Brewing Methods Research Articles

THE EFFECT OF COFFEE BREWING METHODS ON TOOTH DISCOLORATION

Background: The color of teeth in each individual varies greatly in which it is influenced by the color of dentin and enamel. The most frequent tooth discoloration that happened is caused by extrinsic stains like coffee. Coffee consumption habits are increasing along with the level of creativity in serving coffee. Nowadays, coffee with conventional methods like black/Turkish coffee and manual brewing methods such as drip brewing and espresso become popular coffee that are fancied by Indonesian people. Exposure to chromogenic substances and the acidic nature of coffee can cause the formation of pores in enamel and facilitate the deposition of dyes, which cause the color changes. Aim: The aim of this research was to analyze the effect of brewing methods on tooth discoloration. Method: This research was a true experimental study with a pre-post test control group design. Twenty eight post-extracted first premolar teeth samples divided into 4 groups for drip, espresso, black coffee and control by implementing random allocation. All samples were immersed in each coffee brewing group for 3 hours, 6 hours, and 9 hours. The teeth color was measured using a Chromameter based on the CIE L*a*b system. Statistical tests used Kruskal Wallis and Mann-Whitney test. Result: The Kruskal Wallis test showed differences in the color change ∆a * between the four groups (p < 0.05). Mann-Whitney test indicated a significant difference between the treatment group (drip, espresso, and black coffee group) and the control group (p < 0.05). Conclusion: Drip coffee, espresso and black coffee brewing methods can affect tooth discoloration, especially affects the red discoloration. But there is no difference in the effect of the drip, espresso, and black coffee brewing methods on tooth discoloration.

Impact of Brewing Methods on Total Phenolic Content (TPC) in Various Types of Coffee.

Coffee is a widely consumed beverage, both in Europe, where its consumption is highest, and on other continents. It provides many compounds, including phenolic compounds. The aim of the study was to assess the effect of various brewing methods on the total phenolic content (TPC) in the infusion. Research material comprised commercially available coffees: Instant Arabica and Robusta, freshly ground Arabica and Robusta (immediately prior to the analysis), ground Arabica and Robusta, decaffeinated Arabica, and green Arabica and Robusta. The following preparation methods were used: Pouring hot water over coffee grounds or instant coffee, preparing coffee in a percolator and using a coffee machine. Additional variables which were employed were water temperature (90 or 100 °C) and its type (filtered or unfiltered). In order to determine the impact of examined factors, 225 infusion were prepared. Total phenolic content was determined by the spectrophotometric method using the Folin-Ciocalteu reagent and the obtained results were expressed in mg gallic acid (GAE) per 100 g of brewed coffee. The highest value was obtained for 100% Arabica ground coffee prepared in a coffee percolator using unfiltered water at a temperature of 100 °C: 657.3 ± 23 mg GAE/100 g of infusion. High values were also observed for infusions prepared in a coffee machine, where the highest TPC value was 363.8 ± 28 mg GAE/100 g for ground Arabica. In turn, the lowest TPC was obtained for Arabica green coffee in opaque packaging, brewed with filtered water at a temperature of 100 °C: 19.5 ± 1 mg GAE/100 g of infusion. No significant effect of temperature and water type on the TPC within one type of coffee was observed. Due to its high content of phenolic compounds, Arabica coffee brewed in a coffee percolator should be the most popular choice for coffee drinkers.

