Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
10 results
Search Results
Item Use of antioxidants for enhancing oxidative stability of bulk edible oils: a review(Blackwell Publishing Ltd, 2021) Mishra, S.K.; Belur, P.D.; Iyyaswami, R.Edible oils industry is using synthetic and natural antioxidants to enhance the oxidative stability of bulk edible oils. Due to safety concerns of BHA, BHT and TBHQ, there is an ongoing effort to find an effective and safe replacement. Finding a safe antioxidant or its synergistic mixture, which delays, retard or prevent the oxidation of bulk oil without changing the colour or flavour upon addition is a challenge. In this review, a brief account of chemical basis of oxidative deterioration of the stored oil is given. The effectiveness of most widely experimented antioxidants such as tocopherols, carotenoids, ascorbic acid and its derivatives, lignan compounds, flavonoids, polyphenols and phenolic acids in various edible oils have been reviewed. Further, the synergistic and antagonistic combination of these antioxidants in controlling oxidative degradation of edible oils has been discussed. © 2020 Institute of Food, Science and Technology (IFSTTF)Item An overview of the density functional theory on antioxidant bioactivity predictive feasibilities: Insights from natural antioxidant products(Elsevier B.V., 2024) Shaker, L.M.; A Al-Amiery, A.A.; Abed, T.K.; Khalid Al-Azzawi, W.K.; Kadhum, A.A.H.; Sulaiman, G.M.; Mohammed, H.A.; Khan, M.; Khan, R.A.Antioxidants play a crucial role in protecting biological systems from oxidative stress, which is implicated in a wide range of diseases. Computational methods have become increasingly valuable in studying the mechanisms of antioxidants, with density functional theory (DFT) being a popular approach. This review provides an overview of the theoretical basis of DFT and its application to molecular systems. It discusses the advantages and limitations of using DFT for studying antioxidants and explores the relationship between antioxidant activity and molecular structure. The paper also highlights the importance of solvation effects in determining antioxidant efficacy and suggests DFT-based methods for incorporating solvation effects into calculations. Case studies of specific antioxidants are presented to illustrate the role of the solvent environment in determining the antioxidant efficacy. Finally, it discusses the relationship between antioxidant activity and certain DFT parameters, and suggests future directions for research. Overall, this review provides valuable insights into the use of DFT in studying antioxidants, and sheds light on the future of computational studies in this field. © 2023Item Synthesis and biological evaluation of new imidazo[2,1-b][1,3,4]thiadiazole-benzimidazole derivatives(Elsevier Masson SAS infos@masson.fr 62 rue Camille Desmoulins Issy les Moulineaux Cedex 92442, 2015) Ramprasad, J.; Nayak, N.; Udayakumar, U.; Yogeeswari, P.; Sriram, D.; Peethambar, S.K.; Achur, R.; Santosh Kumar, H.S.S.In this report, we describe the synthesis and biological evaluation of a new series of 2-(imidazo[2,1-b][1,3,4]thiadiazol-5-yl)-1H-benzimidazole derivatives (5a-ac). The molecules were analyzed by 1H NMR, 13C NMR, mass spectral and elemental data. The structure of one of the pre-final compounds, 6-(4-methoxyphenyl)-2-(4-methylphenyl)imidazo[2,1-b][1,3,4]thiadiazole-5-carbaldehyde (4d) and that of a target compound, 2-[2-methyl-6-(4-methyl phenyl) imidazo[2,1-b][1,3,4]thiadiazol-5-yl]-1H-benzimidazole (5aa) were confirmed by single crystal XRD studies. All the target compounds were screened for in vitro anti-tuberculosis activity against Mycobacterium tuberculosis H37Rv strain. Seven (5c, 5d, 5l, 5p, 5r, 5z and 5aa) out of twenty nine compounds showed potent anti-tubercular activity with a MIC of 3.125 ?g/mL. A p-substituted phenyl group (p-tolyl or p-chlorophenyl) in the imidazo[2,1-b][1,3,4]thiadiazole ring and/or a chloro group in the benzimidazole ring enhance anti-tuberculosis activity whereas a nitro group in the benzimidazole ring reduces the activity. In the antibacterial screening, compounds 5i, 5w and 5ac showed promising activity against the tested bacterial strains. Further, antifungal and antioxidant activities of these molecules were also investigated. In the cytotoxicity study, the active antitubercular compounds exhibited very low toxicity against a normal cell line. © 2015 Elsevier Masson SAS.Item Probiotic and biotherapeutic properties of tannase positive lactobacillus plantarum MTCC 2621 strain(Media Sphera Publishing Group mediashp@mediasphera.ru 46, Dmitrovskoe Shosse, Build. 