Roast Degree Research Articles

Smart Online Coffee Roasting Process Control: Modelling Coffee Roast Degree and Brew Antioxidant Capacity for Real-Time Prediction by Resonance-Enhanced Multi-Photon Ionization Mass Spectrometric (REMPI-TOFMS) Monitoring of Roast Gases.

Process control with high time resolution is essential to maintain high product quality in coffee roasting. However, analytical techniques for quality assurance or measurements of desired coffee properties are often labor-intensive and can only be conducted after dropping the coffee beans. Resonance-enhanced multi-photon ionization time-of-flight mass spectrometry (REMPI-TOFMS) at 248 nm and 266 nm was applied to analyze the composition of the roast gas from small-scale Arabica coffee roasting. Coffee beans were dropped after different roasting times, ground and analyzed by Colorette to obtain the roast degree. Additionally, the antioxidant capacity of the coffee brew was determined by Folin–Ciocalteu (FC) assay. Models for the prediction of Colorette and FC values from REMPI mass spectra were constructed by partial least squares (PLS) regression. REMPI-TOFMS enables the prediction of Colorette values with a root-mean-square error in prediction (RMSEP) below 5 for both wavelengths. FC values could be predicted using REMPI at 248 nm with an RMSEP of 80.3 gallic acid equivalents (GA-eq) mg L−1, while REMPI at 266 nm resulted in RMSEP of 151 GA-eq mg L−1. Finally, the prediction of Colorette and FC value at 5 s time resolution were demonstrated with online measurements.

Roasting Conditions and Coffee Flavor: A Multi-Study Empirical Investigation

This research investigates the relative importance of two roasting parameters—colour (i.e., roast degree) and time—on the sensory properties of coffee. The paper draws on data from eight studies conducted using sensory descriptive analysis with trained (in six studies) or semi-trained (in two studies) assessors, focusing on a common set of attributes. The results indicated that, while both parameters significantly affected coffee flavour, colour was the stronger predictor of the two. The effects direction for both colour and time were similar and related to the rate of non-enzymatic browning, with darker roasts/longer roasting times associated with an increase in bitterness and a decrease in acidity, fruitiness, and sweetness. With respect to roasting time, we distinguished two phases, “time to first crack”, corresponding to the time between the onset of roasting and the moment where the accumulated steam pressure causes the beans to crack, and “development time”, corresponding to the time elapsed from the first crack to the end of the roasting process. The results clearly indicated that, under the same colour, time variation also influenced flavour, and in particular, development time, rather than time to first crack, had the largest effect on coffee flavour.

Production of instant coffee from cold brewed coffee; process characteristics and optimization

This study aimed to develop a process for producing instant coffee from cold brewed Arabica and Robusta roasted coffee beans. The process starts by selecting an appropriate mixture of Arabica and Robusta coffee beans, degree of roasting (light, medium, dark) and degree of grinding (coarse, fine). Sensory evaluation by a trained panel showed that a mixture of 92.5% Arabica and 7.5% Robusta medium roasted, coarsely ground coffee beans produces instant cold brewed coffee equally or better accepted from other instant coffees available to consumers. The selected coffee beans were subjected to vacuum assisted cold extraction and the extract was spray dried. Spray drying conditions (inlet temperature, air volumetric flow and air aspiration rate) were optimized by a 33 full factorial design. Response variables were solids yield, process thermal efficiency and anti-oxidant capacity of the produced powder measured as %DPPH scavenging ability, FRAP and total phenolic content. The produced powder was analysed for its physicochemical characteristics (caffeine content, phenolics, moisture content, hygroscopicity, bulk density, solubility, particle size distribution, acrylamide content and shelf life determination).

Distinguishing the region-of-origin of roasted coffee beans with trace element ratios

Determining coffee region-of-origin is most appropriately addressed through analyses of the product available to the consumer. We analyzed the concentrations of 44 trace elements in 53 samples of roasted Arabica coffee beans (Coffea arabica) from 21 different countries. Variations in absolute elemental concentrations of coffee beans arise through varying degrees of roasting (from green through dark roasts). Since trace elements are not volatilized at roasting temperatures, we conducted analyses of element ratios to evaluate concentration-related differences among beans of different origins. We used kernel density estimates to compare the distributions of 1892 element ratios for each of these countries with the combined distribution of coffee samples from the other countries. Using this quantitative approach, we demonstrated that many of the world’s coffee-producing regions can be distinguished from other regions of the world on the basis of element ratios.

