Evaluation of the Phenolic Content and the Nutraceutical Potential of Ancestor and Cultivated Artichokes

Wild cardoon (Cynara cardunculus var. sylvestris) is the ancestor of many cultivated forms, including globe artichoke (C. cardunculus var. scolymus). Four organs (receptacles, bracts, leaves and stems) of wild and cultivated artichokes (organic and conventional) were assessed considering their individual phenolic constituents (HPLC-DAD), total phenol-flavonoid content, and pharmaceutical potentials (antibacterial and antioxidant). All three sources of artichokes had the highest concentration of 1,3-dicaffeoylquinic acid (cynarin) in their receptacles and cultivated artichoke receptacles had more cynarin than wild one. On the other hand, receptacles of wild cardoon had the highest 1,5-dicaffeoylquinic acid and caffeic acid than the cultivated ones. Generally, receptacles, stems and leaves of wild cardoon were superior to both cultivated artichokes on antioxidant potential, and total phenol-flavonoid content. The rise in total phenolic content can be attributed to an increase in antioxidant capacity in all artichoke organs. Only the leaves of all different artichokes showed antibacterial activity against Gram-positive bacteria. The investigated wild cardoon was believed to be a true ancestor since a comparison of wild and cultivated varieties revealed similar trends in terms of phenolic profile and biological properties. The nutraceutical industry can profit from this invasive wild cardoon due to their strong antioxidant potential and phenolic content.

Identification and Quantification of Bioactive Compounds in Organic and Conventional Edible Pansy Flowers (Viola × wittrockiana) and Their Antioxidant Activity

The use of edible flowers has become increasingly popular as a good source of bioactive compounds. Many flowers can be consumed, but there is a lack of information about the chemical composition of organic and conventional flowers. Organic crops represent a higher level of food safety because pesticides and artificial fertilizers are prohibited. The present experiment was carried out with organic and conventional edible pansy flowers of different colors: double-pigmented violet/yellow and single-pigmented yellow flowers. In fresh flowers, the contents of dry matter and polyphenols (including phenolic acids, flavonoids, anthocyanins, carotenoids, and chlorophylls) and the antioxidant activity were determined by the HPLC-DAD method. The results showed that organic edible pansy flowers contained significantly more bioactive compounds, especially polyphenols (333.8 mg/100 g F.W.), phenolic acids (40.1 mg/100 g F.W.), and anthocyanins (293.7 mg/100 g F.W.) compared to conventional methods. Double-pigmented (violet/yellow) pansy flowers are more recommended for the daily diet than single-pigmented yellow flowers. The results are unique and open the first chapter in a book on the nutritional value of organic and conventional edible flowers.

Effect of surface properties on the electrochemical response of cynarin by electro-synthesized functionalized-polybithiophene/MWCNT/GNP

Cynarin is one of the biologically active functional components present a wide range of pharmacological applications. Herein, we reported the fabrication and surface properties investigation of a new highly sensitive electrochemical sensor for the detection of cynarin. The electrochemical sensors were fabricated in several steps; the first being the synthesis of bi-thiophene derivatives-based monomers 3,3'-bithiophen (M1); 2-methoxy-5-carbaldehyde-[3,3'-bithiophene] (M2) and 2-((2-methoxy-[3,3'-bithiophen]-5-yl)methylene)malononitrile) (M3) followed by electrochemical polymerization on a glassy carbon electrode after which multi-walled carbon nanotube (MWCNT) and gold nanoparticles (GNP's) were electrodeposited layer-by-layer on the polymer coating to obtain multilayer electrochemical sensors. The morphological properties of the formed polymers were evaluated using SEM analysis and the apparent contact angles to preview the changes in surface properties after the functionalization of monomers and therefore their effects on the detection of cynarin. Analytical parameters such as the accumulation time and pH of the PBS solution which influence the sensitivity of the electrochemical sensors were optimized. Under the optimal conditions the GCE/P3/MWCNT/GNP's showed a wide range of analyte concentrations (1 to 100 μM and 0.01 to 1 μM) and detection limit of 0.0095 using pulse differential voltammetry. In addition, the electrochemical sensors showed good reproducibility, stability and selectivity and they were used successfully for the determination of cynarin in real solutions.