Fractionation of flax shives by water and aqueous ammonia treatment in a pressurized low-polarity water extractor

Fractionation of flax shives into cellulose, hemicellulose, and lignin with a two-stage extraction process using water and aqueous ammonia was carried out in a pressurized low-polarity water extractor operated at different temperatures, flow rates, and ammonia concentrations. During the first stage with water, 84% of hemicellulose and 32% of lignin were removed at 190 degrees C at a flow rate of 1.5 mL/min for 30 min. During the second stage with aqueous ammonia, more than 77% of the lignin was removed, and hemicellulose removal reached 95% at 200 degrees C at a flow rate of 0.5 mL/min and with a solvent/feed ratio of 40 mL/g. The temperature and flow rate had a significant effect on lignin removal. The impact of additives (anthraquinone and hydrogen peroxide) and modifications (overnight soaking, reduced particle size, and elevated temperature) on lignin extraction was also studied. The combination of higher temperatures and reduced particle sizes resulted in enhanced lignin extraction. The extraction profiles of free phenolics (vanillin, acetovanillone, and vanillic acid) during the two-stage processing were monitored and compared with those of lignin.

Flavonoids and heart health: proceedings of the ILSI North America Flavonoids Workshop, May 31-June 1, 2005, Washington, DC

This article provides an overview of current research on flavonoids as presented during a workshop entitled, "Flavonoids and Heart Health," held by the ILSI North America Project Committee on Flavonoids in Washington, DC, May 31 and June 1, 2005. Because a thorough knowledge and understanding about the science of flavonoids and their effects on health will aid in establishing dietary recommendations for bioactive components such as flavonoids, a systematic review of the science of select flavonoid classes (i.e., flavonols, flavones, flavanones, isoflavones, flavan-3-ols, anthocyanins, and proanthocyanidins) was presented. The objectives of the workshop were to 1) present and discuss current research on flavonoid intake and the relation between flavonoids and heart health; 2) develop information that could lead to expert consensus on the state-of-the-science of dietary intake of flavonoids on heart health; and 3) summarize and prioritize the research needed to establish the relations between specific flavonoids and heart health. Presentations included the basics of the biology of flavonoids, including the types and distribution in foods, analytical methodologies used to determine the amounts in foods, the bioavailability, the consumption patterns and potential biomarkers of intake, risk assessment and safety evaluation, structure/function claims, and the proposed mechanism(s) of the relation between certain flavonoids and heart health endpoints. Data presented support the concept that certain flavonoids in the diet can be associated with significant health benefits, including heart health. Research gaps were identified to help advance the science.

Multislice CT in emergency room management of patients with chest pain and medium-low probability of acute coronary syndrome

PURPOSE

The main cause of acute chest pain, which accounts for 6.5% of urgent medical examinations in emergency rooms in Italy, is acute coronary syndrome (ACS). We performed this prospective study to evaluate the diagnostic accuracy of a 16-channel computed tomography (CT) scanner with dedicated software in a group of patients with chest pain and medium to low risk of ACS.

MATERIALS AND METHODS

This study involved a selected group of 31 patients reporting chest pain with a medium to low probability of ACS, defined on the basis of preliminary tests [electrocardiogram (ECG) and serum cardiac markers]. Coronary angiography, performed within 24 h of MSCT, was used as the gold standard.

RESULTS

MSCT identified the presence of occlusions and significant (>50%) or nonsignificant stenoses in the main coronary segments, with a sensitivity of 65%, a specificity of 98.8%, a positive predictive value (PPV) of 81.2%, a negative predictive value (NPV) of 97.3% and an accuracy of 96.4%. Significant stenoses and occlusions were detected with a sensitivity of 71.4%, a specificity of 99.6%, a PPV of 93.7%, an NPV of 97.7% and an accuracy of 97.5%.

CONCLUSIONS

Due to its high NPV, this technique can rule out significant stenoses or coronary occlusions provided that image quality is excellent. In patients with a medium to low coronary risk, MSCT is a more accurate indicator of the need for coronary angiography than is exercise stress testing, which is less expensive but has lower predictive values.

