Coffee Flavor Research Articles

Systematically Improving Espresso: Insights from Mathematical Modeling and Experiment

Summary Espresso is a beverage brewed using hot, high-pressure water forced through a bed of roasted coffee. Despite being one of the most widely consumed coffee formats, it is also the most susceptible to variation. We report a novel model, complimented by experiment, that is able to isolate the contributions of several brewing variables, thereby disentangling some of the sources of variation in espresso extraction. Under the key assumption of homogeneous flow through the coffee bed, a monotonic decrease in extraction yield with increasingly coarse grind settings is predicted. However, experimental measurements show a peak in the extraction yield versus grind setting relationship, with lower extraction yields at both very coarse and fine settings. This result strongly suggests that inhomogeneous flow is operative at fine grind settings, resulting in poor reproducibility and wasted raw material. With instruction from our model, we outline a procedure to eliminate these shortcomings.

Manufacture of a Coffee Substitute from Date Kernels of the Algerian Variety Mech-Degla

The present study has two components, in the first place the morphological and physicochemical characteristics of the inedible part of the date (kernels) have been determined, in order to bring additional knowledge on these characteristics, which helps to highlight the possibility of their valuations. The dimensions of the date kernels are between (0.9021 to 1.2829g) for the weight, (1.9 to 2.5cm) for the length and (0, 5 to 0.8cm) with an average of 0.6cm for the width of the core. An acidic pH of 4.55, and a moisture content of 6.38% has 0.8% ash content and a crude fiber content of 76.37%, a total sugar content of 4.69%, a crude protein content of 5.42% a fat content of 15.9% and the pulp / core ratio is 4.79. The second part deals with the valorization of the “Mech-Degla” date kernels in the manufacture of a coffee substitute. A sensory evaluation of color, smell, flavor and general appreciation of the date kernel coffee substitute was performed. The production of a date-kernel-based coffee substitute is one of the processes for exploiting the by-products of date processing. Statistical analysis of the sensory evaluation results of color, odor, flavor,and general acceptability reveals that although this is the first time for most tasters to taste a coffee substitute at core dates, but they showed great acceptability towards this new product especially when they added sugar (sweetener).

The Decision Support System in Selecting The Characteristics of Coffee By Using Analytic Hierarcy Process Method

This study is to determine whether the characteristics of coffee flavor can be implemented into a decision support system. In this study, the problem is the difficulty in finding coffee experts with adequate understanding and knowledge of coffee. The purpose is to implement Analytic Hierarchy Process (AHP) method to determine the characteristics of coffee flavor and to transfer the knowledge about the taste of coffee to coffee lovers.
 The expected results are to assist in making a decision support system application in selecting the characteristics of coffee, so that it can provide the advice to the common consumers who want to enjoy and the knowledge about the coffee itself as well.

Efficacy of Oral Protein Supplementation “PRO 360 Diabetic” on Diabetic Foot Ulcer Patients-A Pilot study

Foot ulcers are the main source of morbidity and a leading cause of hospitalization for persons suffering from diabetes. There is a steady increase in type 2 diabetes globally, especially among young and obese people. The main objective of the study is to assess the efficacy of oral supplementation “Pro360 Diabetic” a nutrition supplement in diabetic foot ulcers a complication predominant in diabetes. The subjects were randomly divided into two groups. Group 1 received Pro 360 coffee flavor Protein supplement and Group 2 received Pro360 Badam flavour Protein supplement daily for a period of 3 months. The following parameters CBC, HbA1c, Lipid profile, Urea, Creatinine and Total Protein were analyzed at baseline and every visit. The data obtained along with the patients’ age and gender was subjected to statistical analysis by SPSS to evaluate the efficacy of supplement in foot ulcer patients. The results showed that there is statistical variation in the clinical variables of both the groups and badam flavor is found to be better than coffee flavor. It can be inferred that p value <0.05 is statistically significant for total protein on 0th day and 90th day related to age. In conclusion Pro 360 diabetic with micronutrients can be implemented as oral protein supplement in diabetic foot ulcer patients but further studies need to be conducted.

