S. Manikandan

Bio: S. Manikandan is an academic researcher from SRM University. The author has contributed to research in topics: Response surface methodology & Box–Behnken design. The author has an hindex of 7, co-authored 7 publications receiving 969 citations.

Box-Behnken design based multi-response analysis and optimization of supercritical carbon dioxide extraction of bioactive flavonoid compounds from tea (Camellia sinensis L.) leaves

Abstract: The popularity of tea is increasing on the global aspect because of its role as a significant source of phenolic compounds in human diet. The objectives of this present study is to develop a supercritical carbon dioxide (SC-CO2) extraction method suitable for extraction of phenolic compounds such as total phenolics, flavonoids and tannin from tea leaves at various extraction conditions such as extraction pressure (100–200 bar), temperature (40–60 °C) and co-solvent (ethanol) flow rate (1–3 g/min). Furthermore, the total antioxidant activity of the SC-CO2 tea leaves extracts was assessed using ABTS+ (2, 2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid)) method. Response surface methodology (RSM) combined with Box-Behnken design was used to investigate and optimize the process variables. The results showed that, extraction pressure and co-solvent flow rate have significant effect on the responses. From the experimental data, second order polynomial mathematical models were developed for each response with high coefficient of determination value (R2 > 0.95). An optimization study using Derringer’s desired function methodology was performed and the optimal conditions based on both individual and combinations of all independent variables (extraction pressure of 188 bar, temperature of 50 °C and co-solvent flow rate of 2.94 g/min) were determined with maximum total phenolic content of 131.24 mg GAE/100 ml, total flavonoid content of 194.60 mg QE/100 ml, total tannin content of 49.99 mg TAE/100 ml and totalantioxidant activity of 262.23 μMol TEAC/100 ml of extracts respectively with a overall desirability value of 0.983, which was confirmed through validation experiments.

Green and Sustainable Solvents in Chemical Processes

Abstract: Sustainable solvents are a topic of growing interest in both the research community and the chemical industry due to a growing awareness of the impact of solvents on pollution, energy usage, and contributions to air quality and climate change. Solvent losses represent a major portion of organic pollution, and solvent removal represents a large proportion of process energy consumption. To counter these issues, a range of greener or more sustainable solvents have been proposed and developed over the past three decades. Much of the focus has been on the environmental credentials of the solvent itself, although how a substance is deployed is as important to sustainability as what it is made from. In this Review, we consider several aspects of the most prominent sustainable organic solvents in use today, ionic liquids, deep eutectic solvents, supercritical fluids, switchable solvents, liquid polymers, and renewable solvents. We examine not only the performance of each class of solvent within the context of the...

Natural Antioxidants in Foods and Medicinal Plants: Extraction, Assessment and Resources

Abstract: Natural antioxidants are widely distributed in food and medicinal plants. These natural antioxidants, especially polyphenols and carotenoids, exhibit a wide range of biological effects, including anti-inflammatory, anti-aging, anti-atherosclerosis and anticancer. The effective extraction and proper assessment of antioxidants from food and medicinal plants are crucial to explore the potential antioxidant sources and promote the application in functional foods, pharmaceuticals and food additives. The present paper provides comprehensive information on the green extraction technologies of natural antioxidants, assessment of antioxidant activity at chemical and cellular based levels and their main resources from food and medicinal plants.

Clean recovery of antioxidant compounds from plant foods, by-products and algae assisted by ultrasounds processing. Modeling approaches to optimize processing conditions

Abstract: Ultrasound treatment is an alternative affordable, effective and reproducible method for the improved recovery of bioactive compounds from various processing streams. The objective of this review is to discuss the impact of ultrasound-assisted extraction on the recovery of polyphenols, carotenoids and chlorophylls from vegetal and algae matters. Optimization strategies will need to focus on appropriate equipment design and configuration of ultrasonic components, and extrinsic and intrinsic control parameters including ultrasonic power, temperature and extraction time to maximize the yield and biological activity of the extract. Modeling strategies to characterize and optimize ultrasound processes are also be highlighted in the manuscript.