Aleurone Fractions Research Articles

Response of Phytic Acid to Nitrogen Application and Its Relation to Protein Content in Rice Grain

Nitrogen (N) fertilization has been recognized as improving the grain beneficial micronutrients, including Zn and Fe, in rice. However, only a few studies have explicitly focused on N-induced variation in anti-nutritional components such as phytic acid (PA), PA synthesis-related gene expression, and variation in grain protein fractions. Therefore, in this study, two culture systems (hydroponic and detached panicle culture systems) were used to elucidate the influence of N application on PA concentration and its relation to the grain protein fractions, such as albumin, globulin, prolamin, and glutelin, and total protein in rice. Results showed that N application generally decreased the grain PA concentration in brown rice and down-regulated the PA synthesis-related genes in the lipid-independent pathway. In contrast, total grain protein and its fractions concentrations increased significantly. For grain positional distribution, PA and protein concentration were generally higher in the aleurone fraction than in the milled rice, regardless of N application. However, higher N application decreased the PA in both aleurone fraction and milled rice, while increased the grain protein fractions mainly in milled rice. These findings imply that N application could substantially improve the rice nutrition by reducing the PA while increasing the protein concentration. Hence, these findings may provide critical bases for rice nutritional improvement through optimal N management.

Wheat grain zinc concentration as affected by soil nitrogen and phosphorus availability and root mycorrhizal colonization

Nitrogen (N) fertilization increases zinc (Zn) acquisition in cereal crops. However, little is known about the effects of N fertilization on grain Zn concentration in relation to availability of soil N and phosphorous (P) and root mycorrhizal colonization. The present study used a 12-year location-fixed field experiment with winter wheat grown at five N fertilization rates (0, 80, 160, 240 and 320 kg N ha−1). The objective was to assess effects of phytoavailability of soil N and P and root mycorrhizal colonization on wheat Zn nutrition during three-year field measurements. Zinc concentration in wheat grains was increased with N fertilization in a linear-plateau fashion, and it reached the plateau of 30.3 ± 0.4 mg kg−1 when soil mineral N (nitrate-N) levels were 8.5 ± 1.0 mg kg−1 and above at maturity. Similarly, total shoot Zn uptake and Zn remobilization from vegetative tissues to grains were also increased significantly and then attained a plateau as the N rates increased. The enhancements in grain Zn concentration by N fertilization mainly occurred in the crease tissue, embryo and aleurone fractions of the grain. Long-term N fertilization was also associated with increases in root mycorrhizal colonization up to 8.8 ± 2.9 mg kg−1 soil available mineral N at maturity. Shoot Zn uptake at maturity increased quadratically with the increase in shoot N uptake and root mycorrhizal colonization rate, whereas there was an inverse relationship between shoot Zn uptake and soil P availability. The results suggest that grain Zn concentration of wheat plants grown under long-term N fertilization was closely related to the soil mineral N status and showed clear increases with decreased soil available P concentration and improved root mycorrhizal colonization rates.

Distribution of free and bound phenolic compounds, and alkylresorcinols in wheat aleurone enriched fractions

Several companies have focused their attention on the development of technologies able to enrich/isolate the wheat aleuronic layer because it is a source of bioactive compounds. In this work two different wheat bran fractions enriched in aleurone (AF1, 55–70% aleurone and AF2, 75–90% aleurone) were obtained by a dry fractionation based on air classification. Free and bound phenolic compounds, and alkylresorcinols were determined in the two fractions by HPLC-DAD-ESI-TOF-MS and GC–MS, respectively. To our knowledge, feruloyl di-hexoside was described for the first time in wheat aleurone and flavonoids were quantified for the first time in this fraction. The results have shown that the most concentrated free phenolic compounds were flavonoids, and AF1 was the fraction that presented the highest flavonoid content; whereas trans ferulic acid was the most abundant bound phenolic acid, which highest content was obtained in AF2. Besides, total content of ferulic acid monomers in AF2 was 33.63% higher than in AF1, whereas total content of ferulic acid dimers/trimers in AF1 was 33.9% higher than in AF2. The highest content of alkylresorcinols was obtained in AF1 and it was 10.30% higher than the obtained in AF2. Therefore, it can be stated that this green technology could be used to produce enriched aleurone fractions as source of phenolic and alkylresorcinol compounds. These fractions could be of great interest for the formulation of enriched foods.

