Quantification of Caffeine and Chlorogenic Acid in Green and Roasted Coffee Samples Using HPLC-DAD and Evaluation of the Effect of Degree of Roasting on Their Levels
Authors : Shady Awwad, Reem Issa, Lilian Alnsour, Dima Albals, Idrees Al-Momani
Abstract : Chlorogenic acid and caffeine are among the important components in coffee beans, determining the taste and aroma. In addition, phenols and antioxidants content possess vital health values. The main aim of this study is to determine the levels of caffeine and chlorogenic acid in several coffee samples of different origins and degrees of roasting. The coffee samples were extracted using hot water. The levels of caffeine and chlorogenic acid were quantified using high-performance liquid chromatography (HPLC) equipped with a diode array detector, a reverse phase system, and an ODS column (C18). Total phenol and antioxidant contents were previously determined for the same samples. The results showed that the highest content of caffeine was found in the medium roasted coffee (203.63 mg/L), and the highest content of chlorogenic acid content was found in the green coffee (543.23 mg/L). The results demonstrated a negative correlation between the chlorogenic acid levels with the degree of roasting, while it showed a positive correlation between the caffeine levels with the degree of roasting till a certain point where the levels dropped in the dark roasted coffee. The origin of coffee samples did not show any effect on any of the measured variables. Antioxidant effects of coffee samples were largely determined by chlorogenic acid content.
Keywords : Caffeine; chlorogenic acid; coffee; extraction; high-performance liquid chromatography (HPLC); quantification
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Quantification of Total Phenols and Antioxidants in Coffee Samples of Different Origins and Evaluation of the Effect of Degree of Roasting on Their Levels
Authors : Lilian Alnsour, Reem Issa, Shady Awwad, Dima Albals, Idrees Al-Momani
Abstract : Phenolic and antioxidant compounds have received considerable attention due to their beneficial effects on human health. The aim of this study is to determine the content of total phenols and antioxidants in fifty-two coffee samples of different origins, purchased from the Jordanian local market, and investigate the effect of the degree of roasting on the levels of these compounds. The coffee samples were extracted using the hot water extraction method, while Folin–Ciocalteu (FC) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay methods were used to analyze these compounds. The results showed that the highest content of total phenol (16.55 mg/g equivalent to GAE) was found in the medium roasted coffee, and the highest content of antioxidants (1.07 mg/g equivalent to TEAC) content was found in the green coffee. Only light and medium roasted coffee showed a significant correlation (p < 0.05, R2 > 0.95) between the average of total phenolic and antioxidant content. A negative correlation between the antioxidant content and the degree of roasting (p < 0.05, R2 > 0.95) were shown, while it did not correlate with phenolic contents. Previously, a positive correlation between antioxidant and chlorogenic acids content was observed, with no correlation between the origin of coffee samples nor heavy metal content, which was previously determined for the same coffee samples. These findings suggest that the antioxidant content for coffee extracts is largely determined by its chlorogenic acid content, rather than the coffee origin or total phenolic and heavy metals content.
Keywords : coffee, phenols, antioxidant, TEAC, roasting, GAE
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Circulatory Leptin Levels as a Key Link in the Potential Association between Insulin Resistance and Vitamin D Deficiency: A Review Article
Authors : Mahmoud Abu-Samak, Beisan A Mohammad, Ibrahim Mosleh, Omar Abdel-Majeed, Abeer Braham, Shady H Awwad, Ahamed Abu-Zaiton, Abdel Rahman M. Tawaha
Abstract : Vitamin D deficiency (VDD) and diabetes mellitus (DM) are worldwide problems. Many recent studies have shown a high prevalence of T2DM and VDD in Mediterranean countries including Jordan. Remarkably, VDD is more prevalent in obese people with inverse association with 25-hydroxy vitamin D (25OHD). Nevertheless, randomized clinical trials (RCTs) point did not confirm that yet in particular the association with an obesity marker (leptin hormone). Leptin is involved in the insulin resistance (IR) pathogenesis and development of T2DM. Some RCTs showed that the treatment of VDD by 1,25OHD2D3 (VD3) may improve the control of diabetes and insulin sensitivity or decrease the risk of disease. Conversely, leptin levels were positively associated with 25OHD levels. Overall, taking into account the U-shaped curve, it seems that the association between VD3 supplementation is a dose dependent. In this context, it can be concluded that when VD intake is below, the serum leptin level will be low and vice versa VD supplementation may cause raising serum leptin as shown in this review. Therefore, we suggest further clinical trials wither to confirm or negation of existence of diabetogenic or anti-diabetogenic effects for VD3 supplementations.
