Green and Efficient Processing of Cinnamomum cassia Bark by Using Ionic Liquids: Extraction of Essential Oil and Construction of UV‐Resistant Composite Films from Residual Biomass

Abstract

There is significant interest in the development of a sustainable and integrated process for the extraction of essential oils and separation of biopolymers by using novel and efficient solvent systems. Herein, cassia essential oil enriched in coumarin is extracted from Cinnamomum cassia bark by using a protic ionic liquid (IL), ethylammonium nitrate (EAN), through dissolution and the creation of a biphasic system with the help of diethyl ether. The process has been perfected, in terms of higher biomass dissolution ability and essential oil yield through the addition of aprotic ILs (based on the 1-butyl-3-methylimidazolium (C mim) cation and chloride or acetate anions) to EAN. After extraction of oil, cellulose-rich material and free lignin were regenerated from biomass-IL solutions by using a 1:1 mixture of acetone-water. The purity of the extracted essential oil and biopolymers were ascertained by means of FTIR spectroscopy, NMR spectroscopy, and GC-MS techniques. Because lignin contains UV-blocking chromophores, the oil-free residual lignocellulosic material has been directly utilized to construct UV-light-resistant composite materials in conjunction with the biopolymer chitosan. Composite material thus obtained was processed to form biodegradable films, which were characterized for mechanical and optical properties. The films showed excellent UV-light resistance and mechanical properties, thereby making it a material suitable for packaging and light-sensitive applications.

Ionic Liquid Stabilized Gelatin–Lignin Films: A Potential UV‐Shielding Material with Excellent Mechanical and Antimicrobial Properties

“…[14] Recently,w ec onstructedaUV-resistant film from the IL-processed residual biomass of cinnamomum cassia bark and chitosan. [15] The films showede xcellent UV-light resistance andm echanical properties but lacked transparency and bioactivity. Herein, we have reported the formation of choline citrate (a bioactive IL) stabilized gelatin-lignin antibacterial, UV-shielding, biodegradable, flexible, and transparent film with an exceptionally good mechanical strength and sun protection factor.…”

“…Recently, we constructed a UV‐resistant film from the IL‐processed residual biomass of cinnamomum cassia bark and chitosan . The films showed excellent UV‐light resistance and mechanical properties but lacked transparency and bioactivity.…”

Ionic Liquids in Biomass Processing

“…Mehta et al. has reported the use of protic IL ethyl ammonium nitrate for the extraction of coumarin enriched cassia essential oil from Cinnamomum cassia bark . In another application ILs have been used as a reaction medium for the dehydration of biomass derived galactaric acid to adipic acid.…”

“…In addition to the use of ionic liquids in processing lignocellulosic materials, ILs have been used in applications such as extraction of essential oils, [216] lipids, hydrophobic compounds, proteins, amino acids, nucleic acids and these reports have been reviewed recently. [217] Mehta et al has reported the use of protic IL ethyl ammonium nitrate for the extraction of coumarin enriched cassia essential oil from Cinnamomum cassia bark.…”

“…[217] Mehta et al has reported the use of protic IL ethyl ammonium nitrate for the extraction of coumarin enriched cassia essential oil from Cinnamomum cassia bark. [216] In another application ILs have been used as a reaction medium for the dehydration of biomass derived galactaric acid to adipic acid. In this instance, use of an IL enabled the separation of rhenium catalyst used in the hydrogenation step from the products by simple decant- Table 4.…”