Free Glycerol Concentrations Research Articles

Regenerated Cellulose Membrane from Peanut Shell for Biodiesel Purification

Biodiesel purification by water washing has been proved to be an unattractive process from an economic and environmental point of view. In this work, we propose the use of regenerated cellulose membranes from peanut shell as an alternative in the biodiesel purification. The preparation of the membranes was optimized from a central composite design, resulting in dense and non-porous membranes. However, in contact with biodiesel, the membranes undergo expansion due to the retention of methanol, water, and glycerol molecules, allowing the permeation of fatty acid methyl esters. The filtered biodiesel presents quality parameters, such as total ester content of 98.3 ± 1.4% and free glycerol content < 0.02%, in agreement with the main regulatory agencies. The regenerated cellulose membranes from peanut shell are easily prepared, with high repeatability (relative standard deviation (RSD) < 1.8%) and are presented as an economical and environmental solution for the biodiesel purification.

Evaluating the need for free glycerol blanking for serum triglyceride measurements at Charlotte Maxeke Johannesburg Academic Hospital.

Background The accurate and precise measurement of triglycerides is important due to the adverse effects associated with hypertriglyceridaemia. Most laboratory methods are based on enzymatic hydrolysis of triglycerides with measurement of the total glycerol. An elevated free glycerol concentration may result in overestimation of triglyceride concentrations. The removal of free glycerol by blanking may therefore be of clinical importance. The aim of this study was to compare the glycerol blanking and non-glycerol blanking triglyceride methods. Methods This was a method comparison study of 1518 samples from both in-patients and out-patients at Charlotte Maxeke Johannesburg Academic Hospital. Triglycerides were measured in each sample using both the blanking and the non-blanking methods. Analytical performance was assessed based on the National Cholesterol Education Program (NCEP) goals. Clinical impact was assessed according to the NCEP Adult Treatment Program III (ATP III) risk classification. Results The method median was significantly higher in the non-blanking compared to the blanking method (1.33 vs. 1.12 mmol/L, p < 0.0001) in all patients. The average bias was above the total allowable error of 15% across all groups. There was a significant change in NCEP ATP III risk classification, with fewer patients classified as normal (67.6% vs. 74.6%, p < 0.0001) with the non-blanking method compared to the blanking method. Conclusions There was a significant error when glycerol blanking for triglyceride determination was not performed. The non-blanking triglyceride method overestimates triglyceride concentrations. This does not only exceed analytical performance goals, but also impacts on patient categorisation and clinical decision making in all patients.

Free Glycerol Sensing in Biodiesel: Automatic System Based on Sequential Enzymatic Reactions Using a Fit-for-Purpose Chemiluminescence Detection Chamber

The transesterification reaction to produce biodiesel generates a residual content of free glycerol, which may cause several problems to the engines. According to the international specification, t...

A comparison of the nutritional physiology and gut microbiome of urban and rural house sparrows (Passer domesticus).

Urbanization influences food quality and availability for many wild species, but our knowledge of the consequences urbanization has on the nutritional physiology of these animals is currently limited. To fill this gap, we captured House Sparrows (Passer domesticus) from rural and urban environments and hypothesized that increased access to human refuse in urban areas may significantly alter the gut microbiome and nutritional physiology of Sparrows. While there were no significant differences in circulating triglycerides or free glycerol concentrations between populations, urban birds had significantly greater blood glucose concentrations, which suggests greater circulating glucagon concentrations, accessibility to carbohydrates, and/or higher rates of gluconeogenesis in an urban setting. Rural birds had significantly more plasma uric acid, suggesting that they may metabolize more proteins or experience lower inflammation than urban birds. Rural birds also had significantly higher liver free glycerol concentrations, indicating that they metabolize more fat than urban birds. There were no significant differences in the relative abundance of gut microbial taxa at the phyla level between the two populations, but linear discriminant analysis effect size (LEfSe) showed that urban House Sparrows were more enriched with class- and order-level microbes from the phylum Proteobacteria, which are implicated in several mammalian intestinal and extra-intestinal diseases. These findings demonstrate that urbanization significantly alters the nutritional physiology and the composition of the gut microbiome of House Sparrows.

