Displaying publications 1 - 20 of 80 in total

Abstract:
Sort:
  1. Fulltext The contradictory effects of coffee intake on periodontal health: a systematic review of experimental and observational studies
    Bramantoro T, Zulfiana AA, Amir MS, Irmalia WR, Mohd Nor NA, Nugraha AP, et al.
    F1000Res, 2022;11:924.
    PMID: 36313542 DOI: 10.12688/f1000research.124547.3
    Background: Drinking coffee is known to have both positive and negative aftermath on periodontal health. The current study is aiming to systematically review the impact of coffee consumption on periodontal health status. Methods: An article search was carried out in two electronic databases (PUBMED and Web of Sciences). All type of experimental and observational studies were included. The assessment of the included articles were conducted using Joanna Briggs Institute (JBI) critical appraisal tool. Data were analyzed qualitatively. Result: A total of 10 articles were included in this study. Most (5) of the studies discovered a negative correlation between coffee intake and periodontal health, while 4 other studies found the protective effect of daily coffee consumption against alveolar bone loss. Last, only one study found that coffee intake did not relate with periodontitis. Conclusion: The effect of coffee consumption on periodontal health was fragmented since coffee has complex components that may give either beneficial effects or negative impact on periodontal health.
    Matched MeSH terms: Coffee*
  2. Green additive to upgrade biochar from spent coffee grounds by torrefaction for pollution mitigation
    Lee KT, Du JT, Chen WH, Ubando AT, Lee KT
    Environ Pollut, 2021 Sep 15;285:117244.
    PMID: 33965857 DOI: 10.1016/j.envpol.2021.117244
    A green approach using hydrogen peroxide (H2O2) to intensify the fuel properties of spent coffee grounds (SCGs) through torrefaction is developed in this study to minimize environmental pollution. Meanwhile, a neural network (NN) is used to minimize bulk density at different combinations of operating conditions to show the accurate and reliable model of NN (R2 = 0.9994). The biochar produced from SCGs torrefied at temperatures of 200-300 °C, duration of 30-60 min, and H2O2 concentrations of 0-100 wt% is examined. The results reveal that the higher heating value (HHV) of biochar increases with rising temperature, duration, or H2O2 concentration, whereas the bulk density has an opposite trend. The HHV, ignition temperature, and bulk density of biochar from torrefaction at 230 °C for 30 min with a 100 wt% H2O2 solution (230-100%-TSCG) are 27.00 MJ∙kg-1, 292 °C, and 120 kg∙m-3, respectively. This HHV accounts for a 29% improvement compared to that of untorrefied SCG. The contact angle (126°), water activity (0.51 aw), and moisture content (7.69%) of the optimized biochar indicate that it has higher resistance against biodegradation, and thereby can be stored longer. Overall, H2O2 is a green treatment additive for SCGs solid fuel. This study has successfully produced biochar with greater HHV and low bulk density at low temperatures. The green additive development can effectively reduce environmental pollutants and upgrade wastes into resources, and achieve "3E", namely, environmental (non-polluting green additives), energy (biofuel), and circular economy (waste upgrade). In addition, the produced biochar has great potential in the fields of bioadsorbents and soil amendments.
    Matched MeSH terms: Coffee*
  3. Dual pretreatment of mixing H2O2 followed by torrefaction to upgrade spent coffee grounds for fuel production and upgrade level identification of H2O2 pretreatment
    Chen WH, Ho KY, Lee KT, Ding L, Andrew Lin KY, Rajendran S, et al.
    Environ Res, 2022 Dec;215(Pt 1):114016.
