Glucoseand Fructose Research Articles

Non-enzymatic browning reaction of isomaltulose

Isomaltulose is a naturally occurring reducing disaccharide composed of glucose and fructose monomers. It is gaining interest as an alternative sweetener to sucrose in past years. It has been successfully used in various food products like chocolate, breakfast cereals, chewing gums, and dairy products especially, ice cream and yogurt. Nonenzymatic browning reactions in foods continue to be an active area of research because of their important roles in color, flavor and nutritional quality. The present study aimed to investigate the influence of different environmental factors on the non-enzymatic browning reaction of isomaltulose. The formation of colored products as a result of the non-enzymatic browning reaction was monitored. The most significant color change occurs in isomaltulose solution under the studied conditions (pH, temperature and amino component), which is a clear indication of a more intense course of the non-enzymatic browning reaction. The most intense staining was observed at pH 10, t = 80°C with the amino component glycine. It has been found that while glucose solutions are coloured more intensely in the presence of lysine, isomaltulose solutions are coloured more intensely in the presence of glycine. In addition to the type of amino component, the degree of staining is influenced by the pH value and the temperature. The results obtained showed that the use of isomaltulose in the composition of foods, that are subject to heat treatment, will affect the color formation of the final product.

스팀 및 동결 전처리가 건조 감잎 열수추출물의 이화학적 특성에 미치는 영향

This study was conducted to develop a preservation technology that can induce changes in physicochemical properties to effectively utilize of persimmon leaves. The application effects of steaming or freezing technique were investigated. Astringent persimmon leaves were steam-blanched (100°C, 30 sec) or frozen (−20°C, 15 d), followed by hot-air drying (50°C). The physicochemical properties of the extract obtained by hot-water leaching from the dried leaves were compared. The extract of leaves dried without pretreatment was used as a control. L* value was higher in steamed than in control and frozen. a* value was highest in the control. The browning index was higher in the frozen and lower in the steamed than in the control. Soluble solids were the highest in the steamed and the lowest in the frozen. Sucrose content was relatively high in the steamed, and the glucose and fructose contents were relatively high in the frozen. Total polyphenol content and DPPH radical scavenging activity were higher in steamed and lower in frozen than in control. Thus, it was confirmed that steam or freeze pretreatment after harvesting persimmon leaves affects the extraction yield, color, antioxidant capacity and component changes of dried persimmon leaves. Unlike steaming, freezing pretreatment showed the effect of promoting decomposition and browning reactions, and it is considered useful when such an effect is needed.

Long-Term Morpholino Oligomers in Hexose Elicit Long-Lasting Therapeutic Improvements in mdx Mice

Approval of antisense oligonucleotide eteplirsen highlights the promise of exon-skipping therapeutics for Duchenne muscular dystrophy patients. However, the limited efficacy of eteplirsen underscores the importance to improve systemic delivery and efficacy. Recently, we demonstrated that a glucose and fructose (GF) delivery formulation effectively potentiates phosphorodiamidate morpholino oligomer (PMO). Considering the clinical potential of GF, it is important to determine the long-term compatibility and efficacy with PMO in mdx mice prior to clinical translation. Here, we report that yearlong administration of a clinically applicable PMO dose (50 mg/kg/week for 3 weeks followed by 50 mg/kg/month for 11 months) with GF elicited sustainably high levels of dystrophin expression in mdx mice, with up to 45% of the normal level of dystrophin restored in most peripheral muscles without any detectable toxicity. Importantly, PMO-GF resulted in phenotypical rescue and mitochondrial biogenesis with functional improvement. Carbohydrate metabolites measurements revealed improved metabolic and energetic conditions after PMO-GF treatment in mdx mice without metabolic anomaly. Collectively, our study shows PMO-GF’s ability to elicit long-lasting therapeutic effects with tolerable toxicity and represents a new treatment modality for Duchenne muscular dystrophy, and provides guidelines for antisense oligonucleotides with GF in clinical use.

The effect of ethoxylated oleyl-cetyl alcohol on metabolism of some fungi and their potential application in mycoremediation

The effect of ethoxylated oleyl-cetyl alcohol at a concentration of 1% on the growth and metabolism of A. tenuis Nees and P. verrucosum Dierckx was examined in this paper. The fungal growth was investigated by monitoring the diameter of colonies on solid media and dry weight biomass in liquid media. A. tenuis had better response to applied pollutant in solid medium, whereas P. verrucosum had better response in liquid medium. During exponential fungal growth in liquid media with and without pollutant (control), the following physico-chemical and biochemical parameters were carried out: pH, quantity of free and total organic acids, proteins, carbohydrates, proteolytic activity. The ethoxylated oleyl-cetyl alcohol had influence on decrease in pH value and increase in free organic acids of both fungi. Furthermore, it has influenced production in way that lower amount of total organic acids, proteins, glucose and fructose were gained in fermentation broth of P. verrucosum compared to A. tenuis. The proteolityc activity of fungi was partially (A. tenuis) or fully inhibited (P. verrucosum) by presence of pollutant in liquid medium. Based on the obtained results, these fungal species act as potential candidates for mycoremediation of alcohol ethoxylated contaminated environments and biotechnology.

