Brewing Time Research Articles

Pengaruh Suhu dan Waktu Penyeduhan Teh Daun Kelakai (Stenochlarna Palutris) Dengan Treatmen Asam Lemon (Citrus Limon) Terhadap Kadar Besi (Fe)

Iron (Fe) is one of the many nutrients found in kelakai. Lemon acid treatment (Citrus lemonade) is used in the processing of kelakai tea powder as an effort to increase the nutritional value of the plant. The aim of this research is to determine how temperature and brewing time affect the iron (Fe) content in kelakai leaf tea (Stenochlarna palutris) prepared with lemon acid (Citrus lemonade). This research used a 2 factorial completely randomized design (CRD) and was experimental. There are two factors: the first is the temperature at which the brewing is done (40, 50 and 60 degrees Celsius), and the second is the brewing time (1, 5 and 10 minutes) with three repetitions. Two-Way Analysis of Variance (ANOVA) was used in data analysis, along with an additional 5% Honestly Significant Difference (BNJ) test. These findings show a very significant influence of brewing temperature, brewing time, and the combination of temperature and brewing time. The results of the research show that moderate temperatures produce high iron (Fe) levels, moderate brewing results in high iron (Fe) levels. The brewing temperature treatment T2 (50oC) had the highest amount of calcium at 2.73778 ppm. Iron (Fe) levels are low at temperature T1 (400C) of 1.42000 ppm. The effect of brewing time on high iron (Fe) levels at F2 time (5 minutes) is 2.73778 ppm. The lowest iron (Fe) content was located at the longest brewing time, namely F3 (10 minutes) at 1.12267 ppm. T3F2 (600C, 5 Minutes) with iron (Fe) content of 3,707 ppm. The treatment that produces the lowest iron (Fe) content is T2F3 (500C, 10 minutes) with a value of 0.702 ppm

Sensory analysis of the flavor profile of full immersion hot, room temperature, and cold brewed coffee over time

With the growing popularity of cold brewed coffee comes a need for brewing efficiency while preserving the desirable flavor profile. Despite the wide use of full immersion brewing techniques, the effect of brew time on the dynamic sensory profiles of full immersion brewed coffee remains underexplored. Here, we investigated the relationship between coffee sensory quality and extraction dynamics, measured as Total Dissolved Solids (TDS) and Extraction (E) of full immersion brewed coffee at various roast levels, and brewing temperatures (4 °C, 22 °C and 92 °C), over brew time using a generic descriptive analysis method. Specifically, different brew time points were selected for different temperatures based on five targeted coffee extraction stages. Furthermore, the unique experimental design also explored a sensory-driven engineering research process. Roast level had the greatest impact on the sensory profile of the coffees, followed by brewing temperature, but brew time, especially the longer brew times as TDS plateaued, had subtler impacts than expected. Twenty-five of 28 sensory attributes were significantly different among the 30 coffee samples, indicating a single source green coffee blend can produce a wide range of complex sensory profiles using different combinations of roast level, temperature, and brew time. Specifically, the intensity of sweetness was negatively correlated with TDS, and 19 other attribute intensities were positively correlated with TDS. Interestingly, we found that certain long time cold brews had similar sensory profiles to those of some short time hot brews, suggesting the sensory profiles of certain hot brews and cold brews could possibly be matched through controlled preparation. Overall, our study demonstrated an approach of integrating food engineering and sensory analysis for product development, and our findings provide valuable insights into the extraction dynamics and sensory quality of full immersion brewed coffee and opens new brewing avenues for the coffee industry.

Brewing method-dependent changes of volatile aroma constituents of green tea (Camellia sinensis L.).

The determination of optimal levels of green tea amount and brewing time would have a crucial role in the accumulation of desired aromatic volatile compounds to meet worldwide market demand. Aroma is the most important factor influencing tea consumers' choices along with taste, price, and brand. This study aims to determine how the brewing time and amount of green tea affect the aroma profile of green tea infusion. The effect of the amount of Turkish green tea (5-10 g) and brewing time (5-60 min) on aromatic volatile compounds was evaluated using solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) technique. The SPME/GC-MS analysis identified 57 components in the aroma profile of green tea infusions including 13 esters, 12 alkanes, 7 unknowns, 6 ketones, 3 alcohols, 2 terpenes, 2 terpenoids, 1 alkaloid, 1 phenolic compound, 1 lactone, 1 pyrazine, and 1 norisoprenoid. The green tea amount and brewing time had significant effects on the number of chemical compounds. A total of 42, 47, and 36 aromatic volatile compounds were determined by brewing 5, 7.5, and 10 g of green tea. The most abundant constituents in green tea infusions were phytone, 2-decenal, lauric acid, unknown 1, methoxy-1-methylethyl pyrazine, α-ionone, β-ionone, and diethyl phthalate (DEP). With this study, the aroma structures of green tea infusion have been revealed for the first time depending on the brewing time and quantity.

