Amount Of Resistant Starch Research Articles

Characterization of resistant waxy maize dextrins prepared by simultaneous debranching and crystallization

Waxy maize starch was debranched using isoamylase and simultaneously crystallized in the same batch at 50 °C for 7 days. The crystallized starch dextrins were isolated as precipitates and characterized for chain length distribution, crystallinity, thermal transition property, morphology, and in vitro digestibility. The long B chains released from the amylopectin crystallized more readily than the short A chains. The dextrins exhibited a typical A-type crystalline arrangement with high thermal stability. The recovery yield from the waxy maize starch was 70.4% after 7 days. The amount of resistant starch (RS) in the crystallized dextrin treated for 7 days was 83% (uncooked) or 46% (cooked). The simultaneous debranching and crystallization process was effective for the formation of dextrin crystals from waxy maize starch with thermal stability and good resistance to digestive enzymes.

The resistant starch from sorghum regulates lipid metabolism in menopausal rats via equol.

Equol is a metabolite of daidzein and has a higher biological activity than daidzein. High levels of non-starch polysaccharides can stimulate fermentation in the intestine leading to rapid conversion of daidzein into equol that has great potential to reduce obesity in postmenopausal women. In the present study, female Sprague-Dawley rats were used to establish a menopausal model by oral administration of formestane and to compare the protective effect of resistant starch on lipid metabolism, with or without soybean feed. The resistant starch was found to effectively control body weight and adipose tissue quality, while increasing the high-density lipoprotein cholesterol (HDL-C) concentration and lowering the glycerol, triacylglycerols (TG), total cholesterol (TC), and low density lipoprotein cholesterol (LDL-C) concentrations with soybean feed. Equol inhibited the expression of SREBPC1 gene by inhibiting SHP in the liver via transcription factor FXR, thereby inhibiting the synthesis of triglyceride and fatty acid in the liver. PRACTICAL APPLICATIONS: Intake of a certain amount of resistant starch while eating the soy product can better regulate lipid metabolism in menopausal obese rats compared to consumption of resistant starch alone. Studies have shown that resistant starch converts daidzein to Equol by regulating the structure of the intestinal flora and acts as an estrogen in menopausal rats. This research will further expand the health applications of resistant starch and provide useful information for the food industry.

Microbiome Composition and Relationships Among Glycemic Responses Following Resistant Starch Intake from Potatoes

Abstract Objectives We explored the relationship between microbiome α-diversity and relative abundance (RA) of resistant starch (RS)-degrading bacteria and glycemic responses following the intake of Russet potatoes with varying amounts of RS. Methods Healthy females who were overweight consumed 250gm of hot (∼8.5 gm RS) or cold potatoes (∼10.8 gm RS) in a randomized crossover study. Stool was collected prior to the intervention and microbiomes were profiled using 16S rRNA gene sequencing. Only bacterial genera prevalent in ≥ 50% of subjects were included. Diet journals were collected for 10 days. Participants had postprandial blood drawn at 15, 30, 60, & 120 min following the potatoes for glucose, insulin, glucose-dependent insulinotropic peptide (GIP), and glucagon-like peptide-1 (GLP-1) analysis. “Responders” to RS were those with a ≥ 20% reduction (mean % difference) in area under the curve (AUC) of insulin following cold vs hot potatoes. Insulin was chosen because it had the most pronounced change among the biomarkers. Spearman's correlation identified relationships between bacteria and the diet and glycemic responses. Wilcoxon signed rank test compared data between Responder groups. Linear mixed models assessed glycemic responses over time. Results Thirty subjects (29.6 ± 6.0 y, BMI 32.8 ± 3.7 kg/m2) completed the study. There were significant reductions in AUC insulin and GIP across the interventions following the cold potato compared to the hot potato: P = 0.012, partial ŋ2 = 0.213 (insulin) and P < 0.0001, partial ŋ2 = 0.875 (GIP). No differences in glucose or GLP-1 were found. Shannon α-diversity score negatively correlated with mean dietary fat (r = -0.776, P < 0.0001) and positively correlated with % kilocalories from carbohydrates and insoluble fiber (r = 0.568, P = 0.001 & r = 0.527, P = 0.003, respectively). Responders (59%) to increased RS intake only differed in the RA of Subdoligranulum (P = 0.011), a butyrate-producing bacterium. Conclusions Most participants responded to RS resulting in lower AUC insulin. Several Ruminococcaceae genera correlated with AUC GIP or GLP-1 following both potatoes, which may glean insight on potential mechanisms that affect insulin response following cold or hot potatoes with varying amounts of RS. Funding Sources The Alliance for Potato Research and Education and the university's Small Grant Program.

