Brewing Quality Research Articles

Novel continuous cold brewing method for coffee using a combined screw extraction and mechanical expression approach

This study investigated a novel continuous cold brewing method accomplished through a combined countercurrent single-screw extraction process and mechanical expression approach. The effects of four processing parameters (grind size (GS), motor rotation speed (RPM), press cone piston pressure (PCPP), and dry unbrewed coffee grounds feed rate (GFR)) on the particle size of coffee grounds, the mass balance of coffee grounds and water/brew in the brewer, and the physicochemical quality (total dissolved solids (TDS), extraction yield (EY), titratable acidity (TA), total polyphenols (TPP), pH, caffeine and 5-caffeoylquinic (5-CQA) concentration) of the brew were evaluated. The processing parameters significantly affected the mechanical interactions between the coffee grounds and brewer, resulting in changes in the packing density of coffee grounds, the moisture content of the spent coffee grounds, the extent of grind size reduction, and the amount of fines in the brew. These changes affected the physicochemical quality of the resultant brew leading to significant differences in TA, TPP, and 5-CQA, which were positively correlated with TDS.

The effects of pre-harvest glyphosate rate and timing on yield and pre-malt quality of malting barley

The production of barley cultivars with malting and brewing quality characteristics is subject to strict grading and technical standards for the end-use market. Environmental and management factors can significantly alter grain quality, and the qualities required for malting. Crop and kernel uniformity are critical factors where variability can exceed the tolerance for meeting malt quality. A practice to address variations in crop maturity is the application of pre-harvest glyphosate. Pre-harvest glyphosate applications can, however, alter malting characteristics in barley, and, if mis-timed, can also reduce yield. A 4-year study at five locations in Alberta and Saskatchewan from 2013 to 2017 was conducted to determine the effects of pre-harvest glyphosate applications on malting barley characteristics. Glyphosate was applied at 900 and 1125 g ae ha−1 on malting barley cultivars ‘CDC Meredith’ and ‘AC Metcalfe’ malting barley at soft dough, hard dough, and physiological maturity growth stages. Yield reductions of up to 12% were observed from glyphosate applications at soft dough, and yield was maximized with applications at physiological maturity. Glyphosate application, at two rates, reduced percentage plump kernels, but did not affect kernel weight or protein concentration. The growth stage of barley plants did not provide an accurate indicator of seed moisture levels at the time of application, which motivated our conclusion that glyphosate applications can be mistimed by inaccurate indicators. The results motivate our questioning of the utility of pre-harvest glyphosate applications, given the adverse effects to barley yield and quality observed, even when applied according to the label instructions.

Storability and Brewing Quality of Corn Grits: Impacts of Storage Temperature, Particle Size and Key Compositional Factors

Across international brewing operations corn grits from different suppliers vary substantially in terms of their physical properties and chemical composition. Present research aimed to highlight the key factors determining the brewing quality of stored corn grits. Six grits samples were sourced with different particle sizes (that ranged from 0% to 74% of particles ≤0.355 mm) and stored at 10 °C, 20 °C, or 30 °C for 0, 2, 4, 8, 12, and 16 months. Samples were analysed for moisture, extract, lipid, trihydroxy fatty acids (THFA) and pro-oxidant metal ion contents. Particle size range was measured using sieve analysis. Increasing levels of THFA occurred on storage due to lipid oxidation and are negative indicators of brewing quality. PLS-R modelling of THFA levels (R 2 = 0.83) revealed particle size (hence surface area for oxidation) was the most important factor (∼60% of the total R 2) followed by storage time (∼25%) and temperature (∼7%). Metal ion content and lipid content of grits were minor contributors. Results showed that coarser milling of grits offers protection against lipid oxidation even after 8 months at 30 °C. These insights into key factors determining the rate of lipid oxidation in stored corn grits will help to develop better supply chain management and storage practices with which to assure their brewing quality.

