Preservation of roasted and ground coffee during storage. Part 2: Bulk density and intergranular porosity

ABSTRACT The determination of physical properties is an important factor in the design of machinery and the scaling of post-harvest operations. The present study evaluates the influence of the level of roasting and the size of grinding on the physical properties of coffee during storage. The following physical properties were evaluated: true and bulk density, and intergranular porosity. Raw coffee beans (Coffea canephora and Coffea arabica), hulled and dried, were roasted to two different levels: medium light (SCAA#65) and moderately dark (SCAA#45). The beans were then grinded into three different sizes: fine (0.59 mm), medium (0.84 mm) and coarse (1.19 mm). An additional coffee lot was kept whole. Following grinding, samples were stored at two different temperatures (10 and 30 ºC) and analyzed after five different storage durations (0, 30, 60, 120 and 180 days). The medium light roast had higher values for each of the measured physical properties. Finely ground samples had higher true and bulk densities, and porosities. It is concluded that the size of grinding, level of roasting and duration of storage significantly affect the physical properties of coffee.

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Preservation of roasted and ground coffee during storage Part 1: Moisture content and repose angle

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v20n6p581-587 ◽

2016 ◽

Vol 20 (6) ◽

pp. 581-587 ◽

Cited By ~ 2

Author(s):

Paulo C. Corrêa ◽

Gabriel H. H. de Oliveira ◽

Ana P. L. R. de Oliveira ◽

Guillermo A. Vargas-Elías ◽

Fábio L. Santos ◽

...

Keyword(s):

Moisture Content ◽

Coffea Arabica ◽

Coffea Canephora ◽

Angle Of Repose ◽

Coffee Beans ◽

Duration Of Storage ◽

Different Temperatures ◽

Different Levels ◽

Ground Coffee

ABSTRACT The present study evaluates the influence of the level of roasting and the grind size on the moisture content and repose angle of coffee during storage. Raw coffee beans (Coffea canephora and Coffea arabica), hulled and dried, were roasted to two different levels: medium light (SCAA#65) and moderately dark (SCAA#45). The beans were then ground into three different grind sizes: fine (0.59 mm), medium (0.84 mm) and coarse (1.19 mm). An additional coffee lot was kept whole. Following grinding, samples were stored at two different temperatures (10 and 30 ºC) and analyzed after five different storage durations (0, 30, 60, 120 and 180 days). The moderately dark roast was found to have a lower moisture content. Finely ground samples had higher angles of repose. It is concluded that the grind size, level of roasting and duration of storage significantly affect the moisture content and angle of repose of coffee.

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Determination of Three Main Chlorogenic Acids in Water Extracts of Coffee Leaves by Liquid Chromatography Coupled to an Electrochemical Detector

Antioxidants ◽

10.3390/antiox7100143 ◽

2018 ◽

Vol 7 (10) ◽

pp. 143 ◽

Cited By ~ 4

Author(s):

Rocío Rodríguez-Gómez ◽

Jérôme Vanheuverzwjin ◽

Florence Souard ◽

Cédric Delporte ◽

Caroline Stevigny ◽

...

Keyword(s):