Keywords : VDD, diabetes, T2DM, vitamin D, leptin, obesity, insulin resistance
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The combination of omega−3 fatty acids with high doses of vitamin D3 elevate A1c levels: A randomized Clinical Trial in people with vitamin D deficiency
Authors : Abeer Barham, Beisan Mohammad, Luai Hasoun, Shady Awwad, Ibrahim Mosleh, Ahmad Aljaberi, Mahmoud Abu-Samak
Abstract : Purpose: This randomised clinical trial (RCT) was created to assess the influence of 1,25-dihydroxyvitamin D (VD3 ), omega-3 fatty acids (n-3FA) and their combination (D+) on glycated haemoglobin (A1c) levels in Jordanian peoples with vitamin D deficiency (VDD). Participants and methods: This RCT was designed to examine the follow-up (2 months) effect of either 50 000 IU VD3 , 300 mg n-3FA, or the combination of the two supplements on glycated Haemoglobin (A1c) levels in 146 Jordanian women and men with VDD, aged from 25 to 55 years. The eligible participants were randomised into four groups: Control (C); VD3 supplementation (50 000 IU of VD3 was taken weekly) (D3 ); n-3FA supplementation (300 mg of omega-3FA was taken daily) (n-3FA); VD3 and omega-3 supplementation group (D+) with the same protocol as the previous two groups. Results: The combination therapy (n-3FA plus VD3) for 8 weeks significantly increased A1c levels (5.79 ± 0.34 vs 5.41 ± 0.33, P < .001). Tukey test for post hoc comparisons of A1c at follow-up showed that the A1c mean levels were remarkably higher in the D+ study group comparing to the control group (5.78 vs 5.38). Conclusion: The intervention of n-3FA alone or in combination with high doses of VD3 may lead to negative effects on glycaemic control or accelerate the insulin resistance's development in susceptible people for diabetes mellitus (type 2).
Keywords :
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The supplementary effects of omega-3 fatty acid alone and in a combination with vitamin D3 on serum leptin levels: A randomized clinical trial on men and women with vitamin D deficiency
Authors : Mahmoud S. Abu-Samak, Luai Z. Hasoun, Abeer Barham, Beisan A. Mohammad, Ibrahim Mosleh, Ahmad Aljaberi, Shady H. Awwad
Abstract : Purpose: This randomized clinical trial (RCT) was designed to assess the effect of VD3, n-3FA, and their combination on serum leptin levels in people with vitamin D deficiency (VDD). Subjects and methods: One hundred and forty six participants, were randomly assigned into four groups supplemented with the dose of 50,000 IU VD3 taken weekly (D), 300 mg n-3FA taken daily (Om), and their combination (D+Om) or control (C) for eight weeks. Fasting baseline and follow-up (10 weeks; 8 weeks supplementation plus washout period of 2 weeks) of serum 25 hydroxyvitamin D (25OHD), leptin, glucose, triglycerides (TG), parathyroid hormone (PTH), calcium, and phosphorus were assayed. A paired T-test was used to assess the changes in serum leptin levels over of the follow-up period. Results: Significant increase in follow-up serum leptin (10.62 ± 7.18 to 14.42 ± 8.29 ng/mL, P = 0.002) and TG (154 ± 84.4 to 200.1 ± 79, P = 0.015) levels were observed in n-3-FA supplemented group. Combination therapy (VD3 plus n-3 FA) significantly increased serum 25OHD (13.49 ± 4.64 to 37.09 ± 11.13 ng/mL, P < 0.001), TG levels (114.3 ± 57.3 to 139.1 ± 60.7 mg/mL, P = 0.007) and insignificantly serum leptin (6.74 ± 4.87 to 8.01 ± 6.77 ng/mL, P = 0.269). Conclusion: Our study referred that notable elevation in leptin and TG levels might be linked to leptin resistance. However, further RCTs are required to clarify possible consequences resulted from the extensive administration of n-3FA supplements and their combinations with high doses of VD3 supplements on humans’ health.
