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

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.

Coffee Infusions: Can They Be a Source of Microelements with Antioxidant Properties?

Coffee is a beverage that is very popular all over the world. Its pro-health effect has been demonstrated in many publications. This drink can counteract the effects of oxidative stress thanks to its antioxidant properties. The aim of this study was to collect data on the content of microelements with antioxidant activity (manganese, zinc, copper, iron) in coffee infusions, taking into account various factors. The study considered publications from the years 2000–2020 found in Google Scholar and PubMed databases. It was noted that coffee can provide up to 13.7% of manganese requirements per serving, up to 4.0% and 3.1% of zinc requirements for women and men, up to 2.7% and 2.1% of copper requirements for women and men, and up to 0.4% and 0.6% of iron requirements for women and men. Coffee infusions can also be a source of fluoride (up to 2.5%), chromium (up to 0.4% of daily intake for women and 0.2% for men), and cobalt (up to 0.1%). There are no data in the literature regarding the content of selenium in coffee infusions. The origin of coffee beans and the type of water used (especially regarding fluoride) may have an impact on the content of minerals in infusions. The brewing method does not seem to play an important role. As it is a very popular beverage, coffee can additionally enrich the diet with such micronutrients as manganese, zinc, and copper. This seems beneficial due to their antioxidant properties, however the bioavailability of these elements of coffee should be taken into account. It seems necessary to carry out more research in this area.

Effect of Brewing Method on Quality Parameters and Antioxidant Capacity of Black Tea

Introduction: The traditional method for brewing tea in Turkey involves use of a two-vessel apparatus known as a “caydanlik.” The caydanlik allows for tea to be brewed for a longer time than typical brewing methods and involves introducing boiling water to tea leaves and steeping them in a teapot as the temperature declines over 15 minutes. In comparison, the typical tea brewing method used in other parts of the world involves steeping tea leaves in a single vessel teapot for 5 minutes. This study evaluated the effects of these two methods of brewing using two brands of tea. Results: Results of this experiment indicate that use of the caydanlik and the accompanying longer brewing time significantly changed key quality parameters and increased the antioxidant capacity of the brewed black tea beverage. Use of the caydanlik method resulted in significantly higher (P < 0.05) theaflavins, thearubigins, theabrownins, and total polyphenols in the resultant tea than in tea brewed in a traditional teapot. Additionally, analysis of color values of the brewed tea indicated the L and b-values were significantly (P < 0.05) lower in the caydanlik brewed tea while a and hue values were significantly higher (P < 0.05). However, chroma values were not significantly different (P < 0.05) between the two methods. Conclusions: In addition to influencing color, flavor and aroma, the brewing method also influenced the functional properties of prepared black tea. Use of the traditional two-vessel caydanlik for tea preparation increased concentrations of beneficial functional components in the tea.Keywords: Black tea, Caydanlik, Brewing, Camelia sinensis, ORAC, Total Phenolic Content

Consumer Choices and Habits Related to Coffee Consumption by Poles

Coffee is one of the most popular drinks consumed in the world, also in Poland. In the literature, much attention is paid to the influence of coffee on human health, especially daily intake of caffeine, and also purchasing consumer behavior. There is a lack of research devoted to consumer choices and habits in relation to coffee consumption and brewing method. Therefore, the aim of this study is to describe the characteristics of coffee consumers and present their segmentation based on consumer choices and habits towards coffee consumption. The study was performed using the computer-assisted web interviewing (CAWI) method on a group of 1500 adults respondents in Poland reporting the consumption of coffee. We collected information about consumer choices and habits related to coffee consumption, including brewing method, place of consuming coffee, and factors determining coffee choices. Using cluster analysis, we identified three main groups of coffee consumers. There are “Neutral coffee drinkers”, “Ad hoc coffee drinkers”, and “Non-specific coffee drinkers”. The respondents in the study are not coffee gourmets; they like and consume coffee, but these are often changing choices. To conclude, it can be stated that the Polish coffee consumer prefers conventional methods of brewing coffee (like a “traditionalist”) but is open to novelties and new sensory experiences. Based on study results it is possible to know the coffee drinking habits in Poland.

Comparative assessment of phenolic compounds and antioxidant properties of green tea made by microwave assisted and stove heating

Efficiency of microwave-assisted extraction (MAE) and a commonly practiced brewing method, i.e. heating on stove were compared for preparation of green tea (Camellia sinensis L.). The steeping time was invariant as 2 min. Three green tea samples (Lipton, Tapal and local herbal green tea) were used in the present experiment. Results showed that microwave extracts had significantly higher quantities of phenolics and flavonoids from all tea samples as compared to conventional stove heating. Moreover, microwave assisted extraction showed highest amount (2.19%) of gallic acid in Lipton green tea while the Quercetin content (1.23%) was found invariable in the samples.

Coffee consumption and mortality from cardiovascular diseases and total mortality: Does the brewing method matter?

Aim The aim of this study was to investigate whether the coffee brewing method is associated with any death and cardiovascular mortality, beyond the contribution from major cardiovascular risk factors. Methods and results Altogether, 508,747 men and women aged 20–79 participating in Norwegian cardiovascular surveys were followed for an average of 20 years with respect to cause-specific death. The number of deaths was 46,341 for any cause, 12,621 for cardiovascular disease (CVD), 6202 for ischemic heart disease (IHD), and 2894 for stroke. The multivariate adjusted hazard ratios (HRs) for any death for men with no coffee consumption as reference were 0.85 (082–0.90) for filtered brew, 0.84 (0.79–0.89) for both brews, and 0.96 (0.91–1.01) for unfiltered brew. For women, the corresponding figures were 0.85 (0.81–0.90), 0.79 (0.73–0.85), and 0.91 (0.86–0.96) for filtered, both brews, and unfiltered brew, respectively. For CVD, the figures were 0.88 (0.81–0.96), 0.93 (0.83–1.04), and 0.97 (0.89–1.07) in men, and 0.80 (0.71–0.89), 0.72 (0.61–0.85), and 0.83 (0.74–0.93) in women. Stratification by age raised the HRs for ages ≥60 years. The HR for CVD between unfiltered brew and no coffee was 1.19 (1.00–1.41) for men and 0.98 (0.82–1.15) for women in this age group. The HRs for CVD and IHD were raised when omitting total cholesterol from the model, and most pronounced in those drinking ≥9 of unfiltered coffee, per day where they were raised by 9% for IHD mortality. Conclusion Unfiltered brew was associated with higher mortality than filtered brew, and filtered brew was associated with lower mortality than no coffee consumption.

Effect of the Yerba mate (Ilex paraguariensis) brewing method on the content of selected elements and antioxidant potential of infusions

Yerba mate is a source of biologically active substances. The aim was to determine whether the place of origin of Yerba and the brewing method have any influence on the levels of Ca, Mg and Fe and antioxidant activity of infusions. Samples were steeped in cold water (25°C) and hot water (three consecutive infusions with 85°C water). Infusions had a high antioxidant activity and high Mg level. The levels of elements and the antioxidant activity were influenced by the brewing method. There were no significant differences in the examined parameters depending on the country of origin. The results on the levels of elements and the antioxidant activity indicate that the most efficient brewing method was infusion in hot water. The highest levels of elements were found in first infusions, with the highest antioxidant activity in the third infusions.