    PMID: 35977586 DOI: 10.1016/j.envres.2022.114016
    Biochar is a carbon-neutral solid fuel and has emerged as a potential candidate to replace coal. Meanwhile, spent coffee grounds (SCGs) are an abundant and promising biomass waste that could be used for biochar production. This study develops a biochar valorization strategy by mixing SCGs with hydrogen peroxide (H2O2) at a weight ratio of 1:0.75 to upgrade SCG biochar. In this dual pretreatment method, the H2O2 oxidative ability at a pretreatment temperature of 105 °C contributes to an increase in the higher heating value (HHV) and carbon content of the SCG biochars. The HHV and carbon content of biochar increase by about 6.5% and 7.8%, respectively, when compared to the unpretreated one under the same conditions. Maximized biochar's HHV derived via the Taguchi method is 30.33 MJkg-1, a 46.9% increase compared to the raw SCG, and a 6.5% increase compared to the unpretreated SCG biochar. The H2O2 concentration is 18% for the maximized HHV. A quantitative identification index of intensity of difference (IOD) is adopted to evaluate the contributive level of H2O2 pretreatment in terms of the HHV and carbon content. IOD increases with increasing H2O2 pretreatment temperature. Before torrefaction, SCGs' IOD pretreated at 50 °C is 1.94%, while that pretreated at 105 °C is 8.06%. This is because, before torrefaction, H2O2 pretreatment sufficiently weakens SCGs' molecular structure, resulting in a higher IOD value. The IOD value of torrefied SCGs (TSCG) pretreated at 105 °C is 10.71%, accounting for a 4.59% increase compared to that pretreated at 50 °C. This implies that TSCG pretreated by H2O2 at 105 °C has better thermal stability. For every 1% increase in IOD of TSCG, the carbon content of the biochar increases 0.726%, and the HHV increases 0.529%. Overall, it is demonstrated that H2O2 is a green and promising pretreatment additive for upgrading SCG biochar's calorific value, and torrefied SCGs can be used as a potential solid fuel to approach carbon neutrality.
    Matched MeSH terms: Coffee*
  4. Multi-objective operation optimization of spent coffee ground torrefaction for carbon-neutral biochar production
    Chen WH, Lee KT, Ho KY, Culaba AB, Ashokkumar V, Juan CJ
    Bioresour Technol, 2023 Feb;370:128584.
    PMID: 36610482 DOI: 10.1016/j.biortech.2023.128584
    Many energy-intensive processes are employed to enhance biomass fuel properties to overcome the difficulties in utilizing biomass as fuel. Therefore, energy conservation during these processes is crucial for realizing a circular bioeconomy. This study develops a newly devised method to evaluate SCG biochars' higher heating value (HHV) and predict moisture content from power consumption. It is found that the increasing rates of HHV immediately follow decreases in power consumption, which could be used to determine the pretreatment time for energy conservation. The non-dominated sorting genetic algorithm II (NSGA-II) maximizes SCG biochar's HHV while minimizing energy consumption. The results show that producing SCG biochar with 23.98 MJ∙kg-1 HHV requires 20.042 MJ∙kg-1, using a torrefaction temperature of 244 °C and torrefaction time of 27 min and 43 sec. Every kilogram of biochar with an energy yield of 85.93 % is estimated to cost NT$ 12.21.
    Matched MeSH terms: Coffee*
  5. Bioadsorbent nanocellulose aerogel efficiency impregnated with spent coffee grounds
    Ahmad A, Omar KM, Alahmadi AA, Rizg WY, Bairwan RD, Abdul Khalil HPS
    Int J Biol Macromol, 2024 Feb;258(Pt 1):128746.
