Water-soluble Non-starch Polysaccharides Research Articles

Hydroxypropylmethylcellulose, viscosity, and plasma cholesterol control.

The mechanism for the lowering of plasma cholesterol by water-soluble nonstarch polysaccharides (NSP) could involve alteration of intestinal viscosity leading to attenuated fat and steroid digestion and absorption. Alternatively, there may be direct inhibition of hepatic cholesterol synthesis by short-chain fatty acids produced by large bowel bacterial fermentation. A synthetic NSP, hydroxypropylmethylcellulose (HPMC), has been shown to lower plasma low-density lipoprotein (LDL) cholesterol in humans. This polysaccharide is not fermented by the large bowel microflora and has been shown to lower the plasma and liver cholesterol in hamsters, with no change noted in hepatic sterol synthesis. In further studies with hamsters, a linear relationship has been identified between plasma cholesterol and the logarithm of hydroxymethylcellulose viscosity. Only a relatively small increment in viscosity was necessary to achieve a maximal effect, suggesting that intestinal digestion may be quite sensitive to increased NSP intake.

Effect of finger millet ( Eleusine coracana, Indaf-15) malt esterases on the functional characteristics of non-starch polysaccharides

Acetic acid esterase (AAE) (E.C 3.1.1.6) and ferulic acid esterase (FAE) (E.C 3.1.1.73) cleaves the acetyl groups substituted at O-2/O-3 of the xylan backbone and feruloyl groups substituted at 5′–OH group of arabinosyl residues, respectively of arabinoxylans. These enzymes modulate the functional properties of cereal arabinoxylans such as viscosity, foam stabilization and gelling. In the present study, water-soluble non-starch polysaccharides (WSPs) from ragi, wheat flours were isolated, and their functional characteristics were studied in the presence of purified esterases. Relative viscosities of the enzyme treated WSPs were marginally less than the untreated ones. Untreated WSPs from wheat and ragi were found to stabilize the thermal disruption of protein foams compared to the esterase treated ones. AAE treated WSPs of wheat and ragi showed increased gelation while FAE treated ones showed slight decrease in comparison with their respective controls. Xanthan gum (XG), which was deacetylated by purified AAE, showed improved gelation (ratio of relative viscosities for 0, 1 and 2 h of control and enzyme treated blend is 1:1.16, 1:1.35 and 1:1.20, respectively) when blended with locust bean gum (LBG).

Effects of cooking methods on starch hydrolysis kinetics and digestion-resistant fractions of rice and soybean

In this study, we investigated the effects of cooking methods and digestion-resistant fractions on the starch hydrolysis kinetics of rice and soybeans. The RS1 contents in unheated rice and soybeans were found to be high at 5.3 and 4.9%, respectively. After heating, the RS1 levels of the rice and soybeans were significantly reduced to 0.4 and 2.4%, respectively. The total nonstarch polysaccharide (NSP) content was not significantly different according to heat treatment, but the heat treatments affected the amounts of water insoluble nonstarch polysaccharides (WISNSP) and water soluble nonstarch polysaccharides (WSNSP). The level of WISNSP in the unheated samples was higher than the WSNSP of both samples; however, the WISNSP level showed a reducing trend after heating. Also, total pentosan and water soluble pentosan contents showed similar trends with total NSP and WSNSP. The hydrolysis indices (HI) of the unheated rice and soybeans were low (36.2 and 40.3%), while the heated group had high levels (89.5 and 45.0%). Among the cooking methods, the highest kinetic constants (0.284 and 0.199) were found with autoclaving for both rice and soybeans, followed by electric cooker (0.282 and 0.170), microwave oven (0.256 and 0.155), and stone pot (0.238 and 0.167). Particularly, all soybean samples appeared to have lower starch hydrolysis kinetics than the rice samples. The RS contents of the rice and soybeans were highest in the samples that were cooked in the stone pot, at 1.2 and 3.8%, respectively.

