Dietary Fiber Content of Corn Bran

1980 ◽  
Vol 43 (10) ◽  
pp. 760-762 ◽  
Author(s):  
N. E. ANDERSON ◽  
F. M. CLYDESDALE

The dietary fiber (DF) content in a corn bran flour obtained from Tabor Milling Company was estimated and analyzed using a fractionation procedure developed previously. This method includes estimation of cold and hot water-soluble biopolymers as well as total pectic substances, hemicellulose, cellulose and Klason lignin. Quantitative and qualitative analysis of the neutral sugars in the carbohydrate polymers was achieved by gas-liquid chromatography. Acidic sugars were estimated by a modified carbazole reaction. The corn bran flour was estimated to contain 50.12% total DF. The DF was composed of 34.49% hemicellulose, 12.34% cellulose, 0.23% Klason lignin and 3.06% total pectic substances. These values were similar to those obtained from the analysis of a standard wheat bran using the same methodology in another study.

Author(s):  
MA Scheijen ◽  
B Brandt-de Boer ◽  
JJ Boon ◽  
W Hass ◽  
V Heemann

AbstractThis paper presents an evaluation of a fractionation procedure for use with tobacco. Correlation coefficients calculated from the weights of the polymer fractions obtained and data obtained with classical wet-chemical methods show that these parameters have a low resolving power, which precludes any detailed distinction between tobaccos and tobacco-derived fractions. Pyrolysis mass spectrometry combined with multivariate analysis is presented as a promising approach for investigating the variability in the chemical composition of tobacco. Multivariate analysis performed on the pyrolysis mass-spectrometric fingerprints of all tobacco fractions indicates that the differences between the individual tobaccos are smaller than the differences induced by the fractionation procedure. Multivariate analysis of subfiles of the pyrolysis mass-spectrometric fingerprints of separate polymer fractions is an excellent method for classifying tobaccos. Leaf and stem material can easily be distinguished. A further differentiation is made between the flue-cured and Burley-type tobaccos. The strong clustering of tobacco samples after treatment with potassium hydroxide points to a uniform cell-wall skeleton. The greater variability in the ethanolized tobacco samples, and samples subjected to hot-water extraction or amylase digestion, is related to the cytosol characteristics. These fractions appear to reflect both the dissimilarities between the distinct tobacco types and phenotypic variations due to differences in cultural management. Pyrolysis mass spectrometry of the Klason lignin residues points to a large variety of chemical constituents unrelated to lignin. Pyrolysis gas-chromatography mass-spectrometric data on the Klason lignin residues of a Burley tobacco showed that the correlation made between the organic-nitrogen content and the protein content of this fraction might be misleading. As a consequence the maximum value for the lignin content of this tobacco is estimated incorrectly.


1995 ◽  
Vol 78 (4) ◽  
pp. 1030-1044 ◽  
Author(s):  
Olof Theander ◽  
Per Åman ◽  
Eric Westerlund ◽  
Roger Andersson ◽  
Dan Pettersson

Abstract A joint AOAC/American Association of Cereal Chemists (AACC) collaborative study was conducted to determine by the Uppsala method the dietary fiber content and its composition in various foods. The method includes preparation of a residue by treatment with thermostable α-amylase and amyloglucosidase and then ethanol precipitation of solubilized dietary fiber components while leaving low-molecular weight carbohydrates in solution. After acid hydrolysis of residue, neutral polysaccharide residues are determined as alditol acetates by gas-liquid chromatography, uronic acid residues are determined by colorimetry, and ash-free acid-insoluble residue (Klason lignin) is determined gravimetrically. Total dietary fiber, including enzyme-resistant starch, is calculated as the sum of nonstarch polysaccharide residues and Klason lignin. Nine laboratories completed the study, analyzing in duplicate 8 unknown dried products that included 4 cereal products, green peas, potato fiber, carrots, and apples. Total dietary fiber contents of products tested ranged from 4.6 to 84.3%, with an average RSDR value of 8.4% (range, 4.8–11.1%). Total neutral polysaccharide residues ranged from 3.8 to 64.1%, with an average RSDR value of 7.5% (range, 5.4–10.5%). Individual neutral sugars (rhamnose, arabinose, xylose, mannose, galactose, and glucose) and uronic acid residues present at more than 1% generally had good RSDR values (3.3– 22.8%), whereas, as expected for Klason lignin, only the wheat bran sample with a high content (16%) had an excellent RSDR value (5.0%). The gas chromatographic-colorimetric-gravimetric method (Uppsala method) for determination of total dietary fiber (as neutral sugar residues, uronic acid residues, and Klason lignin) has been adopted first action by AOAC INTERNATIONAL.


Nutrients ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 152
Author(s):  
Kanako Omori ◽  
Hiroki Miyakawa ◽  
Aya Watanabe ◽  
Yuki Nakayama ◽  
Yijin Lyu ◽  
...  

