The effect of soaking time on mucilage removal from the coffee bean using pectinase enzyme

The synthesis of Ag-TiO2 coating using AgNO3 precursor is expected to give the properties as pure as Ag nanoparticles. Commonly, high concentration of Ag attributed to agglomeration of silver species and reduction to Ag0 particles on TiO2 surface. In contrast, at lower concentration, Ag species exist as AgO, Ag2O and Ag0. Hence, the exact amount of Ag, which can effectively control the particle growth and agglomeration, surface area, thermal stability and band gap of the TiO2 coating, are still vague and stated differently. In the present study, the effect of Ag content on the phase transformation and surface morphology of Ag-TiO2 coating were reported. TiO2 sol were prepared by incorporating Ag at 2.5, 5 and 7.5 mol % and deposited on unglazed ceramic tiles thru five times dip coating. The deposited Ag-TiO2 coatings were heat treated at 500 °C for 1 hour soaking time. XRD analyses revealed that the deposited Ag-TiO2 coating consists of anatase, rutile, Ag2O and metallic Ag. Almost all the coating surfaces illustrated cracks. Increased Ag content lead to presence of tiny particles on the surfaces and EDX spectrum revealed the presence of Ti, O and metallic Ag particles. However, at the addition of 5 mol % Ag, there was no metallic Ag presence and a dense coating with the lowest thickness of ±11.4µm is observed.

Download Full-text

Kinetics of Light-Induced Effects in Mixed-Phase Hydrogenated Silicon Solar Cells

MRS Proceedings ◽

10.1557/proc-762-a12.2 ◽

2003 ◽

Vol 762 ◽

Cited By ~ 1

Author(s):

Guozhen Yuea ◽

Baojie Yan ◽

Jeffrey Yang ◽

Kenneth Lord ◽

Subhendu Guha

Keyword(s):

Solar Cells ◽

Fill Factor ◽

Equivalent Circuit Model ◽

Open Circuit ◽

Mixed Phase ◽

Silicon Solar Cells ◽

Initial Increase ◽

Soaking Time ◽

Hydrogenated Silicon ◽

Kinetics Of

AbstractWe have observed a significant light-induced increase in the open-circuit voltage (Voc) of mixed-phase hydrogenated silicon solar cells. In this study, we investigate the kinetics of the light-induced effects. The results show that the cells with different initial Voc have different kinetic behavior. For the cells with a low initial Voc (less than 0.8 V), the increase in Voc is slow and does not saturate for light-soaking time of up to 16 hours. For the cells with medium initial Voc (0.8 ∼ 0.95 V), the Voc increases rapidly and then saturates. Cells with high initial Voc (0.95 ∼ 0.98 V) show an initial increase in Voc, followed bya Voc decrease. All light-soaked cells exhibit a degradation in fill factor. The temperature dependence of the kinetics shows that light soaking at high temperatures causes Voc increase to saturate faster than at low temperatures. The observed results can be explained by our recently proposed two-diode equivalent-circuit model for mixed-phase solar cells.

Download Full-text

The Utilization of Ftir (Fourier Transform Infra-Red) Method Combined with Chemometrics For Authentication of Indonesian Coffee Powder

International Journal of Pharmaceutical and Clinical Research ◽

10.25258/ijpcr.v9i3.8320 ◽

2017 ◽

Vol 9 (3) ◽

Author(s):

Firmansyah A. ◽

Winingsih W. ◽

Soebara Y S

Keyword(s):