Androgens sensitise mice to glucocorticoid-induced insulin resistance and fat accumulation.

Chronic glucocorticoid therapy causes insulin resistance, dyslipidaemia, abnormal fat accumulation, loss of muscle mass and osteoporosis. Here we describe a hitherto unknown sexual dimorphism in the metabolic response to chronic glucocorticoid exposure in mice. This led us to investigate whether glucocorticoid-induced insulin resistance and obesity were dependent on sex hormones. Male and female CD1 mice were treated for 4weeks with supraphysiological doses (~250μg/day) of corticosterone, the main glucocorticoid in rodents, or equivalent volume of vehicle (drinking water without corticosterone). To investigate the effects of sex hormones, a separate group of mice were either orchidectomised or ovariectomised prior to corticosterone treatment, with or without dihydrotestosterone replacement. Body composition was determined before and after corticosterone treatment, and insulin tolerance was assessed after 7 and 28days of treatment. Adipocyte morphology was assessed in white and brown adipose tissues by immunohistochemistry, and fasting serum concentrations of NEFA, triacylglycerols, total cholesterol and free glycerol were measured using colorimetric assays. Obesity- and diabetes-related hormones were measured using multiplex assays, and RNA and protein expression in adipose tissues were measured by RT-PCR and immunoblotting, respectively. Chronic corticosterone treatment led to insulin resistance, fasting hyperinsulinaemia, increased adiposity and dyslipidaemia in male, but not female mice. In males, orchidectomy improved baseline insulin sensitivity and attenuated corticosterone-induced insulin resistance, but did not prevent fat accumulation. In androgen-deficient mice (orchidectomised males, and intact and ovariectomised females) treated with dihydrotestosterone, corticosterone treatment led to insulin resistance and dyslipidaemia. In brown adipose tissue, androgens were required for corticosterone-induced intracellular lipid accumulation ('whitening'), and dihydrotestosterone specifically exacerbated corticosterone-induced accumulation of white adipose tissue by increasing adipocyte hypertrophy. Androgens also suppressed circulating adiponectin concentrations, but corticosterone-induced insulin resistance did not involve additional suppression of adiponectin levels. In white adipose tissue, androgens were required for induction of the glucocorticoid target gene Gilz (also known as Tsc22d3) by corticosterone. In mice, androgens potentiate the development of insulin resistance, fat accumulation and brown adipose tissue whitening following chronic glucocorticoid treatment.

Modification of Chemical Properties of Shellac with Glycerol and Acrylic Acid

Shellac is a natural product which has been presumed as a fragile polymer due to itschemical properties. The objective of this study was to improve chemical properties of shellac by themodification with different concentration of glycerol and acrylic acid. Shellac was reacted withglycerol at various temperature and amounts of glycerol. The intermediate product was reacted withacrylic acid at different concentration. Acid value, hydroxyl groups, and free glycerol concentrationof modified shellac was determined. The result showed that acid value gradually decrease alongincreasing temperature for each ratio of glycerol and acrylic acid to shellac. The concentration ofhydroxyl groups rise as temperature and ratio increases. Furthermore, free glycerol concentration felldown along with the rise temperature. Modification chemical properties of shellac with glycerol andacrylic acid can be applied for the further study to enhance shellac properties.

Evaluation of glycerol encapsulated with alginate and alginate-chitosan polymers in gut environment and its resistance to rumen microbial degradation.

