Availability, fermentability, and energy value of resistant maltodextrin: modeling of short-term indirect calorimetric measurements in healthy adults

Is Fibersol-2 efficacious in reducing duration of watery diarrhea and stool output in children 1-3 years old? A randomized, parallel, double-blinded, placebo-controlled, two arm clinical trial

BACKGROUND

Fibersol-2 has innumerable beneficial effects on human health. It is a fermentable, non-viscous, water-soluble, indigestible dextrin containing 90% dietary fiber produced from corn starch. We aimed to evaluate whether additional intake of Fibersol-2 along with oral rehydration solution treatment can reduce the duration of watery diarrhea and daily stool output in children 1-3 years as well as recovery of such children within 72 hours, compared to placebo.

METHODS

This placebo-controlled double-blinded, randomized parallel two arm trial conducted in Kumudini Women's Medical College Hospital in rural Bangladesh between March and October, 2018 used 5 gm of either Fibersol-2 or placebo dissolved in 50-ml drinking water which was given orally to ninety-two children with watery diarrhea on enrollment twice daily for a period of 7 days. Randomization was done using a randomization table. We randomly allocated 45 (49%) and 47 (51%) children in Fibersol-2 and placebo groups, respectively. Outcome measures were duration of resolution of watery diarrhea, daily stool output and the proportion of children recovered within 72 hours. Primary and safety analyses were by intention to treat. This trial was registered at ClinicalTrials.gov, number NCT03565393.

RESULTS

There was no significant difference observed in terms of duration of resolution of diarrhea (adjusted mean difference 8.20, 95% CI -2.74 to 19.15, p = 0.14, adjusted effect size 0.03); the daily stool output (adjusted mean difference 73.57, 95% CI -94.17 to 241.32, p = 0.38, adjusted effect size 0.33) and the proportion of children recovered within 72 hours (adjusted odds ratio 0.49, 95% CI = 0.12 to 1.96, p = 0.31, adjusted risk difference -0.06 (95% CI -0.19 to -0.06), after regression analysis between Fibersol-2 and placebo.

CONCLUSION

No beneficial role of Fibersol-2 was observed in diarrheal children aged 1-3 years.

TRIAL REGISTRATION

This trial is registered at ClinicalTrials.gov, number NCT03565393. The authors confirmed that all ongoing and related trials for this drug/intervention are registered. https://clinicaltrials.gov/ct2/show/NCT03565393.

Digestive tolerability and acceptability of Fibersol-2 in healthy and diarrheal children 1–3 years old at a rural facility, Bangladesh: Results from a four arm exploratory study

Background

Fibersol-2 has some beneficial effects on human health. We aimed to evaluate the digestive tolerability and acceptability of Fibersol-2 in healthy and diarrheal children, as well as improvement in stool consistencies in young diarrheal children.

Methods

Sixty children of either sex, aged 1–3 years having four groups (healthy children/low dose, healthy children/high dose, children with diarrhea/low dose and children with diarrhea/high dose) were enrolled into this exploratory study between 1st August to 23rd October 2017. Two presumptive doses, low (2.5g) and high (5g), twice daily with 50 ml drinking water for seven days were the interventions. Outcomes were to observe the development of possible abdominal symptoms, such as pain, distension, rumbling, and bloating during the intervention and post-intervention periods in healthy and diarrheal children as well as improvement in stool consistencies in diarrheal children.

Results

Among the diarrheal children, the median (IQR) duration of resolution of diarrhea was 3.9 (2.9, 5.1) days vs. 3.5 (2.0, 8.0) days, p = 0.885; in low dose and high dose groups, respectively. Significant difference was observed in terms of abdominal pain (27% vs. 7%, p = 0.038) and distension (40% vs. 0%, p<0.001) in diarrheal children, compared to healthy children during the pre-intervention period. We also observed significant difference in respect of abdominal distension (23% vs. 0%, p = 0.011), rumbling (27% vs. 0%, p = 0.005) and bloating (43% vs. 3%, p = 0.001) in diarrheal children, compared to healthy children during the intervention period. However, no significant difference was observed in relation to abdominal pain (p = 0.347) and distension (p = 0.165) during the pre-intervention period, compared to the intervention period in diarrheal children. Moreover, no significant difference was observed during the post-intervention period for the diarrheal and healthy children.

