Increase In Concentration Of Fructose Research Articles

The Acute Effect of Fructose on Cardiac Hemodynamic Responses and Infarcted Area in Isolated Rat Heart During Ischemia-Reperfusion

Introduction: This study aimed to investigate the effects of fructose on cardiac hemodynamics and infarct size and the role of the antioxidant mechanism in these effects in isolated rat hearts undergoing ischemiareperfusion. Patients and Methods: Isolated hearts obtained from female Wistar rats were perfused with Krebs-Henseleit solution containing 12 mM glucose or solution containing 12 mM fructose or 48 mM fructose and underwent lowflow ischemia followed by reperfusion on the Langendorff apparatus. Left ventricular developed pressure (LVDP), timedependent pressure changes (dp/dt max, dp/dt min) and heart rates were recorded at the 1st, 15th and 120th minutes of reperfusion following ischemia, and the percentage of the infarct area and the size of the risk area were determined. At the end of the reperfusion, total oxidant capacity (TOS), malondialdehyde (MDA) and glutathione (GSH) levels were examined in perfusion fluid samples. Results: Basal dp/dt max values were lower in the high fructose group compared to the glucose group (p= 0.032). When the hearts were perfused with 12 mM fructose, a significant increase was observed in the percentage of the ischemic area and risk area compared to equivalent glucose and high fructose (p< 0.001 and p< 0.001, respectively). MDA, GSH and TOS values were comparable in all groups. Conclusion: The present study shows that fructose perfusion plays a role in reduced ventricular contractile function relative to glucose in isolated rat hearts. This reduction triggered by fructose appears to be independent of antioxidant mechanisms. Furthermore, fructose perfusion at glucose-equivalent concentration causes a greater increase in infarct area in ischemic hearts, whereas an increase in fructose concentration appears to prevent this effect.

Isomerization and Evaporation of Red Sorghum Hydrolyzate Sugar into Fructose Syrup through Water and Ethanol-Water as the Media

Red sorghum flour has considerable potential to be used as fructose syrup. The process of making fructose syrup was started with making hydrolyzate sugar by enzymatic hydrolysis of the polysaccharide into glucose syrup, then being isomerized using glucose-isomerase into fructose syrup. The study aimed to determine the best temperature in the isomerization process of hydrolyzate sugar from red sorghum flour through water and ethanol-water as the media and determine the optimum temperature of evaporation process to produce fructose syrup appropriate with SNI and HFS 42 commercials products. Isomerization was carried out on water media and ethanol-water media (2.5: 1) with temperature variations of 27 °C, 40 °C and 60 °C, with a total volume of 100 mL, for 43 hours, and enzyme concentration 1% (b/v) while the evaporation process was carried out at a pressure of 0.8 atm with a temperature variations of 55 °C, 60 °C, 75 °C, and a total volume of 30 ml. The best results of the isomerization process was obtained at 60 °C by water media with the concentration of fructose of 71.60 g/L and the evaporation process at 60 °C obtained an increase in fructose concentration by 70 % from initial fructose concentration and viscosity of 1.60 poise.

PRODUCTION OF 5-HYDROXYMETHYLFURFURAL (HMF) VIA FRUCTOSE DEHYDRATION: EFFECT OF SOLVENT AND SALTING-OUT

5-Hydroxymethylfurfural (HMF) is a key renewable platform compound for production of fuels and chemical intermediates. The production of 5-hydroxymethylfurfural (HMF) from fructose dehydration was studied using H3PO4 as catalyst, in organic/water system with different solvents (acetone, 2-butanol and ethyl ether). The effect of fructose concentration, temperature and acid concentration was investigated in acetone/water medium. The increase in fructose concentration favors the formation of condensation products and rehydration products are favored at high acid concentration. The solvents exhibited similar performance when the volume ratio of organic to aqueous phase was 1:1, but when this ratio increases to 2:1, the HMF yield obtained with ether was much lower. NaCl addition to the aqueous phase promoted the extraction of HMF to the organic phase, with an HMF yield of 80% in the case of 2:1 acetone/water medium.