Application of the Agrimonia eupatoria L. Extract for the Kvases Production

The article concerns the research of the herb Common Agrimony (Agrimonia eupatoria L.) use in the kvass manufacture, because the plant has a high content of flavoring and biologically active substances (flavonoids, tannins, arbutin, etc.). Researchers used standard, adopted in the brewing and soft drinks industry test methods and methods of processing obtained results. To produce kvass with the best quality characteristics, a man has to use Agrimonia eupatoria L. extract. In order to obtain this extract with the maximum amount of flavoring and biologically active substances (polyphenolic substances, ascorbic acid) a man must macerate 3-5 mm cut grass using purified water as a solvent in a ratio of 1:10 at a temperature of 40 ± 3 °C for 5-6 hours. Agrimonia eupatoria L. extract is an opaque brown liquid with a weak greenish tint, weakly expressed sweet-apricot aroma and taste; the mass fraction of dry substances is 3.0 ± 0.1 %; acidity – 2.5 ± 0.2 units; the content of polyphenolic substances is not less than 13.5 mg / 100 cm3; the content of ascorbic acid – not less than 4.5 mg / 100 cm3 . The authors developed kvass technology, including the preparation of kvass wort and Agrimonia eupatoria L. extract separately, its blending, fermentation, cooling, clarification and bottling. Based on the organoleptic and physical and chemical parameters obtained during the study, the researchers recommended the optimal ratio of kvass wort and Agrimonia eupatoria L.: 90:10 – 80:20. They developed regulated quality indicators of the new kvass: appearance – a transparent foaming liquid with opalescence, without foreign inclusions; color – brown with greenish tones; aroma and taste – refreshing, sweet and sour, bread, with light tones of Agrimonia eupatoria L. extract. The use of an aqueous extract from the herb Agrimonia eupatoria L. in the kvass production enables to get products with original organoleptic characteristics

Determining the impact of roasting degree, coffee to water ratio and brewing method on the sensory characteristics of cold brew Ugandan coffee

In today’s market, there is a growing demand for high-quality coffee with distinctive sensory characteristics, such a cold brew (CB) coffee. The objectives of this study were to determine the impact of a) degree of roasting, b) coffee to water ratio (C2WR), and c) brewing method on the sensory characteristics of CB coffee from d) various Ugandan coffee beans, both Robusta and Arabica. Four distinct coffee samples, sourced from lowland and mountainous regions in Uganda, were roasted and tested using a factorial design. A highly trained sensory panel evaluated the samples using 42 attributes. Results showed that all factors studied had an impact on most of the attributes. Not surprisingly, Robusta coffees generally had more bitter taste than Arabica coffees and the dark roast samples generally were more bitter than the medium roast coffees. Also, coffee samples that were brewed using a higher C2WR generally were more bitter than the coffees using a lower C2WR. However, although most of the main effects had a significant impact, their effects were mitigated by their interaction with other factors. For example, Medium roast Robusta that was slow-dripped with a high C2WR had a more bitter taste than the corresponding Arabica samples. However, when the Medium roast Robusta was steeped with a high C2WR it had a similar bitter intensity with the corresponding Arabica samples. Thus, although major impacts are critical, individual sample combinations must be considered when evaluating coffee samples for their impact on the sensory characteristics.

Yeşil çay ekstresinin soğuk muhafaza koşullarında depolanan levrek (Dicentrarchus labrax) filetolarında kaliteye etkisi

Despite its high nutritional value, antioxidants are used in aquaculture products that have a short lifetime, as in other foods, to maintain quality during preservation. The purpose of this study; It is to observe the oxidative stability of sea bass (Dicentrarchus labrax) fillets at 0-4 ℃ using green tea extract obtained by classical brewing method, which is a method that can be applied by the consumer with ease. Determined concentrations (0.4-0.8-1.2 g / ml) and immersion times (10-20 min) green tea extract is applied and the fillets stored at 0-4 Thiobarbituric acid reagents (TBARs) analysis, sensory analysis and color analysis were performed on days 0, 3, 6 and 9 of storage. Depending on the literature, although no significant effect is expected, total aerobic mesophilic bacteria (TAMB) analysis was also performed additionally. As a result of the analyzes, significant differences were found when the TBARs results of all samples with green tea extract applied were compared with the results of the control group after 9 days of storage (p <0.05). At the end of storage, the 4th group (0.8% g / ml-20min) gave the best results with 0.31 ± 0.009 μ mol MDA / g and there is a significant difference was found between the other groups (p <0.05). Green tea extract; As expected, it was determined that it did not have a significant antimicrobial and sensory effect. The color values caused a negative increase in the a * value, which expresses its green color as expected due to the color substances in its content, and a positive increase in the b * values, which express the yellow color. As a result of this study, it was found that green tea extract can be used as natural antioxidant in sea bass fillets.