Effect of heat-moisture treatment of unpolished red rice on its starch properties and in vitro and in vivo digestibility

Changes in physicochemical and digestible characteristics of starches isolated from untreated and heat-moisture treated unpolished rice grains were investigated in this study. Heat-moisture treatment (HMT) at moisture content of 20%, 25% or 30% and heating temperature of 100 °C or 120 °C were applied for treating unpolished rice grains. The results indicated that granular morphology and crystalline structure of starches remained almost unchanged. However, a significant difference in the format and degree of agglomeration of starches of the rice grains treated at moisture content of 30% was observed. The HMT also suppressed the swelling and breakdown of the starch granules when treating at high moisture content and heating temperature. After HMT, amounts of resistant starch (RS) in the treated rice grains significantly increased as compared to that in the untreated rice grains. Moreover, the rice grains were heat-moisture treated with higher moisture contents or heating temperatures had higher RS contents. As a result, the rice grains treated at moisture content of 30% and heating temperature of 120 °C contained the highest amount of RS (49.1%), released the lowest blood glucose level and had GI value of 55, which is considered as low GI food.

An in-vitro investigation on the effect of chilling and reheating different starchy meals on resistant starch content

AbstractFood processing has been shown to influence starch digestibility, due to the formation of indigestible starches known as resistant starch (RS). RS has been shown to have similar health promoting properties to those of insoluble dietary fibre. These beneficial effects include lower glycaemic response, improved insulin sensitivity, enhanced overall gut health, and better plasma lipid profile. Additionally, the presence of other nutrients such as proteins or lipids may also impact the amount of RS formed.The present work aimed to measure the effect of cooking and /or additional meal ingredients on the RS content of 5 different starchy meals, 3 made with pasta (one of which had cheese added) and 2 made with potato, using the Megazyme RS kit (K-RSTAR). The cooked meals were tested either freshly cooked, chilled overnight, or chilled overnight and reheated. Moreover, different amounts of fat were used in the test meals (10 g fat per 100 g pasta, 30 g fat per 100 g pasta, 5 g fat per 100 g potato and 10 g fat per 100 g potato) in order to examine the effect of the amount of fat on RS formation. The total number of meals tested was 15.The amount of RS in the 2 pasta meals without cheese were 40% and 44% higher in the chilled and reheated meals compared to the same meals freshly cooked for the 10 g and 30 g of fat meals, respectively. The chilled overnight meals were not different from the freshly cooked meals for both fat amounts. Moreover, the potato meals showed a more substantial difference between the meals for the two fat amounts. The chilled and reheated potato meals were 73% and 85% higher in RS content than the freshly cooked identical meal, in the 5 g and 10 g of fat, respectively. Additionally, the chilled potato meals had higher RS contents compared to freshly cooked potato meals (68% and 83%, respectively). Furthermore, the presence of protein reduced the total amount of digested starch and RS in all pasta meals when compared to the meals without cheese. The findings of this in-vitro investigation suggests that chilling and reheating starchy meals significantly increases their content of RS. Future work will determine if these in vitro findings will translate to health benefits in vivo.

