Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
5 results
Search Results
Item Model generation and process optimization of microwave-assisted aqueous extraction of anthocyanins from grape juice waste(Blackwell Publishing Inc. subscrip@blackwellpub.com, 2017) Venkatramanan, V.; Shanmugam, S.; Arulvel, A.The microwave-assisted extraction of anthocyanins from grape juice waste was investigated in this study. The optimization was implemented using response surface methodology with Box–Behnken design and genetic algorithm (GA). Anthocyanins from grape juice waste were extracted under various microwave power (100–600 W), exposure time (1–5 min) and solvent/solid ratio (10–50 ml/g). The total monomeric anthocyanin yield was considered as the response for optimization experiments. The results indicated that the quadratic model was significant for the chosen response at p <.0001. The analysis of variance and response surface plots showed a significant interaction of all the selected independent variables over anthocyanin extraction process. The maximum anthocyanin yield of 1.31881 mg/g of grape juice waste was predicted by response surface methodology, and the prediction was improved to 1.32244 mg/g of grape juice waste by GA. A confirmatory experiment performed under optimum conditions showed anthocyanin yield of 1.3215 mg/g of grape juice waste. Hence, this model was successful in predicting anthocyanin extraction from grape juice waste under microwave-assisted extraction conditions. Practical application: Anthocyanin pigments find a broad range of implementation as food colorants, antioxidants, and anticancerous agents. The waste residue obtained during grape juice production and processing is also rich in anthocyanins and can be used as an alternative source for anthocyanin extraction. This study exploits the use of grape juice waste for anthocyanin extraction, and it can be the best way of waste management and cost reduction in grape juice production units. © 2016 Wiley Periodicals, Inc.Item Simultaneous extraction of four different bioactive compounds from Garcinia indica and their enrichment using Aqueous Two-Phase Systems(Institution of Chemical Engineers, 2019) Nainegali, B.S.; Iyyaswami, R.; Belur, P.D.Garcinia indica fruits contain several important bioactive compounds like anthocyanin, garcinol, isogarcinol and hydroxycitric acid. Simultaneous extraction of these bioactive compounds from the dried G. indica fruit by employing water, acidified water and an aqueous mixture of ethanol and propanol as solvents and subsequent enrichment using Aqueous Two-Phase Systems (ATPS) were studied. Aqueous 1-propanol (60% (v/v)) and aqueous ethanol (80% (v/v)) were found to be a superior solvent to extract anthocyanin, garcinol, isogarcinol and HCA compared to acidified water and water alone as solvent. The crude extract was further subjected to the PEG-salt and alcohol–salt based Aqueous Two-Phase Extraction (ATPE) for the simultaneous enrichment of garcinol, isogarcinol into top phase and anthocyanins and hydroxycitric acid towards the bottom phase. The ATPS containing ethanol and ammonium sulfate system with TLL of 38.60–43.28% was found suitable to enrich 86.33% of anthocyanins and 75.17% of HCA in salt-rich bottom phase and 96.39% of garcinol and 94.26% of isogarcinol in ethanol-rich top phase. © 2019 Institution of Chemical EngineersItem Activated carbon-based dye-sensitized solar cell for development of highly sensitive temperature and current sensor(Institute of Physics Publishing helen.craven@iop.org, 2019) Dasari, K.K.; Gumtapure, V.Activated carbon was produced from coconut shells using steam activation method. The process followed by intermediate pyrolysis performed at 575° C. The production yields end products as carbon, biofuels and gases. The developed activated charcoal is implemented as counter electrode in demonstrating Dye Sensitised Solar Cell using naturally available sensitizer. In addition, Dye Sensitised Solar Cell based current and temperature sensors were developed for highly remote optoelectronics applications. Anthocyanin dye extracted from pomegranate juice generated maximum current of 10 mA cm-2. The characteristics of the cell was performed with different optic filters wavelength ranging 400-650 nm and the maximum efficiency was developed for wavelength of 445 nm. © 2019 IOP Publishing Ltd.Item Partitioning of bio-active compounds from rinds of garcinia indica using aqueous two-phase system: Process evaluation and optimization(Elsevier B.V., 2020) Nainegali, B.S.; Iyyaswami, R.; Belur, P.D.The simultaneous extraction of anthocyanins (ACNs), garcinol (GL), isogarcinol (IGL) and hydroxycitric acid (HCA) from the rinds of Garcinia indica (GI) fruit and their partition behaviour in the aqueous two-phase system (ATPS) formed by 1-propanol-(NH4)2SO4 was investigated. The effect of different variables that govern the partition characteristics were studied and the amount of crude loaded into the ATPS, the concentration of 1-propanol and (NH4)2SO4 were found to be the significant variables. The Response Surface Methodology (RSM) was adopted to optimize the process variables through desirability based multi-response optimization for the partitioning of GL and IGL to the alcohol rich top phase and ACNs and HCA to the salt-rich bottom phase by considering the partitioning coefficients (K) and extraction efficiency of all the four bioactive components as responses. A ATPS consisting of 15.202% (w/w) 1-propanol, 10.242% (w/w) (NH4)2SO4 having the TLL of 28.505% (w/w) at a crude load of 25% (w/w) able to partition 97.39% GL (K = 370.770) and 92.38% IGL (K = 120.581) in the top phase and 99.19% ACNs (K = 0.080) and 99.83% HCA (K = 0.016) in the bottom phase with a purity higher than 99% by implementing secondary ATPS. © 2020 Elsevier B.V.Item Simultaneous partitioning of multiple bioactive compounds from Garcinia indica rinds in a three-liquid-phase extraction systems(Taylor and Francis Ltd., 2025) Shanbhag, C.C.; Salimuddin, R.M.H.; Iyyaswami, R.; Belur, P.D.Simultaneous extraction and purification of principal bioactive compounds, anthocyanins (ACNs), garcinol (GL), and hydroxycitric acid (HCA) from the rinds of Garcinia indica (Kokum) fruits in a single-step using Three Liquid Phase Systems (TLPS) were investigated. Among the various phase-forming components studied, TLPS formed by n-hexane-ethanol-(NH4)2SO4-water system was considered for partitioning GL into the n-hexane-rich top phase, ACNs into the ethanol-rich middle phase, and HCA into the aqueous salt-rich bottom phase. The present system was even able to separate carbohydrates into the bottom phase, which can be detrimental to the stability of ACNs. The effect of n-hexane, ethanol, and (NH4)2SO4 concentration on the partitioning behavior of biomolecules was analyzed. The TLPS composed of water-n-hexane-ethanol-(NH4)2SO4 could purify and extract 95.08% of ACNs, 95.33% of GL, and 67.98% of HCA in a single-step extraction process while the other extraction methods require multi-step extraction process to separate these three compounds. The effect of pH studies on the partitioning characteristics of biomolecules revealed that pH 4 is optimum and more efficient than the native pH of the system to achieve maximum yield of all the bioactive compounds. © 2025 Taylor & Francis Group, LLC.