Constipation is a common condition that occurs in many people worldwide. While magnesium oxide (MgO) is often used as the first-line drug for chronic constipation in Japan, dietary fiber intake is also recommended. Dietary fiber is fermented by microbiota to produce short-chain fatty acids (SCFAs). SCFAs are involved in regulating systemic physiological functions and circadian rhythm. We examined the effect of combining MgO and the water-soluble dietary fiber, inulin, on cecal SCFA concentration and microbiota in mice. We also examined the MgO administration timing effect on cecal SCFAs. The cecal SCFA concentrations were measured by gas chromatography, and the microbiota was determined using next-generation sequencing. Inulin intake decreased cecal pH and increased cecal SCFA concentrations while combining MgO increased the cecal pH lowered by inulin and decreased the cecal SCFA concentrations elevated by inulin. When inulin and MgO were combined, significant changes in the microbiota composition were observed compared with inulin alone. The MgO effect on the cecal acetic acid concentration was less when administered at ZT12 than at ZT0. In conclusion, this study suggests that MgO affects cecal SCFA and microbiota during inulin feeding, and the effect on acetic acid concentration is time-dependent.


Nutrients ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1155 ◽  
Author(s):  
Ghada A. Soliman

Observational studies have shown that dietary fiber intake is associated with decreased risk of cardiovascular disease. Dietary fiber is a non-digestible form of carbohydrates, due to the lack of the digestive enzyme in humans required to digest fiber. Dietary fibers and lignin are intrinsic to plants and are classified according to their water solubility properties as either soluble or insoluble fibers. Water-soluble fibers include pectin, gums, mucilage, fructans, and some resistant starches. They are present in some fruits, vegetables, oats, and barley. Soluble fibers have been shown to lower blood cholesterol by several mechanisms. On the other hand, water-insoluble fibers mainly include lignin, cellulose, and hemicellulose; whole-grain foods, bran, nuts, and seeds are rich in these fibers. Water-insoluble fibers have rapid gastric emptying, and as such may decrease the intestinal transit time and increase fecal bulk, thus promoting digestive regularity. In addition to dietary fiber, isolated and extracted fibers are known as functional fiber and have been shown to induce beneficial health effects when added to food during processing. The recommended daily allowances (RDAs) for total fiber intake for men and women aged 19–50 are 38 gram/day and 25 gram/day, respectively. It is worth noting that the RDA recommendations are for healthy people and do not apply to individuals with some chronic diseases. Studies have shown that most Americans do not consume the recommended intake of fiber. This review will summarize the current knowledge regarding dietary fiber, sources of food containing fiber, atherosclerosis, and heart disease risk reduction.


1986 ◽  
Vol 66 (2) ◽  
pp. 377-381 ◽  
Author(s):  
P. A. SCHUPPLI

Soils were extracted by hot water, dilute CaCl2, and by mannitol-CaCl2 solutions and boron was determined by either azomethine-H or the curcumin method. Results were strongly method dependent; in particular results by the simplest method, mannitol-CaCl2, were generally lower and not highly correlated (r = 0.64) with those by the recommended procedure. This procedure involves extraction with hot distilled H2O (2:1 solution:soil), centrifugation, filtration, color development with azomethine-H and correction for background color. Extractable boron values by this procedure ranged from 0.1 to 1.4 mg kg−1. Background color can be further reduced by the substitution of 0.02 M CaCl2 for distilled water. Key words: CSSC reference soil samples, hot-water-soluble boron


1974 ◽  
Vol 14 (68) ◽  
pp. 343 ◽  
Author(s):  
RJ Jones

Experiments with Siratro were conducted at Samford, south east Queensland to study the effects of previous cutting and defoliation treatments on regrowth. In the first experiment, swards of Siratro were cut at 7.5 cm above ground level every 4 weeks, every 8 weeks or cut once at 16 weeks during spring and summer. Regrowth of all treatments over ten weeks was measured after varying (by leaf removal) the stubble leaf area index (LAI) of the plots cut every four weeks. Pattern of regrowth yield was similar for all treatments with a pronounced lag phase after cutting. Regrowth yield after 10 weeks differed between treatments and was linearly related (P < 0.01 ) to residual LAI in the stubble at the start of regrowth. In the absence of stubble leaves, plots previously cut at 16 weeks or at 8 weeks yielded marginally more than those cut every 4 weeks. There were no marked treatment differences in gross root morphology other than a two fold increase in stolon rooting for the 16-week treatment. Nitrogen content of the roots (mean 1.38 per cent) was unaffected by treatment, but the per cent hot water soluble sugars were lower for the 16 week defoliation treatment than for the 8-week and the 4-week treatments. In the second experiment individual plants were cut to a uniform stubble every 4 weeks and either 0, 5, or 10 leaves were left. Dry weight of regrowth and stolon development were greatest when most leaves were left. Two thirds of the plants died after six cuttings with complete defoliation but none died when either 5 or 10 leaves were retained. Plant survival was not related to plant yield or degree of stoloniferous development. However, there was a strong correlation between stolon number and plant yield under this intensive cutting regime. The practical implication of the results in the management of Siratro is discussed.


