# Quantitative Analysis of Caffe in Roasted Coffee: A Comparison of Brewing Methods
## 3 Results and Discussion
### Brewing Methods' Comparison  
This review compared the caffeine content of coffees prepared by different brewing methods: Cold Brew, Espresso, French Press, AeroPress, and Moka. Although the authors used the same brewing methods, the individual parameters within the method diverged. This resulted in a wide range of caffeine content within the brewing method, which made a clear comparison of the results impossible. A common feature across all brewing methods analyzed was a longer extraction time, increasing caffeine content. Furthermore, a similar relationship was observed in the Cold Brew and French Press methods, influenced by higher temperature and coffee-to-water ratio.  
Figure 4 shows the range of caffeine content in coffees prepared with different brewing methods.  
The analyzed brewing methods show considerable variation in the caffeine content of the brew. The Espresso and Moka had higher caffeine content than the other methods, possibly due to the higher coffee-to-water ratio and the pressure applied during brewing. In addition, in these methods, the coffee is in single contact with the water, which maximizes the concentration gradient between the two and leads to more efficient extraction. A high caffeine value can result from a combination of all these factors. In the case of the Cold Brew method, the extended brewing time promoted efficient caffeine extraction, but the low water temperature limited this process. The French Press and AeroPress methods had similar caffeine content due to similar brewing parameters (water temperature, coffee-to-water ratio). In addition to the parameters analyzed, caffeine content may have been influenced by other factors such as coffee grade, roasting degree, and origin. Moreover, the absence of information on coffee grade, roasting degree, origin, and other associated factors, including post-harvest processes, drying methods, and altitude of cultivation above sea level, makes it difficult to compare the results.  
Furthermore, the HPLC method was mainly used in studies to determine caffeine. The parameters of this method, in particular different wavelengths, gradient profiles, and column temperatures, can affect the precision and accuracy of the analysis; these differences  
Figure 4: Caffe content in coffee by brewing method. (Results expressed in mg/100 mL to accurately reflect coffee consumption conditions. The interquartile range (IQR) was used to define a representative range for each brewing method).  
can modify the retention of the analyte and its detection, leading to discrepancies in the results.  
An attempt was made to determine safe coffee consumption based on the available data. Considering the lowest caffeine content for each brewing method and the EFSA [21] recommendations (up to 400 mg/day), a daily intake of approximately four servings (200 mL) of Cold Brew coffee, three servings of French Press or AeroPress, one serving of Moka can be considered safe, provided no other sources of caffeine are consumed. In the case of Espresso, calculations suggest the possibility of consuming up to 26 servings (a standard 30 mL serving), but this should not be recommended and is unrealistic in practice due to consumption habits.