Faculty Publications
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Item A new strategy to refine crude Indian sardine oil(Japan Oil Chemists Society yukagaku@jocs-office.or.jp, 2017) Charanyaa, S.; Belur, B.D.; Iyyaswami, R.Current work aims to develop a refining process for removing phospholipids, free fatty acids (FFA), and metal ions without affecting n-3 polyunsaturated fatty acid (n-3 PUFA) esters present in the crude Indian sardine oil. Sardine oil was subjected to degumming with various acids (orthophosphoric acid, acetic acid, and lactic acid), conventional and membrane assisted deacidification using various solvents (methanol, ethanol, propanol and butanol) and bleaching with bleaching agents (GAC, activated earth and bentonite) and all the process parameters were further optimized. Degumming with 5%(w/w) ortho phosphoric acid, two stage solvent extraction with methanol at 1:1 (w/w) in each stage and bleaching with 3% (w/w) activated charcoal loading, at 80ºC for 10 minutes resulted in the reduction of phospholipid content to 5.66 ppm from 612.66 ppm, FFA to 0.56% from 5.64% with the complete removal of iron and mercury. Under these conditions, the obtained bleached oil showed an enhancement of n-3 PUFA from 16.39% (11.19 Eicosapentaenoic acid (EPA) + 5.20 Docosahexaenoic acid (DHA)) to 17.91% (11.81 EPA + 6.1 DHA). Replacing conventional solvent extraction with membrane deacidification using microporous, hydrophobic polytetrafluoroethylene membrane (PTFE), resulted in a lesser solvent residue (0.25% (w/w)) in the deacidified oil. In view of lack of reports on refining of n-3 PUFA rich marine oils without concomitant loss of n-3 PUFA, this report is significant. © 2017 by Japan Oil Chemists’ Society.Item Anionic surfactant based reverse micellar extraction of l-asparaginase synthesized by Azotobacter vinelandii(Springer Verlag, 2017) Murugesan, S.; Iyyaswami, R.; Kumar, S.V.; Surendran, A.Abstract: l-Asparaginase synthesized by Azotobacter vinelandii via submerged fermentation in the presence of sucrose was successfully extracted using Reverse micellar extraction. Single step enzyme purification process was developed by varying the process variables which resulted in maximum specificity and extraction of l-asparaginase. The effect of different variables, including broth pH, addition of alcohol during the forward extraction and pH of the fresh stripping aqueous phase, addition of alcohol and electrolyte during backward extraction process were studied. Lower concentration of butanol resulted in maximum activity of the enzyme during forward extraction while enzyme activity was found to increase further with the addition of higher concentrations of ammonium sulphate during backward extraction. Chromatographic analysis of l-asparaginase peak at ~7.65 min was intense for the back extracted sample confirming the maximum purity of l-asparaginase obtained. Purity of l-asparaginase was increased to about 379.68 fold. Graphical abstract: [Figure not available: see fulltext.]. © 2017, Springer-Verlag Berlin Heidelberg.Item Nonionic surfactants induced cloud point extraction of Polyhydroxyalkanoate from Cupriavidus necator(Taylor and Francis Inc. 325 Chestnut St, Suite 800 Philadelphia PA 19106, 2017) Murugesan, S.; Iyyaswami, R.Polyhydroxyalkanoate synthesized by Cupriavidus necator DSM 428 was purified from the crude fermentation broth as such by performing nonionic surfactants (Triton X100, Triton X114 & Tergitol 6) induced cloud point extraction. Polyhydroxyalkanoate was extracted into the micelle-rich bottom phase (coacervate phase), while most of the cellular impurities partitioned into the aqueous phase. Cloud point temperatures and the extraction efficiency of different cloud point systems were studied at different pH value and in the presence of additives. Maximum extraction of biopolymer was achieved (recovery of 84.4%) with a purity of 92.49% at 3 pH with the addition of 0.1 M ammonium chloride in the mixed surfactant system at a reduced cloud point temperature of 33°C. © 2017 Taylor & Francis.Item Low frequency sonic waves assisted cloud point extraction of polyhydroxyalkanoate from Cupriavidus necator(Elsevier B.V., 2017) Murugesan, S.; Iyyaswami, R.Low frequency sonic waves, less than 10 kHz were introduced to assist cloud point extraction of polyhydroxyalkanoate from Cupriavidus necator present within the crude broth. Process parameters including surfactant system variables and sonication parameters were studied for their effect on extraction efficiency. Introduction of low frequency sonic waves assists in the dissolution of microbial cell wall by the surfactant micelles and release of cellular