Coffee flavour modification through controlled fermentation of green coffee beans by Lactococcus lactis subsp. cremoris

To achieve controlled coffee flavour biotransformation, direct fermentations of sterilized green coffee beans by a lactic acid bacterium (LAB), Lactococcus lactis subsp. cremoris, with and without 0.5% w/w glucose supplementation were investigated. The major metabolic activity of Lc. lactis subsp. cremoris was lactic acid production, and 2,3-butanedione (diacetyl) was also formed from amino acid metabolism and mixed acid fermentation. Glucose supplementation boosted lactic acid production but repressed 2,3-butanedione formation. The modifications of flavour-related constituents in green coffee beans were translated into modulations of roasted coffee flavour. The glucose-supplemented- and non-supplemented-fermented coffees features enhanced productions of O-heterocyclic and N-heterocyclic volatiles upon roasting, respectively. In particular, the highest level of total furfurals of coffees roasted at 235 °C for 12 min was found in glucose-supplemented-fermented sample, which was 1.4-fold of that in the untreated coffee. The 12-min roasted non-supplemented-fermented coffee featured the highest level of pyrazines, which was 2-fold of that in the untreated coffee. Glucose-supplemented fermentation yielded roasted coffee with an enhanced caramel aroma, together with preserved acidity and sweetness. Non-supplemented fermentation resulted in roasted coffee with an elevated nutty aroma. The undesirable smokiness in the untreated coffee was reduced by both fermentations.

Roasting optimization and kinetics of raw and instant controlled pressure drop pre-treated coffee beans

Introduction: Coffee is one of the most widely consumed beverages in the world. The desired aroma and flavour of coffee are developed duringroasting which is the most important step in coffee processing. Instant Controlled Pressure Drop Process (DIC) technology is controlled hightemperature and short time process which been used successfully to improving the kinetics of drying, extraction, and decontamination of fresh and dried natural products. The main advantages of DIC are that it is a master controlled temperature and time process, the dwell times are short, reducing the chemical degradation, so new products with superior quality attributes may be developed. Materials and Methods: Two coffee beans varieties were investigated by Brazilian and Ethiopian sources. The raw beans were pre-treated using the DIC process under adopted conditions prior to roasting. A two-factor central composite design was used to optimize the settings of roasting time and roasting temperature on response variables of bulk, true and normalized density, and roasting degree. Also, microscopic analysis using Scanning Electron Microscopy (SEM) and kinetics of the roasting processes are included. Results and Discussion: The obtained results confirmed that the roasted DIC treated beans for both varieties have lower densities, higher roasting degree and lower activation energy needed for roasting compared to the raw beans. The physical properties’ magnitude is highly relevant to coffee origin. Roasting time and the temperature seemed to be of significant regarding all the physical characteristics of the beans, however, time was of topmost significance. Besides, treating coffee been by DIC prior to roasting leads to texture modification and conservation of time and energy needed for roasting. Conclusions: The physical properties of the roasted coffee beans are highly affected and changed with the coffee origin, roasting conditions and pre-treatment of coffee beans prior to roasting using the DIC process. The incorporation of the DIC process prior to roasting seemed to achieve more conservation of time and energy needed for roasting compared to the raw untreated beans. The higher degree of roasting and the competitive roasting activation energy of Brazilian coffee beans give aconclusion that more economic roasting process could be achieved with the Brazilian coffee. The pre-treatment by DIC enhances the remarkable reduction in coffee beans density and increasing in the roasting degrees that are in line with the industrial needs of coffee beverages. Response Surface Methodology is an efficient tool for optimization and mathematical modeling of the coffee roasting process.

Gas Chromatography-Mass Spectrometry and Single Nucleotide Polymorphism-Genotype-By-Sequencing Analyses Reveal the Bean Chemical Profiles and Relatedness of Coffea canephora Genotypes in Nigeria.