Selection of Yeast Strains for Ethanol Fermentation of Glucose-FructoseSucrose Mixture

This study was aimed to compare the ability of some yeast strains to consume sugars (sucrose, glucoseand fructose) and to convert them into ethanol during fermentation. The results of this comparison will be thebasis of considerations in choosing the right strain to be used as a mixed culture to increase the productionof ethanol from substrate containing a mixture of sucrose, glucose and fructose, such as juice of cane andsweet sorghum. The study was conducted using fermentation in substrate consisting of glucose, fructose,and sucrose separately, glucose-fructose mixture, and glucose-fructose-sucrose mixture using some yeaststrains: FNCC3012, OUT7009, OUT7027, OUT7055, OUT7080, OUT7096, OUT7903, OUT7913, and OUT7921.Following the fermentation, analysis of the produced ethanol and the remaining sugar was conducted. Theresults of study indicated that the strains with the highest substrate consumption were OUT7921, OUT7096,OUT7055, OUT7027, and OUT7913 for glucose, fructose, glucose-fructose mixture, sucrose, and glucosefructose-sucrose mixture, respectively. Strains that produced highest concentration ethanol were OUT7096 inglucose and sucrose substrates, OUT7921 in substrate of glucose-fructose mixture and sucrose, OUT7913 insubstrate of glucose-fructose-sucrose mixture. Upon consideration of each strain capacity, both in consumingsugar and producing ethanol, the recommended strains for use in mixed culture in bioethanol fermentationusing mixed substrate of glucose, fructose and sucrose are OUT7096, OUT7913, and OUT7921.

An Isocaloric Glucose-Fructose Beverage’s Effect on Simulated 100-km Cycling Performance Compared With a Glucose-Only Beverage

A number of recent research studies have demonstrated that providing glucose and fructose together in a beverage consumed during exercise results in significantly higher oxidation rates of exogenous carbohydrate (CHO) than consuming glucose alone. However, there is insufficient evidence to determine whether the increased exogenous CHO oxidation improves endurance performance. The purpose of this study was to determine whether consuming a beverage containing glucose and fructose (GF) would result in improved cycling performance compared with an isocaloric glucose-only beverage (G). Nine male competitive cyclists (32.6 +/- 5.8 years, peak oxygen uptake 61.5 +/- 7.9 ml x kg(-1) x min(-1)) completed a familiarization trial and then 2 simulated 100-km cycling time trials on an electronically braked Lode cycle ergometer separated by 5-7 d. During the randomly ordered experimental trials, participants received 36 g of CHO of either G or GF in 250 ml of water every 15 min. All 9 participants completed the 100-km time trial significantly faster when they received the GF beverage than with G (204.0 +/- 23.7 vs. 220.6 +/- 36.6 min; p = .023). There was no difference at any time point between trials for blood glucose or for blood lactate. Total CHO oxidation increased significantly from rest during exercise but was not statistically significant between the GF and G trials, although there was a trend for CHO oxidation to be higher with GF in the latter stages of the time trial. Consumption of a CHO beverage containing glucose and fructose results in improved 100-km cycling performance compared with an isocaloric glucose-only beverage.

Postexercise Muscle Glycogen Synthesis with Combined Glucose and Fructose Ingestion

To evaluate the efficacy of using combined glucose and fructose (GF) ingestion as a means to stimulate short-term (4 h) postexercise muscle glycogen synthesis compared to glucose only (G). On two separate occasions, six endurance-trained men performed an exhaustive glycogen-depleting exercise bout followed by a 4-h recovery period. Muscle biopsy samples were obtained from the vastus lateralis muscle at 0, 1, and 4 h after exercise. Subjects ingested carbohydrate solutions containing G (90 g x h(-1)) or GF (G = 60 g x h(-1); F = 30 g x h(-1)) commencing immediately after exercise and every 30 min thereafter. Immediate postexercise muscle glycogen concentrations were similar in both trials (G = 128 +/- 25 mmol x kg(-1) dry muscle (dm) vs GF = 112 +/- 16 mmol x kg(-1) dm; P > 0.05). Total glycogen storage during the 4-h recovery period was 176 +/- 33 and 155 +/- 31 mmol x kg(-1) dm for G and GF, respectively (G vs GF, P > 0.05). Hence, mean muscle glycogen synthesis rates during the 4-h recovery period did not differ between the two conditions (G = 44 +/- 8 mmol x kg(-1) dm x h(-1) vs GF = 39 +/- 8 mmol x kg(-1) dm x h(-1), P > 0.05). Plasma glucose and serum insulin responses during the recovery period were similar in both conditions, although plasma lactate concentrations were significantly elevated during GF compared to G (by approximately 0.8 mmol x L(-1), P < 0.05). Glucose and glucose/fructose (2:1 ratio) solutions, ingested at a rate of 90 g x h(-1), are equally effective at restoring muscle glycogen in exercised muscles during the recovery from exhaustive exercise.