ObjectiveTo determine the effect of gut pH and rumen microbial fermentation on glycerol encapsulated in alginate and alginate-chitosan polymers.MethodsGlycerol was encapsulated at 2.5%, 5%, 7.5%, or 10% (w/w) with sodium alginate (A) and alginate-chitosan (AC) polymers. Surface morphology and chemical modifications of the beads were evaluated using scanning electron microscopy and Fourier transform infrared (FTIR) spectra. Encapsulation efficiency was determined at the 5% glycerol inclusion level in two experiments. In experiment 1, 0.5 g of alginate-glycerol (AG) and alginate-chitosan glycerol (ACG) beads were incubated for 2 h at 39°C in pH 2 buffer followed by 24 h in pH 8 buffer to simulate gastric and intestinal conditions, respectively. In experiment 2, 0.5 g of AG and ACG beads were incubated in pH 6 buffer at 39°C for 8 h to simulate rumen conditions. All incubations were replicated four times. Free glycerol content was determined using a spectrophotometer and used to assess loading capacity and encapsulation efficiency. An in vitro experiment with mixed cultures of rumen microbes was conducted to determine effect of encapsulation on microbial fermentation. Data were analyzed according to a complete block design using the MIXED procedure of SAS (SAS Institute, Cary, NC, USA).ResultsFor AG and ACG, loading capacity and efficiency were 64.7%, 74.7%, 70.3%, and 78.1%, respectively. Based on the FTIR spectra and scanning electron microscopy, ACG treatment demonstrated more intense and stronger ionic bonds. At pH 6, 36.1% and 29.7% of glycerol was released from AG and ACG, respectively. At pH 2 minimal glycerol was released but pH 8 resulted in 95.7% and 93.9% of glycerol released from AG and ACG, respectively. In vitro microbial data show reduced (p<0.05) fermentation of encapsulated glycerol after 24 h of incubation.ConclusionThe AC polymer provided greater protection in acidic pH with a gradual release of intact glycerol when exposed to an alkaline pH.

Butanolysis: Comparison of potassium hydroxide and potassium tert-butoxide as catalyst for biodiesel preparing from rapeseed oil

Biodiesel is a mixture of esters of fatty acids (most often palmitic, stearic and oleic) and lower alcohols (in our work butanol) produced by transesterification. It is a renewable source of energy, prepared from triacylglycerides, which are contained in vegetable oils and animal fats. This work focuses on alkaline catalyzed transesterification of rapeseed oil with butanol and comparison of two catalysts (potassium hydroxide and potassium tert-butoxide). In industry is usually transesterification of rapeseed oil carried out like reaction catalyzed by potassium hydroxide. Potassium hydroxide have high content of K2CO3, KHCO3 and water. Moreover water is formed by neutralization of potassium hydroxide with free fatty acids contained in oil. In cause of tert-butoxide catalyzed reaction, it is not possible because tert-butoxide have not a OH− aniont, which is needed for water forming. The influence of various conditions (addition of water, temperature of separation, intensity of stirring and type of catalyst) on butanolysis process was studied for both catalysts. For both catalysts dependence of conversions on time were plotted. When tert-butoxide was used, satisfactory phase separation was not achieved. The only way was separation of hot crude reaction mixture without adding water. Ester formed by this method had high content of free glycerol and soaps, but reached higher conversion. The best results were obtained with KOH and subsequent separation of cold crude reaction mixture with the addition of water and slow stirring. The difference between reactions catalyzed by potassium hydroxide and potassium tert-butoxide was described.

Emitter/receiver piezoelectric films coupled to flow-batch analyzer for acoustic determination of free glycerol in biodiesel without chemicals/external pretreatment

This paper describes for the first time the use of emitter and receiver piezoelectric films coupled one in front of the other into a flow-batch analyzer for acoustic determination of free glycerol in biodiesel without chemicals/external pretreatment. Online extraction of free glycerol from biodiesel was carried out into aqueous solution without chemicals/external pretreatment. While the emitter piezoelectric is activated to sonicate the solution, the receiver piezoelectric translates the acoustic signal received into an electrical signal, which is measured and recorded by a digital oscilloscope. Multivariate calibration models were built for prediction of free glycerol concentration. In this sense, results of partial least square regression (PLS), the interval PLS (iPLS) and PLS coupled with the Successive Projections Algorithm for interval selection (iSPA-PLS) were compared. The proposed low-cost flow-batch analyzer exhibited good performance, satisfactory detection limit (0.12 mg kg−1) and a linear response from 72 to 372 mg kg−1 of free glycerol in biodiesel. The procedure was successfully applied to the analysis of biodiesel samples, and the results agreed with the reference method (ASTM D6584-07) at 95% confidence level.

