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Determination of curcuminoid content in turmeric using fluorescence spectroscopy
摘要： The potential of fluorescence spectroscopy is exploited for the characterization and comparison of different turmeric varieties based on curcuminoids content in turmeric powders. Fluorescence spectra from turmeric powders has been acquired by using excitation wavelengths from 300 to 470 nm with step of 10 nm to investigate the effect of excitation wavelengths on the emission of valuable ingredients for their characterization. Emission spectra revealed that fresh wet turmeric rhizomes show emission bands at 571 nm which is due to curcumin. It is found that main ingredient of turmeric powder is curcumin and best excitation wavelength is 467 nm for its maximum emission intensity. High Pressure Liquid Chromatography (HPLC) was used as alternate standard technique for determination of curcuminoid content in the reference samples. The curcumin content in the commercially available local turmeric brands were also evaluated, one brand showed significant covariance from standard fluorescent spectra of turmeric meaning this particular brand contained minimum curcumin content or have been severely adultered. In the next step the powders were heated at different temperatures from 60 ℃ to 150 ℃ (Normal cooking & frying temperatures) to observe the difference in emission spectra particularly keeping in view the molecular composition and curcuminoid content in turmeric. The results indicate that curcumin content gradually decreases above 90 ℃. Principal component analysis (PCA) has been employed on all the data to statistically differentiate small molecular changes and adulteration by covariance calculations.
关键词： Anti-inflammatory.,Turmeric,Fluorescence emission spectroscopy,Anti-oxidant,Curcumin
更新于2025-09-23 15:22:29
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Optical and structural properties of Curcuminoids Extracted from Curcuma longa L. for hybrid white light diode
摘要： In this study, curcuminoids were extracted from turmeric (Curcuma longa L.) by means of three methods, comprising the normal method, use of Soxhlet apparatus and by combining the normal method with the Soxhlet extraction approach. The limitation of stickiness in the use of curcuminoids was resolved by mixing it with silica gel. The curcuminoids used light down-conversion of UV light (390 nm) for the white light-emitting diode (WLED). The characteristics of the white light chromaticity were controlled by changing the current and concentration of the curcuminoids. The chromaticity coordinates (CIE) and correlated color temperature (CCT) were measured for different applied currents (20, 60 and 100 mA) and weights (25, 35 and 50 mg) of curcuminoids. It was observed from the concentration of phosphor that the combination of the normal and Soxhlet apparatus methods is most effective extraction approach. The results showed that increasing the concentration of phosphor signi?cantly and remarkably increased the value of CCT when different values of current were applied. The stress test showed that the prolongation of dye degradation can be improved using air gap and glass slid, with air gap being more effective. An optimum color rendering index (CRI) value of 61.2 is obtained. The white phosphor exhibited CIE values of 0.333, 0.3151 and color temperature (CCT) of 5405 K.
关键词： white light-emitting diode,turmeric,curcuminoids,correlated color temperature,chromaticity coordinates
更新于2025-09-10 09:29:36