    PMID: 38104681 DOI: 10.1016/j.ijbiomac.2023.128746
    Due to growing environmental concerns for better waste management, this study proposes developing a composite aerogel using cellulose nanofibers (CNF) and spent coffee grounds (SCG) through an eco-friendly method for efficient methylene blue (MB) adsorption. Adding SCG to the CNF aerogel altered the physical properties: it increases the volume (4.14 cm3 to 5.25 cm3) and density (0.018 to 0.022 g/cm3) but decrease the water adsorption capacity (2064 % to 1635 %). FTIR spectrum showed distinct functional groups in both all aerogels, showing hydroxyl, glyosidic bonds, and aromatic compounds. Additionally, SCG improved thermal stability of the aerogels. In term of adsorption efficacy, CNF-SCG40% aerogel as exceptionally well. According to Langmuir isotherm models, the adsorption of MB happened in a monolayer, with CNF-SCG40% showing a maximum adsorption capacity of 113.64 mg/g, surpassing CNF aerogel (58.82 mg/g). The study identified that the pseudo-second-order model effectively depicted the adsorption process, indicating a chemical-like interaction. This investigation successfully produced a single-use composite aerogel composed of CNF and SCG using an eco-friendly approach, efficiently adsorbing MB. By utilizing cost-effective materials and eco-friendly methods, this approach offers a sustainable solution for waste management, contributes to an eco-friendly industrial environment, and reduces production expenses and management costs.
    Matched MeSH terms: Coffee*
  6. Night eating and its relationship with BMI, stress, sleep quality and duration of study among university students
    Emmy HKI, Boleh NC, Ali MS, Jakiwa J, Mardiyati NL, Ahmad MF
    Med J Malaysia, 2024 Mar;79(Suppl 1):134-139.
    PMID: 38555898
    INTRODUCTION: Night eating is a very common dietary behaviour among university students. This study aims to investigate the relationship between night eating and BMI, stress, sleep quality and duration of study among university students.

    MATERIALS AND METHODS: A total of 385 university students including foundation and undergraduate students took part in this study. Self-administered online surveys were used to obtain sociodemographic data, and anthropometry measurements including weight and height, night eating during studying, duration of the study, opinion on eating and academic performance, sleep quality, level of depression, anxiety, and stress of the respondents. Questionnaires were validated and IBM SPSS Statistics Software version 26.0 was used to analyse categorical and continuous variables.

    RESULTS: The findings showed that there was an association between night eaters and coffee consumption with BMI (p<0.001) and sleep quality (p<0.05). However, there was no association (p>0.05) found between the types of food eaten during night studying and the mean duration of the study. The results showed drinking coffee had an association with depression, anxiety, and stress (p<0.05) among Malaysian university students.

    CONCLUSION: Coffee consumption was common among undergraduate students during studying. Awareness of the risk of overconsumption of caffeine intake should be implemented in the future. However, this study did not include all types of food choices and drinks. Thus, frequency of eating energy dense food during night studying among students should be conducted in the future.

    Matched MeSH terms: Coffee*
  7. A survey of coffee shop prostitutes in Kuala Trengganu
    HOLMES W
    Med J Malaya, 1955 Dec;10(2):178-80.
    PMID: 13308619
    Matched MeSH terms: Coffee*
  8. Fulltext Improving layout and workload of manufacturing system in small and medium enterprise (SME) using delmia quest
    Dzullijah Ibrahim, Alifah Alyana, Hasrul Hafizuddin Hassim, Yusli Yaakob, Hamid Yusuf
    ESTEEM Academic Journal, 2018;14(1):83-92.
    MyJurnal
    A facility layout can be defined as an arrangement of the equipment area in the
    industry or organization of the factory. The main objective of this project was to
    improve the existing layout in SMEs using DELMIA QUEST simulation. In this
    project, new layouts are proposed to reduce the waiting time in a production
    line and increase the productivity. This study focused on packaging production
    line of a coffee manufacturing company located in Tasek Gelugor Pulau
    Pinang. The problems identified in this production line are limited working
    space, some processes overlap and are stuck due to high demands of the
    products. This results in high lead time. The existing layout was studied and
    simulated to improve certain parameters such as labour, machines, and shape
    of the layout. The workstations were repositioned in the proposed layout before
    undergoing simulation process using DELMIA QUEST software. From the
    simulation results, the significant improvement was determined and the best
    layout was chosen in terms of machines utilization and total output. Based on
    this, a new layout is proposed to increase the productivity capacity and to meet
    customers’ demands. Simulation data of the proposed layout showed its
    productivity had increased to approximately 41.5%.