Short-Term Microbiota Manipulation and Forearm Substrate Metabolism in Obese Men: A Randomized, Double-Blind, Placebo-Controlled Trial

Objective: To investigate the impact of gut microbiota manipulation on fasting and postprandial skeletal muscle metabolism in humans. Methods: 40 obese, insulin-resistant males were randomized to amoxicillin (broad-spectrum antibiotic), vancomycin (narrow-spectrum antibiotic), or placebo (7 days, 1,500 mg/day). Before and after treatment, forearm blood flow and metabolite fluxes across forearm muscle were measured under fasting and postprandial (high-fat mixed-meal) conditions. Results: Vancomycin decreased bacterial diversity, reduced the abundance of Gram-positive Firmicutes, and increased the abundance of Gram-negative Proteobacteria, whereas amoxicillin did not affect microbial composition. Neither vancomycin nor amoxicillin treatment affected fasting and postprandial plasma glucose, free fatty acid (FFA), triacylglycerol (TAG), glycerol, lactate, and insulin concentrations or forearm blood flow. Fasting and postprandial net forearm muscle glucose uptake and the release of lactate were not significantly altered by antibiotic treatment as compared to placebo. Finally, antibiotic treatment did not change fasting and postprandial glycerol, FFA, and TAG fluxes across forearm muscle. Conclusion: The present study demonstrates that short-term antibiotic treatment has no effects on fasting and postprandial forearm substrate metabolism and blood flow in obese men with impaired glucose metabolism. These data suggest that short-term strategies targeting the gut microbiota to improve metabolic health may not be effective in obese humans.

Wearing lower-body compression garment with medium pressure impaired exercise-induced performance decrement during prolonged running.

ObjectiveTo investigate the effect of wearing a lower body compression garment (CG) exerting different pressure levels during prolonged running on exercise-induced muscle damage and the inflammatory response.MethodsEight male participants completed three exercise trials in a random order. The exercise consisted of 120 min of uphill running at 60% of VO2max. The exercise trials included 1) wearing a lower-body CG with 30 mmHg pressure [HIGH]; 2) wearing a lower-body CG with 15 mmHg pressure [MED]; and 3) wearing a lower-body garment with < 5 mmHg pressure [CON]. Heart rate (HR), and rate of perceived exertion for respiration and legs were monitored continuously during exercise. Time-course change in jump height was evaluated before and immediately after exercise. Blood samples were collected to determine blood glucose, lactate, serum creatine kinase, myoglobin, free fatty acids, glycerol, cortisol, and plasma interleukin-6 (IL-6) concentrations before exercise, 60 min of the 120 min exercise period, immediately after exercise, and 60 min after exercise.ResultsJump height was significantly higher immediately after the exercise in the MED trial compared with that in the HIGH trial (P = 0.04). Mean HR during the 120 min exercise was significantly lower in the MED trial (162 ± 4 bpm) than that in the CON trial (170 ± 4 bpm, P = 0.01). Plasma IL-6 concentrations increased significantly with exercise in all trials, but the area under the curve during exercise was significantly lower in the MED trial (397 ± 58 pg/ml·120 min) compared with that in the CON trial (670 ± 86 pg/ml·120 min, P = 0.04).ConclusionWearing a lower body CG exerting medium pressure (approximately 15 mmHg) significantly attenuated decrease in jump performance than that with wearing a lower body CG exerting high pressure (approximately 30 mmHg). Furthermore, exercise-induced increases in HR and the inflammatory response were significantly smaller with CG exerted 15mmHg than that with garment exerted < 5 mmHg.

Colonic infusions of short-chain fatty acid mixtures promote energy metabolism in overweight/obese men: a randomized crossover trial

Short-chain fatty acids (SCFA), formed by microbial fermentation, are believed to be involved in the aetiology of obesity and diabetes. This study investigated the effects of colonic administration of physiologically relevant SCFA mixtures on human substrate and energy metabolism. In this randomized, double-blind, crossover study, twelve normoglycaemic men (BMI 25–35 kg/m2) underwent four investigational days, during which SCFA mixtures (200 mmol/L) high in either acetate (HA), propionate (HP), butyrate (HB) or placebo (PLA) were rectally administered during fasting and postprandial conditions (oral glucose load). Before and for two hours after colonic infusions, indirect calorimetry was performed and blood samples were collected. All three SCFA mixtures increased fasting fat oxidation (P < 0.01), whilst resting energy expenditure increased after HA and HP compared with PLA (P < 0.05). In addition, all three SCFA mixtures increased fasting and postprandial plasma peptide YY (PYY) concentrations, and attenuated fasting free glycerol concentrations versus PLA (P < 0.05). Colonic infusions of SCFA mixtures, in concentrations and ratios reached after fibre intake, increased fat oxidation, energy expenditure and PYY, and decreased lipolysis in overweight/obese men. Human intervention studies are warranted to investigate whether these effects translate into long-term benefits for body weight control and insulin sensitivity in the obese insulin resistant state.