Bioavailability and metabolism of phenolic compounds from wholegrain wheat and aleurone‐rich wheat bread

This work aimed at investigating absorption, metabolism, and bioavailability of phenolic compounds after consumption of wholegrain bread or bread enriched with an aleurone fraction. Two commercially available breads were consumed by 15 participants on three occasions and matched for either the amount of ferulic acid in the bread or the amount of bread consumed. Urine was collected for 48 h from all the volunteers for phenolic metabolite quantification. Blood samples were collected for 24 h following bread consumption in five participants. A total of 12 and 4 phenolic metabolites were quantified in urine and plasma samples, respectively. Metabolites were sulfate and glucuronic acid conjugates of phenolic acids, and high concentrations of ferulic acid-4'-O-sulfate, dihydroferulic acid-4'-O-sulfate, and dihydroferulic acid-O-glucuronide were observed. The bioavailability of ferulic acid was significantly higher from the aleurone-enriched bread when all ferulic acid metabolites were accounted for. The study shows that low amounts of aleurone-enriched bread resulted in equivalent plasma levels of ferulic acid as wholegrain bread. This could suggest that, if the absorbed phenolic metabolites after wholegrain product intake exert health benefits, equal levels could be reached through the consumption of lower doses of refined products enriched in aleurone fraction.

Using NMR-Based Metabolomics to Evaluate Postprandial Urinary Responses Following Consumption of Minimally Processed Wheat Bran or Wheat Aleurone by Men and Women.

Wheat bran, and especially wheat aleurone fraction, are concentrated sources of a wide range of components which may contribute to the health benefits associated with higher consumption of whole-grain foods. This study used NMR metabolomics to evaluate urine samples from baseline at one and two hours postprandially, following the consumption of minimally processed bran, aleurone or control by 14 participants (7 Females; 7 Males) in a randomized crossover trial. The methodology discriminated between the urinary responses of control, and bran and aleurone, but not between the two fractions. Compared to control, consumption of aleurone or bran led to significantly and substantially higher urinary concentrations of lactate, alanine, N-acetylaspartate acid and N-acetylaspartylglutamate and significantly and substantially lower urinary betaine concentrations at one and two hours postprandially. There were sex related differences in urinary metabolite profiles with generally higher hippurate and citrate and lower betaine in females compared to males. Overall, this postprandial study suggests that acute consumption of bran or aleurone is associated with a number of physiological effects that may impact on energy metabolism and which are consistent with longer term human and animal metabolomic studies that used whole-grain wheat diets or wheat fractions.

Wheat aleurone fractions and plasma n−3 fatty acids in rats

The main aim of this study was to compare the effects of two wheat aleurone (WA) fractions on circulating n−3 fatty acids in rats. We demonstrated that only the fraction able to induce the highest urinary excretion of polyphenol metabolites (>1µmol) resulted in a significant increase in plasma level of Eicosapentanoic acid (+22%, p < 0.05). While other constituents of whole wheat can be involved in this response, our data suggest that cereals containing high levels of phenolic compounds can increase blood n−3 without affecting n−6 fatty acids. Further studies are required to confirm this hypothesis and explore the underlying biological mechanisms.

Postprandial plasma betaine and other methyl donor-related responses after consumption of minimally processed wheat bran or wheat aleurone, or wheat aleurone incorporated into bread.