    Matched MeSH terms: Coffee
  9. Fulltext Spectrophotometric Analysis of Caffeine
    Ahmad Bhawani S, Fong SS, Mohamad Ibrahim MN
    Int J Anal Chem, 2015;2015:170239.
    PMID: 26604926 DOI: 10.1155/2015/170239
    The nature of caffeine reveals that it is a bitter white crystalline alkaloid. It is a common ingredient in a variety of drinks (soft and energy drinks) and is also used in combination with various medicines. In order to maintain the optimum level of caffeine, various spectrophotometric methods have been developed. The monitoring of caffeine is very important aspect because of its consumption in higher doses that can lead to various physiological disorders. This paper incorporates various spectrophotometric methods used in the analysis of caffeine in various environmental samples such as pharmaceuticals, soft and energy drinks, tea, and coffee. A range of spectrophotometric methodologies including chemometric techniques and derivatization of spectra have been used to analyse the caffeine.
    Matched MeSH terms: Coffee
  10. Fulltext Optimization of roasting conditions for high-quality Arabica coffee
    Ku Madihah, K.Y., Zaibunnisa, A.H., Norashikin, S., Rozita, O., Misnawi, J.
    International Food Research Journal, 2013;20(4):1623-1627.
    MyJurnal
    Central Composite Design (CCD) was used to optimize roasting conditions (temperature and
    time) for Arabica coffee beans. Current method of roasting was able to give good quality beans
    in term of flavour but the formation of acrylamide was not studied. In this study, optimization
    based on high quantity of flavour compounds (pyrazines) with low level of acrylamide resulted
    in roasting temperature of 167ºC for 22 minutes. The coffee beans produced using the optimized
    conditions have the following characteristics: flavour compounds: 2,3,5 trimethyl pyrazine (0.48
    mg/100 g), 2,3,5,6 tetramethyl pyrazine (0.42 mg/100 g), 2 methyl pyrazine (0.25 mg/100 g)
    and 2,5 dimethyl pyrazine (0.13 mg/100 g) and low concentration of acrylamide (0.11 mg/100
    g) with sensory evaluation of 7.5 from 10 points. This proposed roasting condition will be very
    useful for coffee manufacturers in order to produce high quality coffee beans.
    Matched MeSH terms: Coffee
  11. Fulltext Coffee packaging: Consumer perception on appearance, branding and pricing
    Harith, Z.T., Ting, C.H., Zakaria, N.N.A.
    International Food Research Journal, 2014;21(3):849-853.
    MyJurnal
    In determining consumer’s acceptance of any products in the market, packaging appearance, branding and pricing of the products are important. This study focused on consumer’s perception towards the outlook of the coffee packaging which resulted in influencing their purchasing decision through survey study. This current study was done on three main issues namely appropriateness of appearance, branding and pricing as reflected by the first impression towards the product’s packaging. Survey was done targeting on consumers (n = 100) reside in Kelantan, Malaysia through printed and online questionnaires distribution. Results obtained shows that consumers notice the differences possessed by each coffee packaging in the market and they purchase what they like based on their perception. According to Pearson Correlation, respondents also have the opinion that appearance, branding and pricing are correlated to each other in order to convey the correct messages to the correct group of people (p-value > 0.5). Response from the respondents reflected the behaviour of consumers reside in Kelantan that the overall outlook (packaging appearance, branding and pricing) of a coffee packaging were taken into consideration during their buying process. Therefore, it is crucial for the packaging itself to be able to create emotional attachment in consumers’ mind during their first glimpse.
    Matched MeSH terms: Coffee
  12. Coffee, its roasted form, and their residues cause birth failure and shorten lifespan in dengue vectors
    Dieng H, Ellias SB, Satho T, Ahmad AH, Abang F, Ghani IA, et al.
    Environ Sci Pollut Res Int, 2017 Jun;24(17):14782-14794.