2, Floor 4, Moscow 127238, 2019) Oriabinska, L.B.; Prasanna, D.B.; Lazarenko, L.M.The article presents the data on the probiotic properties of Lactobacillus plantarum MTCC 2621 strain obtained from the collection of microorganisms and the gene bank of the Institute of Microbial Technologies of India. The distinctive feature of the strain is its ability to produce tannase enzyme, which is connected with the antioxidant properties of the probiotic. It was shown that L.plantarum MTCC 2621 is antagonistic to Gram-positive and Gram-negative bacteria, as well as yeast. Its high potential for adhesion (IAM — 7.10±0.39) and selective resistance to a wide range of antibiotics (oxacillin, benzylpenicillin, gentamicin, kanamycin, enrofloxacin, polymyxin C and polymyxin M) were established. The immunological tolerance of the strain as well as its ability to stimulate nonspecific antiviral defense and innate immune system of the organism due to the activation of the synthesis of type I interferon were revealed in series of preclinical studies. The method of spectral-dynamic analysis shows the potential antitumor activity of L.plantarum MTCC 2621 against such oncological diseases as squamous and keratinized cervical cancer, uterine myoma, and cystic process. © 2019 Media Sphera Publishing Group. All rights reserved.Item One step synthesis of silver nanowires using fructose as a reducing agent and its antibacterial and antioxidant analysis(Institute of Physics Publishing helen.craven@iop.org, 2019) Sharma, D.; Rakshana, D.A.; Mohan Balakrishnan, R.M.; JagadeeshBabu, P.E.Silver nanowires were synthesised using hydrothermal method by reducing silver nitrate (AgNO3) using fructose in the presence of poly-vinylpyrrolidone (PVP). The parameters such as the effect of process temperature, AgNO3 molarity, PVP and fructose (C6H12O6) concentration influencing the synthesis of silver nanowires (Ag NWs) were investigated. The scanning electron microscope (SEM) images showed that ultra-long, uniform and thin silver nanowires were obtained under optimized conditions; 0.02 M AgNO3, 0.016 g ml-1 of fructose, 0.16 g ml-1 of PVP at 160 °C within 22 h. The dynamic light scattering (DLS) analysis revealed that the silver nanowires obtained have an average diameter of 77 nm possessing high level of crystallinity with face centered cubic (fcc) phase that is evident from the x-ray diffraction (XRD) patterns peaked at (111), (200), (220), (311) and (222) planes. FT-IR (Fourier transform infrared spectroscopy) results suggested that there is adsorption of PVP molecules on the silver atoms. Ag NWs exhibited better antibacterial activity against Escherichia coli and high antioxidant activity against 2,2-diphenyl-1- picrylhydrazyl (DPPH) free radical scavenger. This work gives a green approach to the hydrothermal synthesis of Ag NWs using fructose with a promising antibacterial and antioxidant properties. © 2019 IOP Publishing Ltd.Item Effects of different cooking methods on chemical compositions, in vitro starch digestibility and antioxidant activity of taro (Colocasia esculenta) corms(John Wiley and Sons Inc, 2022) Kapcum, C.; Pasada, K.; Kantiwong, P.; Sroysang, B.; Phiwtawee, J.; Suphantharika, M.; Belur, P.D.; Agoo, E.M.G.; Janairo, J.I.B.; Wongsagonsup, R.The impacts of different cooking methods (boiling, steaming, baking, microwaving and frying) on chemical compositions, starch digestibility and antioxidant activity of taro corms were investigated. Compared with raw taro, boiling and frying reduced crude protein and ash contents. Frying significantly increased crude fat and fibre contents but decreased carbohydrate content. All cooking methods reduced oxalate content, especially frying. Among the cooked products, the boiled taro had the highest rapidly digestible starch (RDS) but the lowest resistant starch (RS) contents. In contrast, the fried taro provided the lowest RDS but the highest RS contents. All cooking methods reduced the total phenolic content and antioxidant activity of taro. The boiled taro had the lowest antioxidant activity but the fired taro provided the highest. Frying was able to retain most of the health-promoting compounds with the lowest oxalate content; however, the high consumption of high-fat fried taro may adversely affect human health. © 2022 Institute of Food Science and Technology.Item Probing the synergistic effects of rutin and rutin ester on the oxidative stability of sardine oil(Springer, 2022) Chandrasekar, V.; Arunachalam, S.S.; Hari, H.; Shinkar, A.; Belur, P.D.; Iyyaswami, R.Multicomponent antioxidant mixture is proved to be highly effective in imparting oxidative stability to the edible oil. It is believed that the high efficacy of those mixtures is due to the synergistic effect exhibited by two or more components. The current study aims to analyse the synergistic effect of a flavonoid and its corresponding ester in improving the oxidative stability of n-3 PUFA rich sardine oil. The oxidative stability of rutin, esterified rutin and their combinations at three different concentrations was studied in sardine oil stored at 37 ºC for 12 days in contact