The bran and particularly the aleurone fraction of wheat are high in betaine and other physiological methyl donors, which may exert beneficial physiological effects. We conducted two randomised, controlled, cross-over postprandial studies to assess and compare plasma betaine and other methyl donor-related responses following the consumption of minimally processed bran and aleurone fractions (study A) and aleurone bread (study B). For both studies, standard pharmacokinetic parameters were derived for betaine, choline, folate, dimethylglycine (DMG), total homocysteine and methionine from plasma samples taken at 0, 0·5, 1, 2 and 3h. In study A (n 14), plasma betaine concentrations were significantly and substantially elevated from 0·5 to 3h following the consumption of both bran and aleurone compared with the control; however, aleurone gave significantly higher responses than bran. Small, but significant, increases were also observed in DMG measures; however, no significant responses were observed in other analytes. In study B (n 13), plasma betaine concentrations were significantly and substantially higher following consumption of the aleurone bread compared with the control bread; small, but significant, increases were also observed in DMG and folate measures in response to consumption of the aleurone bread; however, no significant responses were observed in other analytes. Peak plasma betaine concentrations, which were 1·7-1·8 times the baseline levels, were attained earlier following the consumption of minimally processed aleurone compared with the aleurone bread (time taken to reach peak concentration 1·2 v. 2·1h). These results showed that the consumption of minimally processed wheat bran, and particularly the aleurone fraction, yielded substantial postprandial increases in plasma betaine concentrations. Furthermore, these effects appear to be maintained when aleurone was incorporated into bread.

Impact of wheat aleurone structure on metabolic disorders caused by a high-fat diet in mice.

The present study investigated the potential of native and structurally modified wheat aleurone, by dry-grinding or enzymatic treatments, to counteract metabolic disorders in mice with diet-induced obesity (DIO). C57BL6/J mice were first fed ad libitum with a high-fat diet for 9 weeks to induce obesity, after which the native or treated aleurone fractions were added (13% (w/w)) in the high-fat diets for an additional 8 weeks. The effects of the aleurone-enriched diets were evaluated by assessing body weight gain, adiposity, fasting blood glucose, plasma insulin and leptin, and anti-inflammatory and oxidative stress markers. Enrichment of the diet with native or finely ground aleurone did not improve any parameter analyzed; finely ground aleurone even slightly increased (p = 0.03) body weight gain. Enrichment of the diet with enzymatically treated aleurone only had a tendency toward lower body weight gain, visceral adipose tissue accumulation, fasting plasma insulin, and leptin levels.

Antioxidant bioaccessibility from wheat aleurone throughout the canine gastrointestinal tract: an in vitro study (1044.14)

Enhancing overall health status through nutrition has growing interest in humans and animals and thus, the market for food and feed formulations with added functional dietary ingredients is on the rise. Health‐promoting properties of wheat are documented in vivo and in vitro, and are partially attributed to antioxidant compounds in the bran fraction. Cargill isolates the aleurone fraction from wheat bran which is used as an ingredient in companion animal diets with the expectation of promoting a healthier diet. However, for bioactive compounds to be efficacious, they must be bioaccessible (available for absorption) during the digestive process. Our studies indicated antioxidants from aleurone are more bioaccessible than those from beet pulp fiber (BP) in an in vitro dynamic digestive system (TNO) validated for the GI‐tract of dogs. Results show low molecular weight antioxidant compounds become bioaccessible in the jejunum compartment of the small intestine but not in the ileum (TIMdog‐1), and antioxidant activity is comparable among the substrates. Furthermore, additional antioxidant compounds are released during fermentation (lower GI, TIMdog‐2) of the non‐digested fraction, with cumulative antioxidant activity being about 25% higher from aleurone than BP. Thus, supplementing pet food with wheat aleurone fractions may be a strategy for improved health benefits in a canine diet.