Conclusion

Fibersol-2 was found to be well tolerated in healthy and diarrheal children aged 1–3 years.

Trial registration

This study was registered as part of a randomized trial at ClinicalTrials.gov, number NCT03565393. The authors confirmed that all ongoing and related trials for this drug/intervention were registered.

Tapioca Resistant Maltodextrin as a Carbohydrate Source of Oral Nutrition Supplement (ONS) on Metabolic Indicators: A Clinical Trial

Tapioca resistant maltodextrin (TRM) is a novel non-viscous soluble resistant starch that can be utilized in oral nutrition supplements (ONS). This study aims to evaluate acute and long-term metabolic responses and the safe use of ONS containing TRM. This study comprised of two phases: In Phase I, a randomized-cross over control study involving 17 healthy adults was conducted to evaluate three ONS formulations: original (tapioca maltodextrin), TRM15 (15% TRM replacement), and TRM30 (30% TRM replacement). Plasma glucose, serum insulin, and subjective appetite were evaluated postprandially over 180 min. In Phase II, 22 participants consumed one serving/day of ONS for 12 weeks. Blood glucose, insulin, lipid profile, and body composition were evaluated. Gastrointestinal tolerability was evaluated in both the acute and long-term period. During phase I, TRM30 decreased in area under the curve of serum insulin by 33.12%, compared to the original formula (2320.71 ± 570.76 uIU × min/mL vs. 3470.12 ± 531.87 uIU × min/mL, p = 0.043). In Phase II, 12-week TRM30 supplementation decreased HbA1C in participants (from 5.5 ± 0.07% to 5.2 ± 0.07%, p < 0.001), without any significant effect on fasting glucose, insulin, lipid profile, and body composition. The ONS was well-tolerated in both studies. TRM is therefore, a beneficial functional fiber for various food industries.

Attenuation of glycaemic and insulin responses following tapioca resistant maltodextrin consumption in healthy subjects: a randomised cross-over controlled trial

Resistant maltodextrin (RMD) from various sources of starch has been extensively studied. However, studies which reported the effects of tapioca RMD (TRM) on glucose and insulin response are lacking. This study investigated the effect of TRM on postprandial plasma glucose and serum insulin in healthy subjects. Additionally, satiety and gastrointestinal tolerability were also evaluated. Sixteen healthy participants received five different treatments on five separate days. Participants received 50 g of either: glucose (GL), tapioca maltodextrin (TM), TRM, MIX15% (7⋅5 g TRM + 42⋅5 g TM) or MIX50% (25 g TRM + 25 g TM). Plasma glucose, serum insulin and subjective appetite responses were measured postprandially over 180 min. Gastrointestinal symptoms were evaluated by questionnaire before and after each test day. Results showed that at 30 min after treatment drinks, plasma glucose after TRM was significantly lowest (104⋅60 (sem 2⋅63 mg/dl) than after GL (135⋅87 (sem 4⋅88) mg/dl; P <0⋅001), TM (127⋅93 (sem 4⋅05) mg/dl; P = 0⋅001), MIX15% (124⋅67 (sem 5⋅73) mg/dl; P = 0⋅039) and MIX50% (129⋅33 (sem 5⋅23) mg/dl; P = 0⋅003) (1 mg/dl = 0⋅0555 mmol/l). In addition, TRM also significantly reduced serum insulin (13⋅01 (sem 2⋅12) μIU/ml) compared with GL (47⋅90 (sem 11⋅93) μIU/ml; P = 0⋅013), TM (52⋅96 (sem 17⋅68) μIU/ml; P = 0⋅002) and MIX50% (33⋅16 (sem 4⋅99) μIU/ml; P = 0⋅008). However, there were no significant differences in subjective appetite between treatments (P > 0⋅05). A single high dose of TRM (50 g) caused flatulence (P < 0⋅05). Tapioca resistant maltodextrin has low digestibility in the small intestine and, therefore, reduced incremental plasma glucose and serum insulin, without affecting satiety in healthy subjects over 180 min. Gastrointestinal tolerability of TRM should be considered when consumed in high doses.