The flavor and health benefits of coffee (Coffea spp.) are derived from the metabolites that accumulate in the mature bean. However, the chemical profiles of many C. canephora genotypes remain unknown, even as the production of these coffee types increases globally. Therefore, we used Gas Chromatography-Mass Spectrophotometry to determine the chemical composition of C. canephora genotypes in Nigeria—those conserved in germplasm repositories and those cultivated by farmers. GC-MS revealed 340 metabolites in the ripe beans, with 66 metabolites differing (p-value < 0.05) across the represented group. Univariate and multivariate approaches showed that the ‘Niaouli’ genotypes could be clearly distinguished from ‘Kouillou’ and ‘Java’ genotypes, while there was almost no distinction between ‘Kouillou’ and ‘Java,’. Varietal genotyping based on bean metabolite profiling was synchronous with that based on genome-wide Single Nucleotide Polymorphism analysis. Across genotypes, the sucrose-to-caffeine ratio was low, a characteristic indicative of low cup quality. The sucrose-to-caffeine ratio was also highly correlated, indicative of common mechanisms regulating the accumulation of these compounds. Nevertheless, this strong correlative link was broken within the ‘Niaouli’ group, as caffeine and sucrose content were highly variable among these genotypes. These ‘Niaouli’ genotypes could therefore serve as useful germplasm for starting a Nigerian C. canephora quality improvement breeding program.

Kopi Arabika Kalosi Produk Unggulan Kabupaten Enrekang

Kopi Arabika merupakan salah satu produk unggulan perkebunan Kabupaten Enrekang. UMKM Maqfirah sebagai produsen kopi baik dalam bentuk green bean maupun produk kopi roasted di Kabupaten Enrekang menghadapi permasalahan belum memiliki peralatan produksi, sehingga perlu peralatan pendukung untuk menjamin mutu dan meningkatkan produksi. Target mengembangkan UMKM ini sebagai produsen kopi arabika kalosi dengan peningkatan kapasitas produksi, mutu, variasi produk, serta perluasan pasar. Program pendampingan UMKM ini dilaksanakan melalui sinergi antara Tim Politeknik Pertanian Negeri Pangkajene Kepulauan dan Dinas Perindustrian Kabupaten Enrekang pada Maret-Agustus 2018. Metode penerapan melalui sosialisasi program, penyuluhan, pendampingan, dan pengembangan aspek produksi dan pemasaran. Dengan mengimplementasikan ipteks didapat peningkatan produksi, peningkatan kualitas citarasa dan aroma kopi, peningkatan pendapatan, dan peningkatan jaringan pasar kopi arabika kalosi yang merambah keluar provinsi.

Spent coffee grounds cookies: Sensory and texture characteristics, proximate composition, antioxidant activity, and total phenolic content

Spent coffee grounds (SCG) represent an environmental problem, although their composition makes them an interesting, re-valuable product to be incorporated in food. In this work, texture characteristics, proximate composition, total phenolic compounds (TPCs) content, and antioxidant activity were evaluated in cookies added with SCG (0.0, 10.0, 17.5 and 25.0 g/100 g). Intensity of specific sensory characteristics in cookies added with SCG was evaluated by 131 consumers using the just-about-right scale. Texture characteristics were not affected by SCG content. Crude fiber, fat, ash and TPC content increased with the increment of SCG in cookies (p < .01). All the cookies added with SCG were pleasant for consumers, although cookies with 17.5 g SCG /100 g were preferred (p < .05). Intensity of coffee flavor and granulosity seemed to determine its acceptance. Adding 17.5 and 25.0 g SCG/100 g in cookies allows to obtain a product acceptable for consumers, considered as dietary fiber source. Practical applications Spent coffee grounds (SCG) are considered an underutilized by-product by its high content of fiber and presence of antioxidant compounds. During development of functional foods, it is recommendable that the product shows an attractive composition, but also enjoyable sensory characteristics, which make it acceptable for consumers. Inclusion of SCG in cookies is a viable alternative for adding value to this by-product, reducing waste, and, at the same time, obtaining an interesting, functional food.

Health Risks of Drinking Caffeinated Energy Drink Among Students

This study aimed to determine awareness on the health risk of drinking caffeinated energy drink among students of Polytechnic College of Botolan, SY 2018-2019. Descriptive method of research is used. The findings conclude that respondents preferred drinking caffeinated energy drink with coffee flavor, preferably in the morning, once a day for stress relief which only lasted for a couple of hours; “moderately agree” on perceptions towards health risk of drinking caffeinated energy drinks; “moderately agree” on the perception towards adverse effects on health risk in drinking caffeinated energy drinks. There is significant difference towards health risk when grouped according to course; and little or weak relationship between adverse effect on drinking caffeinated drinks and the preferred time of drinking.

Microencapsulation of Caramel Flavor and Properties of Ready-to-drink Milk Beverages Supplemented with Coffee Containing These Microcapsules.