Fortification of Ground Roasted Coffees with Iron, Zinc and Calcium: Evaluating the Impact of Quality and Roast Degree on Sensory Responses

Micronutrients’ deficiency is a relevant public health issue with considerable socio-economic consequences. Food fortification has been widely used as a simple low-cost strategy to increase mineral intake. Considering that coffee is among the most consumed food products worldwide, gourmet and traditional medium and dark roasted C. arabica and C. canephora beans were ground and singly or jointly fortified with ferrous bisglycinate chelate (21mg iron/kg), zinc lactate (10.5mg zinc/kg), and calcium lactate (1.5g/kg) salts. Beverages were prepared at 10%, (w/v) using electric coffee dripper with nylon filter, and mineral recoveries were evaluated by Inductively Coupled-Plasma-Optical-Emission-Spectrometry (ICP-OES). Coffee beverages’ acceptance and sensory characterization were performed by 103 regular coffee consumers, using a 9-point hedonic scales and Check-all-that-apply (CATA) questions. The impact of coffee quality (gourmet or traditional), roast degree (medium and dark) and mineral fortification (singly or jointly) on the beverage were evaluated. Mineral recoveries were 51.1%, 47.6%, and 51.3% for ferrous bisglycinate chelate, zinc lactate, and calcium lactate, respectively. Mean acceptance scores varied from 6.0 to 3.4. Unfortified blends and fortified blends with the three minerals were more liked by participants and were associated with positive attributes such as caramel, characteristic flavor, and chocolate. Roast degree and quality affected acceptance results, especially in blends fortified with a single mineral. The iron-fortified dark roasted blend was the least liked due to a strong metallic flavor, while dark roast was important to mask astringency in calcium-fortified gourmet blend, which had similar acceptance to unfortified blends. The beverage fortified with zinc was more accepted in medium roasted blend, regardless of being gourmet or traditional. Therefore, when fortifying coffee, issues related to the quality of the blend, roast degree and association with other components should be considered. In addition, results showed that the association of minerals had a positive effect on the consumer acceptance.

Cascade Control of Coffee Roasting Degree in a Spouted Bed Batch Process Based on a Real-Time Imaging Analysis

On this work, the experimental implementation of a cascade control algorithm to regulate coffee roasting degree in a batch spouted bed process is presented. The control algorithm is composed of an inner control loop that regulates the temperature of the hot air inflow used to roast coffee grains inside a spouted bed, while an outer control loop, based on imaging processing techniques, tracks on real time the coffee roasting degree and decides if the inflow air temperature must be modified. To achieve this goal, a colour-matching algorithm is used to compare a colour spectrum obtained from images acquired on real time, from a peephole on the spouted bed, with the colour spectrums of several reference images with different degrees of roasting. Match scores are computed based on the similarity between the colour spectrums. With the match scores, a roasting index is finally calculated to assess the degree of roasting, allowing to automatically track the roasting progress to decide if the batch roasting process has achieved the desired roasting degree. The experimental results show that the control scheme is able to robustly achieve the desired roasting degree with excellent effectiveness.

Effects of regular and decaffeinated roasted coffee (Coffea arabica and Coffea canephora) extracts and bioactive compounds on in vitro probiotic bacterial growth.

The aim of this study was to investigate the effects of coffee species, roast degree and decaffeination on in vitro probiotic bacterial growth, and to identify the major coffee compounds responsible for such effects. Six C. arabica and C. canephora extracts (regular medium and dark roasted and decaffeinated medium roasted), and five bioactive compounds (chlorogenic acid, galactomannan, type 2 arabinogalactan, caffeine and trigonelline) were individually incorporated into a modified low-carbon broth medium-(mMRS), at different concentrations (0.5 to 1.5% soluble coffee and 0.05 to 0.8 mg mL-1 standard solutions). Inulin and fructooligosaccharides (FOS) were used as prebiotic references. MRS and mMRS were used as rich and poor medium controls, respectively. The growth of Lactobacillus rhamnosus GG ATCC 53103-(GG), L. acidophilus LA-5-(LA), Bifidobacterium animalis DN-173010-(BA) and B. animalis subsp. lactis BB12-(BB12), as well as the growth inhibition of non-probiotic Escherichia coli ATCC 25922 were evaluated. Differences in growth between mMRS and treatments (Δlog CFU mL-1) were compared by ANOVA and Tukey's test, and considered when p ≤ 0.05. Overall, after 48 h incubation, the medium roasted arabica coffee extract increased the growth of GG, LA and BA (range: Δlog CFU mL-1 = 0.5 to 1.8), while the dark roasted arabica coffee extract increased BB12 growth (range: Δlog CFU mL-1 = 0.9 to 1.7), in a dose dependent manner. Improved performances of GG, LA and BA were promoted by higher polysaccharides and CGA concentrations, with better performance for Lactobacillus sp. The tested coffee bioactive compounds promoted the poor growth of BB12. Plain caffeine did not promote Bifidobacterium sp. growth and limited the growth of Lactobacillus sp. Regular C. arabica and C. canephora extracts inhibited the growth of E. coli, while the decaffeinated extracts promoted its growth. The present results show that coffee consumption can selectively improve the growth of probiotic strains, thus exerting a prebiotic effect, and show that coffee roasting and decaffeination affect this property and that different strains utilize different coffee components to grow.