Separation of Free Glycerol and Glycerides from Biodiesel by Means of Liquid-Liquid Extraction

This paper investigates glycerol and glycerides extraction process from fresh and waste sunflower oil biodiesel. Deep eutectic solvent choline-chloride: ethylene-glycol (molar ratio 1:2.5) was used as extraction media in both batch experiments and continuous Karr column. Biodiesel was synthesized in an alkali catalysed chemical transesterification reaction. Three process variables, namely hydrodynamic conditions, solvent to biodiesel ratio and extraction duration were investigated and their impact on the extraction efficiency was found to be largely negligible. Throughout the whole range of process variables the extraction efficiency was relatively high, getting slightly lower only during the continuous experiments. After the extraction, free glycerol content was below the limit for all samples, but the total glycerol and glycerides content was too high to fully comply with biodiesel quality standards. Selected extraction solvent has proved to be efficient for free glycerol removal in the tested range of conditions, but further process modifications and possible raw material and biodiesel processing will be needed to reduce the content of total glycerol and glycerides.

Fibroblast Growth Factor 21 Deficiency Attenuates Experimental Colitis-Induced Adipose Tissue Lipolysis.

Aims Nutrient deficiencies are common in patients with inflammatory bowel disease (IBD). Adipose tissue plays a critical role in regulating energy balance. Fibroblast growth factor 21 (FGF21) is an important endocrine metabolic regulator with emerging beneficial roles in lipid homeostasis. We investigated the impact of FGF21 in experimental colitis-induced epididymal white adipose tissue (eWAT) lipolysis. Methods Mice were given 2.5% dextran sulfate sodium (DSS) ad libitum for 7 days to induce colitis. The role of FGF21 was investigated using antibody neutralization or knockout (KO) mice. Lipolysis index and adipose lipolytic enzymes were determined. In addition, 3T3-L1 cells were pretreated with IL-6, followed by recombinant human FGF21 (rhFGF21) treatment; lipolysis was assessed. Results DSS markedly decreased eWAT/body weight ratio and increased serum concentrations of free fatty acid (FFA) and glycerol, indicating increased adipose tissue lipolysis. eWAT intracellular lipolytic enzyme expression/activation was significantly increased. These alterations were significantly attenuated in FGF21 KO mice and by circulating FGF21 neutralization. Moreover, DSS treatment markedly increased serum IL-6 and FGF21 levels. IL-6 pretreatment was necessary for the stimulatory effect of FGF21 on adipose lipolysis in 3T3-L1 cells. Conclusions Our results demonstrate that experimental colitis induces eWAT lipolysis via an IL-6/FGF21-mediated signaling pathway.

Direct transesterification of Botryococcus sp. catalysed by immobilized lipase: Ultrasound treatment can reduce reaction time with high yield of methyl ester

Methyl esters have been considered a promising alternative fuel for fossil fuels. However, the methyl ester production from lipase catalysed direct transesterification is a time-consuming process. It is necessary to develop the method to reduce the operating time of the lipase catalysed direct transesterification. Various operating parameters were studied such as solvent/algae ratio, catalyst addition, water addition, temperature and reaction time on the direct transesterification of Botryococcus sp. with and without ultrasound. The maximum yield, 88% methyl esters (w/w of oil) was achieved in 4h with ultrasound treatment under optimum conditions, compared to a maximum yield of 78% methyl esters (w/w of oil), after 36h without ultrasound. Under optimum conditions, the transesterification of Botryococcus sp. oil with dimethyl carbonate produced 2.7% glycerol carbonate and 5.7% glycerol dicarbonate (w/w of oil) with an added benefit of very low free glycerol content. The properties of methyl esters obtained were found to be within the acceptable limits. The obtained results indicate that this ultrasound assisted direct transesterification of Botryococcus sp. oil catalysed by lipase is very promising for biodiesel production using microalgae as the feedstock.