Sensory description of beverages of intervarietal hybrids of Conilon and Robusta: Natural and fermented coffees

AbstractThis study describes the sensory profile of beverages of Coffea canephora hybrids (clones BRS 2314 and BRS 2357) in natural (N) and fermented (F) versions. Flash Profile and Temporal Dominance of Sensations were performed; physicochemical characteristics were evaluated. Increase in total titratable acidity and reduction in pH was observed with fermentation. BRS 2314 beverages had higher contents of 5‐caffeoylquinic acid and caffeine. Natural coffees were described as having brown/coffee color, coffee aroma and flavor, roasted aroma and flavor, sweet aroma, and sour taste, and presenting dominance of coffee and tobacco flavors, and bitter and sour tastes. Fermented coffees were described as full‐bodied and having non‐characteristic, fermented and herbal aromas, astringent sensation, bitter taste and bitter aftertaste, and residual flavors, with the dominance of chocolate, fermented and roasted flavors, and bitter taste. BRS 2357 beverages were characterized by bitter taste and bitter aftertaste. BRS 2314N beverage presented attributes considered positive for quality.Practical ApplicationsThe results are relevant for the coffee production chain and consumers. Intervarietal hybrids of Conilon and Robusta are grown in an area characterized by family farming and with great prospects for sustainable production (in the Rondônia/BR state, Western Amazon) and are developed to express the best characteristics of both botanical varieties, as the high potential of Robusta coffees for fine cup beverages. The hybrid clones were successfully evaluated by experts, but the results do not necessarily correspond to the consumers' insights into coffee brew quality. In addition, fermentation allows to produce beverages with different nuances. The joint use of quick methodologies for static (Flash Profile) and temporal (Temporal Dominance of Sensations) sensory descriptions provided a closer representation of the consumers' perception of those products. This information brings new market perspectives for high‐yield Coffea canephora coffees that are now going through a moment of breaking paradigms regarding quality.

Quantitative lipidomics in green robusta coffees from the Brazilian Amazon by LC-HRMS

Lipids play an important role in coffee bean development and impact the coffee brew quality. The lipid fraction of raw coffee beans is mainly composed of triacylglycerols (TG) and other minor constituents, such as diterpenes, sterols, phospholipids (PL), and βN-alkanoyl-5-hydroxytryptamides (Cn-5HT). Despite these classes of compounds having been previously characterized by lipidomics, this approach was limited to semi-quantitative analysis. In this work, we developed a multiclass quantitative approach using liquid chromatography-high resolution mass spectrometry to quantify lipids in raw robusta coffees from different producers of the Brazilian Amazon region. The quantitative method for LPC, PC, PI, PG, DG, TG, and Cn-5HT classes was successfully developed and validated. The total lipid content in the robusta coffees ranged from 17.13 to 29.03 g 100 g−1 for TG, 1.44 2.10 g 100 g−1 for DG, 0.27–0.53 g 100 g−1 for PC, 0.34–0.36 g 100 g−1 for FI, 0.10–0.19 g 100 g−1 for Cn-5HT, and 0.01 g 100 g−1 for LPC. In addition, individual components from the Cn-5HT class were analyzed. PC, PI, TG, DG, and Cn-5HTs were relevant factors in discriminating the coffee samples according to their origin. Therefore, these results can help to further understand how the lipid composition of coffee beans is related to the place of harvest and the development of origin certificates of Amazon robusta coffees.

Investigation of extraction phenomena in continuous circulation coffee brewing and comparison with other brewing methods