A Glucose-Fructose Beverage Improves 100-km Cycling Performance Compared to a Glucose-only Carbohydrate Beverage

Ingesting carbohydrate during endurance exercise improves performance by maintaining blood glucose levels and high rates of carbohydrate oxidation. Recent research has demonstrated mixing glucose and fructose together in a beverage results in significantly higher exogenous carbohydrate oxidation rates compared to glucose alone. PURPOSE: To determine if a beverage containing glucose and fructose will improve cycling performance compared to a glucose-only beverage. METHODS: Nine male competitive cyclists (32.6 ± 5.8 yrs, peak oxygen uptake 61.5 ± 7.9 ml/kg/min) completed two simulated 100-km cycling time trials on a Lode cycle ergometer separated by at 5-7 days. The 100-km trials contained four 1-km sprints at 10, 32, 52 and 72 km and four 4-km sprints at 20, 40, 60 and 80 km. Subjects were encouraged to complete the entire distance and each individual sprint as quickly as possible. During the trials, subjects received 36 grams of carbohydrate containing isocaloric amounts of glucose (G) or glucose and fructose (GF) in 250 mL of water every 15 minutes. Blood samples were analyzed for glucose and lactate before, every 30 minutes during, and immediately following each trial. Total CHO oxidation was estimated using indirect calorimetry and was measured before and every 30 minutes of the time trial. RESULTS: All nine subjects completed the 100-km time trial faster when they received the GF beverage compared to G (204 ± 23.7 vs. 220.58 ± 36.6 min; p < 0.05). Individual sprint performances were not significantly different between beverages. There was no significant difference at any time point for blood glucose or for blood lactate. Total CHO oxidation increased significantly during exercise but was not statistically significant between GF and G, although there was a trend in the latter stages of the time trial. CONCLUSIONS: Consumption of a carbohydrate beverage containing glucose and fructose results in improved 100-km cycling performance compared to an isocaloric glucose-only beverage.

Superior Endurance Performance with Ingestion of Multiple Transportable Carbohydrates

The aim of the present study was to investigate the effect of ingesting a glucose plus fructose drink compared with a glucose-only drink (both delivering carbohydrate at a rate of 1.8 g.min(-1)) and a water placebo on endurance performance. Eight male trained cyclists were recruited (age 32 +/- 7 yr, weight 84.4 +/- 6.9 kg, .VO(2max) 64.7 +/- 3.9 mL.kg(-1).min(-1), Wmax 364 +/- 31 W). Subjects ingested either a water placebo (P), a glucose (G)-only beverage (1.8 g.min(-1)), or a glucose and fructose (GF) beverage in a 2:1 ratio (1.8 g.min(-1)) during 120 min of cycling exercise at 55% Wmax followed by a time trial in which subjects had to complete a set amount of work as quickly as possible (approximately 1 h). Every 15 min, expired gases were analyzed and blood samples were collected. Ingestion of GF resulted in an 8% quicker time to completion during the time trial (4022 s) compared with G (3641 s) and a 19% improvement compared with W (3367 s). Total carbohydrate (CHO) oxidation was not different between GF (2.54 +/- 0.25 g.min(-1)) and G (2.50 g.min(-1)), suggesting that GF led to a sparing of endogenous CHO stores, because GF has been shown to have a greater exogenous CHO oxidation than G. Ingestion of GF led to an 8% improvement in cycling time-trial performance compared with ingestion of G.

Changes in soluble carbohydrates during phytochrome-regulated petiole elongation in watermelon seedlings

Changes in soluble carbohydrate composition and concentration in leavesand petioles of watermelon (Citrullus lanatus (Thunb)Matsum and Nakai cv. Sugar Baby) seedlings during early stages ofphytochrome-regulated petiole elongation were investigated. Watermelon seedlingswere grown in a controlled environment with 350 μmolm−2 s−1 photosynthetically activeradiation (PAR) during a 12-h photoperiod. Low intensity end-of-day(EOD) light treatments (for 15 min) of red (R), far-red (FR) and FRfollowed by R (FR/R) were initiated when the seedlings were 14 days old.Seedling growth, and soluble carbohydrate concentration and composition inleaves and petioles were determined after 3 and 6 days of EOD light treatments.The EOD FR increased the petiole length and dry mass partitioned to petioles asearly as 3 days into the treatment. This increased petiole dry mass inFR-treated plants was accompanied with an increase in reducing sugar (glucoseand fructose) concentration in the petioles. Although both leaves and petiolesshowed this effect, the relative increase was greater in petioles than leaves.While the most abundant sugars in petioles were fructose and glucose, thepredominant sugars in leaves were sucrose, raffinose, and stachyose. Thephotoreversion of FR induced changes in growth and sugar concentrations by Rindicates the involvement of phytochrome in these processes.