Optimization of extraction of phenolic compounds from flax shives by pressurized low-polarity water

Pressurized low-polarity water (PLPW) extraction of phenolic compounds from flax shive was investigated using statistically based optimization and the "one-factor-at-a-time" method. Extraction variables examined using central composite design (CCD) included temperature, flow rate, and NaOH concentration of the extracting water. Extraction of phenolic compounds including p-hydroxybenzaldehyde, vanillic acid, syringic acid, vanillin, acetovanillone, and feruric acid was affected by temperature and NaOH concentration; and extraction of all phenolic compounds, except ferulic acid, increased with temperature and NaOH concentration of the extracting water. Flow rate had little effect on concentration of phenolic compounds at equilibrium, but the extraction rate at the early phase was higher for higher flow rates. The mechanism of PLPW extraction of flax shive phenolics was also investigated using a two-site kinetic model and a thermodynamic model. To determine the extraction mechanism, flow rate was varied from 0.3 to 4.0 mL/min while temperature and NaOH concentration were fixed at 180 degrees C and 0.47 M, respectively. The flow rate tests showed the extraction rates of total phenolic (TP) compounds increased with flow rate and can be described by a thermodynamic model. The results from the thermodynamic model demonstrated that a K(D) value of 30 agreed with the experimental data in the flow rate range of 0.3-4.0 mL/min. When the effect of the three independent variables was evaluated simultaneously using CCD, a maximum TP concentration of 5.8 g/kg of dry flax shive (DFS) was predicted from the combination of a high temperature (230.5 degrees C), a high initial concentration of NaOH (0.63 M), and a low flow rate (0.7 mL/min). Maximum TP concentration of 5.7 g/kg of DFS was obtained from extraction conditions of 180 degrees C, 0.3 or 0.5 mL/min, and 0.47 M NaOH at equilibrium. A second-order regression model generated by CCD predicted a maximum TP concentration of 5.8 g/kg of DFS under the same extraction conditions, which is well matched with the results from experimental data.

Antimicrobial activity of vanillin against spoilage microorganisms in stored fresh-cut mangoes

The antimicrobial activity of vanillin against four bacteria (Pantoea agglomerans, Aeromonas enteropelogenes, Micrococcus lylae, and Sphingobacterium spiritovorun), four fungi (Alternaria sp., Aspergillus sp., Penicillium sp., and Fusarium sp.), and three unidentified yeasts isolated from spoiling fresh-cut mango slices was verified in laboratory media adjusted to pH 5.0. MICs of vanillin against the fungi (12.5 to 13.3 mM), bacteria (10 to 13.3 mM), and yeasts (5.0 to 6.7 mM) indicated that all the test species were sensitive to the antimicrobial effects of vanillin. Fresh-cut mango slices were dipped for 1 min in solutions containing 40 and 80 mM vanillin before being packaged in rigid trays and stored at 5 and 10 degrees C to verify the effects of vanillin on the development of the spoilage microflora. Microbiological analysis for up to 14 days of storage revealed that treatment with 80 mM vanillin significantly delayed (P < 0.05) the development of total aerobic bacteria and yeast and mold populations. Vanillin may be a practical preservative for processing fresh-cut mango.

[Effect of anthocyanin rich fruit extract on PGE2 produced by endothelial cells]

OBJECTIVE

To study the effect of anthocyanin rich fruit extract on PGE2 produced by endothelial cells.

METHODS

Normal human endothelial cells, CRL-2606, were cultured in F12K medium (complemented with 10% FBS, 0.1 mg/ml heparin, 0.03 mg/ml ECGS, 50 microg/ml streptomycin and 500U/ml penicillin) in 5% CO2 with 95% air at 37 degrees C. When the cells grow close to confluence, anthocyanin rich fruit extract with/without 100 ng/ml of LPS were added to the medium. After 18 hours of incubation, cells were harvested and the supernatant were collected. Cell viability was assayed. After centrifugation, PGE2 concentration in the supernatant was measured with the STAT-Prostaglandin E2 EIA Kit.