AbstractThis study investigated a continuous circulation cold brewing (CCCB) process using a modified single‐serve brewer that allowed recirculation of the brew within the single‐use capsules. The changes of total dissolved solids (TDS), titratable acidity (TA), caffeine and 5‐caffeoylquinic (5‐CQA) concentrations over time during the CCCB process were evaluated using two masses of coffee grounds (10 and 12.5 g). To elucidate the extraction process, Weibull distribution, pseudo‐first order, and pseudo‐second order models were fitted to the extraction kinetics data. The physicochemical quality of the brews produced from the CCCB process were also compared to brews produced though traditional cold brew steeping (separated by gravity and forced filtration) and single‐serve hot brewing processes. Significantly lower (p < 0.05) TDS, TA, and 5‐CQA concentrations than traditional cold brew methods were observed. This observation was due to flow channeling/detachment phenomena in the coffee bed which resulted in localized flow and reduction of coffee‐water contact area. In comparison, the 30 min full immersion processes resulted in approximately 70% of the TDS, TA, and caffeine levels during the first 30 min of brewing, suggesting that cold brewing processes may not have to be >8 h in length if these are the targeted brew quality indices.Practical applicationsThis study examined the kinetics and physicochemical quality of continuous circulation cold brewing of coffee and compared it to traditional full immersion cold brewing methods. The findings in this study indicated that: (1) The brew recirculation method explored was not on par with traditional full immersion cold brewing methods in terms of extraction yield due to flow channeling issues present in single‐use capsules; (2) The extraction time of traditional cold brewing processes can potentially be shortened on the basis of TDS, TA and caffeine content; (3) The choice of filtration mechanism is significant when considering the extraction yield of a brewing process.

Quality Characteristics of Robusta Coffee (Coffea Canephora) Farmer Group in The Village of Tebat Island, Rejang Lebong Regency with Variation of Roasting Long Time

Tebat Pulau Village is, a formerly protected forest area that has now become a community social forest processed and planted with robusta coffee. Robusta coffee from the Tebat Pulau Village Farmers Group is of good quality because it is in great demand and attracts the attention of large buyers. However, it is not yet known what the quality profile, the criteria for roasted coffee and the preferred quality of brewed coffee are. Therefore, this research was conducted to determine the quality profile of rice coffee, the physical and chemical characteristics of ground coffee and the brewing quality of robusta coffee during roasting time. The experimental design used was Completely Randomized Design with one factor. The factor tested was roasting time (P), which consisted of 4 treatment levels, namely P1:10 minutes, P 2:11 minutes, P3:12 minutes, P4:13 minutes with roaster temperature 200°C and bean temperature 107°C . The research was carried out with 3 repetitions to produce 12 experimental units. The results showed that the coffee from the Tebat Pulau Village Farmer Group had quite large coffee beans with a water content value of 9.00%, had quite a lot of lanang (peaberry bean) coffee beans, and had a total defect value of 13.83. Ground coffee samples with a long roasting time significantly affected water content, color, ash content, coffee essence, and caffeine content. The best-brewed coffee quality was obtained at 12 minutes of roasting time with a final score of 8.50, which is included in the "fine" category.

Comparative Analysis of the Essential Oil Contents of Azadrichta indica and Humulus lulpulus: Could Azadrichta indica Substitute Humulus lulpulus in Beer Brewing?

Hops (Humulus lulpulus) give beer its brewing qualities (iso-alpha acid and essential oil). Hop acid is responsible for bitterness while hop essential oil is responsible for aroma and palate fullness. The aim of the study is to investigate the potentiality of substituting hop oil with neem (Azadrichta indica) oil in beer brewing. The oils were analyzed using Fourier-Transform Infrared (FTIR) spectroscopic technique after extracting the oil by solvent extraction. Hydrocarbon and Sulphur contents were also investigated using their standard methods. FTIR results show that both oils contain similar functional groups. It was observed that some hydrocarbons (myrcene, ocimene and α and β-pinene) present in essential oil of hop were also present in neem leaf oil. Volatile sulphur compounds such as dimethyl sulphide, dimethyl disulphide and dimethyl trisulphide present in hop oil were also found in neem oil. This study revealed that neem oil could be used as a substitute for hop oil in aroma enhancement in beer.

Anti-Coccal Activity and Composition of the Essential Oils and Methanolic Extracts Obtained from Brewing Quality Humulus lupulus L. Hop Pellets.