Detection and formation of fluorescent carbon nanodots in coffee brews and its relationship with other compositions

Coffee, a widely consumed beverage, offers health benefits alongside enjoyment. While coffee chemistry has been studied for years, the existence and formation of nanoparticles in coffee remain incompletely understood. This research explores how carbon nanodots (C-CNDs) form in coffee under various conditions of brewing, including (1) bean types, (2) grind sizes, (3) the coffee-to-water ratios, and (4) brewing time and temperatures. The results show that the C-CNDs formation increased with Arabica beans, coaster grinds, and a 1:15 coffee-to-water ratio (g/g). Higher temperatures (over 90 oC) and longer brewing times also yielded more C-CNDs. Our findings revealed that the isolated C-CNDs have an average size of 3.2 ± 0.9 nm and are characterized using fluorescence spectrophotometer, UV-Vis, and TEM techniques. We also examined fundamental coffee compositions like caffeine content, pH, total dissolved solids (TDS), and browning color, finding the correlation with C-CNDs. While C-CNDs show a strong negative correlation with caffeine content (-0.8), there is a weak negative correlation with pH (-0.33), TDS (-0.48), and browning color (-0.62). This establishes a new link between C-CNDs and caffeine content. These discoveries, backed by robust scientific methods, enhance our understanding of coffee's composition and have potential health implications.

Determination of Element Concentration of Brewed Tea Consumed in Iran Using ICP-OES: A Risk Assessment Study.

Tea is a popular drink enjoyed by many people around the world. However, it is important to note that impurities and contaminants in tea can potentially threaten human health when consumed. The main objective of this research is to assess the concentration of 16 trace elements (As, Fe, Al, Co, B, Li, Cd, Ba, Pb, Cr, Zn, Hg, Ni, Mn, Sb, and Sn) present in different types brewed of tea by using the ICP-OES (the inductively coupled plasma optical emission spectrometer) device, and the human health risks related to its use were evaluated. In this study, manganese (Mn) indicated the highest mean concentration in black (917.64µg/kg) and green tea (912.89µg/kg), respectively. Our study showed that the highest mean concentration of element boron (B) was (44.36µg/kg) in Stachys lavandulifolia brewed tea. Among different packaging, tea bag samples had the highest concentration of Mn (1025.65µg/kg) and aluminum (Al) (396.63µg/kg). However, those unpacked posed the lowest content of Mn (188.13µg/kg) and Al (100.47µg/kg). The lead (Pb), mercury (Hg), and cadmium (Cd) concentrations in all samples were lower than the maximum limit of the Iranian standard and the WHO. In general, the amount of tea metal in Iranian samples was higher than in imported samples. Also, increasing the brewing time (10 min) can be effective in the solubility and extraction of metals such as B, Hg, cobalt (Co), iron (Fe), and lithium (Li). Further, the correlation between the amount of metals and type in tea samples was evaluated with principal component analysis. Based on the conducted non-carcinogenic risk assessment by the Monte Carlo simulation, the hazard index (HI), due to ingestion of heavy metals via tea in the 5-min brewing of tea, was 7.39E - 03 and 2.09E - 03, and in the 10-min brewing of tea, it was 3.20E - 02 and 9.07E - 03 for children and adults, respectively. Therefore, there was no significant non-carcinogenic risk from tea consumption.