Molecules ◽  
2019 ◽  
Vol 24 (1) ◽  
pp. 212 ◽  
Author(s):  
Xiaopeng Peng ◽  
Shuangxi Nie ◽  
Xiaoping Li ◽  
Xiong Huang ◽  
Quanzi Li

Sweet maize stems were treated with hot water and potassium hydroxide to fractionate hemicellulosic polymers. The results showed that the water-soluble hemicelluloses were mainly composed of glucose (27.83%), xylose (27.32%), and galactose (16.81%). In comparison, alkali-soluble hemicelluloses fractionated by acidification and a graded ethanol solution (10%, 20%, 35%, 50%, 65%, and 80%) were mainly composed of xylose (69.73 to 88.62%) and arabinose (5.41 to 16.20%). More highly branched hemicelluloses tended to be precipitated in a higher concentration of ethanol solution, as revealed by the decreasing xylose to arabinose ratio from 16.43 to 4.21. Structural characterizations indicated that alkali-soluble hemicelluloses fractionated from sweet maize stems were mainly arabinoxylans. The results provided fundamental information on hemicelluloses composition and structure and their potential utilization in the fields of biofuels, biochemicals, and biomaterials.


Author(s):  
А.К. ГОРЕЛКИНА ◽  
И.В. ТИМОЩУК ◽  
Н.С. БАГДОНАС

Изучена стойкость нутриентов молокосырья – белков, лактозы, витаминов С и группы В, используемого в производстве сывороточных напитков в присутствии приоритетных органических контаминантов – трихлорэтилена, хлороформа и дихлорэтана, которые обладают токсическим и канцерогенным действием и образуются при хлорировании в процессе водоподготовки в воде, применяемой для производства восстановленных и рекомбинированных молочных продуктов. Содержание белков, лактозы в восстановленной сыворотке определяли методом рефрактометрии; водорастворимых витаминов – методом капиллярного электрофореза; хлороформа, трихлорэтилена и дихлорэтана – методом газожидкостной хроматографии. Установлено, что хлороформ в воде не оказывает влияния на сохранность лактозы, белков и витаминов при приготовлении восстановленной сыворотки. Отмечено снижение содержания белков сыворотки, приготовленной на воде в присутствии трихлорэтилена и дихлорэтана, на 11%, лактозы – на 32% в сравнении с контрольными образцами, произведенными на воде без органических контаминантов. Содержание витаминов в восстановленной молочной сыворотке в присутствии трихлорэтилена снизилось: С – на 19%, В1 – на 28%, В2 – на 53%, В6 – на 8%; для дихлорэтана содержание витаминов снизилось: С – на 17%, В1 – на 36%, В2 – на 38%, В6 – на 36% в сравнении с контрольными образцами без органических примесей. Теоретически обоснован механизм взаимодействия белков, лактозы, витаминов восстановленной сыворотки с трихлорэтиленом и дихлорэтаном. Предложено для предотвращения снижения качества готового продукта воду, используемую для производства сывороточных напитков, подвергать дополнительной очистке от галогенорганических контаминантов. The stability of milk raw materials’ nutrients – proteins, lactose, vitamins C and B used in the production of whey beverages in the presence of priority organic contaminants – trichloroethylene, chloroform and dichloroethane, which have a toxic and carcinogenic effect and are formed during chlorination during water treatment in water used for the production of reduced and recombined dairy products was studied. The content of proteins and lactose in the reduced serum was determined by refractometry; water-soluble vitamins – by capillary electrophoresis; chloroform, trichloroethylene and dichloroethane – by gas-liquid chromatography. It was found that chloroform in water does not affect the safety of lactose, proteins and vitamins in the preparation of reduced whey. There was a decrease in the content of serum proteins prepared in water in the presence of trichloroethylene and dichloroethane by 11%, and lactose – by 32% in comparison with control samples produced in water without organic contaminants. Vitamin C content in the recovered whey in the presence of trichloroethylene has declined by 19%, vitamin B1 – 28%, vitamin B2 – 53%, vitamin B6 – 8%; for dichloroethane content of vitamin C decreased by 17%, vitamin B1 – 36%, vitamin B2 – 38%, vitamin B6 – 36% in comparison with control samples without organic impurity. The mechanism of interaction of proteins, lactose, and reduced serum vitamins with trichloroethylene and dichloroethane is theoretically justified. Therefore, to prevent a decrease in the quality of the finished product, the water used for the production of whey beverages must first be subjected to additional purification from organohalogen contaminants.


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