This study examined the chemical composition and anti-coccal properties of essential oils and methanolic extracts of six different Humulus lupulus L. varieties from Poland: Iunga, Marynka, Sybilla, Magnum, Tradition and Chinook. The activity of an α-acid-enriched fraction of methanolic extracts was also studied. The chemical composition of essential oils and extracts was determined by gas chromatography-mass spectrometry (GC/MS) and liquid chromatography-mass spectrometry (LC/MS) techniques. The compounds characteristic to H. lupulus extracts include xanthohumol, α-acids, β-acids, and prenylated flavonoids. Essential oil compositions showed a high prevalence of monoterpene hydrocarbon, myrcene and sesquiterpene hydrocarbons, α-humulene and β-caryophyllene. The antimicrobial activity was investigated against eight human cocci pathogenic strains: Staphylococcus aureus MRSA (ATCC 43300), S. aureus MRSA (29213), S. aureus MSSA (ATCC 29213), S. epidermidis (ATCC 12228), Enterococcus faecalis (ATCC 29212), E. faecalis VRE (ATCC 51299), E. faecium (ATCC 19434) and Micrococcus luteus (ATCC 10240). The lowest minimum inhibitory concentrations (MIC) were obtained for extracts and essential oils from Iunga hop samples. Extracts were significantly more active than essential oils. The most susceptible strain to both essential oils and extracts was M. luteus, whilst the least susceptible was E. faecium. The antimicrobial activity correlated with a high concentration of xanthohumol of active extracts rather than with the content of α-acids. Xanthohumol showed considerable activity against MRSA with an MIC value of 3.9 µg/mL. The activity of the α-acid-enriched fraction was mediocre compared to the results of all extracts.

Starch Structure of Raw Materials with Different Amylose Contents and the Brewing Quality Characteristics of Korean Rice Beer.

This study aimed to explore suitable processing materials for rice beer (RB) production by analyzing the starch structure of the raw materials utilized for brewing beer and the quality characteristics of RB. We used malt, employing the Heugho cultivar as the main ingredient, and produced beer containing 30% rice. The regular amylose-containing cultivars Samgwang (SA) and Hangaru (HA) and the high-amylose-containing cultivar Dodamssal (DO) were used as adjuncts. Distribution of the short molecular chains of the starch amylopectin was the highest for SA and malt at 29.3% and 27.1%, respectively. Glucose content was the highest in the wort prepared with 100% malt and 30% SA + 70% malt. The alcohol content in SA RB and HA RB was higher than that in beer prepared with 100% malt. DO RB had the least bitterness and volatile components, such as acetaldehyde and ethyl acetate. The three rice cultivars tested in this study are suitable as starch adjuncts for RB production. The characteristics of RBs varied depending on the molecular structure of the ingredients, irrespective of their amylose contents. SA could be considered a craft beer with quality characteristics and rich flavor components, similar to 100% malt beer, compared to other RBs.

Effect of different drying heating sources on quality of brewed green tea

The development of product quality is one of the most critical factors in the industry because rate changes can result in changes in the selling value of the product. Tea processing in the industry is generally a quality analysis process before the product is marketed. Analyzing the quality of brewing in green tea is carried out when the tea is dry and then brewed to specific standards. The tea drying process is carried out using a dryer. The dryer and the fuel used significantly affect the quality of the tea before it is marketed. In this study, green tea brewing quality was tested based on dryer fuels, such as Taiwan element electric (P1), element electric (P2), wood fuel (P3), jumbo wood fuel (P4), gas fuel + element (P5), and fuel gas (P6). This study uses the factorial Randomized Block Design (RAK) method; if it has a significant effect, the BNT will be further tested. The results of this study indicate that the perfect color was found in the dryer with elemental electric with a score of 2.84 (yellowish), and the best taste was found in the gas + element dryer with a score of 2.48 (good). The steeping dregs were the brightest found in the dryer, with an electric element score of 2.34.

Anaerobic germination of green coffee beans: A novel strategy to improve the quality of commercial Arabica coffee

This study aimed to improve the brewing quality of commercial Arabica coffee through anaerobic germination. Changes in important compounds and cupping scores of germination roasting coffee with different germination degrees were investigated by 1H NMR, HS-SPME-GC-MS and sensory analysis. Statistical analysis of multivariate analysis results indicated that 6 water-soluble chemical components and 8 volatile chemical components have the potential to be markers of germinated roasting coffee. In addition, germination significantly reduced caffeine content and acrylamide formation in roasted coffee. Sensory analysis according to the Specialty Coffee Association (SCA) cupping protocol demonstrated that anaerobic germination modified flavor attributes, improved the quality, and increased sensory scores. Furthermore, anaerobic sprouting increased fruity descriptors, but over-sprouting did not improve overall attributes while producing both fermentative and vegetable descriptors. Therefore, suitable anaerobic germination of green coffee beans can be used as a new strategy to improve the flavor of commercial Arabica coffee.

