared (FTIR) spectra revealed the common stretching and bending of bonds in all native starches; however, changes were observed in the fingerprint region (1080, 1000, 926 cm−1) of hydrolyzed starch granules, which indicates the amylolysis of the amylose region and disturbances in the ordered arrangement in the crystalline part. Differential scanning calorimeter (DSC) endotherms revealed the highest and lowest gelatinization peak temperatures in Harfoni (78 °C) and Tulosi Sali (41 °C) rice cultivars, respectively. The findings in this study can help to optimize the usage of rice starch in food and non-food industries. Furthermore, understanding the control points of starch digestion and genetically tailoring rice grains with different digestibility could be beneficial for nutraceutical applications. © 2021 Elsevier Ltd
  • No Thumbnail Available
    Item
    Synthesis and detailed characterization of sustainable starch-based bioplastic
    (John Wiley and Sons Inc, 2022) Chakraborty, I.; Pooja, N.; Banik, S.; Govindaraju, I.; Das, K.; Mal, S.S.; Zhuo, G.-Y.; Rather, M.A.; Mandal, M.; Neog, A.; Biswas, R.; Managuli, V.; Datta, A.; Mahato, K.K.; Mazumder, N.
    There is an urgent requirement of replacing the environmentally hazardous petroleum-based plastics with sustainable and efficient starch-based bioplastics. Development and detailed characterization of the biodegradable bioplastics from plant-based polysaccharides such as starch is essential to reduce plastic pollution in the environment. In this research, bioplastics were developed from an equivalent blend of starch from two different sources namely rice and potato (1:1, w/w), crosslinked with different concentrations of citric acid (CA). The effect of CA cross-linking of starch-based bioplastics was investigated on its physicochemical and functional properties. The X-ray diffraction (XRD) spectra revealed that the synthesized bioplastics were amorphous in nature with broad diffraction peaks. Further, the peak at 1716 cm−1 in Fourier transform infrared (FTIR) spectra indicated the formation of ester bonds in CA cross-linked bioplastics. Atomic force microscopy (AFM) revealed the surface roughness of the bioplastics decreased with increasing concentration of CA. Mechanical and thermal properties of bioplastics were characterized using universal testing machine, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA), respectively. © 2022 Wiley Periodicals LLC.
  • No Thumbnail Available
    Item
    Revealing the Structural Organization of Gamma-irradiated Starch Granules Using Polarization-resolved Second Harmonic Generation Microscopy
    (Oxford University Press, 2023) Chen, M.-C.; Govindaraju, I.; Wang, W.-H.; Chen, W.-L.; Mumbrekar, K.D.; Mal, S.S.; Sarmah, B.; Baruah, V.J.; Srisungsitthisunti, P.; Karunakara, N.; Mazumder, N.; Zhuo, G.-Y.
    Starch is a semi-crystalline macromolecule with the presence of amorphous and crystalline components. The amorphous amylose and crystalline amylopectin regions in starch granules are susceptible to certain physical modifications, such as gamma irradiation. Polarization-resolved second harmonic generation (P-SHG) microscopy in conjunction with SHG-circular dichroism (CD) was used to assess the three-dimensional molecular order and inherent chirality of starch granules and their reaction to different dosages of gamma irradiation. For the first time, the relationship between starch achirality (χ21/χ16 and χ22/χ16) and chirality (χ14/χ16) determining susceptibility tensor ratios has been elucidated. The results showed that changes in the structure and orientation of long-chain amylopectin were supported by the decrease in the SHG anisotropy factor and the χ22/χ16 ratio. Furthermore, SHG-CD illustrated the molecular tilt angle by revealing the arrangement of amylopectin molecules pointing either upward or downward owing to molecular polarity. © 2023 Cambridge University Press. All rights reserved.
  • No Thumbnail Available
    Item
    Assessment of biocompatibility for citric acid crosslinked starch elastomeric films in cell culture applications
    (Nature Research, 2025) Pooja, N.; Ahmed, N.Y.; Mal, S.S.; Bharath, P.A.S.; Zhuo, G.-Y.; Noothalapati, H.; Managuli, V.; Mazumder, N.
    This study investigates the synthesis of potato starch elastomers reinforced with silicon dioxide (SiO2) and citric acid as a crosslinking agent to enhance their mechanical and barrier properties. Surface morphology analysis using optical microscopy revealed that pure potato starch films had uneven surfaces. However, higher SiO2 concentrations increased roughness, while citric acid crosslinked films displayed smoother surfaces overall. Water vapor transmission rates (WVTR) indicated that native starch films were highly hydrophilic, while SiO2 incorporation and citric acid crosslinking significantly reduced WVTR of 17% (30% lower than native film), enhancing the barrier properties. Tensile strength testing revealed that citric acid crosslinking increased the tensile strength by 25%, while SiO2 further reinforced the films but decreased elasticity by 15%. SiO2 had little impact on degradation rates, while citric acid crosslinking delayed microbial growth, extending film longevity by 20%. Biocompatibility assays using SiHa, HT-29, and HEK 293 cell lines revealed that the films had varying degrees of cell confluency. Films with both SiO2 and citric acid showed improved confluency (20% higher) compared to films containing only SiO2. However, citric acid alone resulted in the highest confluency (95% viability), suggesting its significant role in biocompatibility. This eco-friendly approach demonstrates substantial advancements in film properties, offering potential applications in diverse biomedical industries. © The Author(s) 2025.