A Randomized, Double-Blind, Crossover Study to Determine the Available Energy from Soluble Fiber

OBJECTIVE

Determining the available energy (caloric value) of dietary non-digestible fibers that are fermented to varying degrees by intestinal microbes and metabolized to short chain fatty acids is important for provision of accurate information to food and beverage manufacturers for reformulation and labeling purposes. The objective of this human study was to determine the available energy of soluble fiber products by measuring post consumption breath hydrogen, with inulin as a control.

METHODS

PROMITOR^® Soluble Corn Fiber 70 (SCF70) and PROMITOR^® Soluble Corn Fiber 85B (SCF85B) are Tate & Lyle dietary fiber products with 70% and 85% fiber, respectively. The fiber portion of these products is structurally representative of the fiber portion of all PROMITOR^® SCF products. The study conducted was a randomized, double-blind, crossover design. Breath hydrogen was quantified following consumption of beverages consisting of 8 oz. of water and: inulin (control), SCF70, or SCF85B at 5, 10, or 15 g (total ingredient weight, "as is"). Subjects were generally healthy men and women (N = 19), age 18 to 34 years, with body mass index (BMI) 19.3 to 24.8 kg/m². The primary outcome was incremental area under the curve over 10 h (iAUC0-10 h) for inulin, SCF70, and SCF85B at each dose. The available energy (kcal/g ingredient and kcal/g fiber) from SCF70 and SCF85B at each dose was then calculated using inulin as the reference.

RESULTS

Results demonstrated that breath hydrogen production was significantly lower following consumption of SCF70 and SCF85B compared to inulin at all consumption amounts. There were no significant differences in breath hydrogen production following consumption of SCF70 compared to SCF85B.

CONCLUSION

The available energy per gram of fiber was not significantly different between the SCF70 and SCF85B PROMITOR^® products. The available energy of the fiber portion of PROMITOR^® SCF products was determined to be 0.2 kcal/gram.

Effect of dietary graded resistant potato starch levels on growth performance, plasma cytokines concentration, and intestinal health in meat ducks

The objective of the present study was to investigate the effect of dietary graded raw potato starch (RPS) levels on growth performance, plasma cytokines concentration, ileal barrier function, and cecal short-chain fatty acids (SCFA) concentration in meat ducks from 1 to 35 D of age. This study included 2 experiments. In experiment (Exp.) 1, sixteen 35-day-old meat ducks were used to evaluate the AME of RPS by orogastric administration. Results showed the AME value of RPS on ducks is 2.76 kcal/g. In Exp. 2, a total of 600 one-day-old ducklings were randomly assigned to 5 isonitrogenous and isoenergetic dietary treatments that included 0 (control), 6, 12, 18, and 24% RPS, respectively. Samples were collected at both of 14 and 35 D. Neither growth performance nor ileal parameters (length, weight, and pH) at both of 14 and 35 D was affected by dietary RPS. However, the mucosal thickness (14 D), villus height (except for 18% RPS at 14 D), and the villus height: crypt depth ratio (14 and 35 D) of the ileum were increased in the 12 and 18% RPS diets when compared to 0% RPS diet. Meanwhile, proinflammatory factors such as plasma interleukin (IL)-1β and IL-6 (14 D) reduced in 12% RPS diet and tumor necrosis factor α decreased in 12% (except for 14 D) and 18% RPS groups. When compared with the control group, diets with 18% RPS significantly increased mucin 2 gene expression at 14 D, and 12% RPS elevated the mRNA expression of tight junction proteins including Zonula occludens-1 and Claudin 1 (except for 14 D) in the ileal mucosa of birds. Furthermore, ducks fed 12% RPS diet had higher concentrations of acetate, propionate, and butyrate in cecal digesta than other groups. These findings indicated that diets with 12 and/or 18% RPS increased the cecal SCFA concentration, which subsequently enhanced the barrier function and improved intestinal health in the ileum for 14 and 35-day-old meat ducks.