content, polyhydroxyalkanoate granules released were encapsulated by the micelle core which was confirmed by crotonic acid assay. In addition, sonic waves resulted in the separation of homogeneous surfactant and broth mixture into two distinct phases, top aqueous phase and polyhydroxyalkanoate enriched bottom surfactant rich phase. Mixed surfactant systems showed higher extraction efficiency compared to that of individual Triton X-100 concentrations, owing to increase in the hydrophobicity of the micellar core and its interaction with polyhydroxyalkanoate. Addition of salts to the mixed surfactant system induces screening of charged surfactant head groups and reduces inter-micellar repulsion, presence of ammonium ions lead to electrostatic repulsion and weaker cation sodium enhances the formation of micellar network. Addition of polyethylene glycol 8000 resulted in increasing interaction with the surfactant tails of the micelle core there by reducing the purity of polyhydroxyalkanoate. © 2017 Elsevier B.V.Item Reverse micellar extraction of lactoferrin from its synthetic solution using CTAB/n-heptanol system(Springer India sanjiv.goswami@springer.co.in, 2017) Pawar, S.S.; Iyyaswami, R.; Belur, P.D.The partitioning of Lactoferrin (LF) into the reverse micellar phase formed by a cationic surfactant, cetyltrimethylammonium bromide (CTAB) in n-heptanol from the synthetic solution of LF was studied. The solubilization behaviour of LF into the reverse micellar phase and back extraction using a fresh stripping phase were improved by studying the effect of processing parameters, including surfactant concentration, solution pH, electrolyte salt concentration and addition of alcohol as co-solvent. Forward extraction of 100% was achieved at CTAB concentration of 50 mM in n-heptanol solvent, pH of 10 and 1 M NaCl. The electrostatic force and hydrophobic interaction have major influence on LF extraction during forward and back extraction respectively. The size of the reverse micelles and their corresponding water content were measured at different operating conditions to assess their role on the LF extraction. The present reverse micellar system has potential to solubilise almost all the LF into the reverse micelles during forward extraction and could able to allow back extraction from the reverse micellar phase with addition of small amount of co-solvent. © 2017, Association of Food Scientists & Technologists (India).Item Selective extraction of lactoferrin from acidic whey using CTAB/n-heptanol reverse micellar system(Springer, 2019) Pawar, S.S.; Iyyaswami, R.; Belur, P.D.A reverse micellar system comprising CTAB/nheptanol, developed for extracting lactoferrin (LF) from a synthetic solution of LF, was investigated for the selective extraction of LF from synthetic whey protein solution, which was prepared by mixing the pure whey proteins. The process conditions obtained during the process was further extended to extract the LF from real acidic whey. The selective extraction of LF was improved by studying the effect of NaCl concentration (additive) and aqueous phase pH on the partitioning of LF into the micellar phase. The highest extraction of LF (98.7%) from acidic whey to micellar phase was achieved at the aqueous phase pH of 10.3 and NaCl concentration of 1.1 M. The LF was back extracted to the aqueous stripping phase with 94% extraction efficiency and 100% purity. The recycling capacity of the organic phase after the back extraction of LF was analyzed to make the process more economical. © Association of Food Scientists & Technologists (India) 2019.Item Nonionic surfactant-based cloud point extraction of polyhydroxyalkanoate from the fermentation crude in a rotating disc contactor(Bellwether Publishing, Ltd., 2021) Murugesan, S.; Iyyaswami, R.; J Khandelwal, P.Nonionic surfactant-based cloud point extraction of polyhydroxyalkanoate from fermentation broth was implemented in a modified rotating disc contactor. The effect of rotor speed and phase flowrates on dispersed micellar phase holdup, mass transfer coefficient, yield, and purity were studied with micellar system contains TX114 (4.5 wt %)+ TMN6 (0.5 wt %) and 0.1 M ammonium chloride at broth pH of 3. The rotor speed and the micellar phase flowrate had a significant effect. A maximum PHA recovery of 85.48% and purity of 86.01% were achieved. The correlation was developed to predict the dispersed-phase holdup. © 2020 Taylor & Francis Group, LLC.Item Lactoperoxidase partitioning from whey using the reverse micelles of non-ionic/ionic mixed surfactants: Improvement of back extraction(John Wiley and Sons Inc, 2022) Karanth, S.; Iyyaswami, R.The reverse micellar system formed with a mixture of