Statistical optimization of hydrolysis process for banana peels using cellulolytic and pectinolytic enzymes

Dried and ground banana peels (BP) were pretreated and hydrolyzed using a combination of cellulolytic and pectinolytic enzymes. Central composite design (CCD) was used to optimize cellulase, β-glucosidase and pectinase concentrations and hydrolysis time for production of glucose and reducing sugars. Design expert software was used to analyze and evaluate the data. The interactions between filter paper cellulase and β-glucosidase concentrations were statistically significant at a 95% confidence level in production of glucose and reducing sugars from BP. The validation experiment was carried out with cellulase, β-glucosidase and pectinase at 8FPU/g cellulose, 15IU/g cellulose and 66IU/g pectin, respectively, for 15h in a laboratory fermenter. The glucose and reducing sugars concentrations of 28.2 and 48g/l, respectively, obtained through the validation experiment were higher than the theoretical values for glucose and reducing sugars predicted by the software. Glucose, galactose, arabinose, xylose and galacturonic acid concentrations increased with time, but a significant increase in fructose concentration was not observed. Process optimization also led to about 40% savings in hydrolysis time, indicating scale-up potential for the process.

Thyroidectomy modulates rat prostatic monosaccharides.

Earlier studies have shown that thyroid hormones play an important role in glycoprotein metabolism in the prostate. In this paper, hypothyroidism induced changes in prostatic glycoprotein-associated monosaccharides and fructose concentrations were studied in 30-day-old peripubertal rats. Hypothyroidism was induced by total surgical thyroidectomy and confirmed by radioimmunoassay (RIA) of thyroid hormones and thyroid stimulating hormone (TSH). Animals were killed after 30 and 60 days post-thyroidectomy. To test the direct effect of thyroid hormones on prostatic monosaccharides, prostatic tissue was incubated for 24 h at 37 degrees C with 25, 50 or 100 ng/mL T3. Ventral prostatic hexosamines and sialic acid concentrations were significantly decreased in hypothyroid rats aged 30 and 60 days, whereas fucose concentration was increased at 30 days but decreased at 60 days in hypothyroid rats. In the case of the dorsolateral prostate, hypothyroidism enhanced the concentration of hexosamines but caused a decrease in levels of fucose, sialic acid and fructose, irrespective of the duration of hypothyroidism. Concentrations of fucose, fructose and hexosamines in the anterior prostate were decreased and sialic acid concentration was increased in 60-day hypothyroid rats. In in vitro studies, the concentrations of fucose, sialic acid and hexosamines were significantly increased in all three prostatic lobes irrespective of the T3 dose with which they had been incubated. A consistent increase in fructose concentration was observed in anterior and dorsolateral prostates when incubated with different doses of T3 stimulation. It is concluded that the influence of hypothyroidism on prostatic monosaccharides seems to be specific for each sugar in different lobes of the prostate. These results clearly show that thyroid hormones differentially regulate prostatic glycoprotein metabolism.

The metabolism of fructans in roots of Cichorium intybus during growth, storage and forcing.

During the 1993 growing season samples from field-grown roots of chicory (Cicborium intybus L. var. folinsum ev. Flash) were analysed by ion-exchange HPLC (Dionex). We measured the concentrations (μmol g-1 f. wt) of glucose, frurtose, sucrose, 1-kestosc and 1,1 nystose. The concentrations of the higher fructans were relative (units g-1 f. wt). The data showed a significant increase in the concentration of fructans with a high degree of polymerization (DP) during July, August und September and a decrease of the glucose concentration. The Concentrations of sucrose, fructose and oligomeric fructans remained roughly constant over the same period. However, in early October, important changes occurred over a very short period. These changes included: (1) a significant increase in fructose concentration; (2) an increase in the concentration of fructans with a low DP; (3) a decrease in fructans with a high DP; (4) an appearance of alternative peaks (probably representing fructans without terminal glucose); and (5) an increase in sucrose concentration. These changes were not affected by a short-day treatment starting on 6 September. Forcing of the roots for endive production was accompanied by further breakdown, mainly of the larger fructans. Activity of SST (sucrose: sucrose fructosyl transferase) decreased slowly throughout the growing season lo essentially disappear by October. Neutral invertase activity increased more gradually. SST activity decreased very rapidly during cold storage and forcing.

Grafting vinyl monomers onto wool fibers. VIII. Graft copolymerization of methyl methacrylate onto wool using peroxydiphosphate–fructose redox system

The graft copolymerization of methyl methacrylate onto wool fibers was investigated in aqueous solution using the peroxydiphosphate–fructose redox system. The rate of grafting was determined by varying monomer, acidity of the medium, temperature, nature of wool, and reaction medium. The graft yield increases with increase in peroxydiphosphate concentration. With increase in concentration of fructose up to 7.5 × 10−4 mole/l., there is a significant increase in graft yield; and with further increase in concentration of fructose the graft yield decreases. The graft yield increases with increase in monomer concentration up to 65.72 × 10−2 mole/l. and decreases thereafter. The grafting is considerably influenced by chemical modification prior to grafting. The effect of acid, temperature, and solvent on the rate of grafting has been investigated and a suitable rate expression has been derived.