The effect of different application methods of sumac (Rhus coriaria) and tarragon (Artemisia dracunculus) on some quality properties of marinated sea bream (Sparus aurata L., 1758)

In this study, different application methods (Spice, Brew, and Infused Oil) were employed using sumac (Rhus coriaria) and tarragon (Artemisia dracunculus) spices and chemical, sensory, physical, and microbiological quality values of marinated sea bream (Sparus aurata L., 1758) were investigated during 180 days of the experiment at +4 ± 1°C. TVB-N, pH, water activity, NaCl and acidity values, color measurement, and sensory and microbiological analysis were determined in the samples. All groups were within the limits of consumable in terms of TVB-N values during the storage period. According to the sensory analysis results in the present study, the group that was most liked by the panelists was determined as the spice tarragon (ST) group. Microbiological analysis results show that the antimicrobial effect of the brewing method is lower than other methods and sumac was the more suitable spice for marinated sea bream in terms of microbiological and sensorial analysis results. Practical applications Most consumers have a negative view of synthetic preservatives used in food products. Sumac and tarragon plants are among the spice types that have come to fore both in terms of antioxidants and antimicrobials. In this study, different application methods have been tried in marinated sea bream and it has been investigated in which method sumac and tarragon spice provide better preservation and shelf life.

Coffee consumption and overall and cause-specific mortality: the Norwegian Women and Cancer Study (NOWAC)

Coffee consumption has previously been reported to reduce overall and cause-specific mortality. We aimed to further investigate this association by coffee brewing methods and in a population with heavy coffee consumers. The information on total, filtered, instant, and boiled coffee consumption from self-administered questionnaires was available from 117,228 women in the Norwegian Women and Cancer (NOWAC) Study. We used flexible parametric survival models to calculate hazard ratios (HR) and 95% confidence intervals (CI) for all-cause, cardiovascular, and cancer mortality by total coffee consumption and brewing methods, and adjusted for smoking status, number of pack-years, age at smoking initiation, alcohol consumption, body mass index, physical activity, and duration of education. During 3.2 million person-years of follow-up, a total of 16,106 deaths occurred. Compared to light coffee consumers (≤ 1 cup/day), we found a statistically significant inverse association with high-moderate total coffee consumption (more than 4 and up to 6 cups/day, HR 0.89; 95% CI 0.83–0.94) and all-cause mortality. The adverse association between heavy filtered coffee consumption (> 6 cups/day) and all-cause mortality observed in the entire sample (HR 1.09; 95% CI 1.01–1.17) was not found in never smokers (HR 0.85; 95% CI 0.70–1.05). During the follow-up, both high-moderate total and filtered coffee consumption were inversely associated with the risk of cardiovascular mortality (HR 0.79; 95% CI 0.67–0.94; HR 0.80; 95% CI 0.67–0.94, respectively). The association was stronger in the analyses of never smokers (> 6 cups of filtered coffee/day HR 0.20; 95% CI 0.08–0.56). The consumption of more than 6 cups/day of filtered, instant, and coffee overall was found to increase the risk of cancer deaths during the follow-up. However, these associations were not statistically significant in the subgroup analyses of never smokers. The data from the NOWAC study indicate that the consumption of filtered coffee reduces the risk of cardiovascular deaths. The observed adverse association between coffee consumption and cancer mortality is most likely due to residual confounding by smoking.