The effects of age and dietary resistant starch on digestibility, fermentation end products in faeces and postprandial glucose and insulin responses of dogs

ABSTRACTThe same food formulation processed to obtain two different starch gelatinisations (SG) and resistant starch (RS) contents was evaluated in old and adult dogs, regarding apparent total tract digestibility (ATTD) of nutrients, fermentation products in faeces, and postprandial glucose and insulin responses. A diet with corn was ground and extruded in two different ways, obtaining Low RS (2.2 g/kg DM; 99.9% of SG) and High RS (15.3 g/kg DM; 62.6% of SG). Each diet was fed to adults (4.0 ± 0.7 years) or old beagle dogs (11.5 ± 0.4 years) in a 2 (ages) x 2 (RS amounts) factorial arrangement with 8 dogs per food. Data were evaluated by analysis of variance, and postprandial responses by analysis of variance of repeated measurements over time (p < 0.05). Diet × age interaction was observed for protein ATTD, with lower values for old dogs fed High RS than those for the other treatments (p < 0.05). No age or diet effect was verified for the ATTD of other nutrients and faecal score. Faecal moisture and pH were higher for adults than that for old dogs (p < 0.05). The High RS food increased acetate, propionate and butyrate concentrations in faeces, regardless of age (p < 0.01). Old dogs presented lower acetate and total short-chain fatty acids (SCFA) and higher lactate and ammonia than adults (p < 0.05). Only for old dogs the intake of the High RS food reduced ammonia and increased faecal lactate (p < 0.05). An age × diet interaction was verified for glucose postprandial response, with lower values for old dogs fed High RS food (p < 0.05), while no differences were found for the other treatments. Old dogs had higher postprandial insulin secretion regardless of the diet (p < 0.05), and lower insulin increment at 180 min after the meal when fed the Low RS than when fed the High RS food (p < 0.05). In conclusion, the diet with lower SG and higher RS improved the intestinal microenvironment, with higher butyrate and total SCFA without altering faeces production or score. Old dogs presented less acetate and total SCFA and higher lactate and ammonia in faeces than adults. The High RS food increased lactate and reduced ammonia in faeces of old dogs, with possible positive influences for gut health. Old dogs had higher postprandial insulin secretion than that of adults to maintain blood glucose, and the diet with higher RS content reduced the postprandial glucose response of old dogs.

Digestibility and Acceptability of Wheat Flour Cookies Partially Substituted with High Amylose Maize Starch.

Cookies are one of the most consumed bakery products and the formulation could be modified to consider them as a functional food. The high amylose maize starch (HAMS) is considered as resistant starch (RS) type 2. The objective of this work was to assess the starch fractions, texture, sensory properties and acceptability of wheat flour cookies added with HAMS at different percentages. Adding 15% of HAMS into the formulation increased the amount of RS from 2.3 to 12.8%. In sensory analysis, children and adults showed a good acceptability of cookies since the addition of HAMS did not result in significant changes in flavor or color. Cookies made with HAMS could be considered as functional foods since they had an acceptable texture and low caloric content.

Effect of microwave irradiation-retrogradation treatment on the digestive and physicochemical properties of starches with different crystallinity

The effect of microwave irradiation-retrogradation (MIR) treatment on the physicochemical properties and in vitro digestibility of corn starch (A-type crystallinity), potato starch (B-type) and chestnut starch (C-type) were evaluated. After MIR treatment, the amount of resistant starch (RS) increased and rapid digestible starch (RDS) decreased along with the retrogradation time in all three starches. The degree of retrogradation (DR) of starch was significantly positive correlated with amylose and RS content. All three starches subjected to MIR treatment exhibited a B-type crystalline structure. With the increase in retrogradation time, starch granules became more orderly. The DR was significantly positively correlated with relative crystallinity of X-ray pattern, To, ΔH of thermal properties, and the Fourier transform infrared ratio of 1047/1022 cm−1 of starch. The results indicated that MIR treatment is a good industrial method for preparing low digestive starch and retrogradation time is an important parameter for the process.

