Small Amounts Of Fructose Research Articles

292-OR: High-Fat Diets Containing Sucrose and Fructose, but Not Glucose, Induce Obesity and Hepatic Insulin Resistance via Accumulation of Diacylglycerols

Diets high in sugar and fat promote the development of obesity and metabolic complications, while high-sugar, low-fat or high-fat, sugar-free (ketogenic) diets do not. We assessed the importance of sugar in a commonly used 60% high-fat diet (HFD), which contains 6.7% of calories from sucrose. The sucrose content was replaced either with an equal amount of fructose (HFD+RF) or glucose (HFD+RG) and all other components of the diet were identical. After 12 weeks on the diets, the mice on HFD and HFD+RF diets gained more weight, developed hepatic steatosis, glucose intolerance and insulin resistance, compared to the mice on normal chow or HFD+RG diets. A relatively small (6.7%) amount of sucrose or fructose, but not glucose, in a HFD was sufficient to increase the fructolysis (KHK-C, ALDO B and TKFC) and de novo lipogenesis (ME1, ACLY, ACC1, FASN, SCD1) pathways by WB. Metabolomics analysis revealed higher hepatic diacylglycerol (DAG) content in HFD and HFD+RF groups, while HFD+RG group had elevated hepatic triacylglycerol content. Proteomics analysis quantified 3058 unique proteins, 736 of which were significantly different between the mice on chow and HFD. Replacing sucrose with fructose altered only 2 proteins, while replacing sucrose with fructose significantly changed 196 proteins in the liver. Reactome pathway analysis showed that the most altered processes mediate lipid biosynthesis and metabolism. In conclusion, HFDs containing sucrose or fructose but not glucose increase the fructolysis pathway and lead to hepatic DAG accumulation and insulin resistance. Thus, a relatively small amount of fructose, regardless of its source, is sufficient to alter metabolic outcomes in mice consuming a HFD. Disclosure S.Park: None. T.I.Fadhul: None. C.Kahn: None. S.Softic: Research Support; Alnylam Pharmaceuticals, Inc.

Development of rice bran treatment process and its use for the synthesis of polyhydroxyalkanoates from rice bran hydrolysate solution

Rice bran treatment process for the production of 43.7kg of hydrolysate solution containing 24.41g/L of glucose and small amount of fructose from 5kg of rice bran was developed and employed to produce polyhydroxyalkanoates in recombinant Escherichia coli and Ralstonia eutropha strains. Recombinant E. coli XL1-Blue expressing R. eutropha phaCAB genes and R. eutropha NCIMB11599 could produce poly(3-hydroxybutyrate) with the polymer contents of 90.1wt% and 97.2wt%, respectively, when they were cultured in chemically defined MR medium and chemically defined nitrogen free MR medium containing 10mL/L of rice bran hydrolysate solution, respectively. Also, recombinant E. coli XL1-Blue and recombinant R. eutropha 437-540, both of which express the Pseudomonas sp. phaC1437 gene and the Clostridium propionicum pct540 gene could produce poly(3-hydroxybutyrate-co-lactate) from rice bran hydrolysate solution. These results suggest that rice bran may be a good renewable resource for the production of biomass-based polymers by recombinant microorganisms.

