Browsing by Author "Iyyaswami, R."

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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.
A review on adsorptive removal of oil pollutants (BTEX) from wastewater using carbon nanotubes
(Elsevier B.V., 2019) Anjum, H.; Johari, K.; Francisco Nirmala, N.; Ganesapillai, M.; Arunagiri, A.; Iyyaswami, R.; Murugesan, M.
A progressive economic growth and proliferating global population caused adequate provision of clean water as a global issue. The systematic eradication of toxic pollutants from the environment has become a predominant matter from a biological and environmental perspective. Thus, adsorptive removal of hazardous components from wastewater is one of the most captivating strategies for purification technologies. Recently, carbon nanotubes (CNTs) have been reported to be very promising in the adsorption of various stable organic compounds due to their unique properties essential for further surface modification. In order to get the maximum removal of these pollutants, it is mandatory to understand the interaction mechanisms between the sorbent and sorbate. This review summarizes the recent literature on the adsorptive removal of BTEX from wastewater using CNTs. The impact of various factors (sorption sites of CNTs, physical properties of nanotubes, properties of background solution, and surface chemistry of CNTs) on the adsorption of BTEX over CNTs and the plausible interaction mechanisms such as hydrophobic interaction, electrostatic interaction, dispersive/repulsive interactions, π-π interactions and hydrogen bonding are critically reviewed. The present review has sorted out numerous prevailing gaps in the available information whilst recognizing a number of encouraging avenues and approaches for the upcoming research thrust. © 2018 Elsevier B.V.
Alcohol-based aqueous biphasic system applied to partition four different natural bioactive compounds from Garcinia indica Choisy
(Bellwether Publishing, Ltd., 2021) Nainegali, B.S.; Iyyaswami, R.; Belur, P.D.
An attempt was made to simultaneously partitioning Anthocyanins (ACN), Hydroxycitric acid (HCA), Garcinol (GL), and Isogarcinol (IGL) from fruit rinds of Garcinia indica using the 1-propanol and magnesium sulfate system. The influences of 1-propanol and magnesium sulfate concentration and Tie line Length (TLL) were investigated to obtain the optimal partitioning and recovery of GL and IGL into the top-phase and ACN and HCA to the bottom phase. The 25% w/w 1-propanol and 12% w/w magnesium sulfate system showed the maximum extraction efficiency for all the compounds. The purity and recovery were further improved by employing the second stage ATPS. © 2020 Taylor & Francis Group, LLC.
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.
Aqueous two phase based selective extraction of mannose/glucose specific lectin from Indian cultivar of Pisum sativum seed
(Elsevier B.V., 2019) Rashmi, B.S.; Iyyaswami, R.
Pisum sativum lectin (Psl) being a high-value protein has marked its application in the biomedical and therapeutic field. Aqueous two phase extraction (ATPE) was implemented as a selective partitioning technique for the partial purification of Psl from its seeds. PEG/citrate based biodegradable aqueous two phase system (ATPS) was screened and the factors such as the type and concentration of citrate salts, molar mass and concentration of polyethylene glycol (PEG), tie line length (TLL) and additive (NaCl) concentration, pH, crude load and volume ratio were studied for the selective partition of Psl. The Psl was successfully extracted to the top phase in the ATPS formed with 18% PEG 6000/16% sodium citrate at 41.01% TLL, 2% NaCl and pH of 7.5. A volume ratio of 0.76 and a crude load of 20% showed maximum activity yield of 122.12% with the purification factor of 16.26. The subunits of Psl namely ? and ? were identified with a molecular weight of 6 and 18 kDa respectively during the purity analysis using SDS PAGE and HPLC. © 2019 Elsevier B.V.
Aqueous two phase partitioning of fish proteins: partitioning studies and ATPS evaluation
(Springer India sanjiv.goswami@springer.co.in, 2015) Nagaraja, V.H.; Iyyaswami, R.