Functional properties of water-soluble non-starch polysaccharides from rice and ragi: Effect on dough characteristics and baking quality

Water-soluble non-starch polysaccharides (NSP) were isolated from native and malted rice and ragi. The effects of addition of water-soluble NSP on dough rheological characteristics and baking quality were investigated. Water-soluble NSP had low relative viscosity and showed no gelling activity despite considerable amount of ferulic acid (∼492.5–528.0 μg/g). However, they were found to stabilize protein foams against thermal disruption. Addition of water-soluble NSP (0.25 and 0.50%) to wheat flour resulted in increased water absorption and decreased dough development time. However, prolonged mixing resulted in slightly lower dough stability. Increase in dough extensibility and improvement in starch pasting characteristics were observed upon the addition of water-soluble NSP. Significant increase in loaf volume and softness of the bread was also observed. Water-soluble NSP both from malted rice and ragi had higher effect compared to the native one. Results showed that water-soluble NSP can be added to various low-fiber food preparations with positive dough functionality.

Non-starch polysaccharides from different developmental stages of Pleurotus tuber-regium inhibited the growth of human acute promyelocytic leukemia HL-60 cells by cell-cycle arrest and/or apoptotic induction

The chemical compositions and in vitro anti-proliferative activities of the water-soluble non-starch polysaccharides (NSPs) extracted from the fruiting body, mycelium and culture medium (coded as HWE, EDP and CEP, respectively) of a novel edible mushroom Pleurotus tuber-regium (PTR) were compared. HWE is likely to be a heteropolysaccharide–protein complex with a high molecular weight of 186 × 10 4. Glucose-rich EDP had a moderate MW of 50.9 × 10 4 while mannose-rich CEP had a low MW of 4.4 × 10 4. Among all PTR NSPs, HWE had the strongest cytotoxicity (approximate IC 50: 25 μg/ml) and exerted effective anti-proliferative activity at 200 μg/ml against human acute promyelocytic leukemia cells (HL-60). All PTR NSPs induced apoptosis in HL-60 cells with an increase in the ratio of Bax/Bcl-2. Analysis from flow cytometry and Western blot demonstrated that EDP caused G 2/M arrest in HL-60 cells by lowering the Cdk1 expression while HWE caused S arrest in the HL-60 cells by a depletion of Cdk2 and an increase in cyclin E expression.

Nutritive values of corn, soybean meal, canola meal, and peas for broiler chickens as affected by a multicarbohydrase preparation of cell wall degrading enzymes

The effect of a new multicarbohydrase supplement of cell wall degrading activities on the nutritive value of corn, soybean meal (SBM), canola meal (CM), and peas for broiler chickens was investigated. Four isoenergetic and isonitrogenous corn (69% corn), SBM (30% SBM, 59% corn), CM (30% CM, 54% corn), and pea (30% peas, 52% corn) diets, without or with enzyme supplementation, were formulated to meet NRC specifications for broiler chickens (except for AME and CP, which were at 95 and 92% of NRC requirements, respectively). The enzyme supplement supplied 1,000 U of xylanase, 400 U of glucanase, 1,000 U of pectinase, 120 U of cellulase, 280 U of mannanase, and 180 U of galactanase per kilogram of diet. Each diet was fed in a mash form to 9 replicate pens of 5 broilers from 5 to 18 d. When compared with the control treatment, enzyme addition to the corn diet improved (P < 0.05) feed-to-gain ratio, whereas the performance of birds fed the other 3 diets was not affected. An increase (P < 0.05) in total tract nonstarch polysaccharides (NSP) digestibility, ileal starch digestibility, and AMEn was observed in birds fed the enzyme-supplemented corn diet. An improvement (P < 0.05) in total tract NSP digestibility, ileal protein digestibility, and AMEn content with enzyme supplementation was observed for the SBM diet. However, nutrient digestibilities and AMEn of CM and pea diets were not affected (P > 0.05) by enzyme addition even though the NSP digestibilities increased significantly (P < 0.05). A significant increase (P < 0.05) in water-soluble NSP and a decrease (P < 0.05) in water-insoluble NSP concentration of ileal digesta was noted for birds fed all 4 enzyme-supplemented diets. It would appear from this study that the nutrient utilization of corn-SBM diet by broilers could be enhanced by using an appropriate multicarbohydrase enzyme supplement. The nutrient encapsulating effect of cell wall polysaccharides in SBM, CM, and peas may not be the only factor responsible for incomplete nutrient utilization. The improvement in feed efficiency and starch availability in birds fed corn diet likely resulted from the cell wall degrading activity of the enzyme supplement.