Evidence-based treatment of metabolic myopathy

Objective To evaluate the current treatments and possible adverse reactions of metabolic myopathy, and to develop the best solution for evidence-based treatment. Methods Taking metabolic myopathy, mitochondrial myopathy, lipid storage myopathy, glycogen storage diseases, endocrine myopathy, drug toxicity myopathy and treatment as search terms, retrieve in databases such as PubMed, Cochrane Library, ClinicalKey database, National Science and Technology Library (NSTL), in order to collect the relevant literature database including clinical guidelines, systematic reviews (SR), randomized controlled trials (RCT), controlled clinical trials, retrospective case analysis and case study. Jadad Scale was used to evaluate the quality of literature. Results Twenty-eight related articles were selected, including 6 clinical guidelines, 5 systematic reviews, 10 randomized controlled trials and 7 clinical controlled trials. According to Jadad Scale, 23 articles were evaluated as high-quality literature (≥ 4), and the remaining 5 were evaluated as low-quality literature (< 4). Treatment principles of these clinical trials, efficacy of different therapies and drug safety evaluation suggest that: 1) Acid α-glycosidase (GAA) enzyme replacement therapy (ERT) is the main treatment for glycogen storage diseases, with taking a high-protein diet, exercising before taking a small amount of fructose orally and reducing the patient's physical activity gradually. 2) Carnitine supplementation is used in the treatment of lipid storage myopathy, with carbohydrate and low fat diet provided before exercise or sports. 3) Patients with mitochondrial myopathy can take coenzyme Q10, vitamin B, vitamin K, vitamin C, etc. Proper aerobic exercise combined with strength training is safe, and it can also enhance the exercise tolerance of patients effectively. 4) The first choice to treat the endocrine myopathy is treating primary affection. 5) Myopathies due to drugs and toxins should remove pathogenic drugs and toxins. Conclusions Most of metabolic myopathies are genetic diseases, and they cannot achieve a radical cure at present. Gene therapy is the fundamental way. Endocrine myopathy and drug toxicity myopathy need to remove the primary affection or pathogenic drugs. Evidence-based medicine can provide the best clinical evidence assessment method for metabolic myopathy. doi: 10.3969/j.issn.1672-6731.2014.05.006

Nectar secretion in the flowers of comfrey (Symphytum officinale L.) and nectar chemistry

Nectar secretion and nectar chemistry in the flowers of comfrey (&lt;i&gt;Symphytum officinale&lt;/i&gt; L.) were examined in the four stages of anthesis: large buds, before pollen exposure: II - freshy opened flowers with the beginning of anther dehiscence: III- completely opened flowers in the maximum of pollen exposure: lV- flowers at the final stage of anthesis, without pollen in the anthers. Individual flower stays fresh 2,5-3 days, on average. Disc-shaped nectaries of S.officinale are located at the base of the four-lobbed ovary. Nectar is released through the modified stomata. Start of nectar secretion was noted at the bud stage. Nectar volume, mass of nectar and sugars differed in the examined stages of anthesis and the biggest values were noted at the final stages. Dominant sugar in nectar was sucrose with smaller amounts of fructose and glucose. The presence of amino acids was also recorded.

Determination and Comparison of Chemical Characteristics ofArbutus unedoL. andArbutus andrachnaeL. (Family Ericaceae) Fruits

The fruits and leaves of Arbutus species are well known in folk medicine as antiseptics, diuretics, and laxatives in many parts of Turkey. Some chemical properties including pH, soluble solid content, titratable acidity, protein, moisture, ash, ascorbic acid, fructose, glucose, sucrose, total phenols, total antioxidant activity, and minerals were determined in fully matured Arbutus unedo L. and Arbutus andrachnae L. fruits collected from different sites of Canakkale, Turkey in 2006 and 2007. Total soluble solids, titratable acidity, protein, moisture, and ash content of A. unedo and A. andrachnae berries were on average 16.0% and 14.0%, 0.4% and 0.6%, 2.38% and 3.77%, 47.21% and 38.21%, and 2.82% and 4.35%, respectively. The mean values of ascorbic acid were 270.50 mg/100 g for A. unedo and 140.30 mg/100 g for A. andrachnae, which suggested that Arbutus berries contain high amounts of vitamin C. In the strawberry tree fruits, fructose and glucose were determined to be the major sugars. The analysis showed that fructose and glucose occurred in concentrations of 24.09% and 19.09%, respectively. However, ripe A. andrachnae fruits contained small amounts of fructose (4.12%), glucose (2.73%), and sucrose (0.16%) detectable by high-performance liquid chromatography analysis. The general order of abundance of the minerals was K > Ca > P > Mg > Na in whole fruit of the strawberry tree. The chemical composition of Arbutus fruits indicates that the fruits are good sources of minerals and ascorbic acid and that they are high in phenolics and antioxidant capacity and low in soluble sugars, especially A. andrachnae. The data should be useful for research purposes and for compiling local food composition tables. In view of its chemical composition, the use of Arbutus fruits in some food products may be suggested.