    PMID: 28470499 DOI: 10.1007/s11356-017-8711-4
    In dengue mosquitoes, successful embryonic development and long lifespan are key determinants for the persistence of both virus and vector. Therefore, targeting the egg stage and vector lifespan would be expected to have greater impacts than larvicides or adulticides, both strategies that have lost effectiveness due to the development of resistance. Therefore, there is now a pressing need to find novel chemical means of vector control. Coffee contains many chemicals, and its waste, which has become a growing environmental concern, is as rich in toxicants as the green coffee beans; these chemicals do not have a history of resistance in insects, but some are lost in the roasting process. We examined whether exposure to coffee during embryonic development could alter larval eclosion and lifespan of dengue vectors. A series of bioassays with different coffee forms and their residues indicated that larval eclosion responses of Aedes albopictus and Ae. aegypti were appreciably lower when embryonic maturation occurred in environments containing coffee, especially roasted coffee crude extract (RCC). In addition, the lifespan of adults derived from eggs that hatched successfully in a coffee milieu was reduced, but this effect was less pronounced with roasted and green coffee extracts (RCU and GCU, respectively). Taken together, these findings suggested that coffee and its residues have embryocidal activities with impacts that are carried over onto the adult lifespan of dengue vectors. These effects may significantly reduce the vectorial capacity of these insects. Reutilizing coffee waste in vector control may also represent a realistic solution to the issues associated with its pollution.
    Matched MeSH terms: Coffee
  13. Coffee consumption and coronary artery calcium in young and middle-aged asymptomatic adults
    Choi Y, Chang Y, Ryu S, Cho J, Rampal S, Zhang Y, et al.
    Heart, 2015 May;101(9):686-91.
    PMID: 25732752 DOI: 10.1136/heartjnl-2014-306663
    To investigate the association between regular coffee consumption and the prevalence of coronary artery calcium (CAC) in a large sample of young and middle-aged asymptomatic men and women.
    Matched MeSH terms: Coffee*
  14. Utilization of chemically treated municipal solid waste (spent coffee bean powder) as reinforcement in cellulose matrix for packaging applications
    Thiagamani SMK, Nagarajan R, Jawaid M, Anumakonda V, Siengchin S
    Waste Manag, 2017 Nov;69:445-454.
    PMID: 28774586 DOI: 10.1016/j.wasman.2017.07.035
    As the annual production of the solid waste generable in the form of spent coffee bean powder (SCBP) is over 6 million tons, its utilization in the generation of green energy, waste water treatment and as a filler in biocomposites is desirable. The objective of this article is to analyze the possibilities to valorize coffee bean powder as a filler in cellulose matrix. Cellulose matrix was dissolved in the relatively safer aqueous solution mixture (8% LiOH and 15% Urea) precooled to -12.5°C. To the cellulose solution (SCBP) was added in 5-25wt% and the composite films were prepared by regeneration method using ethyl alcohol as a coagulant. Some SCBP was treated with aq. 5% NaOH and the composite films were also prepared using alkali treated SCBP as a filler. The films of composites were uniform with brown in color. The cellulose/SCBP films without and with alkali treated SCBP were characterized by FTIR, XRD, optical and polarized optical microscopy, thermogravimetric analysis (TGA) and tensile tests. The maximum tensile strength of the composite films with alkali treated SCBP varied between (106-149MPa) and increased with SCBP content when compared to the composites with untreated SCBP. The thermal stability of the composite was higher at elevated temperatures when alkali treated SCBP was used. Based on the improved tensile properties and photo resistivity, the cellulose/SCBP composite films with alkali treated SCBP may be considered for packaging and wrapping of flowers and vegetables.
    Matched MeSH terms: Coffee*
  15. Chlorogenic acids and the acyl-quinic acids: discovery, biosynthesis, bioavailability and bioactivity
    Clifford MN, Jaganath IB, Ludwig IA, Crozier A
    Nat Prod Rep, 2017 Dec 13;34(12):1391-1421.