Effect of brewing condition on the quality of Apocynum venetum tea

Apocynum venetum tea is increasingly being recognized for its health benefits. Given that brewing conditions affect the flavor and quality of the final brew, optimal brewing conditions need to be determined to produce high-quality A. venetum tea. In this study, different brewing strategies (hot brewing, room temperature brewing, and cold brewing) were used to prepare A. venetum tea. Subsequently, the physicochemical indexes, functional components, antioxidant activity, and aroma compounds of the brews were compared. The brewing conditions affected the soluble solid content of the brews, as well as their pH, color, polyphenol content, flavonoid content, and aroma compounds. Ketones and aldehydes were the most abundant aroma compounds in the teas prepared using the three brewing conditions. Hot brewing tea had the highest content of functional components and antioxidant activity with aromas of grassy alcohols and caramel, sweet, nutty furans and ethers. Room temperature brewing tea was rich in esters with floral and fruity aromas. In contrast, cold brewing tea had a blue-green color; the most abundant compound in this tea was 2,5-dimethylbenzaldehyde, and it had a grassy and floral aroma. These results showed that hot brewing is the most suitable method for Apocynum preparation of A. venetum tea. Practical applications Apocynum venetum tea has become an ingredient in natural health teas in recent years. The brewing conditions will affect the flavor and quality of the final brewing. Therefore, it is necessary to determine the best brewing conditions to produce high-quality A. venetum tea, so as to provide theoretical support for the determination of brewing conditions for A. venetum tea.

The potential of crop models in simulation of barley quality traits under changing climates: A review

Most of the experimental and modeling studies that evaluate the impacts of climate change and variability on barley have been focused on grain yield. However, little is known on the effects of combined change in temperature, CO 2 concentration, and extreme events on barley grain quality and how capable are the current process-based crop models capture the signal of climate change on quality traits. Here in this review, we initially explored the response of quality traits of barley to heat, drought, and CO 2 concentration from experiential studies. Next, we reviewed the state of the art of some of the current modeling approaches to capture grain quality. Lastly, we suggested possible opportunities to improve current models for tracking the detailed quality traits of barley. Heat and drought stress increase the protein concentration which has a negative effect on malting quality. The rise of CO 2 concentration significantly reduces the grain protein, again resulting in a decline of the malting and brewing quality since the nitrogen concentration of grains needs to be kept at a specific level. The current crop models that simulate barley grain quality are limited to simulation of grain nitrogen concentration, size, and number in response to climate extremes and CO 2 . Nevertheless, crop models fail to account for the complex interactions between the conflicting effects of rising temperatures and droughts as well as increasing CO 2 concentrations on grain protein. They have mainly adapted wheat models that cannot capture barley’s protein composition and whole grain malting quality. Implementation of experiments from gene to canopy scales which are explicitly designed to detect the interactions among environmental variables on detailed quality traits and couple the remote sensing plus data-driven approaches to crop models are possible opportunities to improve modeling of barley grain quality. The development of modeling routines can capture the detailed grain quality provide valuable tools for forming climate adaptive strategies. Equally important, they can guide breeding programs to develop climate-resilient but high-quality barley genotypes. • Barley quality response to climate change and available modeling are explored. • Malting quality declines due to elevated CO2 and heat/drought effects. • Current models do not capture environmental interactions on barley quality traits. • Targeted trials and better models needed to test adaptation strategies on grain quality.