Effect of dietary fructose on lipid metabolism, body weight and glucose tolerance in humans

The prevalence of obesity is increasing worldwide. Increasing body weight together with decreasing physical activity is expected to increase the incidence of several diseases related to lifestyle, such as adult type diabetes and vascular atherosclerotic diseases. It has been postulated that increasing consumption of fructose may be a contributory factor in the development of obesity and the accompanying metabolic abnormalities. Most studies supporting these hypotheses, however, are animal studies, which suggest that consumption of high amounts of fructose may stimulate lipogenesis and thus alter lipid metabolism and increase body weight. This review explores the effects of dietary fructose on lipid metabolism in humans, with the conclusion that the data so far do not support any significant specific adverse effect of fructose apart from its energy content. A small amount of fructose may even improve glucose tolerance, and studies to date on diabetic subjects indic ate that isocaloric replacement of some glucose-based carbohydrates with fructose may improve metabolic control. Keywords: cholesterol; diabetes; fructose; oral glucose tolerance; triglycerides

Restart of Fermentation of Simulated Stuck Wines by Direct Inoculation of Active Dry Yeasts

Fermentation kinetics of nine commercial yeast strains, inoculated at different doses, were studied in a dry wine with fructose added up to 18 or 20 g/L. The ability to complete fermentation appeared to be dose-related for some strains. Other strains appeared to referment to dryness independently of the amount of cells inoculated, while others failed to referment. On average, a dose of 100 g/hL yielded better results than 50 g/hL, but higher doses did not further improve fermentation performance. The effect of pH, SO₂, concentration of alcohol, ammonium ion availability, and temperature on restarting of fermentation was also investigated. The most challenging factors to the yeast were ethanol content and sulfur dioxide levels. In a wine containing a small amount of fructose, the times required for onset and completion of fermentation were inversely related to the amount of alcohol and SO₂. The effect of wine pH was unclear and ammonia addition seemed inefficient, if not inhibitory. The glucose/fructose ratio was found to be crucial for the activity of some strains, while others were less affected by it. Strong differences can be found among yeast strains in their overall sensitivity to wine composition.

Small amounts of dietary fructose dramatically increase hepatic glucose uptake through a novel mechanism of glucokinase activation.

Glucokinase plays a major role in the control of hepatic glucose uptake and storage as glycogen. Small amounts of fructose-1-phosphate, in the presence of relatively high glucose levels, markedly stimulate glucokinase through a novel mechanism of regulation involving dissociation from a regulatory protein and translocation from the nucleus into the cytosol. Using this understanding of glucokinase regulation, a recent study demonstrated that very small amounts of fructose (infused into the duodenum) could increase hepatic glucose uptake and glycogen storage, and reduce peripheral glycemia and insulin levels in the dog. These results suggest that very small amounts of dietary fructose could be beneficial in type 2 diabetes.

In vitro digestibility and fermentability of levan and its hypocholesterolemic effects in rats

This study describes the in vitro digestibility and fermentability of high molecular weight (ca. 2,000,000) levan and its effect on the metabolism of lipids in growing rats fed cholesterol-free diets. Levan was synthesized from sucrose using bacterial levansucrase immobilized on a honeycomb-shaped ceramic support. Although body weight gain, weight of visceral organs, morphologic changes in the digestive tract, and the serum triacylglycerol and glucose concentrations were not affected by feeding levan diets for 4 weeks, a significant hypocholesterolemic effect was observed. Serum cholesterol level was decreased to 83% or 59% by feeding a 1% or 5% levan diet, respectively. The hypocholesterolemic effect was accompanied by a significant increase in fecal excretion of sterols and lipids. High molecular weight levan, though not hydrolyzed by the salivary amylases, was hydrolyzed by artificial gastric juice and was changed to a low molecular weight (ca. 4,000) levan with a small amount of fructose, but did not produce any fructooligosaccharides. Low molecular weight (ca. 6,000) levan was not hydrolyzed by either pancreatic juice or small intestinal enzymes. This suggests that, in vivo, low molecular weight levan derived from the high molecular weight material is not further digested and reaches the colon intact. The fermentation of low molecular weight levan (ca. 6,000) by several strains of bifidobacteria was not observed. These results showed that the hypocholesterolemic effect of levan may result from the prevention of intestinal sterol absorption, and not from the action of the fermentation products of levan.

Metabolism of fructose as an electron acceptor by Leuconostoc mesenteroides

The utilisation of fructose as an electron acceptor was studied in Leuconostoc mesenteroides NCIMB 8023 and Leuconostoc mesenteroides NCFB 811 under anaerobic conditions. Only small amounts of fructose as an electron acceptor were converted to mannitol. Both bacteria produced lactate, ethanol, acetate along with mannitol during the metabolism of fructose in the absence of oxygen. Fermentation of a mixture of glucose and fructose resulted in the production of the same metabolic end-products and small amounts of mannitol were formed. Small concentrations of acetate were also detected.