Sensory quality prediction of coffee assessed by physicochemical parameters and Multivariate model

Beverages from roasted coffee can be classified according to their sensory quality into Gourmet, Superior, Traditional, and not recommended for supply coffee. However, the sensory evaluation of coffee has been questioned as it can induce a subjective bias, since the assessors may be influenced by psychological, physiological, and/or emotional factors. Therefore, the aim of this study was to develop multivariate models capable of predicting the overall quality of Gourmet, Superior, and Traditional coffees, based on the physical and physicochemical parameters. For that, one hundred and eight ground roasted coffee samples were evaluated for particle size, degree of roasting, histological identification, moisture, ash, aqueous extract, soluble solids (Brix), pH, and sensory profiling. All categories presented fine grinding. No significant differences were observed for the moisture content and soluble solids (Brix) of Gourmet, Superior, Traditional, not recommended for supply coffee samples. The Traditional and not recommended for supply presented higher levels of aqueous extract, ash, and pH. A light degree of roast and higher acidity values were observed with the increase in coffee quality grades. The results of the physical and physicochemical parameters and the Principal Component Analysis allowed the separation of coffees into two classes: high-quality (Gourmet and Superior) and low-quality (Traditional and not recommended), while the one-class classification (OCC) method showed good sensitivity and was able to satisfactorily distinguish the Gourmet coffee samples from the other samples. Key words: Coffee quality; sensory; chemometrics; OCC.

Monitoring coffee roasting cracks and predicting with in situ near‐infrared spectroscopy

AbstractThe prediction of start and end times of the first and second crack events in roasting coffee is feasible with in situ near‐infrared (NIR) spectroscopy. Roasting samples analyzed herein consist of eight varieties of arabica coffee with different origins and processing methods, roasted with four temperature–time profiles. Real‐time analysis of recorded audio from coffee bean popping sounds provides a basis for determining the start and end times of each major event. A custom in situ diffuse reflectance probe improved NIR output, and partial least squares (PLS) regression generated a separate model for each crack event. The resulting PLS models show strong potential for process control implementation. A newly developed roast degree scale based on the progression through crack events is arguably more meaningful than common color cues to connect and correlate the complex chemistries and consumer qualities in roasted coffee.Practical ApplicationsThe first and second cracks are two sets of popping sounds that occur during coffee roasting. These events are commonly used as indicators of roast degree for determining the endpoint of the roast, but this judgment can be subjective. This work explores the use of NIR spectroscopy to predict the start and end of the two cracking events to provide a more robust method for controlling the roast based on the cracks. The predictions are used to generate a numerical roast degree scale, which provides a consistent method of comparing the roast degree of coffees from different origins or roasters.

Potential Oral Health Care Agent from Coffee Against Virulence Factor of Periodontitis.

