Validated HPLC-Diode Array Detector Method for Simultaneous Evaluation of Six Quality Markers in Coffee

Abstract

Nicotinic acid, N-methylpyridinium ion, and trigonelline are well studied nutritional biomarkers present in coffee, and they are indicators of thermal decomposition during roasting. However, no method is yet available for their simultaneous determination. This paper describes a rapid and validated HPLC-diode array detector method for the simultaneous quantitation of caffeine, trigonelline, nicotinic acid, N-methylpyridinium ion, 5-caffeoylquinic acid, and 5-hydroxymethyl furfural that is applicable to three coffee matrixes: green, roasted, and instant. Baseline separation among all compounds was achieved in 30 min using a phenyl-hexyl RP column (250×4.6 mm, 5 μm particle size), 0.3% aqueous formic buffer (pH 2.4)-methanol mobile phase at a flow rate of 1 mL/min, and a column temperature at 30°C. The method showed good linear correlation (r2>0.9985), precision (less than 3.9%), sensitivity (LOD=0.023-0.237 μg/mL; LOQ=0.069-0.711 μg/mL), and recovery (84-102%) for all compounds. This simplified method is amenable for a more complete routine evaluation of coffee in industry.

Role of Coffee Caffeine and Chlorogenic Acids Adsorption to Polysaccharides with Impact on Brew Immunomodulation Effects

“…This value is within the range of values reported for caffeine in literature for single-dose coffee capsules (1.1 to 1.8 g/100 g of coffee powder [36,37]) but also comparable to espresso brew [9]. The 52 mg of caffeine per g of brew soluble solids obtained for the instant coffee 1 were also in the accordance with the 49-52 mg of caffeine per g of brew soluble solids described in literature for instant coffee [38][39][40]. Concerning the CGA content, it was 71 mg per g of brew soluble solids (corresponding to 1.4 g/100 g of espresso coffee powder) for espresso, and 32 mg of CGA per g of brew soluble solids for instant coffee, a value comparable to literature when considering the sum of all free CGA compounds [39].…”

Chromatographic Methods for Coffee Analysis: A Review

“…For example, six quality markers in coffee, which are caffeine, trigonelline, nicotinic acid, N-methylpyridinium, 5-caffeoylquinic acid, and 5-hydroxyfurfural were simultaneously detected for three coffee matrices-green, roasted, and soluble-with the limit of quantification 0.069-0.71 µg/ml by HPLC-DAD. This technique is useful for routine determination of the thermal degradation rate during the roasting process (Gant, Leyva, Gonzalez & Maruenda, 2015). Ion chromatography and ion exchange chromatography methods utilize columns filled with ion exchangers to separate ion mixtures.…”

Concurrent HPLC detection of javamide‐I/‐II, caffeine, 3‐ O‐caffeoylquinic acid, 4‐O‐caffeoylquinic acid and 5‐O‐caffeoylquinic acid; their comparative quantification and disparity in ground and instant coffees

“…However, the amounts of javamide‐I/‐II in ground and instant coffee products are currently unknown, thereby being unfeasible to evaluate their purported effects in comparison to 3‐CQA, 4‐CQA, 5‐CQA and caffeine. Related to the measurement of 3‐CQA, 4‐CQA, 5‐CQA, caffeine and javamide‐I/‐II, in fact there are some reported HPLC methods . However, none of them can measure 3‐CQA, 4‐CQA, 5‐CQA, caffeine and javamide‐I/‐II simultaneously; for examples, HPLC methods in ref and were not adequately developed due to the lack of javamide‐I/‐II standards, and the methods in ref were not able to detect javamide‐I/‐II, 3‐CQA, 4‐CQA, 5‐CQA and caffeine concurrently.…”