scholarly journals Process Optimisation of Low-caffeine Coffee Using Steam Treatment

Author(s):  
Riyan Anggriawan ◽  
Ali Maksum ◽  
Fransisca Wijaya ◽  
Ike Sitoresmi Mulyo Purbowati

In addition to being a source of freshener, coffee has an enormous possibility to be developed as a source of antioxidants for functional beverages. However, efforts to increase the value added of coffee as a health functional drink are still hindered by the presence of high level of caffeine, which is thought to have adverse effects on health, especially for coffee lovers who are vulnerable to caffeine. This study aims to optimise the steaming duration to produce low caffeine coffee while maintaining the sensory attributes and antioxidant compounds contained in it. Indonesian Arabica (Leksana variety) green coffee beans were steamed with multi-level steaming durations (0, 20, 40, 60 and 80 min) followed by roasting (medium-dark roast degree), grinding, and brewing (espresso method). The results indicate that caffeine content in the coffee was inversely proportional to the steaming duration. The lowest caffeine content was obtained from the treatment of 80 min steaming with a decrease of caffeine level up to 28.73%. However, the longer process of steaming caused a significant decrease in polyphenol content and antioxidant activity. The hedonic test shows that the steaming treatment of coffee can increase preferences of panellists. There were two driving attributes that influence the overall liking of coffee, namely: bitterness and aftertaste. Coffee obtained from the treatment of 60 min steaming was most preferred by panellists. The results of APLSR biplot mapping show that there was a big change in almost all attributes in the coffee samples after 40 min steaming.

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3681
Author(s):  
Anna Muzykiewicz-Szymańska ◽  
Anna Nowak ◽  
Daria Wira ◽  
Adam Klimowicz

Coffee is one of the most often consumed beverages almost all over the world. The multiplicity of beans, as well as the methods and parameters used to brew, encourages the optimization of the brewing process. The study aimed to analyze the effect of roasting beans, the brewing technique, and its parameters (time and water temperature) on antioxidant activity (determined using several in vitro methods), total polyphenols, flavonoids, and caffeine content. The infusions of unroasted and roasted Arabica beans from Brazil, Colombia, India, Peru, and Rwanda were analyzed. In general, infusions prepared from roasted beans had higher antioxidant activity and the content of above-mentioned compounds. The hot brew method was used to obtain infusions with a higher antioxidant activity, while the cold brew with higher caffeine content. The phenolic compound content in infusions prepared using both techniques depended on the roasting process. Moreover, the bean’s origin, roasting process, and brewing technique had a significant effect on the tested properties, in contrary to brewing time and water temperature (below and above 90 °C), which had less impact. The results confirm the importance of coffee brewing optimization.


2019 ◽  
Author(s):  
Danilo Carmona ◽  
Pablo Jaque ◽  
Esteban Vöhringer-Martinez

<div><div><div><p>Peroxides play a central role in many chemical and biological pro- cesses such as the Fenton reaction. The relevance of these compounds lies in the low stability of the O–O bond which upon dissociation results in radical species able to initiate various chemical or biological processes. In this work, a set of 64 DFT functional-basis set combinations has been validated in terms of their capability to describe bond dissociation energies (BDE) for the O–O bond in a database of 14 ROOH peroxides for which experimental values ofBDE are available. Moreover, the electronic contributions to the BDE were obtained for four of the peroxides and the anion H2O2− at the CBS limit at CCSD(T) level with Dunning’s basis sets up to triple–ζ quality provid- ing a reference value for the hydrogen peroxide anion as a model. Almost all the functionals considered here yielded mean absolute deviations around 5.0 kcal mol−1. The smallest values were observed for the ωB97 family and the Minnesota M11 functional with a marked basis set dependence. Despite the mean deviation, order relations among BDE experimental values of peroxides were also considered. The ωB97 family was able to reproduce the relations correctly whereas other functionals presented a marked dependence on the chemical nature of the R group. Interestingly, M11 functional did not show a very good agreement with the established order despite its good performance in the mean error. The obtained results support the use of similar validation strategies for proper prediction of BDE or other molecular properties by DF Tmethods in subsequent related studies.</p></div></div></div>