Resistant Maltodextrin and Metabolic Syndrome: A Review

Resistant maltodextrin is a non-viscous dietary fiber that is fermentable in the colon by colonic bacteria. The objective of this review is to summarize the studies of resistant maltodextrin and its effect on metabolic profile, such as blood glucose, lipid profile, and body weight. Several studies support the idea that resistant maltodextrin may improve blood glucose, insulin sensitivity, lipid profile, and obesity. However, the use of resistant maltodextrin should be limited to minimize the adverse effect on the gastrointestinal system. This review provides information regarding the benefits of resistant maltodextrin on metabolic health as well as its proposed mechanism to enhance the knowledge of this novel fiber. Key teaching points Resistant maltodextrin is a novel non-viscous dietary fiber classified as resistant starch type V that is produced by debranching of the starch structure. Resistant maltodextrin is fermentable in the colon and thus produces short-chain fatty acid. Resistant maltodextrin helps to maintain blood and lipid profiles as well as promote satiety and reducing food intake. High intake of resistant maltodextrin may cause gastrointestinal discomfort due to the gas production and increased osmotic pressure.

Effects of resistant maltodextrin on bowel movements: a systematic review and meta-analysis

It is well known that dietary fiber helps to relieve and prevent constipation, and there are a number of scientific papers, including systematic reviews and meta-analyses on the effects of naturally derived dietary fiber on bowel movements. In recent years, there has been an increase in the manufacture of dietary fiber ingredients obtained from food raw materials, and these are now commonly available in the market. Resistant maltodextrin (RMD), a soluble dietary fiber, is manufactured from starch, and industrially produced soluble dietary fiber is used worldwide. While there are many reports on the effects of RMD on bowel movements, no systematic review or meta-analysis has been reported. We conducted a systematic review and meta-analysis to clarify the effect of RMD on bowel movements based on stool frequency and stool volume. We also investigated the subjective evaluation of RMD effects on bowel movements. Of a total of 314 potentially relevant articles, 28 articles met the eligibility criteria, and 29 randomized controlled trials were identified. As a result of integration analyses, we found that the intake of RMD significantly increased stool volume and stool frequency compared with placebo intake. Furthermore, RMD intake tended to improve sensation of complete/incomplete evacuation. In conclusion, the evidence suggests that RMD has a positive effect on bowel movements, contributing to normal bowel function. This finding will help in the development of new criteria for choice of dietary fiber in the process of developing food products.

Effects of different heat–moisture treatments on the physicochemical properties of brown rice flour

We evaluated the effect of heat–moisture treatment (HMT) on the main chemical components, physical properties, and enzyme activities of two types of brown rice flour: high-amylose Koshinokaori and normal-quality Koshiibuki. Five different HMTs using brown rice (moisture content was 12.0%) were assessed: 0.1 MPa/120 °C for 5 or 10 min, 0.2 MPa/134 °C for 5 or 10 min and 0.3 MPa/144 °C for 10 min. HMT, decreased the α-amylase and lipase activities, and fat acidity, and slightly increased the dietary fiber and resistant starch levels. After 2 months’ storage at 35 °C, rice samples that were treated with 0.2 MPa/134 °C or 0.3 MPa/144 °C for 10 min had a lower fat acidity than untreated samples, which would be useful for long-term storage and export of rice flour. And HMT exhibited inhibition of retrogradation in the pasting and physical properties, which is profitable to promote the qualities of the rice products.

Digestion-resistant maltodextrin effects on colonic transit time and stool weight: a randomized controlled clinical study

PURPOSE

Increased awareness of the importance of dietary fibre has led to increased interest in "functional" fibre components like digestion-resistant maltodextrin (RMD). This randomized, placebo-controlled, double-blind study assessed the effects of RMD in the colonic transit time (CTT) and defecation characteristics (frequency, stool volume and consistency).

METHODS

Sixty-six healthy adult volunteers (32 men) who did not have a daily defecation habit had a 7-day run-in period before the 21-day intervention period with RMD or placebo. CTT and segmental CTT (SCTT) were assessed by a single abdominal X-ray film taken at the end of both periods after radiopaque marker ingestion. Defecation characteristics and intestinal functions were also assessed, which were self-reported by patients. Intragroup comparisons were evaluated by Student's paired t test, Bonferroni test and Chi-square test, while time comparisons by analysis of variance (ANOVA) and time-by-treatment interaction by repeated-measures ANOVA.