Background: Coffee is a major dietary source of polyphenols. Previous research found that coffee had a protective effect on periodontal disease. In this study, we aimed to investigate whether coffee extract and its primary phenolic acid, chlorogenic acid, affect the growth and protease activity of a periodontopathogen Porphyromonas gingivalis (P. gingivalis). Methods: Coffee extract and chlorogenic acid were prepared by a two-fold serial dilution. The turbid metric test and plate count method were used to examine the inhibitory effects of chlorogenic acid on P. gingivalis. The time-kill assay was used to measure changes in the viability of P. gingivalis after exposure to chlorogenic acid for 0–24 h. The protease activity of P. gingivalis was analyzed using the optical density of a chromogenic substrate. Results: As a result, the minimum inhibitory concentration (MIC) of chlorogenic acid was 4 mg/mL, and the minimum bactericidal concentration was 16 mg/mL. Chlorogenic acid at concentrations above MIC resulted in a longer-lasting inhibitory effect on P. gingivalis viability and significantly reduced associated protease activity. The coffee extract showed antibacterial activity as observed by the disk diffusion test, whereas these inhibitory effects were not affected by different roast degrees of coffee. Conclusions: Collectively, our novel findings indicate that chlorogenic acid not only has antimicrobial activity but also reduced the protease activity of P. gingivalis. In addition, coffee extract inhibits the proliferation of P. gingivalis, which may partly be attributed to the effect of chlorogenic acid.

Design of Portable Coffee Roaster for Home Industry

At present, the availability of an appropriate roaster for home coffee processing industry is very limited. This study aims to design a portable coffee roaster with a maximum capacity of 2 kg per batch. The roasting machine is designed with six main parts, namely as a roasting cylinder, an outer cylinder equipped with an inlet-outlet funnel, a main frame, a heat source with the LPG fuel, a cooling unit, and a temperature control system. The roasting machine has been tested to roast an amount of green bean at a constant temperature of 225 °C with three targets of roasted degree, namely as light, medium and dark. The test result shows that the roasting machine can work properly. The temperature control system is able to regulate the roasting temperature as same as the temperature target during the process. With the stable temperature, the machine can roast the green coffee sample to reach the target roasted degree with good result. The test shows that the roaster can roast the sample of 1 kg of green bean at light roast degree with an average time of 13.2 minutes and an energy consumption of 4708.92 kJ. For the same amount of sample, the coffee roaster can work properly for the roast degree target of medium with an average time of 16.9 minutes and an energy consumption of 4708.92 kJ. Meanwhile, for dark roasted target, the roaster requires an average time of 28.59 minutes and consume an energy of 9417.85 kJ.

Extraction Conditions Affect the Immunoreactivity of Peanut Allergens.

Peanut allergic consumers rely on food package labels to avoid foods containing peanut. The inadvertent presence of peanut in foods due to cross-contact can be fatal if ingestion of such food leads to an allergic reaction. Analytical methods are available to detect undeclared peanut in foods. However, depending on the type of food matrix and food processing parameters, method performance can be adversely affected due to reduction in the extraction efficiency of peanut proteins. Temperature and probe sonication were used as a preincubation treatment for peanut flour slurries to assess their effect on the total peanut protein solubility from raw, light-roasted, and dark-roasted peanut flours. The effect of these treatments on the immunoreactivity of peanut allergens (Ara h 1, Ara h 2, Ara h 3, and Ara h 6) was determined by an indirect enzyme-linked immunosorbent assay using antibodies raised against these individual peanut proteins. Preincubation at 50°C did not significantly improve the peanut protein solubility, whereas an increase in protein solubility was observed when light- and dark-roasted peanut flour slurries were preincubated at 90°C or sonicated. The immunoreactivity of peanut allergens varied depending on the degree of peanut flour roasting and type of preincubation treatment. Overall, the immunoreactivity of peanut allergens from most peanut flour slurries was unaffected when preincubated at 50°C for up to 60min or sonicated with a probe for up to 5min, whereas preincubation at 90°C resulted in a time-dependent reduction in immunoreactivity of peanut allergens. Sonication treatment may improve peanut protein extraction without markedly affecting their immunoreactivity. PRACTICAL APPLICATION: Extraction of peanut proteins is vital for developed analytical methods to estimate peanut allergens in foods. The manuscript describes the effect of two different temperatures (50 and 90°C) and probe-type sonication on peanut protein solubility. The findings suggest sonication can improve peanut protein solubility without markedly affecting their immunoreactivity.