Factors influencing quantities of sugars and organic acids in blackcurrant concentrates

Use of endogenous non-volatile flavour components, i. e. sugars and organic acids, in fruit juice products is desirable. A study of 133 blackcurrant concentrates from three seasons examined variation in sugars and acids arising from storage of fruit at freezing or sub-ambient temperature, seasonal differences, geographical origin and choice of conventional thermal-evaporative or freeze concentration technology. Compared with freeze concentrates, conventional concentrates had significantly higher contents of total sugars and acids, notably malic acid, and higher fructose/glucose, lower malic/citric acid and similar sugar/acid ratios. Concentrates from frozen fruit generally had smaller amounts of fructose, total sugars and fructose/glucose ratios than those from fresh fruit, as well as less citric, ascorbic and total acids and lower sugar/acid ratios. Principal component analysis of 40 randomly chosen concentrates showed that variance is dominated by differences in fructose, total sugars and ascorbic acid contents and sugar/acid ratios. Geographical origin and concentration technology were major sources of variance but changes in post-production sub-ambient storage could not be excluded.

Is Exogenous Fructose Metabolism Truly Insulin Independent?

Although fructose is widely regarded as an insulin-independent fuel source, its in vivo conversion to glucose represents a theoretical limitation to its clinical usefulness in diabetics, particularly if given in large doses. To determine whether small amounts of fructose can be well utilized in the setting of insulinopenia, we administered a low-dose fructose infusion (4.2 g/hr) to a fasting type 1 diabetic patient receiving continuous subcutaneous insulin at a dose that had previously maintained stable euglycemia for 72 hr (plasma glucose = 80-110 mg/dl). Despite the low infusion rate (less than 20% of calorie requirement), fructose caused an immediate and marked rise in plasma glucose (to 370 mg/dl after 27 hr). Glucose loss in the urine and accumulation in plasma could account for fully half of the administered hexose load. Thus, the utilization of even small quantities of exogenous fructose is profoundly impaired under hypoinsulinemic conditions. It is misleading to regard fructose as a truly insulin-independent fuel source.

Action of levan fructotransferase of Arthrobacter ureafaciens on levan and phlein.

Levan fructotransferase of Arthrobacter ureafaciens was shown to degrade Bacillus mesentericus levan up to about 40 %, leaving the levan fragment at the limit of the enzymatic degradation, while it degraded Phleum pratense phlein more than 90 %, with the respective formation of 5 and 6 % reducing sugars as d-fructose. Each enzymatic digest of levan and phlein at the limit of degradation gave, in addition to the main spot of di-d-fructose 2,6′: 2′,6 dianhydride (difructose anhydride IV), two or three minor fructooligosaccharide spots on a thin-layer chromatogram. These minor oligosaccharides semi-quantitatively fractionated at the limit of degradation were found to be essentially different between levan and phlein, though small amounts of fructose and levanbiose were produced in both the digests.

Malabsorption of fructose-sorbitol mixtures. Interactions causing abdominal distress.

Hydrogen breath tests were performed on 10 healthy adults after they had ingested a mixture of sorbitol and fructose, in which these substances were present in amounts corresponding to the individual absorption capacities. A significant malabsorption of this mixture was evident in 7 of 10 subjects. The mixture caused mild to severe gastrointestinal distress in five subjects. When the carbohydrates were given separately, symptoms were absent. There was a significant correlation between the individual absorption capacities of fructose and of sorbitol. A mixture containing a similar amount of fructose, but given as sucrose, and a similar amount of sorbitol was further given to four of the seven subjects showing malabsorption of the fructose-sorbitol mixture. Malabsorption now failed to appear, and symptoms were absent. These findings are of potential importance for the understanding of the physiologic processes involved in fructose absorption and suggest that in healthy adults the presence of sorbitol interferes with fructose absorption and/or vice versa. An interaction between small amounts of fructose and sorbitol causing malabsorption and abdominal distress has not been demonstrated previously. Gastrointestinal discomfort must be suspected to occur in sensitive individuals at a rather limited daily intake of fructose- and sorbitol-containing foodstuffs.