This study aimed to extend the retention of flavor in coffee-containing milk beverage by microencapsulation. The core material was caramel flavor, and the primary and secondary coating materials were medium-chain triglyceride and maltodextrin, respectively. Polyglycerol polyricinoleate was used as the primary emulsifier, and the secondary emulsifier was polyoxyethylene sorbitan monolaurate. Response surface methodology was employed to determine optimum microencapsulation conditions, and headspace solid-phase microextraction was used to detect the caramel flavor during storage. The microencapsulation yield of the caramel flavor increased as the ratio of primary to secondary coating material increased. The optimum ratio of core to primary coating material for the water-in-oil (W/O) phase was 1:9, and that of the W/O phase to the secondary coating material was also 1:9. Microencapsulation yield was observed to be approximately 93.43%. In case of in vitro release behavior, the release rate of the capsules in the simulated gastric environment was feeble; however, the release rate in the simulated intestinal environment rapidly increased within 30 min, and nearly 70% of the core material was released within 120 min. The caramel flavor-supplemented beverage sample exhibited an exponential degradation in its flavor components. However, microcapsules containing flavor samples showed sustained flavor release compared to caramel flavor-filled samples under higher storage temperatures. In conclusion, the addition of coffee flavor microcapsules to coffee-containing milk beverages effectively extended the retention of the coffee flavor during the storage period.

The Effect of Temperature and Roasting Duration on Physical Characteristics and Sensory Quality Of Singgalang Arabica Coffee (Coffea arabica) Agam Regency

The purpose of this study were to determine the effect of temperature and roasting duration on physical characteristics and quality of arabica coffee sensory,: find out the best temperature and roasting duration treatmen to physical characteristics and quality of arabica coffee sensory. This study used a factorial complete randomized design with two factors (200°C, 220°C and 240°C) and duration of roasting (12, 15, and 18 minutes). The variables observed in this study were rendemen (sucrose content of sugar cane crop or sample), water content, color value, acidity and sensory test of arabica coffee. The results showed that temperature and duration of roasting had effect on rendemen, water content, color value, acidity, flavor, taste and color of arabica coffee. The temperature of 220 ° C with 12 minutes of roasting is produceed the best physical characteristics and sensory quality of Singgalang arabica coffee, with 88.1% of rendemen, 1.23% of water content (bb), different color L (Lightness) 6,07, acidity 5.81, scent score 3.5), taste score value of 3.2, color score 3.6.

Sensory Influence of Sweetener Addition on Traditional and Decaffeinated Espresso.

Several factors have led to an increase in the consumption of sweeteners in substitution of sucrose. Studies on the behavior and the sensory properties of sweeteners are relevant, once they provide knowledge about both the adequate sweetener concentration with a sweetness equivalence to a sucrose-sweetened product and the possible sensory changes of the product. The addition of stevia with different rebaudioside A concentrations and sucralose to traditional and decaffeinated espresso coffee was studied, using the just-about-right scale and magnitude estimation method, to determine the ideal sweetness and the acceptance of the samples. The effect of the intensity of sensory attributes sweet taste, bitter taste, coffee flavor, and body in the acceptance was evaluated by penalty analysis. Decaffeinated presented proportionally lower sucrose concentration and sweetness equivalence than the traditional samples. Stevia concentrations were similar, despite the different rebaudioside A concentrations, for both traditional and decaffeinated samples, and rebaudioside A levels from stevia in espresso have no differences in sweetness intensity. Sucralose was the most intense sweetener in espresso. Although no differences were observed in the acceptance test in relation to appearance, aroma, and texture among the samples, the internal preference map showed segmentation of consumers with respect to the acceptability. This segmentation is more related to the type of sample than the added sweetener. Penalty analysis demonstrated that the most penalizing sensory characteristics were "coffee flavor" and "sweet," leading to a significant decrease in the acceptability of the samples. PRACTICAL APPLICATION: Conclusions obtained are important source of knowledge for the coffee industry, in the development and manufacture of beverages with coffee. The present findings can help to understand the behavior and the sensory properties of sweeteners. They provide knowledge about sensory perception of sweet and bitter tastes, and the factors that influence this perception and the sensory profile of the samples, once the behavior of sweeteners varies according to the product to which they are added.