Transcriptomic analysis of starch accumulation patterns in different glutinous sorghum seeds

Sorghum is a high-quality raw material for brewing white wine, and the starch content in seeds has a large impact on brewing quality. Transcriptomic data obtained from a glutinous variety (Liaonian3) and a non-glutinous variety (Liaoza10) at 3, 18, and 30 days after pollination were analyzed to identify genes associated with starch accumulation. The amylopectin content was significantly higher in Liaonian3 compared to Liaoza10, but the amylose content and total starch content were lower. There were 6634 differentially expressed genes found in Liaoza10 between 3 and 18 d after pollination, and 779 differentially expressed genes between 18 and 30 d after pollination. In Liaonian3, there were 6768 differentially expressed genes between 3 and 18 d after pollination, and 7630 differentially expressed genes between 18 and 30 d after pollination. Genes were grouped by expression profiles over the three time points and the profiles were analyzed for enrichment of gene ontology terms and biochemical pathways. Profile 1 (decreasing expression from 3 to 30 d) for Liaoza10 was enriched in ribosomes, metabolic pathways, and carbon metabolic pathways. Profile 0 (decreasing expression from 3 to 18 d and consistent expression from 18 to 30 d) was enriched in pathways related to sugar or starch metabolism. Although the starch accumulation rate in Liaonian3 and Liaoza10 showed a profile of increasing and then decreasing, the expression of genes related to starch synthesis gradually decreased with time since pollination, demonstrating the complexity of starch synthesis. According to orthologous gene alignment and expression analysis, 19 genes such as entrzID_8068390 and entrzID_8066807 were found to be the key genes for starch synthesis and glutinous and non-glutinous differentiation in sorghum grains.

Metagenomics and metabolomic profiles of Coffea canephora processed by honey/pulped natural technique

Post-harvest processing of coffee is the dominant factor affecting the metabolite composition and quality of the final brew. This study proposes a novel coffee processing method based on an established semi-dry process. Honey/pulped natural coffee (HC) process combines fermentation and drying excluding the washing stage thus conserving water, unlike wet method. Robusta coffee (Coffee canephora) mucilage was monitored for the evolution of bacterial and fungal diversity along with metabolites produced. Lactic acid bacteria (LAB) (48%) and the major fungal community of Wallemia (31%), a selective marker of Robusta coffee fermentation, were predominant throughout the processing. The process modulates volatiles without significantly affecting the total polyphenols (4.66%), chlorogenic acid (2.07%), caffeine (1.66%), trigonelline (0.53%) and theophylline (0.16%). HC contained compounds like 2-methoxy-4-vinyl phenol, 2-furancarboxaldehyde, 5-methyl-, acetic acid, pyrazine, methyl-, 2-propanone, 1-hydroxy-, and furfural that promotes sweet, caramelly, nutty, pungent and hazelnut taste to coffee.

Weighted gene co-expression network analysis revealed the synthesis of aromatic compounds in Dendrobium catenatum

Aromatic compounds in Dendrobium catenatum could affect brewing quality. Methyl jasmonate (MeJA) treatment enhances the content of aromatic compounds in D. catenatum, improving the wine quality in brewing industry and medicinal value. In this study, two D. catenatum genotypes, A6 and B1, were used to investigate the effect of MeJA treatment on aromatic compounds. A total of 52 aromatic metabolites were identified using metabolome technique. Based on RNA-seq, weighted gene co-expression network analysis (WGCNA) of 16, 841 highly expressed transcripts uncovered black, cyan and turquoise modules that are significantly associated with the variation of aromatic compounds. These results reveal the changes of aromatic metabolites during MeJA treatment and provide insight into the biosynthesis mechanism of aromatic compounds in D. catenatum, which could be conducive to the synthesis of active bioactive compounds and their use as industrial by-products.