Influence of Roasting Process in Six Coffee Arabica Cultivars: Analysis of Volatile Components Profiles

The complex composition of coffee aroma depends on the several factors regarding green coffee such as species and variety of the beans, origin , seeds size, colour (Toci and Farah, 2014). The most important coffee varieties are known to be Coffea arabica with good organoleptic characteristics, and Coffea canephora , known as Robusta of inferior quality. Development of aroma compounds also is greatly dependent upon the degree of roasting (Lopez-Galilea et al., 2006). In the roasting process almost 840 volatile organic compounds (VOC) are evaluated (Saw et al., 2015). The aim of this work is to investigate of the aromatic profile of six Arabica cultivar from Africa, Central and South America at different roasting degrees (light, medium and dark) and to establish odordescriptor categories as indicators for the assessment of flavour differences. The three roasting degrees were obtained in laboratory considering as target the industrial products and coffee roasting intensity was evaluated by a polychromatic colorimeter. The aromatic compounds of espresso coffee were evaluated by static headspace gas mass chromatography. The 67 key odors identified were classified in ten smell groups: floral, ethereal, fruit, chocolate, sweet and sugary, nut, grain and cereals, roast, spice, vegetal and earthy as suggested by Flament (2001). Results showed a consistent difference between different origins, depending on roasting intensity and maturation time, reflecting the possibility to optimize espresso coffee mixtures in an analytic way.

The influence of brewing method on bioactive compounds residues in spent coffee grounds of different roasting degree and geographical origin

SummaryThe content of bioactive compounds in spent coffee grounds (SGC) was studied. SGC were obtained from Coffea arabica beans of different roasting degrees (light and dark) and different geographical origins (Nicaragua, Columbia and Mexico) processed using four brewing methods (mocha, filtered, drip and infusion). The highest caffeine and chlorogenic acid contents were determined in filtered spent coffee extracts. All extracts of light roasted spent coffee grounds showed lower browning index levels in comparison to that from dark roasted spent coffee grounds. Generally, the highest content of total polyphenolic compounds and highest antioxidant capacity were determined in extracts prepared in drip. In conclusion, the results obtained in this study indicate that the spent coffee grounds produced of domestic levels, especially those obtained from filter coffeemaker, could be considered as a good source of natural antioxidants.

Quality Control Parameters in the Roasted Coffee Industry: a Proposal by Using MicroNIR Spectroscopy and Multivariate Calibration

This research presents the use of near-infrared (NIR) spectroscopy as a fast alternative of conventional methods, suitable for in-line use for quality control in the industrial coffee processing. Chemometric models were constructed from spectra of 217 coffees sampled during the period of 5 months of coffee processing, which demonstrates the viability of the NIR spectroscopy in terms of prediction, since it provides realistic variability in chemometric models. In this work, granulometry, moisture content, color, and the infusion time of commercially roasted coffee beans were evaluated by reference methods, NIR spectroscopy, and partial least squares (PLS). Four models were built using 217 roasted coffee samples, differentiated by type of beverage and roast degree. After the model’s optimization by the outlier evaluation, parameters of merit such as residual prediction deviation, sensitivity, analytical sensitivity, the inverse of analytical sensitivity, limits of detection and quantification, adjust, and linearity were calculated. The models showed predictive capacity and high sensitivity in determining the analyzed ones. All these quality control parameters were predicted with adequate correlation coefficient, which ranged from 0.73 to 0.84 and presented satisfactory performance. The parameters of merit presented promising results, indicating that the prediction models developed for granulometry, color, moisture content, and infusion time can be safely used in the coffee industry as an alternative to reference methods. Moreover, the proposed methodology is sample preparation free, fast, simple, efficient, and suitable for in-line uses.

Effect of harvesting altitude, fermentation time and roasting degree on the aroma released by coffee powder monitored by proton transfer reaction mass spectrometry

This study investigates the effect of harvesting altitude, fermentation time and roasting degree on the volatile profile released by coffee (Coffea arabica, variety Catimor) powder. The analysis of the volatile organic compounds was performed by proton transfer reaction mass spectrometer (PTR-MS). The experimental design consisted of three factors: altitude at two levels (900 m and 1500 m, milder and harsher climate, respectively), four different fermentation times (0, 24, 48 and 72 h) and roasting at three levels (light, medium and dark). Analysis of the released volatile organic compounds (VOCs) revealed that the intensity of m/z 45 and 59 dramatically decreases at a higher harvesting altitude. Longer fermentation times induce a decrease of m/z 61 and 75, probably related to the activity of the isocitrate lyase. Finally, a prolonged roasting degree induces a rise of the m/z 61, 75, 81 and 97. The total count per second measured by PTR-MS was used as an index of “overall coffee aroma intensity” to build a linear regression model. The model was used to predict the total VOCs intensity on the basis of the altitude, fermentation time and roasting level. The validation of the model (adjusted R2 = 0.91 and normalized relative standard deviation in prediction of 7%) reveals that, although the degree of roasting clearly affects the resulting aroma intensity, altitude and fermentation time also play a role in the formation of the volatile profile. Moreover, a significant interaction was observed between the altitude where the bean were grown and the roasting level. These results support the hypothesis that the type of process of the seeds has a strong impact on the resulting coffee’s quality. Furthermore, PTR-MS coupled with linear regression models is a powerful tool for the quality control of coffee process.