Causes for variation in digestibility of starch among feedstuffs

Reasons for starch digestibility variations are reviewed by considering starch granule structure, antinutritional factors and access problems in coarse particles. Feed technology treatments that can overcome low starch digestibilities are also reviewed. Before considering these factors, the particular features of the digestive system of chickens are briefly reviewed.The digestive system of chickens for starch hydrolysis is characterised by a high enzymatic potential. However, in contrast with mammals, the potential of chickens for completing starch digestion by microbial degradation in the distal part of the digestive tract is very low.Variations in starch granule structure especially concern legume seeds compared to cereals, with greater resistance observed for the former. Plant mutants may result in variations in amylose contents of starch granules. Those with high amylose content (70%) produce low starch digestibilities. Cereals with no amylose (waxy starch) do not show strong evidence of benefit despite lower resistance of starch granules.In practical conditions, antinutritional factors such as proteinaceous α-amylase inhibitors, condensed tannins and viscous water-soluble non-starch polysaccharides generally result in low effects on starch digestibility. However, viscosity may induce a noticeable effect with high viscosity barleys. There is much less evidence that viscosity can explain the low starch digestibilities (< 94%) which are observed with some wheat samples. Positive effects of enzyme additives on starch digestibility of cereals probably result from effects both on viscosity and on disruption of coarse particles.Access problems in coarse particles are responsible for low starch digestibilities observed with legume seeds. However, mechanical treatments such as fine grinding and pelleting can readily overcome this problem. Access problem in coarse particles is also probably the reason that explains low starch digestibilities in some cereal samples, as shown by negative relationships between hardness and starch digestibility of wheats. However, grinding and pelleting of cereals seem to be less efficient than with legume seeds. Interactions with feeding behaviour and genetic origin of birds have also to be considered for explaining variations in starch digestibility of cereals.

Causes for variation in digestibility of starch among feedstuffs

Reasons for starch digestibility variations are reviewed by considering starch granule structure, antinutritional factors and access problems in coarse particles. Feed technology treatments that can overcome low starch digestibilities are also reviewed. Before considering these factors, the particular features of the digestive system of chickens are briefly reviewed.The digestive system of chickens for starch hydrolysis is characterised by a high enzymatic potential. However, in contrast with mammals, the potential of chickens for completing starch digestion by microbial degradation in the distal part of the digestive tract is very low.Variations in starch granule structure especially concern legume seeds compared to cereals, with greater resistance observed for the former. Plant mutants may result in variations in amylose contents of starch granules. Those with high amylose content (70%) produce low starch digestibilities. Cereals with no amylose (waxy starch) do not show strong evidence of benefit despite lower resistance of starch granules.In practical conditions, antinutritional factors such as proteinaceous α-amylase inhibitors, condensed tannins and viscous water-soluble non-starch polysaccharides generally result in low effects on starch digestibility. However, viscosity may induce a noticeable effect with high viscosity barleys. There is much less evidence that viscosity can explain the low starch digestibilities (< 94%) which are observed with some wheat samples. Positive effects of enzyme additives on starch digestibility of cereals probably result from effects both on viscosity and on disruption of coarse particles.Access problems in coarse particles are responsible for low starch digestibilities observed with legume seeds. However, mechanical treatments such as fine grinding and pelleting can readily overcome this problem. Access problem in coarse particles is also probably the reason that explains low starch digestibilities in some cereal samples, as shown by negative relationships between hardness and starch digestibility of wheats. However, grinding and pelleting of cereals seem to be less efficient than with legume seeds. Interactions with feeding behaviour and genetic origin of birds have also to be considered for explaining variations in starch digestibility of cereals.

Xylanase, beta-glucanase, and other side enzymatic activities have greater effects on the viscosity of several feedstuffs than xylanase and beta-glucanase used alone or in combination.