In Vitro Bioaccessibility of Phenolics and Vitamins from Durum Wheat Aleurone Fractions

Durum wheat aleurone, thanks to its nutrient-rich composition, might be of potential use as a functional ingredient in cereal-based foods provided nutrients can be made available for absorption. We evaluated the in vitro bioaccessibility of thiamine, niacin, and phenolic acids in different aleurone fractions obtained with an industrial processing aimed to obtain material of different composition and particle size. Results indicate that the main phenolic compounds and vitamins investigated have a higher bioaccessibility when present in the inner part of the aleurone layer compared to the outer part of aleurone or the unfractionated bran. Moreover, an ultramicronization treatment employed to reduce particle size does not further improve the bioaccessibility of these compounds. We conclude that aleurone fractions from durum wheat bran could represent a nutritionally relevant ingredient, bringing together a high fiber content and an excellent bioaccessibility of vitamins and phytochemicals generally associated with nutritional benefits.

Bioavailability and metabolism of hydroxycinnamates in rats fed with durum wheat aleurone fractions.

The consumption of wholemeal cereals has been associated with the reduced risk of several chronic diseases, and the mechanisms behind these protective effects may be linked, besides dietary fiber and micronutrients, to an increased intake of hydroxycinnamates contained in the bran. Among bran fractions, aleurone usually contains the highest concentration of ferulic acid and diferulic acid esters linked to arabinoxylans representing the most relevant subclasses. The aim of the present study was to evaluate the absorption of hydroxycinnamates by measuring the urinary metabolite profiles of rats fed with the two different aleurone fractions (the inner part of the aleurone, named wheat aleurone A, WA-A, and the outer part, named wheat aleurone B, WA-B). An acute feeding experiment with two rat groups consuming equivalent amounts of total ferulic acid from the different aleurone fractions was carried out to evaluate ferulic acid bioavailability as affected by different sources. A chronic feeding experiment was also conducted with two rat groups consuming the same amount of the two different aleurone fractions, carried out to investigate the short-term metabolism and absorption of aleurone phenolics. The results revealed higher increases in the 24 h-excretion of phenolic metabolites/catabolites in aleurone fed rats compared to rats fed with a regular diet. Specifically, in the chronic feeding, ferulic acid was more bioavailable when WA-A was ingested. Based on previous observations, demonstrating various positive physiological responses to ferulic acid and aleurone fractions characterized by higher phenolic bioavailability, our results indicate that the WA-A fraction has potentially interesting nutritional characteristics that might be used for the formulation of new wheat based products.

Disintegration of wheat aleurone structure has an impact on the bioavailability of phenolic compounds and other phytochemicals as evidenced by altered urinary metabolite profile of diet-induced obese mice

BackgroundPhenolic acids are covalently bound to the arabinoxylan fibre matrix of wheat aleurone layer. In order to be bioavailable they need to be released by endogenous or bacterial enzymes and absorbed within the intestinal lumen. The intestinal microbiota can metabolize phenolic acids and other food-born phytochemicals. However, the effect of structure of the cereal bran or aleurone layer on these processes is not comprehensively studied.MethodsThe structure of aleurone layer was modified either by dry-grinding or by enzymatic treatments with xylanase alone or in combination with feruloyl esterase. Diet induced obese C57BL6/J mice were fed with high-fat diets containing either pure ferulic acid, or one of the four differentially treated aleurone preparations for 8 weeks. The diets were designed to be isocaloric and to have similar macronutrient composition. The urinary metabolite profiles were investigated using non-targeted LC-qTOF-MS-metabolomics approach.ResultsThe different dietary groups were clearly separated in the principal component analysis. Enzymatic processing of aleurone caused increased excretion of ferulic acid sulfate and glycine conjugates reflecting the increase in unbound form of readily soluble ferulic acid in the diet. The urinary metabolite profile of the diet groups containing native and cryo-ground aleurone was more intense with metabolites derived from microbial processing including hippuric acid, hydroxyl- and dihydroxyphenylpropionic acids. Furthermore, aleurone induced specific fingerprint on the urinary metabolite profile seen as excretion of benzoxazinoid metabolites, several small dicarboyxlic acids, and various small nitrogen containing compounds.ConclusionsThe structural modifications on wheat aleurone fraction resulted in altered metabolism of aleurone derived phenolic acids and other phytochemicals excreted in urine of diet-induced obese mice.