Effects of mixed intercropping on the agronomic parameters of two organically grown malting barley cultivars (Hordeum vulgare) in Northwest Germany

The market for organic malting barley (Hordeum vulgare L.) is growing. One goal of producing malting barley is to attain a defined protein content. This is challenging in organic farming because nutrient uptake is unpredictable. Since malting barley is quality sensitive to high amounts of available nitrogen (N) during the grain filling phase, artificial competition for N from a second crop within a mixed intercropping system could help to limit N uptake during these later growing stages. The objective of this study was to evaluate the effects of intercropping on the brewing quality parameters of malting barley within the framework of organic farming. In a field trial, with two spring barley cultivars (Odilia, Marthe) as sole crops and in intercropping treatments of 4 intermediate mixing ratios with camelina (Camelina sativa), linseed (Linum usitatissimum) and pea (Pisum sativum), the effects on yield and malting quality were observed. The results from three growing seasons on a study site in north-western Germany showed an opposite protein response for mixtures with linseed and pea. However, sole stands of barley mostly performed as well as the mixtures. For mixtures with camelina, neither yield nor quality aspects were affected. Comparing the two cultivars, the well-established Marthe, from traditional conventional selection, showed the better overall performance with a 13% higher grain yield, a 3% higher hectoliter weight and 5% higher proportion of size fraction > 2.5 mm than Odilia, which was released later from an organic breeding program. However, the yield component analysis showed a consistent yield determination for Odilia regardless of intercropping partner or mixing ratios which might indicate its suitability in polycultures. The observed average land equivalent ratios (LER) of mixtures with linseed (1.04) and pea (1.13) showed the potential to increase land-use efficiency but were lower compared to the mean LER found in a recent meta-analysis.

The changes in chemical properties of coffee during roasting: A review

Due to its chemical compounds, coffee has a good taste, pleasant aroma, stimulant effect, and health benefits. Roasting is a critical process to develop a good flavor and cup quality of the coffee brew. This article reviews the coffee chemical reaction proceeds during roasting, evaluates the roasted degree by physic and chemical approach and biochemical changes. The articles were compiled from ScienceDirect, SpringerLink, ResearchGate, and Google Scholar. Out of all of the collected papers, 40 articles were covered in this paper. The initial process of roasting is water content evaporating and continuously is followed by roasting phase including pyrolysis, Maillard reaction and caramelization. The roasted coffee degree is determined by visual, weight loss, acidity, and pop beans sound. The bioactive compounds of coffee such as chlorogenic acids, caffeine, and trigonelline affect brewed coffee’s cup quality. Chlorogenic acid and trigonelline significantly decrease during the roasting process. However, caffein is quite stable during roasting. The roasted coffee performs a function in the consumers’ health since in vitro and in vivo analysis present that bronze roasted espresso has the most powerful activity as anti-inflammatory and antioxidant.

A Malting Barley (Hordeum Vulgare L.) Variety, ‘Nurimaeg’ with Resistance to Barley Yellow Mosaic Virus and Tolerance to Lodging Stress

Other SectionsAbstract서 언재료 및 방법결과 및 고찰적 요사 사FigureTableReferenceA malting barley variety, ‘Nurimaeg’, was developed with resistance to barley yellow mosaic virus (BaYMV), tolerance to lodging stress, and good brewing quality. ‘Nurimaeg’ was developed by crossing Milyang127 and Miharu gold in 2004. Regional yield trials were conducted for ‘Nurimaeg’ as a breeding line ‘Iksan175’ in four different regions from 2014-2016. It has a type I growth habit, and its average heading and maturity dates were April 12 and May 20, respectively-which were 1 day later than the maturity date of ‘Hopum’ variety. As ‘Nurimaeg’ has a shorter culm length (77 cm) than that of ‘Hopum’, it showed tolerance to lodging stress. This variety possesses the rym5 gene and is resistant to BaYMV. It showed a 42.9 g 1000-grain weight and 90% assortment ratio. The yield potential of ‘Nurimaeg’ was 408 kg/10a, which is approximately 18% higher than that of ‘Hopum’. Analysis of grain quality for malting showed that ‘Nurimaeg’ has high quality of low protein and β-glucan content. Malt quality analysis revealed that it has 72.8% extract, 4.2% soluble protein, 38.9% kolbach index, and 243 WK diastatic power, which all were similar to those of ‘Hopum’. ‘Nurimaeg’ would be suitable for cultivation in the areas of Korea that have a daily minimum temperature of -4℃ in the month of January (Registration No. 7960).Keywords : malting barley, BaYMV resistance, lodging resistance, malt, variety