RESULTS

Fifty-seven subjects were assessed for CTT (placebo, n = 28; RMD, n = 29). In the RMD group, the total CTT, left SCTT and rectosigmoidal SCTT decreased significantly compared to baseline (p < 0.01 each; -13.3, -4.7, -8.7 h, respectively). Significant differences between groups were observed in total CTT and left SCTT. Significant time-by-treatment interaction was observed in the RMD group for stool volume (p = 0.014), increasing 56 % compared to baseline (p < 0.01), while remained unchanged in the placebo group. Stool consistency was improved only in the RMD group (p < 0.01). No adverse effects related to study products were observed.

CONCLUSIONS

The results show that RMD improved CTT, stool volume, stool consistency and some intestinal functions in a healthy population.

Metabolism and bioavailability of newly developed dietary fiber materials, resistant glucan and hydrogenated resistant glucan, in rats and humans

Background

Resistant glucan (RG) and hydrogenated resistant glucan (HRG) are new dietary fiber materials developed to decrease the risk of metabolic syndrome and lifestyle-related diseases. We investigated the metabolism and bioavailability of RG and HRG using rats and humans.

Methods

Purified RG and HRG were used as test substances. After 25 Wistar male rats (270 g) were fed with an experimental diet (AIN93M diet with the cellulose replaced by β-corn starch) ad libitum for 1 week, they were used for the experiment involving blood collection and circulating air collection. Ten participants (5 males, 22.5 y, BMI 20.4 kg/m²; 5 females, 25.8 y, BMI 20.9 kg/m²) voluntarily participated in this study. The study was carried out using a within-subject, repeated measures design. Effects of RG and HRG on the response for blood glucose and insulin and hydrogen excretion were compared with those of glucose and a typical nondigestible and fermentable fructooligosaccharide (FOS) in rats and humans. Available energy was evaluated using the fermentability based on breath hydrogen excretion.

Results

When purified RG or HRG (400 mg) was administered orally to rats, blood glucose and insulin increased slightly, but less than when glucose was administration (P < 0.05). Hydrogen started to be excreted 120 min after administration of RG with negligibly small peak at 180 min, thereafter excreted scarcely until 1440 min. Hydrogen excretion after HRG administration showed a larger peak than RG at 180 min, but was markedly less than FOS. RG and HRG were excreted in feces, but not urine. When purified RG or HRG (30 g) were ingested by healthy humans, blood glucose and insulin levels increased scarcely. Breath hydrogen excretion increased slightly, but remarkably less than FOS. Ingestion of purified RG or HRG (5 g) to evaluate available energy, increased scarcely glucose and insulin levels and breath hydrogen excretion. Available energy was evaluated as 0 kcal/g for purified RG and 1 kcal/g for HRG.

Conclusion

The bioavailability was very low in both humans and rats, because oligosaccharide of minor component in purified RG and HRG was metabolized via intestinal microbes but major components with higher molecular weight were metabolized scarcely. Moreover, the ingestion of 30 g of RG or HRG did not induce apparent acute side effects in healthy adults. RG and HRG might potentially be used as new dietary fiber materials with low energy.

The metabolizable energy of dietary resistant maltodextrin is variable and alters fecal microbiota composition in adult men