Free sugar content, in vitro starch digestibility and predicted glycemic index of ready-to-eat breakfast cereals commonly consumed in Turkey: An evaluation of nutritional quality

Breakfast cereal products are produced using the extrusion technique, which improves their digestion and absorption in the small intestine. However, this technique may cause an increase in the glycemic index of a food. Although high carbohydrate-rich foods are consumed in Turkey, there is not enough information about their GIs. The purpose of this study was to determine the free sugar content, in vitro starch digestibility, and predicted GI of different types of breakfast cereals commonly consumed in Turkey and evaluate their nutritional quality. The hydrolysis index of breakfast cereals ranged from 78.1 to 114.9, whereas the GI ranged from 82.6 to 102.8. The GI of 6 out of 12 breakfast cereal products was higher than that of white bread. Free sugar content, rapidly available glucose, and resistant starch amounts were significantly related to the increase and decrease of GIs in breakfast cereals, but there was no significant relationship between rapidly and slowly digestible starches. This may be related to the free sugar content in the samples and the extent of extrusion used for the samples. When the breakfast cereal groups were evaluated, overall, the GIs of samples containing oats were lower than those containing rice and corn.

Effect of dry heat treatment on the development of resistant starch in rice (Oryza sativa) and barnyard millet (Echinochloa furmantacea)

Resistant starch (RS) is that fraction of starch which does not undergo digestion in the human digestive tract. It maintains gut health by acting as a prebiotic and is also known to play an important role in controlling the glycaemicindex of starch‐based foods. The basic structure of RS contributes to its resistance to enzymes. This work focuses on increasing the RS4 content of the selected rice and millet by dry heat treatment. Pan roasting, fluidized bed drying, tray drying, and convective microwave heating methods were utilized to optimize the maximum yield of RS in rice and barnyard millet. Convective microwave heat‐treated samples gave the maximum amount of RS in both rice (26.25 ± 0.14 g/100 g at 180°C, 10 min) and barnyard millet (15.08 ± 0.20 g/100 g at 170°C, 20 min). Therefore, this study concludes that convective microwave heat treatment is more efficient when compared to other dry heat treatment methods in converting starch to RS in both rice and barnyard millet. PRACTICAL APPLICATIONS: This research focuses on the effect of various dry heat treatments on the development of resistant starch in rice and Barnyard millet. Also, optimization of time and temperature combination for maximum yield of resistant starch in convectional microwave heat treatment data may be then scaled up for use in commercial applications. This has high potential for the development of low‐cost conventional technology for the production of high‐quality food products with high resistant starch content, which can be used in the formulation of several functional foods.

Resistant Starch from Isolated White Sorghum Starch: Functional and Physicochemical Properties and Resistant Starch Retention After Cooking. A Comparative Study

In an effort to promote the formation of resistant starch (RS), four different modification methods are applied to isolated white sorghum (WS) starch by subjecting the latter to heat‐moisture treatment (RSa), annealing (RSb), hydrolysis through pullulanase debranching enzyme (RSc), and dual autoclaving‐cooling cycles (RSd). Functional and physicochemical properties, individual RS content, and the behavior after cooking in terms of apparent RS retention (aRSr) of samples (i.e., WS, RSa, RSb, RSc, and RSd) are compared. Differences in thermal and pasting properties, in the ratio of ordered starch to amorphous starch, along with lower solubility and swelling power values, and greater water absorption capacity are measured in the four RS ingredients when compared to native WS starch. All the four modification methods prove to be similarly effective in increasing the amount of RS with respect to native WS starch, with an average 30% increase. However, based on the aRSr values, analyses revealed that the greater heat stability after cooking was obtained for RSb (93.7%) and decreased in the order of RSb&gt;RSc&gt;RSa = RSd&gt;WS. Present results shed light on the properties of modified WS starch as a potential heat‐stable source of RS for food applications.