Effect of time and amount of fruit thinning on leaf carbohydrates and fruit set in Valencia oranges

Starting in 1970, an “on” year for fruit set, young Valencia orange fruit were thinned in July, September, and November. Degrees of thinning were 0, 33, 66, and 100 per cent. Leaf samples were taken in 1971 for carbohydrate analysis. The fruiting cycle was almost completely reversed when all of the young fruit were removed in July. Less fruit removal or removal at a later date was progressively less effective. Thinning had no effect on the size of the fruit remaining on the tree. In the year after thinning, fruit size was inversely related to number of fruit on the tree. The amount of fall growth in 1970 was increased by fruit removal. Likewise, the spring growth in 1971 was earlier and more extensive on the trees that were 100 per cent thinned in July, 1970. Carbohydrates in the leaves were mainly starch, sucrose and one unidentified compound. Also present were small amounts of fructose, glucose, malic acid, myo-inositol, and one other unidentified soluble carbohydrate. There was a positive correlation between the fruit set in the spring of 1971 and the concentration of starch in the leaves before the beginning of 1971 spring growth. During the June drop period, there was an increase in leaf starch, but not in sugar, associated with an increase in degree of thinning. At the end of the June drop period, there were no significant differences in starch or sugar content. Data presented in this study indicate that carbohydrates, in the amounts present, were not limiting for fruit set.

Ensilage of whole‐crop barley. II.—Composition of barley and barley silage at different stages of growth

AbstractSamples of whole barley cv. Zephyr were cut at 7 stages of growth and after being chopped were ensiled in small laboratory silos. Changes in individual carbohydrates and organic acids during ensilage were studied. The water‐soluble carbohydrates, which rose to a maximum (32.6% of the dry matter) at the milky kernels stage of growth, consisted mainly of fructosans with smaller amounts of fructose, glucose and sucrose. The main organic acid of the plant, malic acid, disappeared during ensilage. The practical significance of the changes is discussed.

The urinary excretion of amino acids and sugars in early infancy

Summary The amino acids have been examined in 273 specimens of urine from 119 infants, aged from a few hours to 8 months. sixty of these specimens have been examined for sugars. In addition, six specimens of fetal urine have been examined for amino acids and sugars. The amino acids have been examined in twenty-four specimens of venous or capillary blood from these infants, and twelve specimens of blood from the umbilical cord. The plasma contained far more lysine,ethanolamine, β-amino-isobutyric acid and, in the case of cord blood, taurine than did that of older children. These amino compounds were also present in high concentration in urine passed at birth. The amounts excreted fell progressively thereafter but at different rates for the different amino compounds. From about the sixth day in fullterm infants, or the fourth week in premature infants, the urine contained high concentrations of proline and hydroxyproline, dropping to the very low levels normal for older children by the fifth to the seventh month. About a third of the specimens ofurine, particularly those from premature infants, contained more lysine and, often, more cystine than those from older children. Glucose was present in about onethirdof the specimens in concentrations slightly exceeding those found in older children. Fetal urine contained small amounts of fructose and glucose and, in one case, a sugar tentatively identified as mannose. The appearance in blood and urineof greater amounts of taurine, lysine, ethanolamine, β-amino-isobutyric acid and hydroxyproline than in the older child is considered to be due to quantitative or qualitative differences in the intermediary metabolism of these compounds. A less efficient renal tubular reabsorptionmechanism than in the older child is probably responsible for the increased excretion of proline and, in some cases, lysine and cystine; this lower efficiency is more marked and lasts longer in the premature than in the full-term infant. A low glomerular filtration rate during the first few days of life in the full-term infant, or first few weeks of life in the premature infant, is considered responsible for the relative absence of proline and hydroxyproline from the urine during this period.

Chemical composition of the cuticle of third stage nematode larvae

Summary Cuticles from third-stage larvae of Haemonchus contortus, Trichostrongylus spp., and Nippostrongylus muris were found to be soluble in boiling water, 0.2 N NaOH and 10% sodium hypochlorite. They contained proline, hydroxyproline, aspartic acid, cysteic acid, glutamic acid, alanine, leucine, glycine, and valine. Small amounts of fructose were probably present. The failure of pepsin and trypsin to digest the cuticles may be correlated with the absence of certain amino acids.