Physicochemical Characteristics of Coffee Brews Using Different Brewing Methods

Physicochemical Characteristics of Coffee Brews Using Different Brewing Methods

The effects of roasting, milling, brewing and storage processes on the physicochemical properties of Turkish coffee

Turkish coffee is a special coffee due to its roasting, milling, brewing and storage processes. The roasting, milling, brewing and storage processes mainly affect the quality and physicochemical properties of Turkish coffee. The aim of this study is to determine; i) the optimum roasting method; oven (160, 180, 200 and 220 °C), microwave (350, 490, 700 W) or infrared (600, 1200 W), ii) the effects of different milling methods (cutter and hammer), iii) the effects of initial brewing temperature and water hardness, iv) the ideal brewing method (copper and electrical) and v) the ideal storage conditions. Microwave roasting at 350 W for 30 min and grinding with a cutter mill were found to be the better processes when compared to the others. Furthermore, the highest foam volume was obtained by using tap water at 4 °C and by brewing with a copper pot. The cold storing of Turkish coffee powder is a good storage condition to preserve the freshness; therefore, higher foam volume and stability were achieved under these conditions.

Aluminum in Coffee

This study investigated the aluminum content in one of the most consumed daily beverages: coffee. The total Al concentration in 10 different samples of coffee beans and their water-extractable fraction were determined. We then tested the influence of different brewing methods on the concentration of the extracted Al in the final beverage. Metal analyses were performed using graphite furnace atomic absorption spectroscopy (GF-AAS) after microwave-assisted acid digestion. The results showed highly variable Al contents in coffee beans (1.5–15.5 mg kg–1), of which ∼2–10% were water-extractable. The brewing technique had a major influence on the Al content in the beverage: significantly higher Al concentrations (72.57 ± 23.96 μg L–1) occurred in coffee brewed in an aluminum moka pot. Interestingly, using ground coffee with this method even reduced the Al content in the final beverage compared to the brewing water used. Coffee brewed from Al capsules did not contain significantly higher Al concentrations compared to other methods.

Swelling properties of roasted coffee particles.

In this study, the swelling behavior of roasted coffee particles in water and particularly its impact on particle diameter is examined by applying laser-diffraction analysis and microscopy. Several potential influencing factors are investigated: initial particle size, roasting degree, and temperature. Additionally, the time dependency of swelling and particle shape is evaluated at two different temperatures. We verify that particle erosion occurs - as observed by an increase of the fine particle fraction after wetting - and it is revealed that this effect is more pronounced with a rise in temperature. The total relative increase in particle size is determined as approximately 15% based on a broad range of different sized coffee grounds. It is demonstrated that the degree of swelling is independent of both the initial particle diameter and the roasting degree. The particle shape is found to be unaffected by swelling. This research reveals that swelling is initially quick, with 60-80% of the final steady-state diameter being reached after 30 s and completed after 4 min of wetting, i.e. within the timescale of conventional coffee brewing methods. This work provides a better understanding of the impact of wetting as part of the coffee brewing process, thus aiding the design, modeling, and optimization of coffee extraction. It clarifies the strong deviation of previous results on coffee-particle swelling by considering particle erosion and degassing and provides a robust method for quantification. © 2020 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Metabolomic profiling of beers: Combining 1H NMR spectroscopy and chemometric approaches to discriminate craft and industrial products

The authentication and traceability of craft beers is an important issue for both beer consumers and producers. Reliable analytical methods able to identify and discriminate products are needed to protect the craft brew market against fraud and counterfeit.Here, 1H NMR analysis of 31 beer samples, differing for beer style and brewing method (craft or industrial) was combined with multivariate statistical analysis, following both an untargeted and a targeted approach. NMR-based analysis of beer samples was sped developing a specific protocol enabling the automatic identification and quantification of metabolites in approximately thirty seconds per spectrum.A clear discrimination was achieved by exploiting 1H NMR analysis and multivariate chemometric methods and the targeted approach identified the metabolites responsible for the segregation.Overall, this study reports an analytical approach addressing beer traceability and is the starting point for the development of a standardized protocol for the discrimination of industrial and craft beers.