RESULTS

300 microg/ml or higher Chokeberry extract showed cytotoxicity effect on CRL-2606 cells, the viability was lower than 60% and showed a dose-response manner. Under using dosage, Blackcurrant extract (100 - 700 microg/ml) and Blueberry extract (50 - 400 microg/ml) did not show any cytotoxicity. When stimulated by LPS, the production of PGE2 by endothelial cells were increased two fold. Blueberry extract inhibit such action. 100 microg/ml of Blueberry extract keeps the production of PGE2 in normal level. 700 microg/mL of Blackcurrant extract and 500 microg/ml Chokeberry extract also inhibit the releasing of PGE2.

CONCLUSION

Anthocyanin rich fruit extract from Blueberry, Blackcurrant, and Chokeberry inhibit PGE2 produced by endothelial cells, there exist antiinflammation and antioxidation.

Analysis of aroma and phenolic components of selected Achillea species

Dried flowers and leaves of four different Achillea species grown wild in several provinces of Iran, including one species collected from three different locations of Isfahan province were analyzed for the headspace volatile components, total phenolics (TP) and tartaric esters (TE). Capillary gas chromatography/mass spectrometry (GC/MS) combined with a purge and trap method was used for quantification of aroma components. Over 70 compounds were determined in the samples. Flower samples from all species contained 2-methyl butanal, alpha-pinene, alpha-thujene, camphene, hexanal, beta-pinene and 1,8-cineole; however, the major constituents of the aerial parts were determined as alpha-pinene, camphene, DL-limonene and 1,8-cineole. The largest number of aroma components were found in Achillea tenuifolia Lam. and Achillea millefolium L. In all species, except A. millefolium, the leaves contained more TP and TE than flowers. However, A. wilhelmsii from Semirom in Isfahan province showed the highest values for TP and TE.

[Application of modified ABTS+ assay method to monitor antioxidant extraction from fruit]

OBJECTIVE

Modify the ABTS method to measure the antioxidant activity of compound. Apply this method to optimize antioxidant extraction from fruit.

METHODS

In microplate, Trolox served as reference. Antioxidant activity was measured according to their ability to scavenge ABTS+ in the reaction mixture. Under different temperatures, solvent solid ratios, solvent concentrations, antioxidants were extracted.

RESULTS

The standard error for measuring Trolox antioxidant activity was under 0.2. The antioxidant activities of fourteen standard samples were consistent with that reported in literatures. Using ethanol as solvent, at about 17 degrees C, for 1 gram of blackcurrant 20 ml of 67% ethanol was appropriate. While using sodium metabisulphite as solvent, at about 30 degrees C, for 1 gram of blackcurrant 20 ml of 300 mg/L metabisulphite would be appropriate.

CONCLUSION

Modified ABTS+ method for measuring antioxidant activity was simple and feasible. This method could be applied to monitor antioxidant extraction from fruit and high throughput screening for antioxidant.

Anthocyanin metabolites in human urine and serum

In the present study we investigated the metabolic conversion of cyanidin glycosides in human subjects using solid-phase extraction,HPLC-diode array detector, MS, GC, and enzymic techniques. Volunteers consumed approximately 20 g chokeberry extract containing 1.3 g cyanidin 3-glycosides (899 mg cyanidin 3-galactoside, 321 mg cyanidin 3-arabinoside, 51 mg cyanidin 3-xyloside and 50 mg cyanidin 3-glucoside). Blood samples were drawn at 0, 0.5, 1, and 2 h post-consumption of the extract. Urine samples were also collected at 0, 4-5,and 22-24h. We have confirmed that human subjects have the capacity to metabolise cyanidin 3-glycosides, as we observed at least ten individual anthocyanin metabolites in the urine and serum. Average concentrations of anthocyanins and anthocyanin metabolites in the urine reached levels of 17.9 (range 14.9-20.9) l.mol/l within 5 h post-consumption and persisted in 24h urine samples at levels of 12.1 (range 11.1-13.0) nmol/l. In addition, average total levels of anthocyanins and anthocyanin metabolites detected in the serum were observed at 5917 (range 197.3-986.1) nmol/ within 2h post-consumption. Cyanidin 3-galactoside accounted for 55.4% (9.9(range 7-2-12-6) l.mol/) and 66.0% (390.6 (range 119.4-661-9) nmol V) of the detected anthocyanins in the urine and serum samples,respectively. The metabolites were identified as glucuronide conjugates, as well as methylated and oxidised derivatives of cyanidin 3-galactoside and cyanidin glucuronide. Conjugation probably affects the biological activity of anthocyanins and these metabolic products are likely in part responsible for the reported health benefits associated with the consumption of anthocyanins.