This study was carried out to evaluate the effects of a pure xylanase, a pure beta-glucanase, a mix of the two pure enzymes, and a commercial enzyme preparation (Quatrazyme HP, Nutri-Tomen Les Ulis, France) on the viscosity exhibited by water-soluble nonstarch polysaccharides of several feedstuffs (Rialto wheat, Sidéral wheat, Isengrain wheat, triticale, rye, barley, oats, corn, wheat bran, rice bran, wheat screenings, soybean meal, rapeseed meal, sunflower meal, and peas). The viscosity depended on the feedstuffs and varieties of the same feedstuff. There was a correlation (R (2) = 0.86) between viscosity of cereals and their arabinoxylan and beta-glucan contents. The correlation was greater (R (2) = 0.99) when the type of cereal was taken into account. The addition of pure xylanase significantly decreased the viscosity of all feedstuffs except sunflower meal (P < or = 0.05). However, pure beta-glucanase was unable significantly to decrease the viscosity of Isengrain wheat, corn, rice bran, wheat screenings, soybean meal, and sunflower meal. There was a greater decrease in viscosity with the combination of xylanase and beta-glucanase than with addition of xylanase or beta-glucanase alone. This synergistic action of xylanase and beta-glucanase was observed only in Rialto wheat, Sidéral wheat, triticale, rye, barley, oats, and peas. Finally, the commercial enzyme preparation produced a greater reduction (P < or = 0.05) in viscosity for all feedstuffs compared to xylanase or beta-glucanase used alone or in combination. The greater effectiveness of the commercial enzyme preparation was due to the presence of side enzymatic activities (arabinofuranosidase, xylosidase, glucosidase, galactosidase, cellulase, and polygalacturonase).

The effect of guar galactomannan and water availability during hydrothermal processing on the hydrolysis of starch catalysed by pancreatic α-amylase

The effects of water-soluble nonstarch polysaccharides (sNSP) on human metabolism are considered to be beneficial because they decrease postprandial glycaemia and insulinaemia following ingestion of starch-rich foods. The mechanisms by which sNSP attenuate the postprandial rise in blood glucose are not well understood but their presence increases the viscosity of gastrointestinal contents, which affects physiological functions, e.g. gastric emptying and peristalsis. Increased viscosity and decreased water activity during hydrothermal treatment of starch could influence α-amylase action. Using guar galactomannan as a representative of sNSP, we found that galactomannan has a direct noncompetitive inhibitory effect on α-amylase with a K i value of approximately 0.5% (3.3 μM). The inhibition is not time dependent and studies suggest direct binding of the enzyme to galactomannan; the resulting galactomannan–amylase complex being inactive. Processing of starch at low water levels greatly affects the catalytic efficiency of α-amylase. The K m value for starch heat treated in limited water is raised and k cat is lowered relative to starch gelatinised in excess water. Since galactomannan has no effect on the K m of α-amylase, we conclude that the inhibitory action of the polymer is not secondary to a decrease in available water. Neither does it seem to be a consequence of impaired diffusion of enzyme, substrate and products because of an increase in viscosity of the medium. Thus, the effects of sNSP in lowering postprandial glycaemia not only involve modifications of gut physiology, but also include direct inhibition of the first stage in the biochemical degradation of starch.

Non-starch polysaccharides and bound phenolic acids from native and malted finger millet (Ragi, Eleusine coracana, Indaf - 15)

Nature of non-starch polysaccharides (NSP) and bound phenolic acids from native and malted ragi were studied using a recently-released hybrid variety of ragi, (Indaf-15). Yields of water-soluble NSP, hemicellulose-B and cellulose polysaccharides increased upon malting whereas a substantial decrease in the yield of hemicellulose-A was observed. Hemicellulose-B is the most viscogenic and its relative viscosity decreased from 3.04 to 1.98 upon 96 h of malting, whereas the solubility and viscosities of the rest of the NSP increased upon malting. The major sugars identified in all the NSP fractions were arabinose, xylose, galactose and glucose. A one- to two-fold decrease in arabinose was observed in all the NSP upon malting except for the alkali-insoluble residue wherein a decrease of glucose was observed. A progressive decrease in the pentose to hexose ratio was observed, indicating mainly pentosan degradation during malting, whereas an increase in the pentose to hexose ratio was observed in the alkaline-insoluble residue (AIR). Ferulic, caffeic and coumaric acids were identified as the major bound phenolic acids in native ragi and one- to two-fold decrease was observed in their contents after 4 days of malting.