Keywords : Leptin, n-3FA, omega, vitamin D3, diabetes
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Dielectric Studies of Tetraaryl and Triaryl Polycarbonates and Comparisons with Bisphenol A-Polycarbonate
Authors : J. J. Fontanella, D. A. Boyles, T. S. Filipova, S. Awwad, C. A. Edmondson, J. T. Bendler, M. C. Wintersgill, J. F. Lomax, M. J. Schroeder
Abstract : The relative permittivity, loss, and breakdown strength are reported for a commercial sample of bisphenol A-polycarbonate (comm-BPA-PC) and a purified sample of the same polymer (rp-BPA-PC) as well as for two new polycarbonates having low molecular cross-sectional areas, namely a copolymer of tetraaryl polycarbonate and BPA-PC (TABPA-BPA-PC) and a triaryl polycarbonate homopolymer (TriBPA-PC). The glass transition temperatures of the new polymers are higher than the Tg of BPA-PC (187 and 191 °C vs. 148 °C). Relative permittivity and loss measurements were carried out from 10 to 105 Hz over a wide temperature range, and results for the α- and γ-relaxation regions are discussed in detail. For the α-relaxation, the isochronal peak position, Tα, scales approximately with Tg. On the other hand, the peak temperature for the γ-relaxation is approximately constant, independent of Tg. Also, in contrast to what is observed for α, γ exhibits a strong increase in peak height as temperature/frequency increases and a significant difference is found between Arrhenius plots determined from isochronal and isothermal data analyses. Next, the γ-relaxation region for comm-BPA-PC and associated activation parameters show strong history/purity effects. The activation parameters also depend on the method of data analysis. The results shed light on discrepancies that exist in the literature for BPA-PC. The shapes of the γ loss peaks and hence glassy-state motions for all the polymers are very similar. However, the intensities of the TriBPA-PC and TABPA-BPA-PC γ peaks are reduced by an amount that closely matches the reduced volume fraction of carbonate units in the two new polymers. Finally, for comm-BPA-PC, the breakdown strength is strongly affected by sample history and this is assumed to be related to volatile components in the material. It is found that the breakdown strengths for TriBPA-PC and TABPA-BPA-PC are relatively close to that for rp-BPA-PC with the value for TriBPA-PC being slightly larger than that for rp-BPA-PC or the value usually reported for typical capacitor grade polycarbonate. Finally, it is shown that the real part of the relative permittivity remains relatively constant from low temperatures to Tg. Consequently, based on the dielectric properties, TriBPA-PC and TABPA-BPA-PC should be usable in capacitors to at least 50 °C higher than BPA-PC.
Keywords : Dielectric properties; dielectric relaxation; glass transition; glassy polymers; high-performance polymers; high temperature materials; polycarbonates
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Salivary Cortisol, Testosterone and DHEA in Healthy University Male Students with Hyperleptinemia: Retrospective Cohort Study
Authors : Mahmoud Abu-Samak, Luai Hasoun, May Ibrahim Abu-Taha, Shady Helmi Awwad, Beisan Ali Mohammad
Abstract : Background: Cortisol, testosterone and DHEA are steroid hormones associated with youth physiology. The aim of this study was to evaluate the association of stress hormones with leptin, the hormone of obesity, in university male students. In this prospective cohort study, ninety university male students in the age range of 18 to 24 years were categorized into two groups; NL=Normal or Borderline Serum Leptin Level (<9.4 ng/ml); HL=High Serum Leptin Level (≥ 9.4 ng/ ml). In these groups, serum leptin and salivary levels for testosterone, dehydroepiendisterone (DHEA) and cortisol were immunoassayed. Correlation coefficients model analysis found that M-DHEA was significantly positively correlated with serum leptin in all subjects regardless of study group (r=- 0.248, p=0.003). The model analysis also found that body weight showed greater significant and positive correlation with serum leptin level than did BMI (NL: r=0.549 vs. 0.429, HL; r=0.517 vs. 0.422, respectively). A positive correlation between hyperlipidemia and hyperleptinemia was noted. Negative correlation was seen between M-DHEA and some obesity parameter including BMI and body weight and serum leptin. Elevated cortisol with declined DHEA balance was noted in this study. Our findings shed some light on the potential mechanisms linking obesity, stress and aging hormones in young men where leptin is the main obesity marker that promotes steroid hormones imbalance leading to maladaptation to chronic stress in young men. We observed that serum leptin levels are proportional to DHEA/cortisol imbalance and suggested to be a new indicator of chronic stress maladaptation in young obese males.