Distribution of carotenoids in endosperm, germ, and aleurone fractions of cereal grain kernels

To compare the distribution of carotenoids across the grain, non-corn and corn cereals were hand dissected into endosperm, germ and aleurone fractions. Total carotenoid content (TCC) and carotenoid composition were analysed using spectrophotometry and HPLC. Cereal carotenoid composition was similar; however, concentrations varied significantly (p<0.05). Endosperm fractions had TCC ranging from 0.88 to 2.27 and 14.17 to 31.35mg/kg in non-corn cereals and corn, respectively. TCC, lutein and zeaxanthin in germ fractions were higher in non-corn cereals than in corn. Lutein and zeaxanthin contents were lower in non-corn cereal endosperms. The aleurone layer had zeaxanthin levels 2- to 5-fold higher than lutein among the cereals. Positive significant correlations (p<0.05) were found between TCC, carotenoids analysed by HPLC and DPPH results. This study is the first to report on carotenoid composition of the aleurone layer. Our findings suggest that the aleurone of wheat, oat, corn and germ of barley have significantly enhanced carotenoid levels.

Formation of Phenolic Microbial Metabolites and Short-Chain Fatty Acids from Rye, Wheat, and Oat Bran and Their Fractions in the Metabolical in Vitro Colon Model

Rye bran and aleurone, wheat bran and aleurone, and oat bran and cell wall concentrate were compared in their in vitro gut fermentation patterns of individual phenolic acids and short-chain fatty acids, preceded by enzymatic in vitro digestion mimicking small intestinal events. The formation of phenolic metabolites was the most pronounced from the wheat aleurone fraction. Phenylpropionic acids, presumably derived from ferulic acid (FA), were the major phenyl metabolites formed from all bran preparations. The processed rye, wheat, and oat bran fractions contained more water-extractable dietary fiber (DF) and had smaller particle sizes and were thus more easily fermentable than the corresponding brans. Rye aleurone and bran had the highest fermentation rate and extent probably due to high fructan and water-extractable arabinoxylan content. Oat samples also had a high content of water-extractable DF, β-glucan, but their fermentation rate was lower. Enzymatic digestion prior to in vitro colon fermentation changed the structure of oat cell walls as visualized by microscopy and increased the particle size, which is suggested to have retarded the fermentability of oat samples. Wheat bran was the most slowly fermentable among the studied samples, presumably due to the high proportion of water-unextractable DF. The in vitro digestion reduced the fructan content of wheat samples, thus also decreasing their fermentability. Among the studied short-chain fatty acids, acetate dominated the profiles. The highest and lowest production of propionate was from the oat and wheat samples, respectively. Interestingly, wheat aleurone generated similar amounts of butyrate as the rye fractions even without rapid gas production.

Evaluating the potential of the wheat aleurone fraction in humans using 1H NMR-based metabolomic analysis

Epidemiological evidence indicates that the increased consumption of whole grain foods is associated with a decreased prevalence of several chronic diseases including obesity, diabetes, CVD and cancer (1) . Whole grain comprises the endosperm and the outer bran layer. The bran includes the aleurone, which is particularly rich in bioactive components that may contribute to the beneficial effects of whole grains. Metabolomics is an untargeted technique that can investigate acute and chronic alterations in metabolite profiles, and thus has the potential for elucidating the overall biochemical effects of the potentially protective components present in aleurone. However, until now, metabolomics has only been used to evaluate whole grain using animal models (2,3) . Thus, the aim of this study was to use the 1 H NMRbased metabolomic analysis to identify alterations in postprandial human urinary metabolite profiles after consumption of a wheat aleurone meal, compared to a control meal. A wheat aleurone meal and a control meal (balanced for fibre and macronutrients) were prepared by boiling with water, and consumed warm by subjects (7 male; 7 female) after an overnight fast, 1 week apart, using a randomized crossover design. Urine samples were collected at baseline, and at 1 and 2h post consumption. For each urine sample, 1 H NMR spectra were acquired with 32000 data points and 128 scans over a spectral width of 8kHz using a 500MHz DRX NMR spectrometer (Bruker Biospin, Karlsruhe, Germany) with the use of a Noesypresat pulse sequence. The SIMCA-P +11.5 software package was used to carry out statistical analysis. Partial least square discriminant analysis (PLS-DA) of these 1 H NMR spectra revealed clear differences between the 1h postprandial urinary metabolome profiles following aleurone consumption compared to the control. The PLS-DA model had R 2 = 0.36 and Q 2 = 0.41. Compared to the control, at 1 h, the aleurone meal, showed a urinary metabolome profile with significantly elevated citrate, dimethylamine, lactate, N-acetylaspartate and N-acetylaspartylglutamate and significantly decreased creatine. Results indicate that wheat aleurone can influence postprandial urinary metabolite profiles. However, further work is needed to elucidate the significance of these effects in relation to the health benefits of whole grain.