1994 ◽  
Vol 30 (10) ◽  
pp. 213-219 ◽  
Author(s):  
Hendrik Pieters ◽  
Victor Geuke

Samples of yellow eel from various locations in the Dutch Rhine area have been analyzed for trend monitoring of mercury since 1977. In the western Rhine delta mercury levels in eels have hardly changed since the seventies, whereas in the eastern part of the Dutch Rhine area a considerable decrease of mercury concentrations in eel has occurred. Because of continuous sedimentation of contaminated suspended matter transported from upstream regions, accumulation rates and concentrations of mercury in eel in the western Rhine delta remained at a relatively high level. Analyses of methyl mercury in biota have been performed to elucidate the role of methyl mercury in the mercury contamination of the Dutch Rhine ecosystem. Low percentages of methyl mercury were observed in zooplankton (3 to 35%). In benthic organisms (mussels) percentages of methyl mercury ranged from 30 to 57%, while in fish species and liver of aquatic top predator birds almost all the mercury was present in the form of methyl mercury (&gt; 80%). During the period 1970-1990 mercury concentrations of suspended matter in the eastern Rhine delta have drastically decreased. These concentrations seemed to be highly correlated with mercury concentrations of eel (R = 0.84). The consequences of this relation are discussed.


Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 165
Author(s):  
Elisabetta Bravi ◽  
Giovanni De Francesco ◽  
Valeria Sileoni ◽  
Giuseppe Perretti ◽  
Fernanda Galgano ◽  
...  

The brewing industry produces high quantities of solid and liquid waste, causing disposal issues. Brewing spent grains (BSGs) and brewing spent hop (BSH) are important by-products of the brewing industry and possess a high-value chemical composition. In this study, BSG and BSH, obtained from the production process of two different types of ale beer (Imperial red and Belgian strong beer) were characterized in terms of valuable components, including proteins, carbohydrates, fat, dietary fiber, β-glucans, arabinoxylans, polyphenols, and phenolic acids, and antioxidant activity (Ferric Reducing Antioxidant Power Assay (FRAP), 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS)). Significant concentrations of total polyphenols were observed in both BSH and BSG samples (average of about 10 mg GAE/g of dry mass); however, about 1.5-fold higher levels were detected in by-products of Belgian strong ale beer compared with Imperial red. Free and bound phenolic acids were quantified using a validated chromatographic method. A much higher level of total phenolic acids (TPA) (about 16-fold higher) was found in BSG samples compared with BSHs. Finally, their antioxidant potential was verified. By-products of Belgian strong ale beer, both BSG and BSH, showed significantly higher antioxidative capacity (about 1.5-fold lower inhibitory concentration (IC50) values) compared with spent grains and hop from the brewing of Imperial red ale. In summary, BSG and BSH may be considered rich sources of protein, carbohydrates, fiber, and antioxidant compounds (polyphenols), and have the potential to be upcycled by transformation into value-added products.


Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2665
Author(s):  
Alexander Baraniskin ◽  
Roland Schroers

Primary central nervous system lymphoma is a rare but highly aggressive form of non-Hodgkin lymphoma that remains confined to the CNS neuroaxis. The diagnosis of PCNSL requires a high level of suspicion as clinical presentation varies depending on the involved CNS areas. Neurological symptoms and MRI findings may mimic gliomas, demyelinating lesions, or infectious and granulomatous diseases. Almost all PCNSL patients undergo invasive surgical procedures for definite diagnosis. Stereotactic biopsy is still the gold standard in achieving a diagnostic accuracy of 73–97%. Both the potential procedural morbidity and mortality, as well as the time to definite histopathologic diagnosis resulting in delays of treatment initiation, have to be considered. On the contrary, minimally invasive procedures, such as MRI, CSF cytology, and flow cytometry, still have limited value due to inferior specificity and sensitivity. Hence, novel diagnostic approaches, including mutation analyses (MYD88) in circulating tumor DNA (ctDNA) and the determination of microRNAs (miR-21, miR-19b, and miR-92) as well as cytokine levels (IL10 and IL6) in blood, cerebrospinal fluid (CSF), and vitreous fluid (VRF), move into the focus of investigation to facilitate the diagnosis of PCNSL. In this review, we outline the most promising approaches that are currently under clinical consideration.