Fractional isolation and partial characterization of non-starch polysaccharides and lignin from sago pith

Sago pith non-starch polysaccharides were fractionated into cold water solubles (2.6%), hot water solubles (0.8%), dimethylsulfoxide solubles (0.8%), 5% NaOH soluble hemicelluloses (1.2%), 24% KOH–2% H 3BO 3 soluble hemicelluloses (0.6%), and cellulose (5.3%). Lignin was measured by 5% NaOH extraction (0.6%) and sodium chlorite oxidation (4.2%). Glucose and rhamnose were the major sugars in cold and hot water soluble non-starch polysaccharides. The neutral sugars in dimethylsulfoxide (DMSO) soluble non-starch polysaccharides were found to be enriched in rhamnose, xylose, glucose, and arabinose. Extraction of sago pith with aqueous 5% NaOH produced hemicelluloses, which were enriched in xylose and, to a lesser extent, glucose, arabinose, galactose, and rhamnose-containing polysaccharides, together with 7.4% uronic acids and 3.9% lignin. Further extraction of the delignified pith residue with aqueous 24% KOH and 2% H 3BO 3 removed the residual hemicellulosic fraction, which was enriched in glucose and xylose-containing polysaccharides, together with 5.8% uronic acids and 1.1% associated residual lignin. Six phenolic acids and aldehydes were detected in the mixtures of alkaline nitrobenzene oxidation of 5% NaOH soluble lignin and associated lignin in hemicelluloses and cellulose fractions. The lignin fraction contained a high proportion of non-condensed syringyl units and small amounts of non-condensed guaiacyl units as well as fewer non-condensed p-hydroxyphenyl units.

Dietary Fiber Fraction for Grains Containing High Levels of Water-Soluble Non-Starch Polysaccharides.

The dietry fiber (DF) content of grains which contain much higher levels of water-soluble non-starch polysaccharide (NSP) was determined. The five most common feedstuffs from monocotyledonus plant materials (corn, barley, wheat, oats and sorghum) used for chickens were ground through a 0.5mm sieve to determine the moisture content. The prepared samples were analyzed for crude protein (CP), ether extract (EE), crude fiber (CF), crude ash (CA), starch, total sugar, neutral detergent fiber (NDF) and water insoluble cell wall (WICW). The contents of dietary fiber (DF) in these five feedstuffs were calculated on the basis of the above analytical results, with the equation as follows.DF(%)=100-(CP+EE+Starch+Total Sugar+CA)The contents of NDF and WICW are very similar in all five feedstuffs, also showing the similar values of DF except for barley and oats. Barley and oats which may have much higher levels of water-soluble non-starch polysaccharide (NSP) would be limited in the choice of chemical analysis for obtaining DF content.

Influence of Non-Starch Polysaccharides Structure on the Metabolisable Energy of U.K. Wheat Fed to Poultry

With the inclusion of wheat in European poultry diets at 600 g/kg, or more, there is increasing concern that its apparent metabolisable energy (AME) is more variable than would be predicted by conventional analysis. Twelve samples of wheat with a range of AME values (8·34–13·74 MJ/kg dry matter when fed to broiler chicks aged 11–14 d at 750 g/kg diet) were used to investigate the causes of this variability. AME was not correlated with the amount of total water-soluble non-starch polysaccharide (sNSP), soluble arabinoxylan (the major polysaccharide contributing to NSP) or (1→3, 1→4)-β-glucan released from the grain or with the viscosity of aqueous extracts. Surprisingly,in vitroviscosity was negatively related to soluble (r2=0·61) and total (r2=0·82) arabinoxylan. This was thought to be due to the slow, but cumulative, action of endogenous hydrolases in the stored grain. Soluble NSP from each wheat was characterised by measurement of molecular weight distribution and the structural features of arabinoxylan determined from the amount and nature of the oligosaccharides released following treatment with an endo-xylanase. Oligomer molecular weight was determined by matrix-assisted laser desorption/ionisation time of flight mass spectrometry and structure by NMR. Multivariate analysis of the 32 variables measured provided a three-term model able to explain approximately 0·80 of the variation between wheat samples: AME=8·07+11·16(XRAX)+30·67(AX-6)−0·355(sNSP) Two terms (XRAX, the proportion of arabinoxylan resistant to hydrolysis by xylanase and AX-6, the properties of branched six-sugar present in hydrolysates) reflected the degree of branching of arabinoxylan and were positively associated with AME while the third term, the amount of sNSP present, was negatively related.