    PMID: 29160894 DOI: 10.1039/c7np00030h
    Covering: 2000 up to late 2017This review is focussed upon the acyl-quinic acids, the most studied group within the ca. 400 chlorogenic acids so far reported. The acyl-quinic acids, the first of which was characterised in 1846, are a diverse group of plant-derived compounds produced principally through esterification of an hydroxycinnamic acid and 1l-(-)-quinic acid. Topics addressed in this review include the confusing nomenclature, quantification and characterisation by NMR and MS, biosynthesis and role in planta, and the occurrence of acyl-quinic acids in coffee, their transformation during roasting and delivery to the beverage. Coffee is the major human dietary source world-wide of acyl-quinic acids and consideration is given to their absorption and metabolism in the upper gastrointestinal tract, and the colon where the microbiota play a key role in the formation of catabolites. Evidence on the potential of the in vivo metabolites and catabolites of acyl-quinic acids to promote the consumer's health is evaluated.
    Matched MeSH terms: Coffee/physiology
  16. Expression of fibronection and fibroblast growth factor in rats cutaneous wound given green coffee bean extract
    Humaryanto, Rahman AO, Fairuz Q
    Med J Malaysia, 2022 Mar;77(2):196-202.
    PMID: 35338627
    BACKGROUND: The application of green coffee bean extract is known to accelerate cutaneous wound healing. Fibronectin and fibroblast growth factors (FGFs) are essential in the wound healing process. However, data on the effect of the green coffee bean extract on fibronectin and FGFs are still limited.

    OBJECTIVE: This study aimed to determine the effect of the green coffee extract on the expression of fibronectin dan FGFs in rats' cutaneous wounds.

    MATERIALS AND METHODS: Forty male Sprague Dawney rats, aged 2-3 months, weighing 150-200 grams, were randomly divided into four groups. Cutaneous wounds were made 1.5 cm in diameter and under lidocaine anaesthesia. Group I without treatment was the control group, group II was given a green coffee extract dose of 15%, group III was given a green coffee extract dose of 30%, and group IV was given a green coffee extract dose of 100%. The treatment was applied every day without wound debridement. In each group, five rats were sacrificed after 7 days of treatment (proliferative phase), and the rest were sacrificed after 16 days of treatment (remodelling phase). An anatomical pathologist carried out the immunohistochemical examination to assess fibronectin and FGF expression using a blind method.

    RESULTS: The expressions of fibronectin and FGF in the treatment groups were slightly higher than those in the control group, both in the proliferative and remodelling phases. Only, fibronectin expression of the green coffee dose of 100% was significantly higher than the control group in the remodelling phase.

    CONCLUSION: The application of green coffee bean extract in cutaneous wounds could increase fibronectin expression.

    Matched MeSH terms: Coffee*
  17. Effects of vermicomposting duration to macronutrient elements and heavy metals concentrations in vermicompost
    Adi Ainurzaman Jamaludin, Noor Zalina Mahmood
    Sains Malaysiana, 2010;39.
    Vermicomposting using Lumbricus rubellus was conducted in two different durations, 10 and 30 weeks in the same plots. Three different of treatments combination were prepared with eight replicates for each treatment namely cow dung : kitchen waste in 30:70 ratio (T1), cow dung : coffee grounds in 30:70 ratio (T2), and cow dung : kitchen waste : coffee grounds in 30:35:35 ratio (T3). Macronutrients elements in the vermicompost from each treatment were measured in the tenth and thirtieth week. Comparatively longer duration of vermicomposting by using Lumbricus rubellus enhanced the quality of vermicompost by the increase of the macronutrient elements while reducing the heavy metal concentration and C/N ratio.
    Matched MeSH terms: Coffee
  18. Enhanced bioaromatics synthesis via catalytic co-pyrolysis of cellulose and spent coffee ground over microporous HZSM-5 and HY
    Lee HW, Farooq A, Jang SH, Kwon EE, Jae J, Lam SS, et al.