Efek Temperatur dan Waktu Seduh terhadap Karakteristik Kimia dan Sensori Liang Teh Pontianak

<em>Liang tea Pontianak consists of herbal ingredients (Dicliptera chinensis leaves, Tradescantia spathacea leaves, Origanum vulgare Wilder leaves, Pandanus amarillifolius leaves and skin of Aloe vera chinensis) and tea ingredients (Caesalpinia sappan wood). Technological developments for preparing tea burrows in fresh form have turned into dry ingredients so that they are practical in preparation. The process of serving liang tea Pontianak by brewing, but currently it is not known when and the brewing temperature that produces the best physicochemical characteristics of the burrow has not been studied. The target of this research was to obtain the temperature and brewing time that produces the best chemical and sensory characteristics of Liang tea Pontianak. This study used a factorial randomized block design (RBD) consisting of 2 treatment, namely the brewing temperature of 70±3°C, 85±3°C and 100°C while the second factor was the length of brewing, consisting of 5, 10, 15 and 20 minutes. The results of this study found that the chemical and sensory characteristics of Liang tea Pontianak were brewed at 100°C for 20 minutes. The physicochemical characteristics of Liang teh Pontianak have antioxidant activity of 73.81%, total phenol content of 97.58 mg GAE/g and flavonoid content of 217.28 mg QE/g. Based on sensory characteristics, the best brewing Liang Teh Pontianak was 70±3°C for 20 minutes with color attribute values of 4.28, aroma 3.80, and taste 3.64. Determination of the best treatment using the value of the effectiveness index.</em>

Coffee brewing sonoreactor for reducing the time of cold brew from several hours to minutes while maintaining sensory attributes

This research designed and developed an ultrasonic reactor for a fast and on demand production of cold brew coffee, remarkably reducing the brewing time from 24 h to less than 3 min. The technology was engineered by utilizing resonance to induce ultrasonic waves around the walls of the brewing basket of an espresso machine. The sound transmission system comprised a transducer, a horn and a brewing basket. This arrangement transformed the coffee basket into an effective sonoreactor that injected sound waves at multiple points through its walls, thereby generating multiple regions for acoustic cavitation within the reactor. Furthermore, acoustic streaming induced greater mixing and enhanced mass transfer during brewing. The design was accomplished by modeling the transmission of sound, and acoustic cavitation. Brew characterization and chemical composition analysis was performed, considering factors such as pH, acidity, color, and the composition of caffeine, fatty acids, and volatiles. The efficiency of the extraction increased by decreasing the basket loading percentage (BLP). For instance, sonicating at 100 W doubled the extraction yield and caffeine concentration, from 15.05 % to 33.44 % at BLP = 33 %, and from 0.91 mg/mL to 1.84 mg/mL at BLP = 67 %, respectively. The total fatty acids increased from 1.16 mg/mL to 9.20 mg/mL, representing an eightfold increase, at BLP = 33 %. Finally, a sensory analysis was conducted to evaluate appearance, aroma, texture, flavor, and aftertaste, which demonstrated that coffee brewed for 1 and 3 min in the sonoreactor exhibited almost undistinguishable properties compared to a standard 24 h brewing without ultrasound.

일본산 품종 녹차의 우림 조건과 품종별 주요 성분

The flavors of tea vary depending on various factors, among which the taste of tea is greatly determined by the elution rate of each component contained in tea leaves. This study analyzed the infusion characteristics of Japanese green tea such as ‘Yabukita’, ‘Fusun’, ‘Okumidori’, and ‘Benifuki’. The brewing water temperature was 20, 40, 60, 80, or 100°C, and the brewing time consisted of one and two minutes. The elution rate of amino acids increased from 22.7-76.6% and 4.0-81.8% in theanine as the brewing water temperature and time were increased. The elution rates for polyphenols, catechins, and caffeine were 4.5-74.8%, 4.9-70.4%n, and 3.5-80.1%, respectively. The result indicated that the elution of components increased as brewing water temperature and time increased from 20 to 100°C and from one to two minutes, respectively. Amino acids were eluted at a slightly higher rate even at low temperatures, whereas polyphenols, and catechins were well eluted at temperatures above 80°C. These results suggest that each component related to the taste of tea has different elution characteristics. In addition, the elution conditions can be adjusted to achieve the favorite taste of tea.