Liquid Chromatography ◽

Coffea Arabica ◽

Limit Of Detection ◽

Coffea Canephora ◽

Antioxidant Compounds ◽

Chlorogenic Acids ◽

Coffea Species ◽

Coffee Species ◽

Coffea Liberica

Coffee is a beverage widely consumed in the world. The coffee species most commercialized worldwide are Arabica (Coffea arabica) and Robusta (Coffea canephora). Roasted coffee beans are the most used, but coffee leaves are also consumed as infusion in several countries for traditional medicinal purposes. They contain several interesting phenolic antioxidant compounds mainly belonging to chlorogenic acids (CGAs). In the present work, a liquid chromatography-electrochemical detection (LC-EC) method was developed for the determination of three main chlorogenic acid isomers, namely 3-, 4-, and 5-caffeoylquinic acids (CQA), in coffee leaves aqueous extracts. Samples from eight coffee species, namely; Coffea arabica, Coffea canephora, Coffea liberica, Coffea humilis, Coffea mannii, Coffea charrieriana, Coffea anthonyi, and Coffea liberica var. liberica, were grown and collected in tropical greenhouses. Linearity of the calibration graphs was observed in the range from the limit of quantification to 1.0 × 10−5 M, with R2 equal to 99.9% in all cases. High sensitivity was achieved with a limit of detection of 1.0 × 10−8 M for 3-CQA and 5-CQA (i.e., 3.5 µg/L) and 2.0 × 10−8 M for 4-CQA (i.e., 7.1 µg/L). The chromatographic profile of the samples harvested for each Coffea species was studied comparatively. Obtained raw data were pretreated for baseline variations and shifts in retention times between the chromatographic profiles. Principal Component Analysis (PCA) was applied to the pretreated data. According to the results, three clusters of Coffea species were found. In the water sample extracts, 5-CQA appeared to be the major isomer, and some species contained a very low amount of CQAs. Fluctuations were observed depending on the Coffea species and harvesting period. Significant differences between January and July were noticed regarding CQAs content. The species with the best CQAs/caffeine ratio was identified. The LC-EC data were validated by liquid chromatography-high resolution mass spectrometry (LC-HRMS).

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Least limiting water range in Oxisols under different levels of machine traffic

Comunicata Scientiae ◽

10.14295/cs.v8i2.2423 ◽

2018 ◽

Vol 8 (2) ◽

pp. 337-346

Author(s):

Karina De Vares Rossetti ◽

José Frederico Centurion

Keyword(s):

Bulk Density ◽

Block Design ◽

Corn Yield ◽

Soil Penetration Resistance ◽

Corn Crop ◽

Randomized Block Design ◽

Crop Development ◽

Least Limiting Water Range ◽

Different Levels

This work aimed, to evaluate the structural behavior of Oxisols based on the least limiting water range (LLWR) and establish relations with corn crop. The experiment was carried out in a randomized block design with five treatments and four replications. Soil samples collected at the layer of 0-0.20 m depth in a Haplustox (LVd) and an Eutrustox (LVef) were used. The compaction treatments consisted of T0= no additional compaction; T1 and T2= two and four passes with a 4 t tractor, respectively; T3 and T4 = two and four passes with a 10 t tractor, respectively. The range of LLWR variation in the LVd was the lowest one and varied from 0.01 to 0.04 m3 m-3, whereas in the LVef varied from 0.03 to 0.13 m3 m-3 for the critical soil penetration resistance (PRc) of 2 MPa. It was observed that critical bulk density (BDc) values were 1.76 and 1.40 Mg m-3 in the LVd and the LVef, respectively. The highest frequency of bulk density (BC ≥ BDc) occurred from the T1 to T4 (LVd) and from the T2 to T4, however, a reduction in corn yield was not observed. The determination of the LLWR was efficient and complementary for identifying more favorable or more impeditive conditions to compaction in the LVef for the corn crop development in relation to the LVd.

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Antioxidant Properties Research of Various Types of Coffee

Food Industry ◽

10.29141/2500-1922-2020-5-4-11 ◽

2020 ◽

Vol 5 (4) ◽

pp. 74-81

Author(s):

Dinara Ignatova ◽

Nadezhda Makarova

Keyword(s):

Coffea Arabica ◽

Antioxidant Properties ◽

Reducing Power ◽

Coffea Canephora ◽

Raw Material ◽

Antioxidant Compounds ◽

Common Source ◽

Coffee Arabica ◽

Coffee Beans ◽

Dpph Method

The article presents results of antioxidant compounds determination (total amount of phenolic compounds, total amount of flavonoids) and parameters of the antiradical activity (by the DPPH method) and reducing power (by the FRAP method) in different types of coffee beans depending on roasting degree (weak, medium, strong), coffee variety (Robusta and Arabica) and the importing country. The researchers used the products presented in the retail chains of Samara. The study purpose was to reveal a universal and most common source of functional substances with an antioxidant effect for the human body and use it both in its pure form and in combination with other products (BAS). According to the research results, Robusta coffee (Coffea Canephora) of medium roasting from Brazil has high indicators for all the conducted analyses and can be used as an additional source of antioxidant substances, and as a raw material for obtaining BAS. Coffee Arabica (Coffea Arabica) of medium roasting of Indonesian origin has the highest restoring power, and the highest content of phenols and flavonoids. Coffee Arabica (Coffea Arabica) of a strong degree of roasting from India has the lowest rates. All other types of coffee have average, slightly different results.