2021 ◽  
Vol 11 (3) ◽  
pp. 968
Author(s):  
Yingchun Sun ◽  
Wang Gao ◽  
Shuguo Pan ◽  
Tao Zhao ◽  
Yahui Peng

Recently, multi-level feature networks have been extensively used in instance segmentation. However, because not all features are beneficial to instance segmentation tasks, the performance of networks cannot be adequately improved by synthesizing multi-level convolutional features indiscriminately. In order to solve the problem, an attention-based feature pyramid module (AFPM) is proposed, which integrates the attention mechanism on the basis of a multi-level feature pyramid network to efficiently and pertinently extract the high-level semantic features and low-level spatial structure features; for instance, segmentation. Firstly, we adopt a convolutional block attention module (CBAM) into feature extraction, and sequentially generate attention maps which focus on instance-related features along the channel and spatial dimensions. Secondly, we build inter-dimensional dependencies through a convolutional triplet attention module (CTAM) in lateral attention connections, which is used to propagate a helpful semantic feature map and filter redundant informative features irrelevant to instance objects. Finally, we construct branches for feature enhancement to strengthen detailed information to boost the entire feature hierarchy of the network. The experimental results on the Cityscapes dataset manifest that the proposed module outperforms other excellent methods under different evaluation metrics and effectively upgrades the performance of the instance segmentation method.


2021 ◽  
Vol 11 (13) ◽  
pp. 6089
Author(s):  
Hamza Gadhoumi ◽  
Maria Gullo ◽  
Luciana De Vero ◽  
Enriqueta Martinez-Rojas ◽  
Moufida Saidani Tounsi ◽  
...  

Functional beverages obtained using medicinal plants and fermented with lactic acid bacteria are gaining much interest from the scientific community, driven by the growing demand for food and beverages with beneficial properties. In this work, three different batches of medicinal plants and organic sugarcane molasses, named FB-lc, FB-sp and FB-lcsp, were prepared and fermented by using Lactobacillus acidophilus ATCC 43121, Bifidobacterium breve B632 and a mix of both strains’ culture, respectively. The three fermented beverages revealed a high level of polyphenols (expressed as gallic acid equivalent), ranging from 182.50 to 315.62 µg/mL. The highest content of flavonoids (152.13 µg quercetin equivalent/mL) and tannins (93.602 µg catechin equivalent/mL) was detected in FB-lcsp trial. The IR spectroscopy analysis showed a decrease in sugar (pyranose forms, D-glucopyranose and rhamnosides). In addition, the aromatic compounds of the fermented beverages, detected by GC-MS headspace analysis, showed twenty-four interesting volatile compounds, which could give positive aroma attributes to the flavor of the beverages. The highest antioxidant activity was observed in the beverage obtained by the mix culture strains. Accordingly, the production of these beverages can be further investigated for considering their well-being effects on human health.


Author(s):  
Oderinu Hassana ◽  
◽  
Kadir Mumini ◽  
Tijani Adebayo ◽  

Nigeria has one of the countries whose experience of poverty and unemployment is on the high side makes this study to look into the effect of the economic lockdown during the global pandemic in the country, with the aim of making effort on how this effect can be translated into economic development. Survey research design method was adopted with self-administered questionnaire used to collect data. Findings revealed that in Nigeria COVID -19 outbreak effects was felt in almost all sectors and the aftermath greatly affected the country’s GDP and this adversely affect rural development in the country, which translated to a worrisome rate of poverty and unemployment. Hence, both individual and government have now seen that campaigning for economic diversification is not sufficient for economic development but rather a prompt swing into action by all is needed for sustainable development of rural areas to respond to the worrisome rate of unemployment and in turn high level of poverty caused by the COVID-19 lockdown in the country. It was recommended that government at all level as well as individuals and stakeholders should put in place actions that would gear up rural development and set policies at their various helms of affairs that would encourage economic participation of all citizens in all sector of the economy.


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