Optimization of Brewing Process Vine Tea and Flavor Analysis of Different Brewing Processes

As a traditional Chinese medicine with the dual use of medicine and food, vine tea has been utilized for centuries as a daily health beverage due to its various health benefits. The primary component responsible for its biological activity is its total flavonoid content. While numerous studies have been conducted on the extracts of vine tea, research has primarily centered on its ingredients and effects, with limited focus on its sensory characteristics. As it has the problems of the undesirable flavor of bitterness and astringency, the development of the vine tea industry is limited. Furthermore, there is currently no standardized brewing process for vine tea. Therefore, it is essential to find a brewing method that is universally applicable and balances a high level of active ingredients with a rich sensory experience. In this study, we conducted a comprehensive investigation into the impact of various water qualities, tea-water ratios, brewing temperatures, steeping times, and frequencies on the total flavonoid content. To investigate the differences between samples from different brewing methods, one-factor experiments (n = 20) and orthogonal experiments were conducted. The total flavonoid content was measured using UV spectrophotometry. To thoroughly examine the flavor compounds, we employed mathematical relationship analysis, radar-gram analysis, principal component analysis (PCA), and odor fingerprinting. By integrating these methods with the electronic tongue and electronic nose, we were able to compare the flavor variances between samples and offer a concise analysis of the flavor compounds. The brewing process is influenced by several factors, with the tea-to-water ratio having the most significant impact, followed by brewing temperature and then brewing time. Electronic tongues and electronic noses can distinguish vine tea samples with different brewing processes to a certain extent. The optimal brewing conditions determined in this study were pure water, a 1 : 50 tea-to-water ratio, an 85°C brewing temperature, an 8-minute brewing time, and a single brew cycle. These conditions produced the highest total flavonoid content in the vine tea, at 326.8 mg/g, and the best flavor quality. This study offers novel approaches to standardize the brewing process of vine tea, along with valuable perspectives for enhancing the sensory attributes of the tea. It can serve as a benchmark for the industry’s future growth in the canning of vine tea, facilitating the creation of diverse vine tea drinks.

The Effect of Brewing Time on the Antioxidant Activity of Tea Infusions

Many studies have found that tea has an antioxidant, anti-inflammatory, anti-cancer, anti-obesogenic and anti-diabetic effect, mostly associated with the content of anti-oxidant compounds. Polyphenols, being the main secondary metabolites in tea, are often considered the physiological markers determining a tea’s quality. Apart from the tea production process and tea components, brewing conditions can also influence the levels of antioxidants in tea. This study aimed to verify whether the brewing time of various tea types (5, 10 and 15 min) affects the level of extraction of antioxidant compounds into infusions and their antioxidant activity. We examined 11 types of tea: green leaf tea, green tea bags, white tea bags, black tea bags, red tea bags, black leaf tea, yerba mate, raspberry tea bags, butterfly pea flower (Clitoria ternatea) tea, white lychee plum tea and hibiscus flower tea. Total polyphenol (TPC), flavonoids and anthocyanins content, as well as determination of antiradical and antioxidant capacity with DPPH radical and ABTS radical cation, were determined using spectrophotometric assays. Due to the antioxidant activity of tea infusions, the optimum brewing time for green tea (leaf and bags), black tea (leaf and bags), butterfly pea flower tea, white tea, white lychee plum tea, raspberry tea and yerba mate is 15 min. Red tea brewing time should be ten minutes, and for hibiscus flower tea it should be five minutes. The results refer to the brewing temperature recommended by tea manufacturers.

Unveiling the presence of fluoride in commercial tea infusion: Factors influencing its release and its adsorptive elimination by indigenously developed nanoadsorbents

Drinking tea, which is globally one of the most widely consumed beverages, is a potential source of fluoride toxicity. This research aimed at fluoride estimation in the infusions of commercial black tea and green tea samples, purchased from the local Indian market, systematic evaluation of the factors influencing the fluoride release and the adsorptive removal of fluoride using the indigenously developed nanoadsorbents. All the prepared infusions had fluoride content above the permissible WHO limits. Various factors, which affect the release of fluoride from tea leaves into the infusion include type of water, tea dosage and brewing time. The investigations revealed that, the fluoride content in the black tea infusions was much higher than the green tea infusions. Further, it also depended on the amount of tea leaves used for brewing. The fluoride, present in tea leaves, is released gradually and within just 1 min of brewing, the concentration of fluoride in the infusions was well above the permissible WHO limits. It was also observed that, the dried unprocessed tea leaves, when brewed in water, had high fluoride content. This further confirmed the presence of fluoride in tea infusion, which demands an efficient remediation technique. The developed nanoadsorbents exhibited efficient defluoridation of groundwater, and were therefore tested for their efficiency in defluoridating tea infusions as well. These nanoadsorbents could efficiently eliminate fluoride from both green and black tea infusions, bringing down the fluoride content below the WHO limits, thereby rendering the infusions safe. They exhibited rapid kinetics with high efficiency in adsorbing fluoride from tea infusions. These properties make them potential adsorbents for defluoridating tea infusion, which provides a probable solution to the problem of fluoride toxicity from drinking tea. This is one of the first reports on a technique for eliminating fluoride from tea infusions.