with air under darkness. The combination of rutin and rutin ester showed maximum reduction of 54.2% in oxidation at 100 mg/kg and 150 mg/kg. Perhaps this is the first report on the synergistic effect of a flavonoid and its lipophilized ester for improving the oxidative stability of n-3 PUFA rich oil. © 2022, Association of Food Scientists & Technologists (India).Item Comparison of efficacy of various natural and synthetic antioxidants in stabilizing the fish oil(John Wiley and Sons Inc, 2022) Mishra, S.K.; Belur, P.D.; Iyyaswami, R.Use of antioxidants (natural and synthetic) can retard oxidative degradation of fish oil having n-3 PUFA. The performance of each antioxidant is found to be affected by the composition of the oil, presence of impurities and storage condition. Hence an attempt was made to find the efficacy of catechin, resveratrol, β-carotene, caffeic acid, sinapic acid, ellagic acid, ferulic acid, vanillic acid, quercetin, rutin, TBHQ, BHA, and BHT at a concentration of 0.9 mM in the bulk fish oil, stored for 50 days exposed to air at 25°C under darkness. The extent of primary and secondary oxidation of the stored oil was determined every 5 days and were compared. The efficacy of TBHQ followed by BHA and BHT was found to be highest among all the antioxidants studied. Among the natural antioxidants, resveratrol and catechin were found to exhibit superior efficacy, whereas β-carotene was found to exhibit proxidant behavior. Novelty impact statement: This is the first comprehensive study carried out to find the most effective antioxidant involving ten natural and three synthetic antioxidants in n-3 PUFA containing fish oil. TBHQ exhibited superior efficacy among all the antioxidants tested and at a concentration of 0.9 mM, the change in TOTOX value by the end of 40 days of storage was about 80%. None of the other antioxidants studied here, exhibited such superior stability. Among the natural antioxidants, resveratrol and catechin were found to be superior. © 2022 Wiley Periodicals LLC.Item Synthesis and characterization of 3,4-dihydroxyphenyl acetic acid esters and study of their efficacy in bulk fish oil(Elsevier Ltd, 2024) Arunachalam, S.S.; Chandrasekar, V.; Belur, P.D.Lipophilization of natural antioxidants is a proven strategy to enhance the solubility in bulk oil systems, thereby increasing their efficacy against oxidative degradation. This study aims to synthesize esters of 3,4-dihydroxyphenylacetic acid (3,4-DHPA) using Amberlyst-15 and to study the application of these esters in refined fish oil. Lipophilic esters were synthesized by esterification and transesterification of 3,4-DHPA in various solvent systems. Esters of methanol, butanol and hexanol were obtained with percent conversion of 81.1, 69.3 and 78.8 respectively, and were subjected to molecular characterization and in vitro oxidant assays. The 3,4-DHPA and its methyl ester showed 36% reduction in the TOTOX value over 30 days of storage. The length of the acyl chain in the ester was found to exert a high influence on its efficacy and lipophilicity. This is the first report of 3,4-DHPA and its lipophilic esters studied for enhancing the oxidative stability of fish oil. © 2024 Elsevier LtdItem Evaluation of Protein-polysaccharide complexes for microencapsulation of anthocyanins from Garcinia indica(Springer, 2025) Chandrakant Shanbhag, C.; N.g, K.; Iyyaswami, R.; D Belur, P.Microencapsulation of Anthocyanins (ACNs) extracted from dried rinds of Garcinia indica (GI) was performed using different polysaccharides (carboxy methyl cellulose, xanthan gum, inulin, chitosan, and gum arabic) in combination with two different proteins (whey protein isolate and sodium caseinate). The whey protein isolate (WPI)-xanthan gum (XG) complex was found to most efficiently encapsulate ACNs; Encapsulation Efficiency (EE) of 94.33% ±1.07 was achieved at 1% (w/v) of WPI, 1.50% (w/v) XG, 0.02 mg/mL ACNs, and pH 3. A comparative study on EE of ACNs from different sources, including standard ACN, GI crude ACNs, and Three-Liquid-Phase Extraction System (TLPES) purified ACNs, before (in the solution) and after freeze-drying (powder), indicated that the encapsulation is stable even after the freeze-drying of the WPI-ACNs-XG microencapsulates. Physicochemical characterization of freeze-dried ACNs microencapsulates done using antioxidant activity assay, particle size analysis, Fourier-transform infrared spectroscopy, scanning electron microscopy, and thermo gravimetric analysis supported the higher compatibility of the WPI-XG complex to encapsulate ACNs. ACNs obtained from TLPES purification were the most suitable for encapsulation as compared to standard ACN and GI crude ACNs due to their higher antioxidant potential (71.10% ± 1.32) and smooth particle surface morphology that shield the ACNs from adverse surroundings. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.