Quantification of caffeine, trigonelline and nicotinic acid in espresso coffee: the influence of espresso machines and coffee cultivars.
Caffeine, trigonelline and nicotinic acid are important bioactive constituents of coffee. In this work, the combination of different water temperatures and pressures in the settings of the espresso coffee (EC) machine was evaluated, to assess how these factors influence how effectively caffeine, trigonelline and nicotinic acid are extracted from both Arabica and Robusta samples. The proposed analytical method, based on a high performance liquid chromatography (HPLC) system coupled to a variable wavelength detector (VWD), showed good linearity (R²> 0.9985) and good recoveries (71-92%); after validation for three monitored compounds, the method was used to analyze 20 commercial samples. The combination of a temperature of 92 °C and pressure at 7 or 9 bar seems to be the ideal setting for the most efficient extraction of these compounds and consequently for their intake; the compound extracted in the greatest quantity was caffeine, which was in the range of 116.87-199.68 mg in a 25 ml cup of coffee.
School of Pharmacy, University of Camerino , Camerino , Italy , and.
Giovanni
G
Caprioli
Manuela
M
Cortese
Filippo
F
Maggi
Caterina
C
Minnetti
Luigi
L
Odello
Gianni
G
Sagratini
Sauro
S
Vittori
D000470:Alkaloids / Q000032:analysis*; D002110:Caffeine / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D040503:Coffea / Q000737:chemistry / Q000378:metabolism; D003069:Coffee / Q000737:chemistry* / Q000191:economics; D003297:Cooking and Eating Utensils; D005513:Food Inspection / Q000379:methods*; D063427:Food Quality; D005525:Food-Processing Industry / Q000295:instrumentation; D006358:Hot Temperature; D006874:Hydrostatic Pressure; D007558:Italy; D009525:Niacin / Q000032:analysis*; D015203:Reproducibility of Results; D012639:Seeds / Q000737:chemistry / Q000378:metabolism; D013053:Spectrophotometry
D000470:Alkaloids; D003069:Coffee; D009525:Niacin; D002110:Caffeine; C009560:trigonelline
Arabica coffee; Robusta coffee; caffeine; espresso coffee machine; extraction pressure; extraction temperature