Structure and physicochemical properties of barley non-starch polysaccharides — I. Water-extractable β-glucans and arabinoxylans

Water-soluble non-starch polysaccharides were extracted from a Canadian malting barley (cv. Harrington) by sequential treatment with water at 40 °C (WE40) and 65 °C (WE65). The yields were 1.4 and 1.3% (w/w), respectively, of the dry barley grist. The WE40 extract was composed of 82.5% glucose, 8.9% xylose, and 7.0% arabiose residues, whereas WE65 contained 93.3% Glc, 3.3% Xyl, and 2.5% Ara. Only minute amounts of mannose and galactose residues were found in either fraction. Both extracts were further fractionated by stepwise (NH 4) 2SO 4 precipitation into several polysaccharide populations. Subfractions from both extracts, obtained up to 45% saturation with (NH 4) 2SO 4, contained mostly β-glucans, whereas subfractions precipitated at increasing saturation levels of (NH 4) 2SO 4 (45–100%) contained progressively more arabinoxylans and less β-glucans. Compared to WE40, the WE65 extract was enriched in β-glucan populations with higher molecular size, higher limiting viscosity values, and higher content of β-(1 → 4) linkages. The ratio of tri-/ tetrasaccharide oligomers was also higher in β-glucans extracted at 65 °C than those extracted at 40 °C. Arabinoxylans in both extracts, WE40 and WE65, were highly substituted and contained large proportions of doubly substituted xylose residues.

Rheological properties of water soluble non-starch polysaccharides from whole grain rye flour

The typical properties of the dough and the characteristic structure of the bread crumb are the result of the interaction of many components. The water soluble non-starch polysaccharides of rye (rye-WSNSP), consisting mainly of pentosans, form viscous solutions and gels in the presence of oxidizing agents. A considerable decrease in the viscosity following the addition of endo-xylanase shows that an intact arabinoxylan moiety was necessary to retain the viscous properties of the rye-WSNSP solutions in water. The presence of the oxidizing (H 2O 2/peroxidase) agent in the aqueous rye-WSNSP solution (6.0 mglml water) caused an increase (5.5x) in the viscosity. Ferulic acid (3% w/w) and cysteine (3.7% wlw) on the other hand, restricted the increase in oxidative viscosity by 60 and 35% respectively. The flow curves showed that the rye-WSNSP solutions were shear thinning. The relationship of shear stress and shear rate was analysed using the Ostwald equation τ = k ⋅ γ ˙ n . The values for the flow behaviour index ( n = 0.45 – 0.72) were <1 for all the solutions confirming a pseudoplastic flow behaviour. The consistency index ( k) increased with the addition of the oxidizing agent to the rye-WSNSP solution and it decreased with the addition of ferulic acid. The presence of rye-WSNSP (0.5% and 0.8%) increased the consistency of wheat flour dough in the farinograph by 30 and 86% respectively and the initial stress relaxation modulus ( G o) by 37 and 160% respectively. A gradual increase of the dough consistency as well as the initial stress relaxation modulus ( G o) with an increase in oxidizing agent, in the presence of 0.5% rye-WSNSP, was observed. The half relaxation time ( t ½) of the standard dough, taken at G o/2, decreased by 12% following the addition of 0.8% rye-WSNSP. However, the oxidative (H 2O 2/peroxidase) gelation of the wheat dough containing rye-WSNSP (0.5%) increased the half relaxation time ( t ½) by 14%.

Digestibility of Water-Soluble Pectin and Organic Acid Losses in Intact or Cecectomized Adult Cockerels

Two experimental diets consisting of a basal diet either undiluted or diluted with 1% pectin-based gelling agent were given to intact or cecectomized adult cockerels for a balance experiment. The digestibilities of the water-soluble added pectin were 83.2 and 61.4% in intact and cecectomized birds (P < .05), respectively. Lactic acid excretion varied from 407 to 2,692 mg/kg, acetic acid from 790 to 1,214 mg/kg, propionic acid from 108 to 240 mg/kg, and butyric acid from 50 to 90 mg/kg dry matter intake. Organic acid excretions were the lowest for intact birds fed the basal diet and the highest for cecectomized birds fed the pectin diet. Addition of pectin induced an increase (P < .001) in organic acid excretion, especially for lactic acid in cecectomized birds. Organic acid excretion was greater (P < .001) in cecectomized than in intact cockerels. The increase in organic acid excretion induced by pectin addition amounted to 9 and 62% of the digested fraction of pectin in intact and cecectomized cockerels, respectively. The results showed the water-soluble nonstarch polysaccharides to be digested both in ceca and upper tract. It was also shown that the major part of organic acids produced from fermentation are absorbed in the ceca.