    Environ Res, 2020 May;184:109311.
    PMID: 32145550 DOI: 10.1016/j.envres.2020.109311
    Catalytic co-pyrolysis (CCP) of spent coffee ground (SCG) and cellulose over HZSM-5 and HY was characterized thermogravimetrically, and a catalytic pyrolysis of two samples was conducted using a tandem micro reactor that directly connected with gas chromatography-mass spectrometry. To access the more fundamental investigations on CCP, the effects of the zeolite pore structure, reaction temperature, in-situ/ex-situ reaction mode, catalyst to feedstock ratio, and the SCG and cellulose mixing ratio were experimentally evaluated. The temperature showing the highest thermal degradation rate of cellulose with SCG slightly delayed due to the interactions during the thermolysis of two samples. HZSM-5 in reference to HY produced more aromatic hydrocarbons from CCP. With respect to the reaction temperature, the formation of aromatic hydrocarbons increased with the pyrolytic temperature. Moreover, the in-situ/ex-situ reaction mode, catalyst/feedstock, and cellulose/SCG ratio were optimized to improve the aromatic hydrocarbon yield.
    Matched MeSH terms: Coffee
  19. Fulltext Lipases immobilization for effective synthesis of biodiesel starting from coffee waste oils
    Ferrario V, Veny H, De Angelis E, Navarini L, Ebert C, Gardossi L
    Biomolecules, 2013 Aug 13;3(3):514-34.
    PMID: 24970178 DOI: 10.3390/biom3030514
    Immobilized lipases were applied to the enzymatic conversion of oils from spent coffee ground into biodiesel. Two lipases were selected for the study because of their conformational behavior analysed by Molecular Dynamics (MD) simulations taking into account that immobilization conditions affect conformational behavior of the lipases and ultimately, their efficiency upon immobilization. The enzymatic synthesis of biodiesel was initially carried out on a model substrate (triolein) in order to select the most promising immobilized biocatalysts. The results indicate that oils can be converted quantitatively within hours. The role of the nature of the immobilization support emerged as a key factor affecting reaction rate, most probably because of partition and mass transfer barriers occurring with hydrophilic solid supports. Finally, oil from spent coffee ground was transformed into biodiesel with yields ranging from 55% to 72%. The synthesis is of particular interest in the perspective of developing sustainable processes for the production of bio-fuels from food wastes and renewable materials. The enzymatic synthesis of biodiesel is carried out under mild conditions, with stoichiometric amounts of substrates (oil and methanol) and the removal of free fatty acids is not required.
    Matched MeSH terms: Coffee
  20. Fulltext Influence of exposure time to coffee on color stability of selected composite resin veneers
    Thiyab, Amar M., Mahmood, Nik Zarina N., Hassan, Mohamed Ibrahim A.
    Compendium of Oral Science, 2016;3(1):9-16.
    MyJurnal
    Objectives: The aim of the study is to evaluate the effect of the time and instant coffee solution on the color stability of three types of composite resin based veneer systems. Materials and Methods: 24 composite resin veneer samples were selected and divided into three groups: two groups of prefabricated veneers (Edelweiss, Ultradent Inc™ (EDL) and Componeer, Coltène/ Whaledent AGTM (CMP)) and one group of laboratory made (Nexco, Ivoclar Vivadent (NEX)) veneer system were tested (n=8). Specimens were prepared and stored in staining solution (instant coffee) and assessed color changes with Minolta spectrophotometer every three days for a period of 27 days, after which color differences (ΔE*) were calculated. Data collection and analysis was done using one-way ANOVA and Student’s t-test (α=0.05). Results: One-way ANOVA revealed a significant difference in color stability between the two veneer systems. NEX group veneer system exhibited the highest color stability (ΔE*= 0.73 ± 0.5) as compared to prefabricated veneer groups (EDL 10.07 ± 5.15, CMP 7.41 ± 4.64) with p value
    Matched MeSH terms: Coffee
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links