Resistant maltodextrin (RM) is a novel soluble, nonviscous dietary fiber. Its metabolizable energy (ME) and net energy (NE) values derived from nutrient balance studies are unknown, as is the effect of RM on fecal microbiota. A randomized, placebo-controlled, double-blind crossover study was conducted (n = 14 men) to determine the ME and NE of RM and its influence on fecal excretion of macronutrients and microbiota. Participants were assigned to a sequence consisting of 3 treatment periods [24 d each: 0 g/d RM + 50 g/d maltodextrin and 2 amounts of dietary RM (25 g/d RM + 25 g of maltodextrin/d and 50 g/d RM + 0 g/d maltodextrin)] and were provided all the foods they were to consume to maintain their body weight. After an adaptation period, excreta were collected during a 7-d period. After the collection period, 24-h energy expenditure was measured. Fluorescence in situ hybridization, quantitative polymerase chain reaction, and 454 titanium technology-based 16S rRNA sequencing were used to analyze fecal microbiota composition. Fecal amounts of energy (544, 662, 737 kJ/d), nitrogen (1.5, 1.8, 2.1 g/d), RM (0.3, 0.6, 1.2 g/d), and total carbohydrate (11.1, 14.2, 16.2 g/d) increased with increasing dose (0, 25, 50 g) of RM (P < 0.0001). Fat excretion did not differ among treatments. The ME value of RM was 8.2 and 10.4 kJ/g, and the NE value of RM was -8.2 and 2.0 kJ/g for the 25 and 50 g/d RM doses, respectively. Both doses of RM increased fecal wet weight (118, 148, 161 g/d; P < 0.0001) and fecal dry weight (26.5, 32.0, 35.8 g/d; P < 0.0001) compared with the maltodextrin placebo. Total counts of fecal bacteria increased by 12% for the 25 g/d RM dose (P = 0.17) and 18% for the 50 g/d RM dose (P = 0.019). RM intake was associated with statistically significant increases (P < 0.001) in various operational taxonomic units matching closest to ruminococcus, eubacterium, lachnospiraceae, bacteroides, holdemania, and faecalibacterium, implicating RM in their growth in the gut. Our findings provide empirical data important for food labeling regulations related to the energy value of RM and suggest that RM increases fecal bulk by enhancing the excretion of nitrogen and carbohydrate and the growth of specific microbial populations.

Comparison of two different in vivo models and an in vitro model for caloric determination of four novel fiber ingredients

The objective of this study was to compare two in vivo methods using pigs and roosters and an in vitro method for determining the caloric value of four fiber sources [i.e., two resistant starches (RS 60 and RS 75), soluble corn fiber (SCF 70), and pullulan]. Metabolizable energy (ME) in pigs and true metabolizable energy (TMEn) in roosters were determined by using 72 barrows and 24 roosters, respectively. A two-step in vitro procedure was used to quantify monosaccharides released. Results of the two in vivo experiments corresponded well with RS 75 having the least caloric value (7.55 MJ/kg in pigs; 6.19 MJ/kg in roosters) and pullulan having the greatest caloric value (12.21 MJ/kg in pigs; 13.94 MJ/kg in roosters). The caloric values for all the fiber ingredients were less (P < 0.05) than in MD both in pigs and in roosters. Despite some limitations, results of the in vitro procedure corresponded well with the in vivo experiments where the concentration of glucose hydrolyzed from RS 60, RS 75, and SCF 70, but not pullulan, was less (P < 0.05) than the concentration of glucose hydrolyzed from MD. However, the greatest accuracy was obtained in the in vivo experiments.

Energy value evaluation of hydrogenated resistant maltodextrin

Hydrogenated resistant maltodextrin (H-RMD) is a dietary fiber whose energy value has not previously been reported. We evaluated the energy value of H-RMD. We conducted an in vitro digestion test, in vivo blood glucose measurement after ingestion, in vitro fermentability test, excretion test by rats and indirect calorimetry combined with breath hydrogen measurement for humans. H-RMD was hydrolyzed in vitro in a very small amount by human salivary amylase and by the rat small intestinal mucosal enzyme. Ingestion of H-RMD did not increase the blood glucose level of human subjects. An examination of in vitro fermentability suggested that H-RMD was fermented by several enterobacteria. Oral administration of H-RMD showed a saccharide excretion ratio of 42% by rats. A combination of indirect calorimetry and breath hydrogen measurement evaluated the metabolizable energy of H-RMD as 1.1 kcal/g in humans. We concluded from these results that H-RMD was not digested or absorbed in the upper gastrointestinal tract and was fermented in the colon to produce short-chain fatty acids which provided a lower amount of energy than that of resistant maltodextrin.