Certain physical properties of water soluble non-starch polysaccharides from wheat, rye, triticale, barley and oats

The yield of water soluble non-starch polysaccharides (WSNSP) prepared from whole grains of wheat, rye, triticale, barley and oats was 0.6, 1.8, 0.7, 1.2 and 1.0% respectively of the dry matter. The WSNSP from wheat, rye and triticale contained mainly pentoses (74, 86 and 81% respectively of the total monosaccharides), while in the WSNSP of barley and oats glucose (74 and 69% respectively of the total monosaccharides) was the main monosaccharide. All the WSNSP samples contained some amount of protein (7% in rye-WSNSP to 18% in triticale-WSNSP) attached to their low molecular weight fractions as observed in the gel permeation chromatographic separation. The major amino acids in these samples were aspartic and glutamic acids. No hydroxyproline was found in these samples. Their water binding capacity determined as the amount of unfreezable water using differential scanning calorimetry showed that the WSNSP of wheat, rye, triticale, barley and oats was 0.41, 0.47, 0.42, 0.49 and 0.44 g/g dry matter respectively. The WSNSP of wheat and barley showed higher emulsifying capacities determined as the amount of oil emulsified by one gram of the sample in water. The intrinsic viscosity of the water solutions of these non-starch polysaccharides shows a direct relation to their molecular weight and their simha shape factors indicated that all the samples were of an extended shape. However, the intrinsic viscosity of the water solution of rye-WSNSP was significantly higher than that of wheat, triticale, barley and oats.

Isolation, separation and characterization of water soluble non-starch polysaccharides from wheat and rye

The water holding capacity of the dough and the freshness of the bread made of rye and wheat are much dependent upon their content of non-starch polysaccharides (NSP), most of which are polymers of xylose and arabinose, i.e. pentosans. The yield of water soluble pentosans from rye flour (1.76%) was higher than that of wheat flour (0.59%), and the xylose to arabinose ratio of rye pentosans was 1:36 while it was 1:16 for wheat pentosans. The galactose content in wheat pentosans was 17% of the total monosaccharides. In rye pentosans the content of galactose was lower (3.5% of the total monosaccharides). The total content of monosaccharides in wheat pentosans (65%) was slightly lower than that in the rye pentosans (71.7%). The weight average molecular weight of rye pentosans (770 000) was higher than that of the wheat pentosans (255 000). The number average molecular weight of the pentosans from rye was 90 000 while the corresponding figure for wheat was 61 000. The rye pentosans showed a higher degree of polydispersity in solution than the wheat pentosans. The separation of the pentosans on a DEAE-Sephadex column resulted in five fractions. The first two fractions contained mainly arabinose and xylose and the protein content in these fractions was ~1%. The protein content of the fractions increased with the increased concentration of the borate. The Xyl: Ara ratio was 2:23 and 2:39 in fractions I and II of wheat and 1:63 and 2:32 in fractions I and II of rye. Galactose appeared in fractions IV and V in wheat and fractions IV, V-A and V-B in rye along with some arabinose which suggests the presence of arabinogalactans in these fractions.

Effects of baking on water-soluble non-starch polysaccharides in white bread fractions

Water-soluble non-starch polysaccharides were extracted from white flour and dough as well as from crumb, inner crust and outer crust fractions of white bread, baked at 210 °C for 22 or 35 min. Results from the two baking experiments were very similar. Extracted polysaccharides were fractionated on DEAE-cellulose and by different solubility properties in aqueous saturated ammonium sulfate. Fractions isolated were characterized by sugar- and 1H-n.m.r. analysis, revealing the presence of arabinoxylan mixtures with widely different degrees of arabinose substitution. Arabinogalactanproteins isolated showed little variation in galactose/arabinose ratio (1·5–1·8). Highfield 1H-n.m.r, of arabinoxylan fractions was particularly useful for estimating the ratios of terminal arabinofuranosidic residues linked to xylose residues at O-2 and O-3 or solely at O-3.