Transesterification of rapeseed oil by butanol and separation of butyl ester

The paper describes the reactions and separations conditions for the transesterification of rapeseed oil by butanol under potassium hydroxide as a catalyst. The product is a mixture of butyl esters of higher fatty acids, which can be used as fuel (biodiesel) for combustion engines. The effect of the chosen reaction conditions (independent variables: the reaction temperature and time, the amount of catalyst, the molar ratio of butanol to oil and the method of oil addition to butanol) on the butanolysis process was studied. The measured data was analysed by multi-linear regression and the statistical models describe the dependency of glycerides (dependent variables) on the independent variables. The transesterification was stopped by neutralization of the catalyst with both a strong and weak acid been added to whole reaction mixture. The advantage of strong acid is a very fast separation and a zero content of potassium and free glycerol, nevertheless a high acid number (1.7–4.5 mg kg−1). In the case of weak acid (gas carbon dioxide), the acid number is less than 0.5 mg kg−1, but the separation takes longer. Moreover, the separation was sped up by the addition of a small amount of water to the reaction mixture after the reaction and removal of butanol. This way also decreased the content of potassium (10 times) and free glycerol (4 times) in the ester phase compare to the separation without water. Moreover, the relationship between the flashpoint and the content of butanol in butyl ester was described, which enables the determination only the butanol content and the calculation of the flashpoint or vice-versa.

The effects of interval- vs. continuous exercise on excess post-exercise oxygen consumption and substrate oxidation rates in subjects with type 2 diabetes

BackgroundFor unknown reasons, interval training often reduces body weight more than energy-expenditure matched continuous training. We compared the acute effects of time-duration and oxygen-consumption matched interval- vs. continuous exercise on excess post-exercise oxygen consumption (EPOC), substrate oxidation rates and lipid metabolism in the hours following exercise in subjects with type 2 diabetes (T2D). MethodsFollowing an overnight fast, ten T2D subjects (M/F: 7/3; age=60.3±2.3years; body mass index (BMI)=28.3±1.1kg/m2) completed three 60-min interventions in a counterbalanced, randomized order: 1) control (CON), 2) continuous walking (CW), 3) interval-walking (IW – repeated cycles of 3min of fast and 3min of slow walking). Indirect calorimetry was applied during each intervention and repeatedly for 30min per hour during the following 5h. A liquid mixed meal tolerance test (MMTT, 450kcal) was consumed by the subjects 45min after completion of the intervention with blood samples taken regularly. ResultsExercise interventions were successfully matched for total oxygen consumption (CW=1641±133mL/min; IW=1634±126mL/min, P>0.05). EPOC was higher after IW (8.4±1.3l) compared to CW (3.7±1.4l, P<0.05). Lipid oxidation rates were increased during the MMTT in IW (1.03±0.12mg/kg per min) and CW (0.87±0.04mg/kg per min) compared with CON (0.73±0.04mg/kg per min, P<0.01 and P<0.05, respectively), with no difference between IW and CW. Moreover, free fatty acids and glycerol concentrations, and glycerol kinetics were increased comparably during and after IW and CW compared to CON. ConclusionsInterval exercise results in greater EPOC than oxygen-consumption matched continuous exercise during a post-exercise MMTT in subjects with T2D, whereas effects on substrate oxidation and lipid metabolism are comparable.

Compression Garment with Moderate Pressure Attenuated Decrement of Muscular Performance and Inflammation During Prolonged Running