[Guidelines for dialysis. Replacement therapy for acute renal failure in critically ill patients]

Acute renal failure (ARF) in patients admitted to the intensive care unit (ICU) is mostly caused by ischemic or toxic injury, with a higher incidence in the latest years due to the growing number of interventions in cardiac and vascular surgery and to the general enhancement of reanimation techniques, which allow a better outcome among ICU patients. In critically ill patients, the ARF incidence reported in the literature ranges between 1 and 25%. Among ICU patients with ARF the mortality is between 40 and 65%, much more than in patients without this complication. Higher mortality rates, longer hospitalisation times and higher therapy costs demand from us an early diagnosis and treatment of ARF. Due to the lack of controlled and randomized proofs, recommended criteria for starting renal replacement therapy (RRT) in critical ARF patients might overlap with those for ESRD therapy. Moreover, randomised and controlled trials, confirming the actual efficacy of early onset of RRT on the mortality rate, are not yet available. As for stable ESRD patients, a direct relationship between dialytic doses and mortality and morbidity has been established for ARF patients. For ARF patients, as well as for ESRD patients, a minimum Kt/V of 1.2 three times a week should be ensured, although higher doses for critical ARF patients may achieve better results. The choice between intermittent (IRRT) and continuous renal replacement therapy (CRRT) in these patients is still a controversial issue. In spite of the fact that most studies report a better outcome in patients treated with CRRT, a recent meta-analysis failed to demonstrate any difference on the relative risk (RR) of mortality and on the rate of renal recovery between patients treated with either IRRT or CRRT. Furthermore, the use of peritoneal dialysis for the treatment of ARF patients in ICU has not been dismissed yet; so far this is indeed considered to be the technique of choice in some specific clinical situations. The intrinsic urgency of dialysis in ARF patients entails the use of temporary central venous catheters. The internal right jugular vein is usually preferred for these catheters because of the easier insertion and the lower risk of stenosis and thrombosis. The anticoagulant procedure should be chosen on the basis of patient characteristics, treatment typology and the likelihood of effectively monitoring its action. The choice of buffers in the dialysate, mostly lactate or bicarbonate, should depend on patient characteristics; so far, however, controlled but not randomized studies do not show any significant difference in the correction of metabolic acidosis between lactate and bicarbonate.

Methods of analysis for anthocyanins in plants and biological fluids

Anthocyanins are the largest group of water-soluble pigments in the plant kingdom. They are responsible for most of the red, blue, and purple colors of fruits, vegetables, flowers, and other plant tissues or products. The analysis of anthocyanins is complex as a result of their ability to undergo structural transformations and complexation reactions. In addition, they are difficult to measure independently of other flavonoids, as they have similar structural and reactivity characteristics. Anthocyanins are generally extracted with weakly acidified alcohol-based solvents, followed by concentration (under vacuum), and purification of the pigments. Paper and/or thin-layer chromatography and UV-Vis spectroscopy have traditionally been used for the identification of anthocyanins. Capillary zone electrophoresis, a hybrid of chromatography and electrophoresis, is gaining popularity for the analysis of anthocyanins; however, liquid chromatography (LC) has become the standard method for identification and separation in most laboratories and may be used for both preparative and quantitative analysis. LC with mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy are possibly the most powerful methods for the structural elucidation of anthocyanins available, to date. At present, the most satisfactory method for mixture analysis is the multistep method of separation, isolation, and quantification by LC with peak identification by MS and high-field NMR.

Absorption of anthocyanins from blueberries and serum antioxidant status in human subjects

In recent years, numerous studies have shown that the polyphenolics present in fruit and vegetable products exhibit a wide range of biological effects. However, there is little reliable information on the absorption of glycosylated and acylated anthocyanins in humans. In the present study, the absorption of anthocyanins in humans was investigated after the consumption of a high-fat meal with a freeze-dried blueberry powder containing 25 individual anthocyanins including 6 acylated structures. Nineteen of the 25 anthocyanins present in the blueberries were detected in human blood serum. Furthermore, the appearance of total anthocyanins in the serum was directly correlated with an increase in serum antioxidant capacity (ORAC(acetone), P < 0.01). These results show that anthocyanins can be absorbed in their intact glycosylated and possibly acylated forms in human subjects and that consumption of blueberries, a food source with high in vitro antioxidant properties, is associated with a diet-induced increase in ex vivo serum antioxidant status.