ionic and non-ionic surfactants, AOT (Sodium bis[2-ethyl hexyl] sulfosuccinate)/Tween 80 in isooctane, was studied for the selective extraction of Bovine Lactoperoxidase (LP) from acid whey. The effect of pH and ionic strength of acid whey and surfactant concentrations were studied and a maximum of 86% LP was extracted from acid whey at pH 9.5 with the addition of 0.2 M KCl to the reverse micelles formed with AOT (115 mM)/Tween 80 (23 mM). The back extraction of LP was studied at different aqueous stripping phase pH, ionic strength and concentration of counter-ionic surfactant Cetyltrimethylammonium bromide (CTAB). The back extraction of 112% with 80% LP recovery was achieved when the stripping phase pH was 10.5 with 1.5 M KCl and 60 mM CTAB. The antimicrobial activity of the extracted LP showed reduction in colony-forming units of S. aureus. Novelty impact statement: The reverse micelles formed with AOT/Tween 80 surfactant mixture minimize the pH-dependent denaturation of LP and widen the pH window (7.5–9.5) for LP extraction. The back extraction of LP from the reverse micellar phase to aqueous stripping phase was improved by the addition of CTAB as counter-ionic surfactant. A purification fold of 11.26 achieved with minimal loss in activity of LP by retaining the native Antimicrobial characteristic. © 2022 Wiley Periodicals LLC.Item Biosurfactant Based Reverse Micellar Extraction of Lactoperoxidase from Whey: Exploitation of Rhamnolipid Characteristics for Back Extraction(Taylor and Francis Ltd., 2023) Karanth, S.; Iyyaswami, R.; Raj, N.T.Biosurfactant-based reverse micellar extraction of Lactoperoxidase (LP) was studied using Rhamnolipid (RL) as a biosurfactant. Different solvents were considered to select a suitable organic phase for forming reverse micelles (RM) to varying concentrations of RL for the extraction of LP from its synthetic aqueous solution. The effect of addition of nonionic surfactant as lipophilic linker, whey pH, and ionic strength of the whey was studied to improve the forward extraction of LP from acid whey. About 96.65% LP was extracted to the RM phase during forward extraction. Further, a new back extraction strategy was developed by harnessing the biosurfactant properties. The pH-specific protonation–deprotonation characteristic of the RL headgroups was exploited to overcome the back extraction of LP, which is the rate-limiting step. The back extraction in citrate buffer at pH 5 using 0.75 M KCl resulted in 85.71% active LP recovery with 8.4-fold purification. The effect of the extraction process on the antimicrobial activity of LP was further examined with S. aureus, and the multiplication of the organism was almost arrested even after 24 hr at 9°C. © 2023 Taylor & Francis Group, LLC.Item Extraction of chrysin from propolis and its selective encapsulation in synthetic/natural surfactant-based micelles(Taylor and Francis Ltd., 2024) Sivanesan, M.; Krishnapura, P.R.; Iyyaswami, R.; Parappa, K.; Belur, P.D.The encapsulation characteristics of chrysin (important flavonoid with potential food, pharmaceutical, and biomedical applications) was studied with nonionic surfactants Triton X-114 (TX) and Quillaja Saponin (QS), individually. The factors influencing the encapsulation efficiency (EE) of standard chrysin that is surfactant concentration, pH, NaCl concentration, and chrysin concentration were analyzed. The maximum EE of standard chrysin was found to be 98.23 ± 1.63% with TX micelles and 83 ± 2.31% with QS micelles under the following conditions: 0.02 mg/mL standard chrysin, 5% NaCl, pH 7, and 4% w/w TX 6% w/w QS. Selective extraction of chrysin from propolis was tried using three extraction techniques namely Maceration, Microwave-assisted Extraction (MAE), and Maceration with Microwave-assisted Extraction (MMAE). MAE, which gave a chrysin yield of 3 mg/g, was deemed the most suitable method for chrysin extraction from propolis. This MAE crude extract was subjected to encapsulation under the conditions previously optimized for standard chrysin. Specific encapsulation of chrysin from the propolis crude extract was achieved, with an EE of 92 ± 0.86% with TX and 84.97 ± 1.34% with QS. The encapsulated chrysin was characterized using particle size analysis and antioxidant activity. TX system was found to be the most suitable for the encapsulation, as it was able to selectively encapsulate chrysin from propolis, despite the presence of other interfering flavonoids in the crude extract. The microwave-assisted extraction combined with surfactant-based micellar encapsulation can be said to be an effective process for the extraction and encapsulation of chrysin from propolis. © 2023 Taylor & Francis Group, LLC.