Fourier Transform ◽

Natural Product ◽

High Performance ◽

Principal Component ◽

Raw Material ◽

Attenuated Total Reflectance ◽

Coffee Bean ◽

Product Analysis ◽

Total Reflectance ◽

And Cluster Analysis

Analysis of natural product remain challenging issues for analytical chemist, since natural products are complicated system of mixture. The most popular methods of choice used for quality control of raw material and finished product are high performance liquid chromatography (HPLC), gas chromatography (GC) and mass spectrometry (MS). The utilization of FTIR-ATR (Fourier Transform Infrared-Attenuated Total Reflectance) method in natural product analysis is still limited. This study attempts to expand the use of FTIR spectroscopy in authenticating Indonesian coffee powder.The coffee samples studied were taken from nine regions in Indonesia, namely Aceh Gayo, Flores, Kintamani, Mandheling, Papua, Sidikalang, Toraja, Kerinci and Lampung.The samples in the form of coffee bean from various regions were powdered . The next step conducted was to determine the spectrum using the FTIR-ATR (Attenuated Total Reflectance) using ZnSe crystal of 8000 resolution. Spectrum samples, then, were analyzed using chemometrics. The utilized chemometric model was the principal component analysis (PCA) and cluster analysis (CA). Based on the chemometric analysis, there are similarities between Aceh Gayo coffee with Toraja coffee, Mandailing coffee, Kintamani coffee and Flores coffee. Sidikalang coffee has a similarity to Flores coffee; Papua coffee has a similarity to Sidikalang coffee; Lampung coffee has a similarity to Sidikalang coffee, while Kerinci coffee has a similarity to Papua coffee.

Download Full-text

A study on customer satisfaction and repurchasing intention by selection attributes of coffee bean

Journal of Tourism and Leisure Research ◽

10.31336/jtlr.2019.1.31.1.311 ◽

2019 ◽

Vol 31 (1) ◽

pp. 311-326

Author(s):

Myeong-Hui Kim ◽

Hyun-Chan Lee ◽

Wii-Joo Yhang

Keyword(s):

Customer Satisfaction ◽

Coffee Bean

Download Full-text

Design of a separation machine using pneumatic system combined with sieve vibration for removing parchment coffee from Robusta green coffee bean

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/999/1/012016 ◽

2020 ◽

Vol 999 ◽

pp. 012016

Author(s):

W Limmun ◽

T Chungcharoen

Keyword(s):

Pneumatic System ◽

Coffee Bean ◽

Green Coffee ◽

Green Coffee Bean

Download Full-text

Electron microscopy investigations on the mineral lorándite (TlAsS2) from Allchar in Macedonia

Zeitschrift für Kristallographie - Crystalline Materials ◽

10.1515/zkri-2020-0070 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Tobias Necke ◽

Maximilian Trapp ◽

Stefan Lauterbach ◽

Georg Amthauer ◽

Hans-Joachim Kleebe

Keyword(s):

Electron Microscopy ◽

Single Crystals ◽

Secondary Phase ◽

Lattice Energy ◽

Local Deformation ◽

Crystal Defects ◽

Coffee Bean ◽

Electron Dose ◽

Chemical Difference ◽

Natural Mineral

Abstract In this paper, we report on electron microscopy studies of single crystals of the natural mineral lorándite, TlAsS2. The main focus of this investigation was to address the question as to whether those lorándite crystals are chemically and structurally homogeneous, in order to be utilized as an effective neutrino detector within the lorándite experiment (LOREX) project. Apart from few secondary minerals, being present only at the surface of the lorándite samples, scanning electron microscopy (SEM) indicated homogeneous crystals. Similarly, transmission electron microscopy (TEM) imaging revealed a homogenous and undisturbed crystal structure, with the only exception of local coffee-bean contrasts; however, rarely observed. These specific contrast variations are known to be a typical strain indicator caused by a local deformation of the crystal lattice. Energy-dispersive X-ray spectroscopy (EDS) in conjunction with electron energy-loss spectroscopy (EELS) did not show any significant chemical difference when analysing regions on or off those coffee-bean features, indicating a chemically homogenous mineral. Since the presence of lattice disturbing secondary phase precipitates could be excluded by imaging and complementary chemical analysis, crystal defects such as dislocations and stacking faults or minor fluid inclusions are discussed as the probable origin of this local elastic strain. The experimental results confirm that the studied lorándite single crystals fulfil all structural and chemical requirements to be employed as the natural mineral that allows to determine solar neutrino fluxes. In addition, critical issues regarding the rather challenging sample preparation of lorándite are reported and a quantification of the maximum tolerable electron dose in the TEM is presented, since lorándite was found to be sensitive with respect to electron beam irradiation. Furthermore, the limits of EDS measurements due to peak overlapping are shown and discussed utilizing the case of Pb in lorándite. In this regard, a comparison with the Tl- and Pb-containing natural mineral hutchinsonite, TlPbAs5S9, is also included.