Comparison of gluten peptides and potential prebiotic carbohydrates in old and modern Triticum turgidum ssp. genotypes

Old wheat genotypes are perceived by consumers as healthier than modern ones. The release of gluten peptides with in vitro digestion and the content of potentially prebiotic carbohydrates (i.e. resistant fraction of starch and cell-wall associated dietary fiber) were evaluated in tetraploid wheats, namely 9 old and 3 modern Triticum turgidum ssp. genotypes. Simulated digestion of wholemeal flours yielded 152 major peptides, 59 of which were attributed a sequence. Principal component analysis revealed that peptide profiles were variable in old genotypes, unlike in modern ones. Digestion of old genotypes generally yielded peptides in greater concentration. In particular, 5 peptides of γ-gliadin, known to trigger the adaptive immune reaction, and two peptides of α-gliadin, known to be toxic to celiac patients, were particularly abundant in some old varieties. Resistant starch (RS) was negligible in modern genotypes (<0.6%), but it was remarkably abundant in some old varieties, reaching the highest value in Dauno III (8.5%, P < 0.05). Dauno III also presented the highest amount of soluble fiber (4.2%, P < 0.05). Pasta was made with an old and a modern genotype (Dauno III and PR22D89, respectively) with opposite RS content. Pasta making and cooking affected starch digestibility, overtaking differences between genotypes and yielding the same amount of RS for both the varieties (approx. 1.7%). The data herein presented suggest that the wholemeal flours of old tetraploid wheat genotypes could not boast particular claims associated to a lower exposure to gluten peptides and, if cooked, to a prebiotic potential.

Development of a Green Banana-based Food and the Effects of Its Consumption on the Intestinal Transit of Hemodialysis Patients

Introduction: Hemodialysis patients are generally subjected to water and food restrictions imposed by treatment, which hamper intestinal transit. The aim of the present study was to develop a green banana food and evaluate its effects on the intestinal functioning of these individuals. Methods: Fifty-three hemodialysis patients were randomized into two groups: those who consumed 50.0 g of green banana cake, and the placebo group, whose recipe was prepared using ripe bananas. Before and after a two-month cake consumption period, the intestinal function was evaluated according to Rome III Criteria and the Bristol Stool Form Scale. A dietary habit assessment was also conducted to estimate fiber intake. Results: After the intervention, the constipation percentages decreased from 23.1% to 5.1% in the green banana group and from 15.4% to 7.7% in the placebo group. Improvements in stool consistency were especially noteworthy in the green banana group. The participants' fiber intake did not undergo significant changes during the study. Conclusions: The study sample showed a high prevalence of intestinal constipation. It was not possible to claim that the green banana was exclusively able to improve intestinal transit. It is believed that higher amounts of resistant starch may lead to statistically significant differences in the results.

Batter Rheology and Quality of Sponge Cake Enriched with High Percentage of Resistant Starch (Hi-maize)

Abstract Addition of resistant starch (RS) to foods improves their health benefits. However, quality and sensory properties of the products are scarified when high amounts of RS (&gt;20%) are added. The main purpose of this study was to develop an acceptable cake containing high level of RS (&gt;20%) and to fix the associated problems by addition of gluten powder. Wheat flour was replaced with 30%, 40% and 50 % of reconstituted flour; a mixture of RS and gluten powder (9:1, w/w) and some quality aspects of the batter and cakes were studied. With increasing the RS+gluten levels, pasting temperature increased while peak and final viscosities decreased. Batter density, viscosity, storage and loss moduli reduced whereas the size of air bubbles increased. Cake volume, height, porosity and hardness reduced, while the crust lightness and crumb darkness increased. Based on the sensory analysis a maximum of 40% RS+Gluten resulted in an acceptable cake quality.

Pullulanase treatments to increase resistant starch content of black chickpea (Cicer arietinum L.) starch and the effects on starch properties

This study aimed to increase resistant starch (RS) content of black chickpeas (Cicer arietinum L.) by using pullulanase enzyme. Physicochemical and functional properties of enzyme treated starch (NE) was compared with that of enzyme-treated and gelatinized starch (GE) and the retrograded control starch (RC). RS contents for native black chickpea starch (NS) and black chickpea flour (NF) were measured as 15.2% and 5.0%, respectively. While for NE and GE, were found as 16.4% and 12.3%, respectively. Treatments made on the NS, increased the amount of RDS and reduced the amount of SDS significantly (p < .05). When the effect of enzyme application-autoclaving and retrogradation were compared, 41.3% increase in RS content was measured. In this study; RS3 production from black chickpea starch by a pullulanase enzyme was successfully performed. Enzymatic applications also improved the functional properties such as water absorption capacity, water solubility index value, fat binding capacity and emulsifying capacity. This enzyme treated black chickpea starch samples, being functionally improved, will possibly help to produce different products with desired quality parameters. Therefore, instead of native starch, pullulanase treated black chickpea starch may be used as a functional ingredient for increasing the amount of RS in food formulations.

