Pigments and their solubility in and extractability by supercritical CO2 - I: the case of curcumin

Novel green production of natural-like vanilla extract from curcuminoids

The demand for natural vanilla extract, and vanillin in particular, by far exceeds the current production, as both the cultivation of vanilla beans and the extraction of vanillin are laborious. For this purpose, most vanillin used today is produced synthetically, contrary to the general trend toward bio-based products. The present study deals with the synthesis of nature-based vanillin, starting with the more accessible rhizomes of the plant Curcuma longa. Besides vanillin, vanillic acid and p-hydroxybenzaldehyde are synthesized that way, which are also found in the natural vanilla bean. The extraction of the curcuminoids and, finally, their conversion to the flavors are performed using visible light and food-grade chemicals only. A binary mixture of ethanol and triacetin, as well as a surfactant-free microemulsion consisting of water, ethanol, and triacetin, are investigated in this context. The results exceed the literature values for Soxhlet extraction of vanilla beans by a factor > 7.

Enhancement of Biological and Pharmacological Properties of an Encapsulated Polyphenol: Curcumin

There is a dearth of natural remedies available for the treatment of an increasing number of diseases facing mankind. Natural products may provide an opportunity to produce formulations and therapeutic solutions to address this shortage. Curcumin (CUR), diferuloylmethane; I,7-bis-(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione is the major pigment in turmeric powder which has been reported to exhibit a number of health benefits including, antibacterial, antiviral, anti-cancer, anti-inflammatory and anti-oxidant properties. In this review, the authors attempt to highlight the biological and pharmacological properties of CUR in addition to emphasizing aspects relating to the biosynthesis, encapsulation and therapeutic effects of the compound. The information contained in this review was generated by considering published information in which evidence of enhanced biological and pharmacological properties of nano-encapsulated CUR was reported. CUR has contributed to a significant improvement in melanoma, breast, lung, gastro-intestinal, and genito-urinary cancer therapy. We highlight the impact of nano-encapsulated CUR for efficient inhibition of cell proliferation, even at low concentrations compared to the free CUR when considering anti-proliferation. Furthermore nano-encapsulated CUR exhibited bioactive properties, exerted cytotoxic and anti-oxidant effects by acting on endogenous and cholinergic anti-oxidant systems. CUR was reported to block Hepatitis C virus (HCV) entry into hepatic cells, inhibit MRSA proliferation, enhance wound healing and reduce bacterial load. Nano-encapsulated CUR has also shown bioactive properties when acting on antioxidant systems (endogenous and cholinergic). Future research is necessary and must focus on investigation of encapsulated CUR nano-particles in different models of human pathology.

Solubilization and extraction of curcumin from Curcuma Longa using green, sustainable, and food-approved surfactant-free microemulsions

Curcumin is a powerful coloring agent widely used in the food industry. Its extraction from the plant Curcuma longa is commonly done with aqueous solvent solutions. In contrast to the conventional extraction methods, the present study aimed to compare two different green and bio-based surfactant-free microemulsion (SFME) extraction systems, which are approved for food and yield a higher extracting power of curcuminoids. Two SFMEs, water/ethanol/triacetin and water/diacetin/triacetin, were investigated via dynamic light scattering. Curcumin solubility in binary mixtures consisting of ethanol/triacetin or diacetin/triacetin was studied both experimentally and theoretically using UV-Vis measurements and COSMO-RS. The SFMEs were further examined and compared to a common ethanol/water (80/20) extraction mixture with respect to their extracting ability using high performance liquid chromatography. The SFMEs containing ethanol were found to extract ~18% more curcuminoids than the SFMEs containing diacetin and ~53% more than the ordinary ethanol/water mixture.

Controlled morphology and size of curcumin using ultrasound in supercritical CO2 antisolvent

Controllable morphology and size of crystal materials prepared by using a supercritical antisolvent (SAS) technique is still challenge. In this study, ultrasound was introduced into the SAS process to produce the particles of curcumin, a model compound. The effects of ultrasound power on the particle morphology and size were investigated in the range of 0 and 240 W at three different pressures. The observation of jet flow indicated ultrasound could accelerate the mixing speed between the liquid solution and the CO2, and thus reduced the gaseous region and the local saturation gradient. Mixed polymorphic and uniform particles of the curcumin were produced at a low and high mixing speed, respectively, confirmed by scanning electron microscopy. The needle- or rod-like particle, irregular lumpy particle and nano spherical particle were generated with the increase of the ultrasound power, attributed to the changes of the degree of supersaturation. Therefore, the ultrasound can be potentially applied to adjust the morphology and size of the crystal materials in supercritical CO2 antisolvent.

The chemistry of curcumin: from extraction to therapeutic agent

Curcumin, a pigment from turmeric, is one of the very few promising natural products that has been extensively investigated by researchers from both the biological and chemical point of view. While there are several reviews on the biological and pharmacological effects of curcumin, chemistry reviews are comparatively scarcer. In this article, an overview of different aspects of the unique chemistry research on curcumin will be discussed. These include methods for the extraction from turmeric, laboratory synthesis methods, chemical and photochemical degradation and the chemistry behind its metabolism. Additionally other chemical reactions that have biological relevance like nucleophilic addition reactions, and metal chelation will be discussed. Recent advances in the preparation of new curcumin nanoconjugates with metal and metal oxide nanoparticles will also be mentioned. Directions for future investigations to be undertaken in the chemistry of curcumin have also been suggested.