Fluorescent detection of (−)-epicatechin in microsamples from cacao seeds and cocoa products: Comparison with Folin–Ciocalteu method

Abstract

Polyphenolic compounds of the flavanoid family are abundantly present in cacao seed and its cocoa products. Results from studies using cocoa products indicate beneficial effects of flavanols on cardiovascular endpoints. Evidence indicates that (-)-epicatechin is the main cacao flavanol associated with cardiovascular effects, so the accurate quantification of its content in cacao seeds or cocoa products is important. Common methods for the quantification of phenolic content in cocoa products are based on the reaction of phenols with colorimetric reagents such as the FolinCiocalteu (FC) In this study, we compared the FC method of phenolic determinations using 2 different standards (gallic acid and (-)-epicatechin) to construct calibration curves. We compare these results with those obtained from a simple fluorometric method (Ex 280 /Em 320 nm) used to determine catechin/(-)-epicatechin content in samples of cacao seeds and cocoa products. Values obtained from the FC method determination of polyphenols yield an overestimation of phenol (flavonoid) content when gallic acid is used as standard. Moreover, the epicatechin is a more reliable standard because of its abundance in cacao seeds and cocoa products. The use of fluorometric spectra yields a simple and highly quantitative means for a more precise and rapid quantification of cacao catechins. Fluorometric values are essentially in agreement with those reported using more cumbersome methods. In conclusion, the use of fluorescence emission spectra is a quick, practical and suitable means to quantifying catechins in cacao seeds and cocoa products.

Antioxidant, antimicrobial, antitumor, and cytotoxic activities of an important medicinal plant (Euphorbia royleana) from Pakistan

“…In the present study, the total phenolic contents of methanol, hexane, and aqueous extracts of fresh E. royleana were determined by the FolineCiocalteu method and results are shown in Table 1. This method involves the reaction of phosphomolybdate and phosphotungstate with all phenolic compounds in the sample [24]. This reaction generates a blue pigment that has extensive light j o u r n a l o f f o o d a n d d r u g a n a l y s i s x x x ( 2 0 1 4 ) 1 e7 3 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 absorption at 760 nm [25].…”

Catechin sublimation pressure and solubility in supercritical carbon dioxide

“…The heating chamber was heated to a desired temperature (313.15, 323.15, 333.15, or 343.15 K). Liquid CO 2 was subsequently pumped into the system using a high pressure pump until a targeted pressure was achieved (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26). After equilibrium condition was achieved in 4 h, the sampling tube (1 ml) was disconnected from the system.…”

“…It is abundantly in various plants such as tea [9][10][11], grape [12][13][14][15] and cocoa [16]. Catechin is also found in the sago (Metroxylon sago) pith.…”

Measurement and modeling of epicatechin solubility in supercritical carbon dioxide fluid

“…High quantities of epicatechin can be found in cocoa [1], tea [2][3][4] and grapes [5][6][7]. Epicatechin is also found in staple plant such as sago (Metroxylon sago) [8].…”

“…Epicatechin exerts beneficial health-related effects since it acts as free radical scavengers and inhibitors of eicosainoid biosynthesis [9,10]. Epicatechin also reduces low-density lipoprotein in oxidation, risk of stroke, heart failure, cancer and diabetes [1,9,11,12].…”