Impact of Dietary Resistant Starch on the Human Gut Microbiome, Metaproteome, and Metabolome.

ABSTRACTDiet can influence the composition of the human microbiome, and yet relatively few dietary ingredients have been systematically investigated with respect to their impact on the functional potential of the microbiome. Dietary resistant starch (RS) has been shown to have health benefits, but we lack a mechanistic understanding of the metabolic processes that occur in the gut during digestion of RS. Here, we collected samples during a dietary crossover study with diets containing large or small amounts of RS. We determined the impact of RS on the gut microbiome and metabolic pathways in the gut, using a combination of “omics” approaches, including 16S rRNA gene sequencing, metaproteomics, and metabolomics. This multiomics approach captured changes in the abundance of specific bacterial species, proteins, and metabolites after a diet high in resistant starch (HRS), providing key insights into the influence of dietary interventions on the gut microbiome. The combined data showed that a high-RS diet caused an increase in the ratio of Firmicutes to Bacteroidetes, including increases in relative abundances of some specific members of the Firmicutes and concurrent increases in enzymatic pathways and metabolites involved in lipid metabolism in the gut.

Effect of Beta-Glucan and Resistant Starch on Prebiotic Dough and Bread Properties

White wheat flour is a poor source of dietary fiber. A demand therefore exists for the enrichment of bread with prebiotic non-digestible ingredients that exert a health-promoting effect. In this study, the effect of beta-glucan (BG) and resistant starch (RS) on the dough properties and bread-making characteristics has been investigated. The water absorption of doughs increased with increasing BG and RS amounts. The development time and farinograph quality number of BG–enriched doughs remained similar to the control while the stability of doughs decreased, and all of these values decreased when the RS was added. BG was more effective in increasing the softening of doughs than RS. The addition of RS or BG increased; the resistance to deformation, energy, maximum resistance and ratio number values, but their extensibility values had decreased compared to the control. Formulation containing BG/RS combination showed the best farinograph (development time, stability) and extensograph (resistance and extensibility) parameters. The application of BG and RS had similar or slightly smaller effect on specific volume and same or higher effect on the moisture content while it caused a decrease in firmness after five days of storage.

Molecular structure and physicochemical properties of starch isolated from hydrothermally treated brown rice flour

The impact of single and dual hydrothermal treatments on the molecular structure, crystalline structure, in vitro digestibility, and physicochemical properties of starches isolated from hydrothermally treated brown rice flour was investigated. Annealed rice starch (ANN) exhibited no significant change in molecular structure, whereas heat-moisture treated rice starch (HMT) showed decreased apparent amylose content, molecular weight of amylopectin, average chain length of amylopectin, and long amylopectin branch chains (DP ≥ 37). The relative crystallinity, intensity ratio of 1045 cm−1–1015 cm−1, and gelatinization enthalpy remained unchanged in ANN, but significantly decreased in HMT. In dually modified starches, the HMT-ANN had higher gelatinization temperatures, gelatinization enthalpy, relative crystallinity and ratio of 1045 cm−1–1015 cm−1 than the ANN-HMT. Hydrothermal treatment substantially increased starch digestibility in the granular state, showing increased rapidly digestible starch (RDS) content and decreased resistant starch (RS) content. However, in the gelatinized starches, ANN and HMT showed decreased RDS level and increased slowly digestible starch (SDS) and RS levels. The changes in amounts of RDS, SDS, and RS in ANN, HMT and dually modified starches could be attributed to the alteration of crystalline and molecular structures.