Coffee in the diet and prevention of diabetes

The impact of coffee consumption on health deserves an attention, especially in the context of patients’ ongoing concerns about its adverse health effects. Knowledge on this subject may also inform the clinical practice. Objective — to present the current state of knowledge about the relationship between coffee consumption and the incidence of diabetes type 2. Epidemiological studies indicate that the habit of coffee consumption reduces the risk of non-insulin-dependent diabetes. Drinking at least 3 cups of coffee a day reduces the risk of this disease by 20–25%, and higher consumption may portend even more protection. The beneficial effect of coffee is most likely due to polyphenols present in the infusion, which have an anti-inflammatory effect and may improve insulin sensitivity. The content of bioactive ingredients in a cup of coffee is variable, depending on both the natural variation in coffee beans and the brewing method. The issue of sweetening coffee is a particularly important one as the addition of sugar can reduce its beneficial effects. Moderate consumption of coffee brewed using filters (3–5 cups per day) is recommended. Current scientific research indicates that coffee not only has no negative impact on health but may even reduce the incidence of diabetes.

Investigating the effects of geographical origin, roasting degree, particle size and brewing method on the physicochemical and spectral properties of Arabica coffee by PCA analysis

Effects of geographical origin of Coffee Arabica beans (Brazil, Colombia and Peru), roasting degree, particle size and different brewing methods (French press, chemex and cold brew) on physicochemical and spectral properties of coffee samples were investigated in this study. Analyses of pH, total phenolic content (TPC) and total antioxidant activity (TA), UV and fluorescence spectroscopy measurements were performed. Principal component analysis (PCA) was used to obtain the most effective parameters on chemical changes. Results indicated that the increase of roasting degree caused decrements in the intensities of UV-spectra because of the degradation of trigonelline and chlorogenic acid molecules while counterpart trend was observed in the fluorescence spectra due to formation of fluorescence Maillard reaction products (MRP) during roasting. French press and cold brew methods caused similar TPC (1873.33-3818.33 and 2648.88-3824.44μg/mL gallic acid equivalent, respectively) and TA (0.18-0.32 and 0.16-0.27μmol/mL Trolox equivalent, respectively) values whereas chemex method showed different physicochemical properties (TPC: 1008.88-3543.88μg/mL gallic acid equivalent and TA: 0.08-0.26μmol/mL Trolox equivalent). Roasting degree and brewing method-compared to other parameters-were the most discriminating factors on the basis of UV spectra and fluorescence spectra of coffee brew samples, respectively. All roasting degrees could be distinguished with the rate of 71.42% on PC1 and 23.45% on PC2 of total variance according to UV-spectra while chemex and French press-cold brew methods could be differentiated with the rate of 97.24% on PC1 and 1.79% on PC2 of total variance based on fluorescence spectra on PCA score graphs.

Organik Çay İnfüzyonlarının Toplam Antioksidan ve Oksidan Kapasitelerinin Değerlendirilmesi