Characterizing cocoa refining by electronic nose using a Kernel distribution model

Refining and conching are two important processes for chocolate manufacturing, as they help improve the flavor and texture of chocolates. However, methods such as GC-MS for assessing flavor changes are expensive. In this study, an e-nose was used to continuously monitor the volatile compounds of cocoa samples undergoing refining, for samples differing in sample mass and degree of roasting. The responses of the e-nose were characterized by three parameters (Rarea, Rpeak and Rwidth) that were able to detect the overall influence of roasting. These values along with sample mass were also used to train Kernel Distribution Models (KDM) which were implemented to better account for temperature and air flow fluctuations. For trained KDMs validated with data taken under the same conditions (sample mass, degree of roasting) the error was ∼1%. When validated under different conditions the error ranged from 2.9 to 9.3%. The degree of roasting had greater affect on the error than the sample mass. A trained KDM can be used to predict the overall volatile compounds at different refining stages, and detect whether the processing variables of sample mass and roasting degree varied from its training samples.

Physical characterization of Arabica ground coffee with different roasting degrees.

Roasting is a determinative operation on the final quality of coffee. Roasting process causes physical, chemical and sensory changes on coffee. In this study roasting degree effect on physical properties of Arabica fine ground coffee was examined. The bulk properties, particle property, reconstitution properties, moisture content, water activities and color properties were investigated in different roasting degrees of coffee. The results showed that the physical characteristics of coffee samples were influenced by the degree of roast. To have longer shelf life, lower cost and better physical attributes of Arabica fine ground coffee, the roasting process should be kept at a lower degree. At the same time the requests and expectations of customer should also be considered.

DETERMINATION OF THERMAL PROPERTIES OF COFFEE BEANS AT DIFFERENT DEGREES OF ROASTING

<p>The aim of this study was to determine the main thermal properties of the granular mass of coffee (specific heat, thermal conductivity, and thermal diffusivity) for different degrees of roasting, as well as to model and simulate thermal conductivity at different degrees of roasting. For determination of specific heat, the mixing method was used, and for thermal conductivity, the theoretically infinite cylinder method with a central heating source. Thermal diffusivity was simulated algebraically using the results of the properties cited above and of the apparent specific mass of the product. Thermal conductivity was also simulated and optimized through finite element analysis software. At darker roasting, there was an increase in specific heat and a reduction in thermal conductivity and thermal diffusivity. Comparing thermal conductivity determined in relation to simulated and optimized conductivity, the mean relative error was 1.02%, on average.</p>

Powder caking and cohesion behaviours of coffee powders as affected by roasting and particle sizes: Principal component analyses (PCA) for flow and bioactive properties

Roasting degree and particle size are two major parameters that affect the mixture homogeneity of powdered food mixtures. This study focused on the flow properties of powdered coffees regarding their roasting degree (light and dark roasted) and particle sizes (0.1; 0.3; 0.5 mm) for aiming to assess the flow and physicochemical properties of coffee and the relationship with the bioactive, sensory properties and flowability. Since the powder caking of foods is highly undesirable due to the stoppage problems during the filling operation in process. Determination of the flow properties of the coffee are very important and the factors affecting the flow properties should be considered in detail. The flow behavior of coffee samples was characterized by powder rheometer with cohesion, caking and powder flow speed dependency (PFSD) tests. Principal component analysis (PCA) was applied in order to explore similarities and hidden patterns among samples. Results indicated that caking was not the case for medium and coarse coffee samples, yet fine grinded samples were subjected to caking. Increasing cake height ratio indicated the powder has a high tendency to form cake. Among the samples, only light coffee with larger particle size (CL) was flow stable since its flow stability value was closed to 1. Light coffee samples had higher 5-hydroxymethyl furfural (5-HMF) content than dark coffees while 5-HMF was not detected in green coffee grinds. There was an augmentation of antioxidant activity of samples with the increasing rate of 5-HMF. The dimension reduction method of PCA could provide beneficial information for the food industry for determining the effect of particle size and roasting degree on the powder flow characteristics.