Analysis of Betaine and Choline Contents of Aleurone, Bran, and Flour Fractions of Wheat (Triticum aestivum L.) Using 1H Nuclear Magnetic Resonance (NMR) Spectroscopy

In conventional milling, the aleurone layer is combined with the bran fraction. Studies indicate that the bran fraction of wheat contains the majority of the phytonutrients betaine and choline, with relatively minor concentrations in the refined flour. This present study suggests that the wheat aleurone layer ( Triticum aestivum L. cv. Tiger) contains the greatest concentration of both betaine and choline (1553.44 and 209.80 mg/100 g of sample, respectively). The bran fraction contained 866.94 and 101.95 mg/100 g of sample of betaine and choline, respectively, while the flour fraction contained 23.30 mg/100 g of sample (betaine) and 28.0 mg/100 g of sample (choline). The betaine content for the bran was lower, and the choline content was higher compared to previous studies, although it is known that there is large variation in betaine and choline contents between wheat cultivars. The ratio of betaine/choline in the aleurone fraction was approximately 7:1; in the bran, the ratio was approximately 8:1; and in the flour fraction, the ratio was approximately 1:1. The study further emphasizes the superior phytonutrient composition of the aleurone layer.

Antioxidant and anti-inflammatory potency of different wheat varieties and fractions

IrNo QuaLirv oJ Ltre' Po Box t*'tl!ioolt;;,1;,',!:,,1;i;yi,!:ri:';,2n,niver'sirt'rtJ Meta';*icttr' Po tso'r 6t6' Risk factors for diet-r'elated disorders are oxiclative stress and chlonic intlarnmation. Wheat is a source of phytochernicals with antioxiclant activity that might play a role in the observed protection of whole-grain diets against metabolic disorders The aims of the present study were first to investigate the bioaccessibility of antioxidant and anti-inflammatory activity t'om difterent wheat fractiolls during gastrointestinal (Gl) transit and second to demonstrate the contribution of wheat cornpounds to these health factors Experiments were perforned in the TIM system, which is a dynamic computer'-controlled model consisting of gastric, duodenal, je.lunal and ileal colnpartlnents simulating conditions in the human GI tract(r'2). Samples were collected in I h aliquots tbr 6h fionr the dialysates of the jejunal and ileal colnpartlnents to measure the kinetics of bioaccessibility of antioxidant capacity and anti-inflanrnl?rtory responses. Antioxidant capacity (Trolox equivalent antioxidant capacity assay) and ferulic acid, polyphenol and prorein conterits were de[ennined. Anti-inflanrmatory effects were measured in extmcts and TIM samples nsing a hunran rnacroplrage cell systenl with lipopolysirccharide (LPS)-induced TNFa and IL-6 secretion. Antioxidant capacity was unevenly distlibuted within the whear fractions (aleurone ti'actions>bran tiactions>flour fractions), without difTerences between cultivars (Tiger and Crousty). Antioxidant capacity was conelated rvith the f-erulic acid content (/l 0.9(r, P<0.00001) Ferulic acid was the rnajor contributor to the antioxidant capacity in bran and aleurone fi'actions (-50-607c). However, fÞr'ulic acid did not reduce TNFo and IL-6 levels in a dose-dependent lnanner. The TIM experirnents showed that the antioxidant capacity was bioaccessible during CI digestion. [n the case of the blan and aleurone fi'actions the bioaccessibility was significantly lower (20-30a/o initial aritioxiclant capacity) than that frorn the flour fraction. The bioaccessibility of ferulic acid was sirnilarly low fronr the bran ancl aleurone fractions. In experiments with flour terulic acid was below the detection limit in the dialysate sarnples, because of the low initial level ât oml intake The dialysates samples collected from TlM showed reduced levels of TNFq, for the bran and aleurone fi'actions, reaching nraxirnal inhibition at the 2nd hour and 3rd hour (Figure). These data corresponded with the maxirnuin levels of the bioaccessibility ol the antioxidant capacity from these fractions.