Keywords : Salivary hormone; Testosterone; DHEA; Cortisol; Leptin; Obesity; Youth
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Associations Between Sleep Deprivation and Salivary Testosterone Levels in Male University Students: A Prospective Cohort Study
Authors : Mahmoud Suleiman Abu-Samak, Beisan Ali Mohammad, May Ibrahim Abu-Taha, Luai Zidan Hasoun, Shady Helmi Awwad
Abstract : Sleep deprivation is a common health problem that is growing rapidly worldwide and it is associated with short- and long-term impacts on health. The aim of this study was to detect potential predictors of salivary testosterone (sT) association with sleep deprivation in Arab male university students. In this prospective cohort study, 77 university male students in the age range of 18 to 26 years were divided into two groups, sleep-deprived (SD) participants and non-sleep-deprived (NSD) participants. Sleep deprivation was defined as sleeping less than 5 hr per night. Blood samples and sT were collected from fasting participants to measure serum levels of glucose, lipid profile, leptin, serotonin, sT, and body mass index (BMI) values. The multiple linear correlation model of high-density lipoprotein cholesterol (HDL-C), BMI, and serotonin was positively correlated with sT ( r = .977, p < .05) in the SD group. No correlations were identified with sT in the NSD group. In the SD study group, the multiple linear regression model of HDL-C, BMI, and serotonin was significantly influenced by sT ( R² = .955, p < .05). These predictors together explained approximately 96% of the variance in sT levels in the SD study group. No predictive variables for sT were reported in the NSD group. Results indirectly confirmed the presence of a positive association between sT and sleep deprivation in young men. This association is mediated by three factors, HDL-C, BMI, and serum serotonin, which are collectively considered as part of a significant physiological adaptation to sleep deprivation in young men.
Keywords : BMI; leptin; lipid; salivary testosterone; serotonin; sleep deprivation
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Monitoring of Polychlorinated Biphenyls in Surface Water Using Liquid Extraction, GC/MS, and GC/ECD
Authors : M. Zaater, Y. Tahboub, S. Qasrawy
Abstract : A rapid and reliable analytical method, at trace level concentration was developed and validated for monitoring polychlorinated biphenyls (PCBs) in Jordanian surface water. The method combines the advantage of liquid extraction together with gas chromatography‐mass spectrometry (GC/MS) and gas chromatography‐electron capture detector (GC/ECD). The performance of the method was evaluated by analyzing certified reference material (CRM) of the analytes and applied on real water samples collected from different sites in Jordan. A mixture of 60∶40 dichloromethan‐petroleum ether was chosen as a convenient binary solvent for liquid–liquid extraction. The GC conditions for GC/MS were optimized using He as a carrier gas, temperature programming, and chlorpropham as an internal standard (IS). The conditions for GC/ECD were performed using N2 gas and a temperature program from 160 to 280°C with different increasing rates. The method of GC/MS in the selective ion mode (SIM) gave linear relationships for all PCBs tested between 0.60–6.0 µg/l with R 2=0.9934 (n=7×18). Recoveries from spiked water samples ranged between 87.6 and 91.4%. The mean accuracy and precision obtained were 4.9% and 2.16%, respectively. The mean of detection limit was 0.14±0.04 µg/l. In GC/ECD, linear relationships for all PCBs examined over the range of 0.3–2.4 µg/l was verified as characterized by a linear regression equation and correlation coefficient, R 2=0.9915 (n=12). The average precision and accuracy were 4.86% and 5.21%, respectively. Analyses results clarified that none of the examined Jordanian water samples contained any of the searched for PCBs within the detection limit achieved.
Keywords : Polychlorinated biphenyls, GC/MS, GC/ECD, liquid extraction, monitoring, surface water
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