A suitable Aqueous Two Phase System (ATPS) has been identified for the partitioning of crude fish proteins from fish processing industrial effluent. A detailed study has been performed to analyze the influence of various parameters on protein partitioning such as molecular weight of PEG, effect of different salts (MgSO4, K2HPO4, Na3C6H5O7, Na2SO4, (NH4) 2PO4, K3C6H5O7) and their concentrations, pH, temperature, Tie Line Length (TLL), effluent loading and volume ratio. PEG 2000 - sodium sulphate ATPS was found to be a most favourable system among the selected ATPS for higher partition coefficient of proteins. The binodal curve and equilibrium characteristics of PEG 2000 - sodium sulphate were established and fitted to empirical equations. The equilibrium compositions (tie line) were correlated using Othmer–Tobias and Bancroft equations. © 2014, Association of Food Scientists & Technologists (India).
Aqueous two phase partitioning of Pisum sativum lectin in PEG/citrate salt system
(Taylor and Francis Inc. 325 Chestnut St, Suite 800 Philadelphia PA 19106, 2018) Bommenahalli Shashidhara, R.; Iyyaswami, R.
Pisum sativum lectin (Psl) is a metalloprotein which is in the center of research interest because of its HIV-1 reverse transcriptase inhibitory activity and mitogenic activity. The application of this lectin in various fields demands the economically feasible and scalable purification strategy other than affinity chromatography. The suitability of aqueous two phase system (ATPS) composed of poly ethylene glycol (PEG) with different salts (sodium citrate, potassium citrate, and ammonium citrate) was evaluated for better partitioning of Psl. The significant factors such as molar mass and concentration of PEG, type and concentration of salts, the effect of tie line length (TLL), ionic strength, and pH were studied to select a suitable system for better partitioning of Psl. ATPS comprising of 18% PEG 6000, 16% sodium citrate, 1% NaCl at the operating condition of pH 8, 40.23% of TLL, and the volume ratio of 1.32 was found to be the best system which gave a maximum partition coefficient and yield of 14.5% and 98.66%, respectively. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.
Aqueous two-phase based simultaneous extraction and purification of cephalopod melanin
(Taylor and Francis Ltd., 2025) Patrick, S.M.; Iyyaswami, R.; Belur, P.D.
The cephalopod processing industry generates large quantities of ink sacs, an underutilized yet valuable source of eumelanin. Conventional extraction of melanin, relying on acid or alkali treatments, often leaves residual proteins and carbohydrates, requires multiple purification steps, and risks pigment integrity. This study investigated a polymer-salt-based aqueous two-phase system (ATPS) as an eco-friendly alternative for the selective extraction and purification of melanin. Screening of polyethylene glycols of varying molecular weights with inorganic salts identified the PEG 6000-K2HPO4 system as the most effective. The equilibrium characteristic of the system was assessed using Othmer-Tobias and Bancroft correlations, while the partitioning behavior of melanin was evaluated by considering the process parameters, including polymer and salt concentrations, tie-line length, volume ratio, and sample loading. Under optimal conditions (tie-line length of 53.23% (w/w), a volume ratio of 0.14, and a sample loading of 15% (w/w)), melanin recovery reached 99.1% with 95% purity in the PEG-rich phase. These results outperform conventional methods in both yield and product quality, highlighting ATPS as a sustainable and scalable strategy for valorizing cephalopod waste, with promising applications in food, pharmaceutical, and biomedicine. © 2025 Taylor & Francis Group, LLC.
Assessment of Arsenic, Vanadium, Mercury, and Cadmium in Food and Drug Packaging
(F1000 Research Ltd, 2024) Mukhi, S.; Rukmini, M.S.; Manjrekar, P.; Iyyaswami, R.; Sindhu, H.