Effect of abscisic acid (ABA) on sugar accumulation in the flesh tissue of peach fruit at the start of the maturation stage

Experiments were conducted on14C-sorbitol, fructose, and glucose uptakeinto flesh discs, and sorbitol efflux from thediscs, with and without ABA application toexamine the effect of abscisic acid (ABA) onsugar accumulation in peach fruit flesh at thestart of the maturation stage in relation tomembrane transport. Total uptake of14C-sorbitol, fructose, and glucose intoflesh discs was effectively promoted by ABA ata concentration of 10−5M. PCMBS(p-chloromercuribenzensulfonicacid)-sensitive uptake, which was considered ascarrier-mediated uptake, of sorbitol into thediscs was clearly stimulated by ABA at10−5M, compared with glucose andfructose uptake. Sorbitol efflux from the discsacross the tonoplast was restricted by ABA at10−5M. ABA application todeveloping fruit increased sugar accumulationin the fruit. Estimated ABA concentration inthis fruit was approximately 10−5M. These results indicate that sugar accumulationin peach fruit flesh is stimulated by ABA at aconcentration of 10−5M both invitro and in vivo. ABA stimulatesuptake of sugars, especially sorbitol, into theflesh by enhancing carrier-mediated transportpossibly across both tonoplast and plasmamembrane.

メロン果実における糖の組織内コンパートメンテーションとアブシジン酸による糖の果肉組織からの流出の抑制

Using the compartmental analysis method, the distribution of sucrose, glucose, and fructose and their efflux from the free space, cytoplasm, and vacuole were determined in melon (Cucumis melo L. cv. Prince) fruits picked 14 days after pollination (DAP), 28 DAP and 42 DAP.1. At all stages, the greatest percentage of total sugar was accumulated in the vacuole. The main sugars accumulated in melon early and late in the season were fructose and sucrose, respectively. Concentration of sugar in the free space increased from 44 mM at 14 DAP to 103 mM at 42 DAP, while that within the cell (cytoplasm+vacuole) increased slightly from 234 mM to 279 mM.2. Permeability of the plasma membrane to sucrose, glucoseand fructose was higher than that of the tonoplast and increased with fruit maturation. 3. CCCP restricted the release of sugar by reducing the rate of efflux across the plasma membrane and tonoplast while PCMBS restricted the release of sugar by reducing efflux across the plasma membrane.4. S-ABA of 10-5 M as compared to 10-4 M restricted the release of sugar from fruit discs; restriction was due to a reduction in the velocity constant of efflux of sugar across the plasma membrane. Thus, S-ABA may stimulate the accumulation of sugar in fruit flesh.

Mechanism of alkaline degradation of sucrose. A study of some model compounds

Alkaline degradation of sucrose proceeds by a slow first stage to yield reactive intermediates (perhaps glucose and fructose) which degrade rapidly to acids (predominantly lactic acid). In an attempt to determine the mechanism of the first stage of the reaction, the rates of alkaline degradation of sucrose and some model compounds have been determined unequivocally by measuring their rates of disappearance by paper or gas chromatography. Selective blocking of hydroxyl groups in sucrose by methylation, indicates that the alkaline degradation probably involves free hydroxyl groups (presumably via the derived anions) on both glucose and fructose components of sucrose. It is unlikely that the hydroxyls at C 6 of the glucose moiety or C 1? of the fructose moiety are involved.

Further Studies on the Effect of Amino Acid Supplementation on the Urinary Nitrogen Compounds in Rats Fed a Low-casein Diet

When 8% casein basal diet was supplemented with 0.3% dl-methionine or 0.3% dl-methionine plus 0.36% dl- or 0.18% l-threonine, the changes in urinary excretions of urea and allantoin were examined in weanling male rats of Wistar strain with the observations on the body weight gain and % nitrogen retention. Carbohydrate sources used were sucrose or an equimolar mixture of glucose and fructose (G-F) in place of pregelatinized starch used in the previous experiments.In contrast to the previous results, differences in nitrogen utilization, expressed in term of growth rate or % nitrogen retention, became significant by the addition of 0.3% methionine to the basal diet and it was further increased by the simultaneous supplementation with 0.36% dl- or 0.18% l-threonine.Urea excretion was the main variable in total urinary nitrogen output to cause the significant difference in % nitrogen retention between the groups. As postulated in the previous paper, thus, the use of sucrose or G-F mixture considerably exaggera...