Effect of Brewing Time on the Psychochemical and Antioxidant Activity of Green Tea Bag

Teabags are commonly used because of their practical use and benefits as antioxidants. However, there are still few studies that report the effect of brewing time of tea bags on their bioactive compounds. This study aims to determine green tea bags' psychochemical properties and antioxidant activity with different brewing times (1, 3, 5, 7, 9, 12, and 15 minutes). The results showed that the length of steeping time influenced the increase in total polyphenols, flavonoids, and antioxidant activity in green tea bags. The highest rehydration ratio value for product A was in the 3rd minute, which was 3.74 g/g, while in product B, it was 3.36 g/g at the 15th minute. In contrast, the highest swelling rate value occurred in the 15th minute with 372.79% and 236.31% in products A and B, respectively. Products A and B had the highest total flavonoids at 12 minutes of brewing time with 132.41 mg Q.E/g and 144.63 mg Q.E/g, respectively. Product A had the highest free radical inhibition activity at the 7th minute, while product B at the 9th-minute steeping was 56.54% and 73.73%, respectively. Pearson Correlation shows a positive correlation between total polyphenols, flavonoids, and antioxidant activity in green tea bags. The results of this study are expected to be a reference and education of reasonable green tea brewing procedures for consumption by the public.

Variables Affecting the Extraction of Antioxidants in Cold and Hot Brew Coffee: A Review.

Coffee beans are a readily available, abundant source of antioxidants used worldwide. With the increasing interest in and consumption of coffee beverages globally, research into the production, preparation, and chemical profile of coffee has also increased in recent years. A wide range of variables such as roasting temperature, coffee grind size, brewing temperature, and brewing duration can have a significant impact on the extractable antioxidant content of coffee products. While there is no single standard method for measuring all of the antioxidants found in coffee, multiple methods which introduce the coffee product to a target molecule or reagent can be used to deduce the overall radical scavenging capacity. In this article, we profile the effect that many of these variables have on the quantifiable concentration of antioxidants found in both cold and hot brew coffee samples. Most protocols for cold brew coffee involve an immersion or steeping method where the coffee grounds are in contact with water at or below room temperature for several hours. Generally, a higher brewing temperature or longer brewing time yielded greater antioxidant activity. Most studies also found that a lower degree of coffee bean roast yielded greater antioxidant activity.

Green Tea Dregs (Camellia sinensis (L.) Extraction Method Effect on Cutibacterium acnes and Development of Spot Cream

Background: Acne is a prevalent skin health problem experienced by teenagers and adults. Green tea is one of the plants that can be used to treat acne. Green tea dregs contain catechins, which have antibacterial activity that causes acne. Objective: This study aims to determine the antibacterial activity of green tea dregs extract against Cutibacterium acnes bacteria. Methods: This study used two brewing time variations and three green tea dregs with maceration variations. The obtained extract was then analyzed for its catechin content using the total phenolic test. Section, which has a high phenolic content, was then tested for its activity against Cutibacterium acnes bacteria using the microdilution method to obtain the MIC50 value. The extract with a brewing time of 2 minutes and the ultrasonic-assisted extraction maceration method had the highest MIC50 value of 8.586 mg/mL. The MIC50 value references extract concentrations used in acne spot cream formulations. The cream obtained after the stability test is semisolid, brown, and smells like tea. Spot cream is also homogeneous and meets the pH range in cosmetic preparations of 5.5. However, the viscosity of spot cream decreased significantly after storage to 4546 cPoise from 8106 cPoise. The decrease in the viscosity of the cream was caused by the catechin content in green tea dregs extract, which is acidic, thus reducing the effectiveness of the emulator in the form of triethanolamine, which is alkaline. The decrease in viscosity of the cream also caused the spreadability of the cream to increase and the stickiness of the cream to decrease.