Background: Food and drug packaging materials are an integral part of our everyday life. Noxious elements can inadvertently be included in packaging materials in various stages of their production. Adulterants, adhesives, colorants and heavy metal interference are the common sources of contamination in food packaging materials. Heavy metal toxicity has far-reaching ill effects on living organisms. The present study aimed at qualitatively and quantitatively analysing heavy metal content of various materials that are used for food and drug packaging in India. Methods: The qualitative detection was done by rapid assay and heavy metals were quantified with the help of inductively coupled plasma-optical emission spectrometry (ICP-OES). A total of thirteen types of food and drug packaging materials were procured from local market and analysed for four heavy metals viz. arsenic (As), vanadium (V), mercury (Hg) and cadmium (Cd). The concentration of each heavy metal in the samples was compared with the permissible values published by the European Council. Results: Heavy metals were qualitatively detected in ten out of thirteen samples. Among the ten samples mercury and arsenic were detected the most followed by cadmium and vanadium. Quantitative estimation by ICP-OES showed presence of vanadium and cadmium in ten samples and arsenic and mercury in all the thirteen samples above the permissible range. Conclusions: The notable elevation in mercury concentration, followed by cadmium, arsenic and vanadium registering the least, presents a potential health hazard to consumers and compromises the food quality. ©: © 2024 Mukhi S et al.
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.
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.
Designing of A Synergistic Mixture of Natural Antioxidants Through Statistical Approaches for Enhancing the Oxidative Stability of Sardine Oil
(Enviro Research Publishers, 2023) Mishra, S.K.; Belur, P.D.; Chandrasekar, V.; Iyyaswami, R.
Given the diverse routes of oxidation and a variety of oxidation products, the right combination of antioxidants is expected to exhibit synergistic effects in retarding refined sardine oil oxidation. In this study, a full factorial design (24) was utilized to choose a combination of natural antioxidants which exhibit interactive effect and response surface modelling (RSM) was used to identify the optimal concentration of the selected antioxidant mixture which exhibit synergistic effect. Catechin and resveratrol showed a strong interactive effect among the four natural antioxidants (sinapic acid, vanillic acid, catechin, and resveratrol) studied in sardine oil stored for 50 days at 25ºC under darkness. Two optimal concentrations of interactive antioxidants were found through RSM. Catechin and resveratrol at 0.5 mM and 0.625 mM respectively, exhibited a strong synergistic effect whereas, at 0.5 mM and 3.7 mM respectively, showed prooxidant effect. This is the first of its kind report on the formulation of a synergistic antioxidant mixture for retarding oxidation using statistical approaches. © 2023 The Author(s).
Development of stable and functional encapsulated chrysin using casein–polysaccharide complexes for food applications
(John Wiley and Sons Inc, 2023) Parappa, K.; Krishnapura, P.R.; Iyyaswami, R.; Belur, P.D.
Chrysin is a hydrophobic flavonoid with multiple health benefits. The various applications of chrysin are challenged by its poor solubility, instability and loss of bioactivity. Casein–chrysin complex and casein–polysaccharide–chrysin complexes have developed to overcome these limitations. Very high encapsulation efficiency of 98.23 ± 0.22% was achieved with casein–inulin–chrysin complex. The chrysin was able to form a stable casein–polysaccharide–chrysin complex suspension with a hydrodynamic diameter of 382.3 nm, zeta potential value of −12.3 mV and a Polydispersity Index (PDI) of 27.7. The antioxidant activity of chrysin increased about threefold after encapsulation. The release of chrysin from its encapsulated complexes to different buffers in the pH range of 3 to 10 was studied at 1:10 ratio. At the end of 48 h, only 6%–8% of chrysin was released in the pH range 3–4, 33%–58% at pH 5–9 and 62% at pH 10. The chrysin encapsulated in casein–inulin–chrysin complex was able to overcome the rapid release of chrysin from the casein–chrysin complex. The results indicate the successful development of a stable encapsulated chrysin complex which can overcome the various limitations of chrysin in its potential applications. © 2023 Institute of Food, Science and Technology (IFSTTF).