Cover Caption

August Online Cover: Flat‐bottomed and semi‐conical coffee brewing baskets, descriptive attributes, and the distribution of overall opinion of coffee flavor and liking, from “Effect of Basket Geometry on the Sensory Quality and Consumer Acceptance of Drip Brewed Coffee” by Scott Frost, William Ristenpart, and Jean‐Xavier Guinard. p. 2297

Modulation of coffee flavor precursors by Aspergillus oryzae serine carboxypeptidases

Aspergillus oryzae was isolated from coffee pulp, screened for the production of carboxypeptidase and confirmed by molecular studies. Coffee pulp posses high protease activity (1.4 × 103 nkat/mL) among the agro-substrates used for the production of proteases but wheat bran was used for further studies considering its easy availability in large volumes. Proximal composition, pre-treatment, auxiliary carbon and nitrogen with growth studies indicated carboxypeptidase activity (2.6 × 103 nkat/g). The RSM was employed to generate a predictive model of the combined effects of independent variables and indicated a significant impact on acid carboxypeptidase with 35% moisture, 30 °C temperature, 108 CFU mL−1 inoculum and 100 h duration with 4.8 × 103 nkat/g activity. The partially purified peptidase had a specific activity of 6.1 × 104 nkat/mg with a molecular weight of 50 kDa, optimal pH 3.6, temperature 35 °C and feature of a serine protease. Enzyme stability was maintained with 50% glycerol and 2 mg/mL BSA. The protease application to develop flavor profiles of coffee was noteworthy with an organoleptic score of 7.5 compared to 4.5 of the untreated sample. GC-MS highlighted enhanced flavor annotations of pyrazines contributing sweet fruit notes. Carboxypeptidase augmented the coffee bean with specialized flavor notes and has been reported for the first time.

Mesoscopic modelling and simulation of espresso coffee extraction

A mesoscopic model for the simulation of espresso extraction based on the Smoothed Particle Hydrodynamics method is presented. The model incorporates some essential features such as bimodal granulometry (fines-coarses) of the coffee bed, double (liquid/intra-granular) molecular diffusion and solid-liquid release mechanism. The porous structures (‘coarses') are modelled as stationary solid regions whereas the migration of cellular fragments (‘fines’) is described by single-particles advected by the flow. The boundary filter is modelled as a buffer region where fines are immobilized while entering it, therefore providing a transient flow impedance. The model captures well the transient permeability of the coffee bed under direct-inverse discharge observed in experiments, showing the importance of fines migration on the hydrodynamics of the extraction. The concentration kinetics for different molecular compounds (i.e caffeine, trigonelline and chlorogenic acid) are compared to experimental data for a traditional espresso extraction, showing excellent results. The present work lays down the basis for the virtual analysis of coffee flavors by monitoring the hydrodynamic and microstructural effects on the balance of extracted key-odorant or taste-actives compounds in the beverage.

Different Chemical Compound Profiles of Indonesian Coffee Beans as Studied Chromatography/Mass Spectrometry

Coffee is a favourite beverage worldwide, with all of its benefits. The taste and flavour of coffee depending on the chemical components of the coffee. And the presence of chemicals in the coffee ground depends on the original tree as well as on processing. In this report, some volatiles from ground and brewed coffee beans of Robusta, Arabica, and peaberry coffee beans were extracted to be described after chemical analysis. Mainly gas chromatography/mass spectrometry methods were the main spectroscopy utilized to obtain chemistry information that was taken from hot brewed coffees. The result showed that peaberry coffee beans were very rich in components compared to others. Arabica coffee beans also had stronger in taste and flavour compared to robusta as seen from the profile compositions of chloroform and n-hexane extracts. Better processing would also be suggested for each type of coffee beans.

Screening for Green Coffee with Sensorial Defects Due to Aging During Storage by MALDI-ToF Mass Fingerprinting

The sensorial quality of coffee can be impaired by prolonged storage. Aged coffee presents an off-note taste which is called “rested coffee flavor.” This quality reduction is accompanied by changes of the lipid profiles. Therefore, we tested the suitability of MALDI-ToF mass fingerprinting to discriminate between unrested (“fresh”) and rested Colombian Arabica (Coffea arabica) coffee samples. The samples represented different varieties, geographic regions, and processing. With an optimized sample preparation and data processing protocol, we obtained informative mass profiles of coffee oil. Principal component analysis (PCA) was insufficient to classify between unrested and rested samples. Thus, we developed a Random Forest model, which demonstrated a specificity of 72% to detect rested coffee across different days of sample analysis. For individual measurement days, 85–92% specificities were obtained. The high throughput of MALDI-ToF mass fingerprinting enables the broad screening of green coffee materials for quality monitoring and shelf-life studies.

