Influence of coffee brewing methods on the chromatographic and spectroscopic profiles, antioxidant and sensory properties

Abstract

Cold brewing coffee has gained increasing popularity as a novel brewing method. A completely different flavour profile during cold brewing extraction (smooth and mild) is a result of the low-energy process, prolonged water-grind contact times and long preparation time. The aim of our research was to compare coffee drinks obtained with an innovative device for a faster, dynamic cold coffee extraction process (Hardtank) to drinks prepared traditionally in 24 h and hot brewed drinks. This study investigated the differences in chemical composition (volatile, non-volatile and lipid compounds), sensory properties and antioxidant capacity of coffee drinks from various extraction processes carried out at variable brewing temperatures, times and percolation modes. The results showed that the new cold maceration technique using coffee bed percolation (Hardtank) improved the quality of cold coffee drinks, making them similar in taste to hot coffee drinks. Among the studied extractions, the combination of a lower temperature (19.3 °C) and percolation process appeared to be the ideal setting for the most efficient extraction of compounds such as chlorogenic acids, gallic acid, caffeine, trigonelline, 5-(hydroxymethyl)furfural and lipids and consequently for their intake. In addition, FTIR spectra indicated an even 4 times greater quantity of lipids in Hardtank drinks than in classic cold brew and up to 5 times more lipids than in hot brew coffee, which contribute to the formation of the aroma and flavour. The decreased extraction time and use of coffee bed percolation could be beneficial for the quality and taste of cold brew products.

Metabolomics-Based Approach for Coffee Beverage Improvement in the Context of Processing, Brewing Methods, and Quality Attributes

“…Moreover, another application of metabolomic fingerprinting in coffee analysis included phenolic compounds and alkaloid analysis in Indonesian arabica and robusta coffee extracts based on FTIR. The study assigned bands at 1280 and 1605 cm −1 for chlorogenic acids and 3123, 3011, 1703 and 1653 cm −1 for caffeine [ 54 ].…”

“…Coffee brewing is a historical coffee preparation method employed using various extraction methods, including drip, French press, boiled brew, pressurized extraction (espresso), and others [ 54 , 55 ]. These forms can be performed by different devices ranging from traditional brewing pots to automatized coffee makers resulting in various coffee beverages according to several factors, mainly related to consumers’ preferences and acceptability for each region or country [ 56 , 57 , 58 ].…”

“…Cold brewing has gained consumers’ preference recently, whereby coffee is extracted at 20 to 25 °C or colder and steeped for a much longer time ranging from 8 to 24 h, compared to the classical hot brewing methods performed on a minute scale [ 59 ]. Beside coffee origin and post-harvest processing, coffee brewing is recognized as a critical step to affect coffee sensory attributes, including flavor and taste [ 54 , 60 , 61 ]. For instance, Nariño cold brew shows unique sweetness and fruity and floral flavors, in addition to medium bitterness and acidity, with a creamy consistency [ 62 ].…”

“…Different variables have been determined in previous coffee brewing studies to ensure the best products, including device used such as coffee maker or traditional coffee pot, temperatures, times of percolation, water/coffee ratio, and water type [ 54 , 72 ]. Some studies have targeted few metabolites, such as caffeine, furan, and 5-HMF [ 73 ], while metabolomics-based approaches using different platforms, i.e., GC/MS, LC/MS, and NMR could provide better readouts of brewing impact on coffee.…”

Characterization of sensory properties of Yunnan coffee

“…A large number of previous studies have demonstrated that the roast level largely influences the composition of flavor compounds in the bean and therefore greatly impacts the final quality of the coffee drink ( Baggenstoss et al, 2008 ). Apart from the degree of roasting, coffee sensory properties are also influenced by the brewing method, and many environmental factors, such as geographical origins, climate, altitude and temperature elevation, and shading, and nutrient availability or fertilizers also have effects on the coffee sensory profile ( Stanek et al, 2021 ; Sunarharum et al, 2014 ).…”