Extraction of anthocyanins and other phenolics from black currants with sulfured water

Health benefits of fruits, vegetables, and red wine are attributed to anthocyanins and other phytochemicals. In this research, the extraction of phenolics from black currants was optimized using different SO(2) concentrations (28, 300, 700, 1100, and 1372 ppm), temperatures (6, 20, 40, 60, and 74 degrees C), and solvent to solid ratios (S/S) (6, 20, 40, 60, and 74 mL/g). Surface response methodology was used to optimize yields of anthocyanins and total phenolics, as well as their antiradical and antioxidant activities. The extraction of phenolics varied with the SO(2) concentration, S/S, and temperature. Maximum yields of total phenolics and anthocyanins were obtained at an SO(2) concentration of 1000-1200 ppm and 19 L of solvent/kg of milled frozen berries. The increase of extraction temperature increased the rate of extraction and, thus, times to reach equilibrium for the extraction of total phenolics and anthocyanins were reduced. However, for the extraction of anthocyanins it is recommended that temperatures of 30-35 degrees C be used, as higher temperatures will degrade these compounds. Antioxidant activity was affected by all three experimental variables evaluated; however, the main variable affecting it was S/S. The higher the S/S, the lower the antioxidant index.

Effects of anthocyanins and other phenolic compounds on the production of tumor necrosis factor alpha in LPS/IFN-gamma-activated RAW 264.7 macrophages

Flavonoids have been reported to demonstrate their benefits in lowering oxidative stress and beneficial effects on cardiovascular and chronic inflammatory diseases. Common phenolic compounds, including phenolic acids, flavonols, isoflavones, and anthocyanins, present in fruits, vegetables, and grains were investigated for their effects on the production of tumor necrosis factor alpha (TNF-alpha) in LPS/IFN-gamma-activated RAW 264.7 macrophages. Gallic acid and (+)-catechin showed small but significant effects, whereas chlorogenic acid had no effect on TNF-alpha production. The flavonol quercetin inhibited TNF-alpha production, but kaempferol and myricetin induced the secretion of TNF-alpha. The isoflavone genistein was an inhibitor of TNF-alpha, whereas daidzein induced TNF-alpha production. Glycosylation of genistein changed its inhibitory effects to TNF-alpha induction, and glycosylation of daidzein had no effect on its activity. Anthocyanidins/anthocyanins and anthocyanin-rich extracts induced TNF-alpha production and acted as modulators of the immune response in activated macrophages. This is the first study to report the effects of anthocyanins and berry extracts on TNF-alpha production.

Diversity and dynamics of the T-cell response to MBP in DR2+ve individuals

It is generally accepted that multiple sclerosis (MS) is mediated by autoreactive T cells and that myelin basic protein (MBP) is one of the target autoantigens. The T-cell response to MBP has been analysed extensively, largely through the use of T-cell lines (TCL) and T-cell clones (TCC), and to date, three immunodominant regions (13-32, 84-103 and 144-163) have been described. However, given that TCL may represent a skewed pattern of peptide reactivity, we have developed a kinetic response assay in which the proliferation of peripheral blood mononuclear cells (PBMC) from MS patients and healthy individuals was measured directly against a panel of peptides spanning the full length of human MBP. Furthermore, PBMC from each subject were tested three times over the course of 18 months. A high proportion of MS patients exhibited a significant response to eight MBP regions (1-24, 30-54, 75-99, 90-114, 105-129, 120-144, 135-159 and 150-170). TCC were subsequently generated from MS subjects and were used to further define the epitope recognized in each case. Overall, normal individuals recognized significantly fewer peptides. In addition, we noted that the T-cell recognition of any one peptide can fluctuate, appearing at one time point, regressing, and subsequently reappearing at a later date. This study provides new insight into the recognition profile and dynamics of myelin-antigen-specific T cells in MS.