THE DIFFERENCE BETWEEN MANUAL BREWING AND MECHANICAL BREWING IN POUR OVER V60

This research aims to provide a comprehensive analysis of the disparities between manual and mechanical brewing techniques in the context of pour-over V60 coffee preparation. The pour-over method, particularly with the V60 cone, has gained popularity for its ability to highlight the unique flavors of coffee beans. Understanding the nuances between manual and mechanical brewing processes can significantly contribute to refining the coffee brewing experience. The first objective of this study is to thoroughly investigate the differences between manual and mechanical brewing in the pour-over V60 method. Manual brewing typically involves a hands-on approach, where the barista controls various parameters such as water flow, pouring technique, and timing. On the other hand, mechanical brewing employs automated devices to handle these variables. By comparing the two methods, we aim to identify how factors like precision, consistency, and control impact the final cup of coffee. The second objective focuses on exploring the outcomes of V60 coffee by manipulating grind size, temperature, and brew time. Grind size plays a pivotal role in extraction, influencing the rate at which flavors are released. Temperature affects the solubility of compounds, and brew time determines the duration of extraction. By systematically varying these parameters, we aim to uncover the intricate relationships between grind size, temperature, brew time, and the resulting flavor profile in V60 coffee. The study employs a rigorous experimental design, using identical coffee beans to isolate the effects of brewing methods and parameters. Through sensory evaluations and analytical measurements, we aim to quantify the impact of each variable on taste, aroma, acidity, and body in the final coffee cup. Additionally, we will explore any potential interactions between the brewing method and the manipulated parameters. This research contributes to the broader understanding of coffee brewing science and provides practical insights for both coffee enthusiasts and industry professionals. The find- ings have the potential to guide coffee brewing practices, leading to improved techniques and heightened appreciation of the subtleties involved in crafting the perfect pour-over V60 coffee. KEYWORDS: Pour-over V60, Manual brewing,Mechanical brewing,Grind size,Temperature,Brew time,Coffee flavor profile,Brewing methods,Sensory evaluation, Coffee extraction.

Effect of ultrasound-assisted fermentation on physicochemical properties and volatile flavor compounds of Chinese rice wine

The traditional fermentation method for Chinese rice wine (RW) production has some limitations such as difficulty in controlling quality, long brewing time, and thin taste. In this study, ultrasonic technology was adopted by adding enzyme with the aim of improving the fermentation efficiency and volatile flavor quality of RW. Results showed that the ethanol yield was increased by 23.53 % and the fermentation time was reduced by nearly 2 days by ultrasonic treatment of (one-time, 28 kHz, 1 h, 35 W/L) on the first day. Flavor analysis (following the ultrasonic treatment) showed that the flavors, especially the esters and alcohols in RW, also enhanced most significantly. The contents of isobutyl acetate, ethyl butyrate, ethyl hexanoate, and phenethyl acetate increased by 58.03 %, 107.70 %, 31.84 %, and 18.71 %, respectively. The results showed that the brewing process could be simplified, brewing time could be reduced and volatile flavor of RW could be improved by ultrasound.

Modelling swelling effects in real espresso extraction using a 1-dimensional coarse-grained model

Swelling of coffee particle is difficult to measure and control, but it could have significant effects on espresso extraction. In this article, we incorporate a particle-level swelling model to a one dimensional bed-level extraction model to investigate the effects of swelling on extraction. Realistic geometric parameters and brewing parameters are used. A small degree of swelling is assumed to be present (≈3.6% in size). Our simulation results show that swelling only slightly affects the yield and the strength if the flow rate is fixed. However, when the pressure drop is fixed swelling will considerably enhance the strength at both fixed brewing time and fixed brewing mass. The finer the coffee particles the more pronounced the enhancement. By tuning the partition coefficient, the one-dimensional extraction model is shown to be able to capture very well the extraction kinetics of a fixing-flow-rate espresso machine in low beverage mass regime (Mc<30g). Our results suggest that better yield and strength control can be achieved by fixing the flow rate in an espresso machine. Moreover, it is indicated that when properly incorporated with relevant physical effects, numerical extraction simulations can be used to predict the extraction kinetics of espresso machine and guide their design and production.

