Studies on Adsorption Kinetics and Thermodynamics of Macroporous Resin for Rosmarinic Acid

Rosemary: Unrevealing an old aromatic crop as a new source of promising functional food additive-A review

Rosemary (Rosmarinus officinalis L.) is one of the most famous spice plants belonging to the Lamiaceae family as a remarkably beautiful horticultural plant and economically agricultural crop. The essential oil of rosemary has been enthusiastically welcome in the whole world for hundreds of years. Now, it is wildly prevailing as a promising functional food additive for human health. More importantly, due to its significant aroma, food, and nutritional value, rosemary also plays an essential role in the food/feed additive and food packaging industries. Modern industrial development and fundamental scientific research have extensively revealed its unique phytochemical constituents with biologically meaningful activities, which closely related to diverse human health functions. In this review, we provide a comprehensively systematic perspective on rosemary by summarizing the structures of various pharmacological and nutritional components, biologically functional activities and their molecular regulatory networks required in food developments, and the recent advances in their applications in the food industry. Finally, the temporary limitations and future research trends regarding the development of rosemary components are also discussed and prospected. Hence, the review covering the fundamental research advances and developing prospects of rosemary is a desirable demand to facilitate their better understanding, and it will also serve as a reference to provide many insights for the future promotion of the research and development of functional foods related to rosemary.

The Selective Separation of Carnosic Acid and Rosmarinic Acid by Solid-Phase Extraction and Liquid-Liquid Extraction: A Comparative Study

Rosmarinus officinalis leaves (ROLs) are widely used in the food and cosmetics industries due to their high antioxidant activity and fascinating flavor properties. Carnosic acid (CA) and rosmarinic acid (RA) are regarded as the characteristic antioxidant components of ROLs, and the selective separation of CA and RA remains a significant challenge. In this work, the feasibility of achieving the selective separation of CA and RA from ROLs by solid-phase extraction (SPE) and liquid-liquid extraction (LLE) was studied and compared. The experiments suggested that SPE with CAD-40 macroporous resin as the adsorbent was a good choice for selectively isolating CA from the extracts of ROLs and could produce raw CA with purity levels as high as 76.5%. The LLE with ethyl acetate (EA) as the extraction solvent was more suitable for extracting RA from the diluted extracts of ROLs and could produce raw RA with a purity level of 56.3%. Compared with the reported column chromatography and LLE techniques, the developed SPE-LLE method not only exhibited higher extraction efficiency for CA and RA, but can also produce CA and RA with higher purity.

Magnetic covalent organic framework for the adsorption of silver nanoparticles and recycled as surface-enhanced Raman substrate and high-efficiency catalysts for 4-nitrophenol degradation

A magnetic covalent organic framework Fe₃O₄@BM was prepared with melamine and 4-4'-biphenyldialdehyde as monomers and used as adsorbent for Ag NP removal. Fe₃O₄@BM was characterized by zeta potential analysis, transform infrared spectrometry, X-ray diffraction, thermogravimetric analysis, contact angle, and N₂ adsorption-desorption. Fe₃O₄@BM possessed plentiful amino groups, positive potential, and rapid separation performance, making it a promising adsorbent for silver nanoparticles. The adsorption process followed the pseudo-second-order kinetic equation and Langmuir isotherm model. The maximum adsorption capacity of Ag NPs calculated by the Langmuir isotherm model was 544.9 mg/g. The adsorption product Fe₃O₄@BM@Ag could be recycled and efficiently catalyze the degradation of 4-nitrophenol within 6 min. Meanwhile, the recycled Fe₃O₄@BM@Ag could also be used as a surface-enhanced Raman substrate for DTNB detection, and the limit of detection of DTNB reached as low as 10^-7 mol/L. This work prepared a promising adsorbent Fe₃O₄@BM for Ag NP adsorption and provided a sustainable approach for the recycling of the adsorption product Fe₃O₄@BM@Ag.