PURPOSE:To investigate the effect of wearing lower body compression garment (CG) with exerting different pressure levels during prolonged running on exercise-induced muscle damage and inflammatory responses. METHODS: Nine male subjects (23.2 ± 0.4 years, 170.5 ± 0.4 cm, 62.6 ± 0.7 kg) completed 3 exercise trials in a random order. The exercise consisted of 120 min of uphill running (7%) on treadmill at 60 % of VO2max. The exercise trials included 1) wearing lower body CG with exertion of 40 hPa of compression [HIGH]; 2) wearing lower body CG with exertion of 20 hPa of compression [MED]; and 3) wearing lower body CG with exertion of under 10 hPa of compression [LOW]. Time-courses of changes in jump height, heart rate (HR) and rating of perceived exertion (RPE) for respiration and legs were monitored. Blood samples were also drawn to determine blood glucose, lactate, serum creatine kinase, myoglobin, free fatty acid, glycerol, cortisol and plasma IL-6 concentrations. P < 0.05 was considered to be statistically significant. RESULTS: Jump performance was decreased immediately after exercise compared with pre-values in the HIGH and LOW trials, whereas jump performance did not change significantly in the MED trial. Furthermore, the MED trial showed significantly higher value of jump height compared with the HIGH trial immediately after exercise. The HR during exercise was significantly elevated in all trials. However, average HR during 120 min of exercise was significantly lower in the MED trial (159 ± 3 bpm) than in the HIGH (163 ± 3 bpm) and LOW trials (169 ± 5 bpm). Although the RPE for respiratory significantly increased during exercise, the MED trial showed significantly lowest value among 3 trials during latter 60 min of exercise. Plasma IL-6 concentration significantly increased with exercise in all trials. However, area under the curve for IL-6 concentration during 120 min of exercise was significantly lower in the MED trial (397 ± 58 pg/ml•120 min) than in the LOW trial (670 ± 86 pg/ml•120 min). No significant difference among 3 trials was observed for time-course changes in other blood variables. CONCLUSIONS: Wearing lower body CG with exerting moderate pressure (20 hPa) significantly attenuated reduction of power output for lower body muscles and inflammatory response during prolonged running.

Separation of glycerolysis product using hexane

Hexane is non-polar solvent and it can dissolve triglyceride and free fatty acid. The aim of this research is to get the hexane ratio to the glycerolysis product that can produce product that has the best characteristics. The study was conducted in five stages. In the first stage, the physicochemical properties of palm oil were analysed. In the second stage, palm oil glycerolysis was conducted. In the third stage, glycerolysis product was extracted by using hexane in various concentrations. In the following stage, physicochemical properties of extracted products were analysed. In the last stage, data were subjected to an analysis of variance. Results showed that ratio between glycerolysis product to hexane in this work did not significantly (α=0.05) affect the yield, the free glycerol content, and the ability of extracted products to reduce the surface tension of water. It was also found that the best treatment had yield of 28.5%. It was able to lower water surface tension from 72.00 to 31.80 dynes/cm and had free glycerol content of 2.40%. Base on this work, we found that further research need to be done.

Altering fatty acid availability does not impair prolonged, continuous running to fatigue: evidence for carbohydrate dependence.

We determined the effect of suppressing lipolysis via administration of nicotinic acid (NA) on fuel substrate selection and half-marathon running capacity. In a single-blinded, Latin square design, 12 competitive runners completed four trials involving treadmill running until volitional fatigue at a pace based on 95% of personal best half-marathon time. Trials were completed in a fed or overnight fasted state: 1) carbohydrate (CHO) ingestion before (2 g CHO·kg(-1)·body mass(-1)) and during (44 g/h) [CFED]; 2) CFED plus NA ingestion [CFED-NA]; 3) fasted with placebo ingestion during [FAST]; and 4) FAST plus NA ingestion [FAST-NA]. There was no difference in running distance (CFED, 21.53 ± 1.07; CFED-NA, 21.29 ± 1.69; FAST, 20.60 ± 2.09; FAST-NA, 20.11 ± 1.71 km) or time to fatigue between the four trials. Concentrations of plasma free fatty acids (FFA) and glycerol were suppressed following NA ingestion irrespective of preexercise nutritional intake but were higher throughout exercise in FAST compared with all other trials (P < 0.05). Rates of whole-body CHO oxidation were unaffected by NA ingestion in the CFED and FAST trials, but were lower in the FAST trial compared with the CFED-NA trial (P < 0.05). CHO was the primary substrate for exercise in all conditions, contributing 83-91% to total energy expenditure with only a small contribution from fat-based fuels. Blunting the exercise-induced increase in FFA via NA ingestion did not impair intense running capacity lasting ∼85 min, nor did it alter patterns of substrate oxidation in competitive athletes. Although there was a small but obligatory use of fat-based fuels, the oxidation of CHO-based fuels predominates during half-marathon running.