Effect of Temperature and Storage on Coffee's Volatile Compound Profile and Sensory Characteristics

Abstract

The study investigated the effects of storage temperature, type of coffee, and brewing method on coffee's volatile compound profile and sensory quality. Three types of coffee were included in the study: Arabica, Robusta, and their 80/20 blend. Samples were stored at 5 °C and 20 °C for one month, after which the changes in the composition of volatile compounds were analysed and the sensory quality of espresso and cold brew coffee was assessed. The results showed that storing coffee at a lower temperature slows the changes in the profile of volatile compounds such as aldehydes, alcohols, pyrazines, and furans, helping preserve the desired aroma and flavour characteristics. Storage at higher temperatures resulted in greater changes in the volatile profile and sensory quality, with higher perceptions of earthy, sharp, and smoky notes and lower chocolatey and sweet notes. The brewing method also had a significant effect on the sensory quality. The espresso coffee had a higher intensity of coffee aroma, chocolate flavour, smoky aroma, and roasted notes. In contrast, cold brew coffee was perceived as sweeter, fruitier, and had more pronounced rum notes. The coffee type also significantly influenced the aroma and flavour profile. Arabica had a more harmonious and mild aromatic profile, while Robusta had a sharper aroma. The blend of Arabica and Robusta combined the characteristics of both coffees and offered a balanced aromatic profile.

Keywords: cold brew; espresso; roasted coffee; sensory profile; storage; volatile compounds.

Figure 1

Differences in the chromatographic profiles of volatile compounds of three types of coffee (in triplicate) presented by PCA distances. Sample designations: Arabica (Ar), Robusta (Ro), and a blend of coffees with a composition of 80% Ar + 20% Ro (ArRo). All coffees were analysed on day 0 (0), after 1 month of storage at room temperature 20 ± 1 °C (1 m, 20 °C), and after 1 month of storage at low temperature 5 ± 1 °C (1 m, 5 °C).

Figure 2

Similarities and differences in the sensory profile of coffee espresso brews on day 0 and after 1 month of storage at temperatures of 20 °C and 5 °C. Legend: 100% Arabica espresso day 0 (100% Ar exp), 100% Robusta espresso day 0 (100% Ro exp), 80% Arabica + 20% Robusta espresso day 0 (80% Ar + 20% Ro exp), 100% Arabica espresso 1 month 20 °C (100% Ar exp 1 m 20 °C), 100% Robusta espresso 1 month 20 °C (100% Ro exp 1 m 20 °C), 80% Arabica + 20% Robusta espresso 1 month 20 °C (80% Ar + 20% Ro exp 20 °C), 100% Arabica espresso 1 month 5 °C (100% Ar exp 1 m 5 °C), 100% Robusta espresso 1 month 5 °C (100% Ro exp 1 m 5 °C), 80% Arabica + 20% Robusta 1 month 5 °C (80% Ar + 20% Ro exp 5 °C).

Figure 3

Similarities and differences in the sensory profile of coffee cold brews on day 0 and after 1 month of storage at temperatures 20 °C and 5 °C. Legend: 100% Arabica cold brew day 0 (100% Ar cb), 100% Robusta cold brew day 0 (100% Ro cb), 80% Arabica + 20% Robusta cold brew day 0 (80% Ar + 20% Ro cb), 100% Arabica cold brew 1 month 20 °C (100% Ar cb 1 m 20 °C), 100% Robusta cold brew 1 month 20 °C (100% Ro cb 1 m 20 °C), 80% Arabica + 20% Robusta cold brew 1 month 20 °C (80% Ar + 20% Ro cb 20 °C), 100% Arabica cold brew 1 month 5 °C (100% Ar br 1 m 5 °C), 100% Robusta cold brew 1 month 5 °C (100% Ro cb 1 m 5 °C), 80% Arabica + 20% Robusta cold brew 1 month 5 °C (80% Ar + 20% Ro cb 5 °C).

Figure 4

Similarities and differences in the sensory profile of coffee espresso and coffee cold brews on day 0. Legend: 100% Arabica espresso day 0 (100% Ar exp), 100% Robusta espresso day 0 (100% Ro exp), 80% Arabica + 20% Robusta espresso day 0 (80% Ar + 20% Ro exp), 100% Arabica cold brew day 0 (100% Ar cb), 100% Robusta cold brew day 0 (100% Ro cb), 80% Arabica + 20% Robusta cold brew day 0 (80% Ar + 20% Ro cb).