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This review covers and discusses various aspects of carotenoids including their chemistry, classification, biosynthesis, extraction methods (conventional and non-conventional), analytical techniques and biological roles in living beings. Carotenoids play a very crucial role in human health through foods, cosmetics, nutraceuticals and pharmaceuticals. Among carotenoids, lycopene acts as best antioxidant.Various extraction methods have been employed for extraction of carotenoids: solvent extraction, soxhlet extraction, centrifugation and non-conventional methods of extraction such as ultrasoundassisted, microwave-assisted, enzymatic and the innovative technique supercritical carbondioxide (SC-CO 2 ) extraction. The green and environmentally friendly technique for extraction of carotenoids is SC-CO 2 extraction which extracts pure compound in high yield without the use of harmful organic solvents, it operates at lower temperature so it is useful for extraction of thermolabile compounds. This technique uses SC-CO 2 as green solvent and other solvents as modifiers which are generally recognized as safe (GRAS) solvents. Green technology is the need of present time in order to keep environment healthy, pollution free and sustainable for coming generation. Present review includes several analytical techniques used to identify and quantify carotenoids are: thin layer chromatography (TLC), high performance thin layer chromatography (HPTLC), high performance liquid chromatography (HPLC), liquid chromatography-mass spectrometry (LC-MS), nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), ultra performance liquid chromatography-tandem mass spectrometer (UPLC-MS), UV-Vis (Ultraviolet-Visible) spectrophotometry; out of these, NMR and FTIR have been explored the least for carotenoid analysis.

-A synthetic rubber powder was used to adsorb the residual oil in palm oil mill effluent (POME). POME is the wastewater produced by the palm oil industry. It is a colloidal suspension which is 95-96% water, 0.6-0.7% oil and 4-5% total solids including 2-4% suspended solids originating in the mixing of sterilizer condensate, separator sludge and hydrocyclone wastewater. POME contains 4,000 mg dm -3 of oil and grease, which is relatively high compared to the limit of only 50 mg dm -3 set by the Malaysian Department of Environment. A bench-scale study of the adsorption of residual oil in POME using synthetic rubber powder was conducted using a jar test apparatus. The adsorption process was studied by varying parameters affecting the process. The parameters were adsorbent dosage, mixing speed, mixing time and pH. The optimum values of the parameters were obtained. It was found that almost 88% removal of residual oil was obtained with an adsorbent dosage of 30 mg dm -3 and mixing speed of 150 rpm for 3 hr at a pH 7. Adsorption equilibrium was also studied, and it was found that the adsorption process on the synthetic rubber powder fit the Freundlich isotherm model.