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Optical and Thermal Properties of Zodiacal Dust

International Astronomical Union Colloquium ◽

10.1017/s0252921100501730 ◽

1996 ◽

Vol 150 ◽

pp. 301-308 ◽

Cited By ~ 2

Author(s):

A.C. Levasseur-Regourd

Keyword(s):

Thermal Properties ◽

Physical Properties ◽

Bulk Density ◽

Thermal Emission ◽

Symmetry Plane ◽

Dust Particles ◽

Orbital Inclination ◽

Zodiacal Dust ◽

Dust Distribution

AbstractRecent progress has been reported in the determination of the zodiacal thermal emission, brightness and polarization. These results, of interest to estimate the foreground sources in astrophysical observations, do not provide immediately information on the dust distribution, and on its optical and thermal properties. To infer local information about the bulk density, and the physical properties of the dust particles, it is necessary to compare the observations with realistic models or to invert the line-of-sight data. The latter approach typically suggests that the bulk density is (in the symmetry plane) inversely proportional to the solar distance, that the particles are not spheroidal, but rather irregular in shape, that their physical properties change with their distance to the Sun and their orbital inclination, and finally that they do not emit like a blackbody. The heterogeneity noticed in the cloud is due to various sources of dust particles, the size, shape or albedo of which evolve as a function of time, under collision and/or evaporation processes.

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Reliable Discrimination of Green Coffee Beans Species: A Comparison of UV-Vis-Based Determination of Caffeine and Chlorogenic Acid with Non-Targeted Near-Infrared Spectroscopy

Foods ◽

10.3390/foods9060788 ◽

2020 ◽

Vol 9 (6) ◽

pp. 788

Author(s):

Adnan Adnan ◽

Marcel Naumann ◽

Daniel Mörlein ◽

Elke Pawelzik

Keyword(s):

Chlorogenic Acid ◽

Near Infrared ◽

Nir Spectroscopy ◽

Coffea Canephora ◽

Green Coffee ◽

Linear Discriminant ◽

Green Coffee Beans ◽

Coffee Beans ◽

Vis Spectroscopy

Species adulteration is a common problem in the coffee trade. Several attempts have been made to differentiate among species. However, finding an applicable methodology that would consider the various aspects of adulteration remains a challenge. This study investigated an ultraviolet–visible (UV-Vis) spectroscopy-based determination of caffeine and chlorogenic acid contents, as well as the applicability of non-targeted near-infrared (NIR) spectroscopy, to discriminate between green coffee beans of the Coffea arabica (Arabica) and Coffea canephora (Robusta) species from Java Island, Indonesia. The discrimination was conducted by measuring the caffeine and chlorogenic acid content in the beans using UV-Vis spectroscopy. The data related to both compounds was processed using linear discriminant analysis (LDA). Information about the diffuse reflectance (log 1/R) spectra of intact beans was determined by NIR spectroscopy and analyzed using multivariate analysis. UV-Vis spectroscopy attained an accuracy of 97% in comparison to NIR spectroscopy’s accuracy by selected wavelengths of LDA (95%). The study suggests that both methods are applicable to discriminate reliably among species.

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Determination of selected physical properties of Brachystegia eurycoma seeds

Research in Agricultural Engineering ◽

10.17221/14/2009-rae ◽

2009 ◽

Vol 55 (No. 4) ◽

pp. 165-169 ◽

Cited By ~ 10

Author(s):

M.C. Ndukwu

Keyword(s):

Moisture Content ◽

Physical Properties ◽

Bulk Density ◽

Surface Area ◽

Angle Of Repose ◽

Coefficient Of Determination ◽

Solid Density ◽

Axial Dimension ◽

Design And Construction

The research looked at some selected physical properties of Brachystegia eurycoma, such as axial dimension, roundness, sphericity, surface area, bulk density, solid density, porosity, and volume which are essential in the design and construction of the processing and handling equipments of Brachystegia eurycoma. All the above physical properties measured showed some deviations from the average values which is typical of agricultural biomaterials. Solid density showed the highest deviation of 4.04 g/mm3 while the volume showed the least deviation of 0.01 mm3 when compared to those of other physical properties. The angle of repose increased with the increase in the moisture content with a coefficient of determination of 0.98.

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