Characteristics of pregelatinized ae mutant rice flours prepared by boiling after preroasting

As ae mutant rice, such as EM10, lacks the starch branching enzyme IIb, its amylopectin contains more long-chain glucans than that of ordinary Indica and Japonica rice grains. Although boiled grains of ae rice cultivars are too hard and nonsticky for table rice, they are promising in terms of biofunctionality, such as prevention of diabetes. The present paper investigates the characterization of a novel group of four ae mutant rice cultivars (EM72, EM145, EM174, and EM189). They were subjected to the evaluation for their main chemical components, physical properties, and enzyme activities at different grain conditions (raw milled rice, roasted rice, boiled rice, and rice boiled after preroasting). These mutant rice grains are characterized by high apparent amylose, high protein and high glucose contents, high pasting temperature, high α-amylase activities, high resistant starch, and low degree of gelatinization. A novel method was developed to maintain the high resistant starch contents of gelatinized rice grains. Rice boild after preroasting showed a higher ratio of resistant starch and a lower amount of glucose than ordinary boiled rice. It became possible to produce high-quality and biofunctional pregelatinized rice flours by boiling with frozen fruits, such as tomatoes, after rice grains had been preroasted. These ae mutants were found to be suitable materials for rice/fruit or rice/vegetable products to serve as palatable, low-glucose, and high resistant starch rice products.

Soluble fiber dextrins and pullulans vary in extent of hydrolytic digestion in vitro and in energy value and attenuate glycemic and insulinemic responses in dogs

The objective of this research was to measure in vitro hydrolytic digestion characteristics, glycemic and insulinemic responses, and true metabolizable energy (TMEn) content of select soluble fiber dextrins (SFDs) and pullulans. The SFDs were derived either from tapioca starch or from corn starch. The pullulans were of low, intermediate, and high molecular weight. Soluble fiber dextrins varied in digestibility, with all substrates resulting in low to intermediate in vitro monosaccharide digestion. Pullulans were nearly completely hydrolyzed after simulated hydrolytic digestion. The glycemic response with dogs varied widely among SFDs, with all but one SFD substrate having lower glycemic response than maltodextrin (Malt). The pullulans all resulted in low glycemic values. Lower relative insulinemic responses (RIR) compared to the Malt control were noted for all SFDs and pullulans. True metabolizable energy (TMEn) values for SFDs obtained using roosters were lower than for Malt, with tapioca-based SFDs having numerically higher values than corn-based SFDs. Pullulans resulted in higher TMEn values than did SFDs. Soluble fiber dextrins and pullulans may be suitable candidates for reduced calorie and glycemic foodstuffs.

Failure of d-psicose absorbed in the small intestine to metabolize into energy and its low large intestinal fermentability in humans

Experiments with rats have produced data on the metabolism and energy value of d-psicose; however, no such data have been obtained in humans. The authors assessed the availability of d-psicose absorbed in the small intestine by measuring carbohydrate energy expenditure (CEE) by indirect calorimetry. They measured the urinary excretion rate by quantifying d-psicose in urine for 48 hours. To examine d-psicose fermentation in the large intestine, the authors measured breath hydrogen gas and fermentability using 35 strains of intestinal bacteria. Six healthy subjects participated in the CEE test, and 14 participated in breath hydrogen gas and urine tests. d-Psicose fermentation subsequent to an 8-week adaptation period was also assessed by measuring hydrogen gas in 8 subjects. d-Psicose absorbed in the small intestine was not metabolized into energy, unlike glucose, because CEE did not increase within 3 hours of d-psicose ingestion (0.35 g/kg body weight [BW]). The accumulated d-psicose urinary excretion rates were around 70% for 0.34, 0.17, and 0.08 g/kg BW of ingested d-psicose. Low d-psicose fermentability was observed in intestinal bacteria and breath hydrogen gas tests, in which fructooligosaccharide (0.34, 0.17, and 0.08 g/kg BW) was used as a positive control because its available energy is known to be 8.4 kJ/g. Based on the results of the plot of breath hydrogen concentration vs calories ingested, the energy value of d-psicose was expected to be less than 1.6 kJ/g. Incremental d-psicose fermentability subsequent to an adaptation period was not observed.