Amaç: Bu çalışma, demlenmiş organik çay örneklerinin (infüzyonlarının) toplam antioksidan (TAS) ve toplam oksidan kapasitelerinin (TOS) değerlendirilmesi amacıyla planlanmış ve yürütülmüştür.
 Gereç ve Yöntem: Tüketime hazır poşetli (sallama) veya dökme olarak satılan organik (O) ve organik olmayan (K) çay çeşitleri marketlerden temin edilmiştir. Çay infüzyonları; i)paket üzerinde yazan demleme tarifine uygun şekilde ve ii)koşullar (konsantrasyon, süre vb.) sabit tutularak iki farklı şekilde demlenerek hazırlanmıştır. TAS (mmol/L) ve TOS (μmol/L) ölçümleri yapılmış ve oksidatif stres indeksleri (OSI) hesaplanmıştır.
 Bulgular: Tarifelerine göre hazırlanmış çay çeşitlerinin TAS değerleri (mmol/L) değerlendirildiğinde; adaçayı (O: 2.92±0.05 ve 1.86±0.02, p<0.05), kuşburnu (O:2.91±0.03 ve K:2.81±0.01, p<0.05), nane-limon (O:2.77±0.01, K:2.33±0.58, p<0.05) ve papatya (O:0.81±0.01, K:0.71±0.02, p<0.05) çaylarının organik olan ve olmayan çeşitlerinin TAS değerleri istatistiksel olarak farklı bulunmuştur (p<0.05). Adaçayı (O:2.124, K:3.295), sade siyah poşet çay (O:1.975, K:2.368), zencefil-limon (O:1.444, K:1.833), dökme siyah çay (O:1.407, K:2.492) ve yeşil çayın (2 g/2 mL) (O:1.182, K:2.937) organik çeşitlerinin organik olmayan çeşitlerine kıyasla OSI değerleri daha düşüktür (p<0.05). Aynı koşullarda demlenen organik çay çeşitlerinin TAS değerleri (mmol/L) karşılaştırıldığında ise; organik adaçayının TAS değeri (3.24±0.01) en yüksek iken organik zencefil-limon (0.99±0.04) ile papatya çayının (1.01±0.01) TAS değerinin daha düşük olduğu saptanmıştır (p<0.05). En yüksek OSI değerine sahip organik çay çeşidinin ise papatya çayı (3.435) olduğu bulunmuştur (p<0.05).
 Sonuç: Bazı organik çayların organik olmayan çeşitlerine kıyasla antioksidan kapasitesinin yanı sıra oksidan kapasitesinin de yüksek olduğu belirlenmiştir. Çayların antioksidan/oksidan kapasitesinin; bitki çeşidine, doza ve demleme yöntemine göre değişebildiği ve bu nedenle tüm organik çay çeşitlerinin organik olmayanlara kıyasla daha sağlıklı olduğu genellemesinin yapılamayacağı düşünülmektedir.

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

Abstract 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.

Mineral Composition and Antioxidant Potential of Coffee Beverages Depending on the Brewing Method.

Coffee, being one of the world’s most popular beverages, is a rich source of dietary antioxidants. The aim of this study was to determine the mineral content and antioxidant activity as well as acidity of coffee beverages depending on the brewing technique. We tested coffee brews made and served at a popular urban coffee shop (Szczecin, Poland). Five coffee brewing techniques were used: Aeropress, drip, espresso machine, French press, and simple infusion. Our findings showed that the brewing method had a significant effect on all parameters tested in the study. The antioxidant activity of the beverages was high (31%–42% inhibition of DPPH (2,2-diphenyl-1-picrylhydrazyl); reduction potential from 3435.06 mol Fe3+/mL to 4298.19 mol Fe3+/mL). Polyphenolic content ranged from 133.90 g (French press) to 191.29 g of gallic acid/L (Aeropress brew), depending on the coffee extraction method. Mineral content was also found to differ between brewing methods. Coffees prepared by simple infusion and Aeropress provided a valuable source of magnesium, manganese, chromium, cobalt, and potassium, whereas the drip brew was found to be a good source of silicon.