Effectiveness of rutin and its lipophilic ester in improving oxidative stability of sardine oil containing trace water
(Blackwell Publishing Ltd customerservices@oxonblackwellpublishing.com, 2018) Chandrasekar, C.; Belur, P.D.; Iyyaswami, R.
Poor oxidative stability exhibited by n-3 polyunsaturated fatty acid rich sardine oil is a major challenge for its utilisation in industry. Considering the fact that water is always present in bulk oil in trace amounts during storage, an effort was made to understand and compare the effectiveness of rutin and its corresponding lipophilic ester in enhancing oxidative stability of refined sardine oil containing trace water (0.16% w/w). Peroxide value, conjugated diene value, p-anisidine value and thiobarbituric acid reactive substances (TBARS) value were determined during 20 days storage. Rutin fatty ester showed 50% reduction in primary oxidation and 42.46% reduction in secondary oxidation, whereas rutin showed 20.6% and 20.43% reduction in primary and secondary oxidation, respectively, by the end of 20 days storage. Thus, it is clearly established that rutin fatty ester is more effective than hydrophilic rutin in sardine oil containing trace water, which contradicts the polar paradox theory. © 2017 Institute of Food Science and Technology
Enhancement of n-3 polyunsaturated fatty acid glycerides in Sardine oil by a bioimprinted cross-linked Candida rugosa lipase
(Elsevier Inc. usjcs@elsevier.com, 2018) Sampath, C.; Belur, P.D.; Iyyaswami, R.
Considering the advantages of bioimprinting and carrier free immobilization, cross-linked enzyme aggregates (CLEA) were prepared by using bioimprinted Candida rugosa lipase (CRL) with Bovine serum albumin (BSA), Polyethyleneimine and glutaraldehyde. Effect of various factors such as CRL-Oleic acid ratio, CRL-BSA ratio, CRL- Polyethyleneimine ratio, glutaraldehyde loading, cross-linking time etc., on lipase activity recovery and aggregate yield were studied and optimized. This immobilized lipase (CRL-CLEA) was used for the selective hydrolysis of ester linkages of non-PUFA glycerides, with an aim to concentrate EPA and DHA glycerides in the Sardine oil. Imprinting with oleic acid in the presence of ethanol and Tween 60, and further immobilization with co-aggregates and cross-linking agent showed 10.4 times higher degree of hydrolysis compared to free enzyme. As result, 2.83-fold increase of n-3 PUFA content in deacidified oil was obtained by using CRL-CLEA. The resultant oil had negligible di- and triglycerides content, proving higher efficiency in hydrolysing ester bonds of fatty acids, other than n-3 PUFA. Reusability studies showed CRL-CLEA could be reused up to 5 runs without a substantial reduction in its performance. Improvement in degree of hydrolysis, thermostability, efficiency of hydrolysis and reusability were achieved due to bioimprinting and subsequent immobilization of CRL in the form of CLEA. © 2017 Elsevier Inc.
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.
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.
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.
Lipase mediated synthesis of rutin fatty ester: Study of its process parameters and solvent polarity
(Elsevier Ltd, 2017) Chandrasekar, C.; Belur, P.D.; Iyyaswami, R.
Lipophilization of antioxidants is recognized as an effective strategy to enhance solubility and thus effectiveness in lipid based food. In this study, an effort was made to optimize rutin fatty ester synthesis in two different solvent systems to understand the influence of reaction system hydrophobicity on the optimum conditions using immobilised Candida antartica lipase. Under unoptimized conditions, 52.14% and 13.02% conversion was achieved in acetone and tert-butanol solvent systems, respectively. Among all the process parameters, water activity of the system was found to show highest influence on the conversion in each reaction system. In the presence of molecular sieves, the ester production increased to 62.9% in tert-butanol system, unlike acetone system. Under optimal conditions, conversion increased to 60.74% and 65.73% in acetone and tert-butanol system, respectively. This study shows, maintaining optimal water activity is crucial in reaction systems having polar solvents compared to more non-polar solvents. © 2017 Elsevier Ltd
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.