Pengaruh Lama Perendaman Buah dan Fermentasi terhadap Warna Kulit Tanduk dan Citarasa Kopi Robusta

&lt;em&gt;Pulping and fermentation of coffee cherry determine the quality of green beans and coffee flavors. Delay in pulping will cause the slime stick to the hull skin hence decreasing the bean quality and flavor. The objective of this study was to examine the effect of soaking before pulping and fermentation time to the color of coffee hull skin and the cup quality. The research was carried out at the experimental station of Indonesian Coffee and Cocoa Research Institute in Malang Regency (ICCRI) and ICCRI laboratory in Jember Regency from July 2018 to January 2019. Experiments used factorial completely randomized design. The first factor was cherry soaking duration (0, 24, 48, and 72 hours) and the second factor was fermentation duration (0, 24, and 48 hours) and then combined into 12 treatments, with three replications. Ten kilograms of coffee cherries were soaked prior to pulping then fermented in a plastic bag and added with &lt;/em&gt;Lactobacillus casei&lt;em&gt; 2,5 x 10&lt;sup&gt;7&lt;/sup&gt;&lt;/em&gt;&lt;em&gt; cfu/ml as starter. Parameters observed were color of hull skin &lt;/em&gt;(&lt;em&gt;L&lt;/em&gt;&lt;em&gt; value&lt;/em&gt;, &lt;em&gt;a*&lt;/em&gt;&lt;em&gt;, dan b*) and the cup quality. The results showed that soaking the cherry decreased the green beans quality which is indicated by less brightness (L), high a* value, and decreasing b* value of hull skin color. While the fermentation treatment can increase the value of L, decrease the a* value, and increase the b* value. The interaction of treatment of soaking and fermentation time significantly affected the lightnessl a* and b* value. Soaking and fermentation treatments did not significantly affect to the flavor, salt/acid, balance, and total score of coffee flavor. Soaking is not recommended for more than 48 hours and fermentation should be carried out 48 hours.&lt;/em&gt;

CHEMICAL COMPOSITION OF ROOT CHICORY

The value of the root chicory is due to the unique chemical composition of its roots. Depending on the variety, place of growth and growing conditions of culture chicory roots contain 72.0-77.0% water, 1.0-1.2% protein, 0.1-0.3% fat, 1.0-6.0% sugar, 12.0-30% inulin, 1.3-1.8% fiber, 1.1-1.9% ash, 0.3-0.4% phosphorus, 1.3-1.4% potassium, 0.3-0.4% calcium. Chicory roots can serve as a raw material for the production of various products: coffee surrogate, alcohol, sugar substitute and inulin in its pure form. Depending on the type of final product, the processing industry has different requirements for the chemical composition of the root crops. Coffee-chicory industry makes demands of the high content of inulin in the roots as the main nutritional flavor substratum, the high content of glucoside of inhibin reporting chicory drink a specific coffee flavor and aroma, and low content of proteins. The sugar industry is interested in a high percentage of inulin and other soluble carbohydrates that are easily converted into sugars, and in a small content of intibin, which gives the product a bitter taste, as well as in a small amount of proteins that are the most malicious pathogens that complicate sugar extraction. In the production of pure inulin, the processing industry is primarily interested in ensuring that the content of this carbohydrate in the root crops is as high as possible. The alcohol industry is interested in a high content of soluble carbohydrates as the main source material for alcohol, in a high content of soluble proteins as a nutrient substrate for the development of yeast cultures in the fermentation of sugar and in a high content of phosphorus and potassium salts, also necessary for the successful reproduction of yeast. The article reflects the economic importance of root chicory as a raw material for the needs of different types of industry (coffee-cyclical, alcohol, sugar), depending on the content of different substances in the root crops. The chemical composition, dynamics of accumulation of substances during the growing season and their distribution in different parts of the root crop are reflected.