Effect of the brewing process on the acrylamide content in coffee beverages

AbstractOne of the latest neurotoxic and carcinogenic substances discovered in food is acrylamide (AA). The main pathway for AA formation in foods is the Maillard reaction (MR). Heat treated carbohydrate-rich foods such as potato, cereal and bakery products, together with coffee contain high levels of acrylamide. The high consumption of coffee in many countries makes it a potentially significant source of daily exposure to acrylamide. The purpose of the present investigation was to study the influence of the brewing method on the acrylamide level in coffee beverages. The experiment was performed with six different roasted coffee from local supermarkets. For coffee beverages preparation four different methods were used: boiled coffee (Turkish coffee), steeping (French press coffee), infusion (filtered coffee), and Italian pressure method (espresso coffee). Each time coffee beans were mechanically powdered and 100 ml brew was prepared using 6 g of ground coffee. AA contents in the brew coffee samples were determined by the RP - HPLC - DAD method. The results for AA contents were presented as mean values ± standard deviations (SDs) of six independent samples, analysed in triplicate (n = 18). Obtained results showed that the method of brewing coffee influences the level of AA in infusions. AA concentrations for Turkish coffee (4.10 μg/100 ml), French press (3.19 μg/100 ml) and filtered coffee (2.95 μg/100 ml) were higher than for espresso (2.13 μg/100 ml). Results showed also that the highly water-soluble acrylamide is easily extracted from the ground coffee to the liquid phase of the beverage. The extraction percentage variation according to the brew method was: from 52% for espresso to 95% for Turkish coffee. The brewing procedure for espresso extracted acrylamide incompletely from ground coffee comparing to other brewing methods, due to the short contact time between coffee and water. When compared with other common coffee beverages, espresso is the most concentrated brew. However, its acrylamide content per cup may be lower, due to the lower level of this substance extraction to the brew. The brewing time has a significant influence on the extraction level of AA for the beverage.

Sensory and Chemical Changes of Cold and Hot Brew Arabica Coffee at Various Resting Time

Coffee is one of the most popular beverages which are rich in sensory attributes. What is the best time for brewing coffee after roasting is important question for consumer. In general, people do not directly brew coffee that has just been roasted. The chemical change which causes sensory changes still continues during the resting time. Enjoying coffee is about taste, everyone has different preferences. Some people prefer bitter coffee; some people like the sour taste and some others consume sweet coffee. Therefore, information about sensory and chemical profile is needed to give several options for consumer to choose their brewing method and brewing time before the coffee has decreased in sensory quality. This current study aims to know sensory and chemical changes of cold and hot brew Arabica coffee at various resting time. The materials were coffee beans Arabica Jawa Gunung Halu obtained from Cibeber, Sidangkerta Village, Mekarsari District, Bandung Regency, West Java. The roasted bean stored at various resting time (1, 3, 5, 7, and 9 days) than brewed in cold and hot brew methods. Sensory evaluation was conducted by 10 trained panelists using quantitative descriptive analysis (QDA). Furthermore, chemical analyses which were evaluated consist of the value of pH, brix and Total Dissolved Solid (TDS). The results showed that longer resting time followed by sensory characteristics changes on aroma, after taste, sweetness that is in line with chemical attributes change in Brix. Moreover color change in line with TDS change. While the different brewing techniques show that hot brew has higher value than cold brew in most all of parameters except Brix value. Keywords — chemical, coffee, panelists , resting time, sensory

Impact of microwave-assisted extraction on roasted coffee carbohydrates, caffeine, chlorogenic acids and coloured compounds.

Microwave-assisted extraction (MAE) allows to quickly achieve soluble compounds from solid matrices due to the promotion of temperatures higher than the solvent (atmospheric) boiling point, once a closed-vessel system is used for operating at high pressure. In this study, the feasibility of MAE for producing high yield coffee extracts with properties that allow their commercial application was tested through a quality by design approach. It was studied the influence of time of extraction (1, 5.5, 10min), temperature (120, 150, 180°C) and the mass-to-volume (m/V) ratio (2, 4, 6g/60mL) in the overall extraction yield (24-47%, w/w), carbohydrates content (18-43%, w/w), sugars composition, caffeine (4-7%, w/w), 5-caffeoylquinic acid (1-2%, w/w), colour and antioxidant activity of the extracts. FTIR analysis was used to study the resemblance of coffee extracts and commercial instant coffee. MAE allowed overall extraction yields considerably higher than the home brewing methods, mainly when performed at 180°C, with a substantial increase in arabinogalactans (AG) extraction associated to higher temperatures. Temperature exerted a crucial role in coffee extracts differentiation, although time and m/V ratio also lead to different values in the responses. Under a circular economy concept, MAE was able to produce extracts that can be used as defined food/brew ingredients and provides a galactomannan and cellulose rich residue that can also be valued as a source of dietary fibre.