From a green chemical point of view, techniques for extracting organic substances employing conventional solvents must be replaced with novel environment-friendly techniques. Dimethyl ether (DME) may be one of such alternative solvents to be used. Rice bran is a co-product of rice milling, which is rich in oil content.Theoretically, around 20-25% of the total weight of rice bran must be oily components known as rice bran oil (RBO). In the present study, liquefied DME was used as a low temperature solvent for extracting RBO.From 10 g of fully dried rice bran used in a single batch extraction with DME, ca. 0.90 g of RBO were recovered (efficiency, 9.0%). Although the efficiency of total RBO extraction by batch extraction with DME was lower than the conventional solvent extraction system using acetone, lipid-pigment complexes potentially beneficial for human health such as ferulic acid-conjugated lipids were efficiently extracted.Fatty acid compositions found in RBO prepared by DME extraction and conventional solvent extraction did not differ. Lastly, improvement of the extraction efficiency was attempted by designing a column-based flow system allowing extraction of RBO with an optimized amount of liquefied DME. By this approach, the efficiency of RBO extraction attained ca. 24% (ca. 0.24 g of RBO extracted and recovered from 1 g of dried rice bran), using 10 to 20 g of liquefied DME applied to 1 g of rice bran packed in the column-type extraction chamber.
In ecological systems, living organisms are surrounded by a number of chemicals, among which certain portion may be toxic to organisms. Therefore, from the environment-centric point of view, importance of accurate eco-toxicological analyses is increasing day-by-day. Eco-toxicity responses in animals and other organisms against chemicals can be scored by several parameters such as median lethal concentration (LC50) and median lethal dose (LD50), for examples. In the present study, we attempted to perform simulations of eco-toxicological nature of given chemicals based on limited data size (showing apparently incomplete curves of toxicity response) through model experiments performed with green paramecia (Paramecium bursaria) exposed to toxic metal ions, by using practically re-arranged logistic equation and Hill-type equations with an aid by graphical elucidation of Gauss-Newton algorithm determining the constants and/or coefficients.
Ferulic acid (FA) is one of phenolics found in most higher plants. It is important to quantify the internal FA level in vegetables and fruits, since it was epidemiologically demonstrated and a number of study supported that consumption of fruits and vegetables rich in phenolic acids including FA is associated with the prevention of chronic diseases such as cancer and cardiovascular disease. In order to allow handling of the intact fresh produces, non-invasive methods are desired. Previously, 355 nm ultraviolet (UV) laser-induced fluorescence spectrum revealed that living plants contain fluorophore corresponding to blue-green fluorescence (shown to be FA). However, quantification of FA based on fluorescence in UVexcited leaves can be hardly achieved since FA fluorescence measured at fixed excitation and emission can be applied only to the limited range of FA concentration. Here, we report a model experiment for fluorometric quantification of FA in solution in vitro which may provide a series of useful information required for estimation of FA concentrations in vivo fluid inside the vegetables. Based on deconvolution of intrinsic fluorescence spectra, we observed that FA fluorescence signals can be deciphered to determine the concentration of FA. By viewing that the recorded FA fluorescence (h) is reflecting the primitive function (f) corresponding to FA concentrations and kernel function (g) determining the spike position in the spectra. Thus, f should be obtained as f h g 1. In practice, cumulative curves of fluorescence signals at fixed emission wavelength (460 nm) along with the changes in excitation wavelength (200 400 nm) were plotted and the midpoints (along the scale of excitation wavelength) in the resultant curves corresponding to different FA concentration were graphically determined. FA's concentration-specific changes in fluorescence profiles must be due to the fact that FA possesses multiple fluorophores within the molecule despite its simple structure. Lastly, simplified protocol for determination of FA concentration using dual UV excitation wavelengths was proposed. In this assay, ratio of 460 nm fluorescence intensities induced by two distinct excitation wavelengths (short, 260 nm; long, 330 380 nm) were shown to be highly correlated with FA concentration ranged from M to mM orders.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with đź’™ for researchers
Part of the Research Solutions Family.