Production and characterisation of two wheat‐bran fractions: an aleurone‐rich and a pericarp‐rich fraction

Wheat bran is a good source of dietary fibre in the form of cell walls, but contains a number of different cell types. We describe a large-scale procedure for the production of an aleurone-rich and a pericarp-rich fraction from hard, Australian wheat. The fractions were characterised by field-emission scanning electron microscopy, by using a range of bright-field stains, colour reagents, and fluorochromes, and by chemical analysis of the walls. The aleurone fraction included the seed coat with its cuticle. Only the pericarp walls showed a histochemical reaction for lignin. The concentrations of ester-linked ferulic acid and (1-->3),(1-->4)-beta-glucans were greater in the aleurone-rich fraction than in the pericarp-rich fraction. The results are consistent with the arabinoxylans in the walls of the pericarp-rich fraction being more highly substituted with arabinose than those in the walls of the aleurone-rich fraction. When the fractions were fed as a dietary supplement to rats and walls were isolated from the faeces, it was found that the pericarp walls were not degraded, but the aleurone walls were partially degraded.

Phytosterols in the aleurone layer of corn kernels

Corn hulls are composed of two major layers: the outer layer, the pericarp, is made up of non-living cell walls, and an inner layer, the aleurone, consists of a single layer of living cells, surrounded by thick cell walls. Dissected pure pericarp and aleurone fractions were ground and extracted with hexane and the yields and compositions of the resulting oils were examined. This study revealed that the high levels of ferulate-phytosterol esters and the high concentration of sitostanol previously reported in corn-fibre oil actually originate in the aleurone cells.

The Dietary Combination of Germinated Barley Foodstuff plus Clostridium butyricum Suppresses the Dextran Sulfate Sodium-induced Experimental Colitis in Rats

Background: Recent studies have suggested that dietary fiber exerts a therapeutic effect on IBD patients. The aim of this study was to evaluate the effects of a dietary combination of germinated barley foodstuff (GBF), derived from the aleurone and scutellum fraction of germinated barley, plus Clostridium butyricum against dextran sulfate sodium (DSS)-induced experimental colitis in rats. Methods: Sprague-Dawley rats were fed a 3% DSS diet containing GBF only, GBF plus C. butyricum, cellulose only (control) or cellulose plus C. butyricum for 8 days. The mucosal damage (macroscopic and microscopic inflammation) and fecal short-chain fatty acid (SCFA) levels were then determined. Results: The combination of GBF plus C. butyricum most effectively prevented bloody diarrhea and mucosal damage. The GBF-only diet also showed some preventive effects. With respect to fecal SCFAs, the combination of GBF plus C. butyricum most effectively increased the fecal SCFA level. Conclusion: The dietary combination of GBF plus C. butyricum most effectively suppressed DSS-induced experimental colitis in rats. These effects may be closely associated with its high activity to increase SCFA levels in the gut lumen. The potential clinical efficacy of GBF in IBD patients is also discussed.