Influence of Various Factors on Caffeine Content in Coffee Brews

Abstract

Coffee brews are one of the most popular drinks. They are consumed for caffeine and its stimulant properties. The study aimed to summarize data on the influence of various factors on caffeine content in brews prepared with different methods. The study was carried out using a literature review from 2010–2020. PubMed and Google Scholar databases were searched. Data on caffeine content was collected by analyzing the following factors: the influence of species, brewing time, water temperature, pressure, degree of roast, grinding degree, water type, water/coffee ratio as well as other factors (such as geographical origin). To sum up, converting caffeine content to 1 L of the brew, the highest content is that of brews prepared in an espresso machine (portafilter), with the amount of 7.5 g of a coffee blend (95% Robusta + 5% Arabica), and water (the volume of coffee brew was 25 mL) at a temperature of 92 °C and a pressure of 7 bar, but the highest content in one portion was detected in a brew of 50 g of Robusta coffee poured with 500 mL of cold water (25 °C) and boiled.

Robusta coffee (Coffea canephora) value chain in East Java, Indonesia

“…In this study, the functional upgrade was carried out in the coffee grinding process. The improvement in the dry coffee bean into the ground coffee process can increase the product's additional value by 41.89 % (Olechno et al, 2021) and 42.97 % (Puspita, 2013). There will be challenges in the coffee trade system in the future, so constant innovations must be carried out to increase its value and ensuring the success in the coffee business.…”

Development of a Caffeine Content Table for Foods, Drinks, Medications and Supplements Typically Consumed by the Brazilian Population

“…Moreover, the distinct climate and environmental conditions and the different food processing methods, in addition to the varied coffee preparations forms and coffee-included food recipes, can result in large variations in the caffeine content for the same food in different countries. Evaluating the caffeine contents in the regional food context can guarantee more reliable data [ 27 ]. Therefore, the BraCaffT was developed considering foods and beverages habitually consumed and the dietary supplements and medications commercialized in Brazil, which makes the table reliable and applicable in the personal, clinical, and research contexts for Brazil.…”

“…It must be noted that several items in the coffee, teas, and infusions categories presented high SDs and CVs. This was expected due to the different food species analyzed, cultivation conditions, and the extraction and processing methods applied that can change the caffeine contents in the beverages [ 24 , 25 , 26 , 27 ]. This high variability between and within sources was attested by McCusker et al (2003) in a study that analyzed the caffeine contents of 20 different coffees purchased at coffee shops in the US.…”

“…For this purpose, initially, data were extracted from the “Household Budget Survey: Analysis of Personal Food Consumption in Brazil (2017–2018)”, which provides information about the individual food intake of the Brazilian population above 10 years old [ 8 ]. Some food categories were also created according to studies regarding the analysis of caffeine contents in foods consumed in Brazil [ 3 , 26 , 27 , 28 ] and from a study that determined the main sources of caffeine consumed by Brazilians [ 7 ]. Subsequently, international studies that compiled foods, drinks, dietary supplements, and medications with caffeine [ 29 , 30 , 31 , 32 ] and the United States Department of Agriculture Food Data Central (USDA FoodData Central) ( accessed on 3 June 2020) were analyzed to include foods, drinks, dietary supplements, and medications that are commercialized on the Brazilian market.…”

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

“…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.…”