Elemental composition of green tea infusions depending on the method of their brewing

Green tea infusions are a source of many bioactive compounds as well as elements, both nutrients and toxic ones. In this study, we assessed the content of elements in green tea infusions depending on the brewing time and their pH values. In instrumental analysis we used atomic absorption spectrometry. Elements such as Ca (calcium), Cu (copper), K (potassium), Mg (magnesium), Na (sodium), Fe (iron), Mn (manganese), Zn (zinc), and toxic Al (aluminium) were quantified in green tea infusions with pH = 6 and pH = 2, and after infusion times of 5, 10, and 20 min. The mean value of the elements in 250 mL of beverage was the following: (mg) K—114.68 ± 33.27, Ca—18.48 ± 334.24, Na—4.00 ± 0.92, Mg—2.71 ± 0.65, and (µg) Al 1266.53 ± 0.56, Mn—488.19 ± 320.46, Zn—46.65 ± 5.18, Fe—34.30 ± 10.96, Cu—5.00 ± 0.01. From 1 g of raw material, the following amounts of elements were leaching, µg/g: Al—ND-1479.89, Ca—190.42–7650.09, Fe—9.52–42.30, K—42108.07–108337.90, Mg—661.14–1760.73, Mn—58.82–931.19, Na—ND-1959.09, Zn—2.50–16.83. Cu content was at the LOD of the method. Based on the statistical analyses, significant differences between the sample series were found. Al and Mn significantly positively correlated with most of the elements studied. Both pH and brewing times affected the amount of extracted elements, especially in the case of Al, Ca, and Mn. The amount of K did not change much during the preparation of the brews. The acidic environment allows a large amount of leaching of Al and Mn into the infusion.

Characterization of phenolic components of black teas of different origins and the effect of brewing duration on quality properties.

This research aims to identify the phytochemical constituents of 79 different samples of black tea, including varieties from India, Iran (IrT), Turkey (TT), and Sri Lanka. In addition, this study investigates the effect of varying brewing times on the quality characteristics of tea. Therefore, we analyzed the phytochemical content of tea using a novel LC-MS/MS method that we developed, which identifies 53 different phenolic compounds. Furthermore, objective evaluations were conducted on the total phenolic compound, total flavonoid compound, antioxidant activity, and color values at 15, 30, and 60-min brewing intervals. The prevailing phenolic compounds discovered in the corresponding tea classifications were quantitatively analyzed to be quinic acid, epicatechin gallate, epigallocatechin gallate, epicatechin, epigallocatechin, gallic acid, nicotiflorine, and isoquercitrin. The study found that the TT and IrT groups had the richest phytochemical content and the highest antioxidant activity. The Turkish tea group had the highest measurement for the desired red color, which is considered a sensory property. Infusion color, antioxidant activity, and total phenolic and flavonoid contents showed significant increases with prolonged brewing time. It was important to note that the chemical composition of tea varies according to its origin and brewing conditions. Extending the brewing time improved the quality of the tea. It should be noted, however, that longer brewing times result in a more intense release of flavonoids, and this increase may have a pro-oxidant effect.

Ultrasound-Assisted Extraction as a Technique for Preparing Improved Infusions as Functional Beverage Bases

Right after water, tea is one of the most popular beverages in the world. The composition of a tea drink is determined by, among other things: the degree of fermentation and the fineness of the tea leaves, as well as the brewing time and temperature. The purpose of this study was to verify the hypothesis that the extraction of selected elements from dried tea during infusion preparation was improved by using ultrasound under laboratory conditions. The effect of increasing the extraction time was also analyzed. The effectiveness of ultrasound was evaluated by measuring the content of selected elements in the extract of teas that were treated with ultrasound compared to a control group. The effectiveness of the application of ultrasound was evaluated by measuring the content of individual elements at intervals of 1 min, 5 min and 10 min comparing the application of ultrasound with the classical technique of tea brewing. In addition, the results were related to measurements of the amounts of overall concentrations of selected ions after the dried tea mineralization procedure. Samples of extracts and mineralizates were analyzed for elemental composition using an ICP-OES iCAP Dual 6500 Thermo® spectrometer. The use of ultrasound was shown to have a positive effect on the extraction process, and the efficiency of the process depended on the tea variety and the extraction time. The percentage of extraction relative to the results of the total amount of extracted ions was also calculated. Analyzing the effect of ultrasound on the leaching of minerals from tea leaves during infusion preparation is another step toward optimizing the tea brewing extraction process and a way to improve the nutritional value of tea infusions as a functional beverage base. The application of ultrasound in the extraction process of tea infusions may be a good solution to support traditional methods of extracting infusions for both research and technological purposes.