AUTHOR=Rosado Mario J. , Marques Gisela , Rencoret Jorge , Gutiérrez Ana , del Río José C. 

TITLE=Chemical Composition of Lipophilic Compounds From Rice (Oryza sativa) Straw: An Attractive Feedstock for Obtaining Valuable Phytochemicals

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.868319

DOI=10.3389/fpls.2022.868319

ISSN=1664-462X

ABSTRACT=Rice (Oryza sativa) straw is a highly abundant, widely available, and low cost agricultural waste that can be used as a source to extract valuable phytochemicals of industrial interest. Hence, in the present work, the chemical composition of the lipophilic compounds present in rice straw was thoroughly characterized by gas chromatography and mass spectrometry using medium-length high-temperature capillary columns, which allowed the identification of a wide range of lipophilic compounds, from low molecular weight fatty acids to high molecular weight sterols esters, sterol glucosides or triglycerides in the same chromatogram. The most abundant lipids in rice straw were fatty acids, which accounted for up to 41.0% of all identified compounds, followed by free sterols (10.2%), sterol glucosides (8.8%), fatty alcohols (7.4%), and triglycerides (7.3%), along with lower amounts of high molecular weight wax esters (5.8%), steroid ketones (5.8%), monoglycerides (3.8%), alkanes (2.6%), diglycerides (2.4%), sterol esters (2.4%), tocopherols (2.2%), and steroid hydrocarbons (0.4%). This information is of great use for the valorization of rice straw to obtain valuable lipophilic compounds of interest for the nutraceutical, pharmaceutical, cosmetic, and chemical industries. Moreover, this knowledge is also useful for other industrial uses of rice straw, as in pulp and papermaking, since these lipophilic compounds are at the origin of the so-called pitch deposits during pulping.