Resistant starch (RS) fermentation is prevented by low potency antibiotics (AB) neomycin and ampicillin

In a previous study we reduced bacterial genera that ferment RS with AB treatment then stopped AB prior to feeding RS. Subsequent fermentation of RS was good even without a transplant of microbiota from other rats fed RS and prior reduced bacterial genera increased (EB14). We now report use of the same AB (neomycin 0.5 g/L and ampicillin 1g/L in drinking water) at the same time as feeding RS. Sprague Dawley rats were assigned into one of four groups and fed ad libitum for four weeks. The groups included: 1. positive control (high RS, low fat diet [LF], no AB), 2. negative control (no RS, LF, no AB); 3. LF, high RS, AB; and 4. high fat (HF), high RS, AB. We measured effects of fermentation: pH of cecal contents, empty cecum weight (ECW), short‐chain fatty acids (SCFA), glucagon‐like peptide 1 (GLP‐1), RS in cecal contents, four bacterial genera known to be involved in fermentation of RS and total bacterial numbers. HF group 4 was included to see if AB might improve fermentation of RS compared to no AB because Cani et al. (2008) had reported that AB reduced endotoxemia in diet‐induced obesity. AB reduced Lactobacillus spp. and Bifidobacterium spp., but not Bacteroides spp. or total bacteria. Empty cecum weights of groups given AB and positive control were greater than the negative control. RS increased acetate and butyrate as well as decreased pH of cecal contents and increased empty cecum weights; AB treatment in both LF and HF prevented these effects (p&lt;0.05). AB also had double the amount of GLP‐1 in serum and double the amount of RS in cecal contents compared to positive control, and negative control had minimal amounts of both GLP‐1 and RS. Thus, it appears that half of the RS was not fermented in the positive control and AB eliminated fermentation of RS when given at the same time as feeding of RS. However, increased ECW and GLP‐1 are a concern for future use of AB for reduction of fermentation of RS for mechanistic studies.Support or Funding InformationFunding: Ingredion Incorporated and LSU AgCenter.

Manipulation of starch bioaccessibility in wheat endosperm to regulate starch digestion, postprandial glycemia, insulinemia, and gut hormone responses: a randomized controlled trial in healthy ileostomy participants

Background: Cereal crops, particularly wheat, are a major dietary source of starch, and the bioaccessibility of starch has implications for postprandial glycemia. The structure and properties of plant foods have been identified as critical factors in influencing nutrient bioaccessibility; however, the physical and biochemical disassembly of cereal food during digestion has not been widely studied.Objectives: The aims of this study were to compare the effects of 2 porridge meals prepared from wheat endosperm with different degrees of starch bioaccessibility on postprandial metabolism (e.g., glycemia) and to gain insight into the structural and biochemical breakdown of the test meals during gastroileal transit.Design: A randomized crossover trial in 9 healthy ileostomy participants was designed to compare the effects of 55 g starch, provided as coarse (2-mm particles) or smooth (<0.2-mm particles) wheat porridge, on postprandial changes in blood glucose, insulin, C-peptide, lipids, and gut hormones and on the resistant starch (RS) content of ileal effluent. Undigested food in the ileal output was examined microscopically to identify cell walls and encapsulated starch.Results: Blood glucose, insulin, C-peptide, and glucose-dependent insulinotropic polypeptide concentrations were significantly lower (i.e., 33%, 43%, 40%, and 50% lower 120-min incremental AUC, respectively) after consumption of the coarse porridge than after the smooth porridge (P < 0.01). In vitro, starch digestion was slower in the coarse porridge than in the smooth porridge (33% less starch digested at 90 min, P < 0.05, paired t test). In vivo, the structural integrity of coarse particles (∼2 mm) of wheat endosperm was retained during gastroileal transit. Microscopic examination revealed a progressive loss of starch from the periphery toward the particle core. The structure of the test meal had no effect on the amount or pattern of RS output.Conclusion: The structural integrity of wheat endosperm is largely retained during gastroileal digestion and has a primary role in influencing the rate of starch amylolysis and, consequently, postprandial metabolism. This trial was registered at isrctn.org as ISRCTN40517475.