Download Full-text

Using seed respiration as a tool for calculating optimal soaking times for ‘on-farm’ seed priming of barley (Hordeum vulgare)

Seed Science Research ◽

10.1017/s0960258521000039 ◽

2021 ◽

pp. 1-9

Author(s):

Javier Carrillo-Reche ◽

Adrian C. Newton ◽

Richard S. Quilliam

Keyword(s):

Morphological Changes ◽

Low Cost ◽

Germination Rate ◽

Seed Priming ◽

Embryonic Axes ◽

Seedling Vigour ◽

Soaking Time ◽

On Farm ◽

Seed Respiration

Abstract A low-cost technique named ‘on-farm’ seed priming is increasingly being recognized as an effective approach to maximize crop establishment. It consists of anaerobically soaking seeds in water before sowing resulting in rapid and uniform germination, and enhanced seedling vigour. The extent of these benefits depends on the soaking time. The current determination of optimal soaking time by germination assays and mini-plot trials is resource-intensive, as it is species/genotype-specific. This study aimed to determine the potential of the seed respiration rate (an indicator of metabolic activity) and seed morphological changes during barley priming as predictors of the priming benefits and, thus, facilitate the determination of optimal soaking times. A series of germination tests revealed that the germination rate is mostly attributable to the rapid hydration of embryo tissues, as the highest gains in the germination rate occurred before the resumption of respiration. Germination uniformity, however, was not significantly improved until seeds were primed for at least 8 h, that is, after a first respiration burst was initiated. The maximum seedling vigour was attained when the priming was stopped just before the beginning of the differentiation of embryonic axes (20 h) after which vigour began to decrease (‘over-priming’). The onset of embryonic axis elongation was preceded by a second respiration burst, which can be used as a marker for priming optimization. Thus, monitoring of seed respiration provides a rapid and inexpensive alternative to the current practice. The method could be carried out by agricultural institutions to provide recommended optimal soaking times for the common barley varieties within a specific region.

Download Full-text

Chemical Analysis, Toxicity Study, and Free-Radical Scavenging and Iron-Binding Assays Involving Coffee (Coffea arabica) Extracts

Molecules ◽

10.3390/molecules26144169 ◽

2021 ◽

Vol 26 (14) ◽

pp. 4169

Author(s):

Nuntouchaporn Hutachok ◽

Pimpisid Koonyosying ◽

Tanachai Pankasemsuk ◽

Pongsak Angkasith ◽

Chaiwat Chumpun ◽

...

Keyword(s):

Free Radical ◽

Mononuclear Cells ◽

Radical Scavenging ◽

Free Radical Scavenging ◽

Chemical Compositions ◽

Coffee Bean ◽

Dependent Manner ◽

Roasted Coffee ◽

Instant Coffee ◽

Radical Scavenging Properties

We aimed to analyze the chemical compositions in Arabica coffee bean extracts, assess the relevant antioxidant and iron-chelating activities in coffee extracts and instant coffee, and evaluate the toxicity in roasted coffee. Coffee beans were extracted using boiling, drip-filtered and espresso brewing methods. Certain phenolics were investigated including trigonelline, caffeic acid and their derivatives, gallic acid, epicatechin, chlorogenic acid (CGA) and their derivatives, p-coumaroylquinic acid, p-coumaroyl glucoside, the rutin and syringic acid that exist in green and roasted coffee extracts, along with dimethoxycinnamic acid, caffeoylarbutin and cymaroside that may be present in green coffee bean extracts. Different phytochemicals were also detected in all of the coffee extracts. Roasted coffee extracts and instant coffees exhibited free-radical scavenging properties in a dose-dependent manner, for which drip coffee was observed to be the most effective (p < 0.05). All coffee extracts, instant coffee varieties and CGA could effectively bind ferric ion in a concentration-dependent manner resulting in an iron-bound complex. Roasted coffee extracts were neither toxic to normal mononuclear cells nor breast cancer cells. The findings indicate that phenolics, particularly CGA, could effectively contribute to the iron-chelating and free-radical scavenging properties observed in coffee brews. Thus, coffee may possess high pharmacological value and could be utilized as a health beverage.

Download Full-text