Water Extract Viscosity Research Articles

Variability of wheat and other cereal water extract viscosity. 2 - Range and causes of variation

Water extract relative viscosity of 502 common wheat, 9 maize, 3 sorghum, 21 durum wheat, 36 triticale, 7 oat and 58 barley samples grown in France were measured. Water extract viscosity in wheat is higher than in maize and sorghum, slightly lower than in triticale and much lower than in most barleys. Variability of the relative viscosity for wheat extracts was mainly explained by varietal differences. The effect of the production location was less important and seemed to be partly explained by drought. Apart from irrigation, neither the differences in production methods (such as crop protection, nitrogen fertilization and date of sowing), nor sprouting nor storing had any effect on relative viscosity.

Ethanol fermentation of HTST extruded rye grain by bacteria and yeasts

AbstractHigh temperature extrusion cooking of rye was used as a pretreatment for ethanol fermentation, and yeasts and bacteria were compared for their fermentation rates. Extrusion cooking caused, on average, a 7.5% increase in ethanol yield in comparison to autoclaved samples. The best results were achieved for grain with a moisture of 21‐23% which was extruded at temperatures of 160‐180 °C.Extrusion decreased the relative viscosity of rye grain water extracts, so it was possible to mash it without α‐amylase. The efficiency of fermentation of extruded rye without Termamyl was equal to that of autoclaved and traditionally mashed rye (using α‐amylase).The rate of fermentation of extruded rye grain by Zymomonas was higher during the first stage, but the final ethanol yield was similar for the bacterium and the yeast.Though both microorganisms gave good quality distillates, the concentration of compounds other than ethanol achieved from extruded rye mashes, which were fermented by Z. mobilis, was five times lower than for yeasts.

Investigations into the Effects of an Enzyme Preparation for Baking on Wheat Flour Dough Pentosans

The modification of pentosans in doughs by a fungal enzyme preparation, used as flour improver, is reported. In the absence of added enzyme, 15-20% of water-unextractable anhydro-arabinose plus anhydro-xylose (ara + xyl) were solubilized during dough processing, depending on the starting flour used. At the optimal dosage for best technological effects, the enzyme preparation brought about a further (ara + xyl) solubilization of 9-29%. This liberation of arabinoxylans modified the viscosity of water extracts from the doughs. The specific viscosities of extracts from enzyme-treated doughs were much enhanced (≈ 40-65%), as compared to the control, because the average apparent intrinsic viscosity of extracted arabinoxylans (both water-extractable and enzyme-released) remained high. The effect of a pure endo-xylanase, isolated from this enzyme preparation, was essentially the same as the crude preparation on dough pentosans. Some hypotheses about mechanisms by which a depolymerizing enzyme can release high Mr arabinoxylans and increase the viscosity were investigated: an alkaline treatment, intended to split ester bonds, did not reduce the viscosity significantly; on the other hand, when a flour from which the water-extractable material had been removed was used as starting material, the intrinsic viscosity of enzyme-released arabinoxylans was much lower. The improving action of the enzyme preparation on doughs may be partly attributed to solubilized arabinoxylans.

IMPROVEMENT IN NUTRIENT RETENTION AND CHANGES IN EXCRETA VISCOSITIES IN CHICKS FED RYE-CONTAINING DIETS SUPPLEMENTED WITH FUNGAL ENZYMES, SODIUM TAUROCHOLATE AND PENICILLIN

Three feeding experiments were performed with chicks to study the effects of supplementing sodium taurocholate, penicillin and a crude fungal enzyme preparation, Trichoderma viride cellulase (T.v. cellulase), in rye- and wheat-based diets on the viscosity of water extracts of feed and excreta and on nutrient retention. Sodium taurocholate had no effect (P > 0.05) on the viscosity of extracts of the diet or excreta but slightly improved fat retention (P < 0.05) in chicks fed a rye-containing diet. Penicillin treatment had no direct effect on the viscous component in rye, but increased (P < 0.05) fecal viscosity and fat retention in chicks fed rye-containing diets. T.v. cellulase produced the most dramatic results among the treatments increasing (P < 0.05) fat and dry matter retention by 12 and 5 percentage units, respectively, in the rye-fed birds, but had no effect (P > 0.05) on these parameters when added to a wheat-based diet. Also, T.v. cellulase dramatically reduced excreta viscosity which was different to the effect of sodium taurocholate and opposite to the effect obtained with penicillin. An in vitro study also tested five crude enzyme preparations of widely diverse origin. T.v. cellulase was by far the most efficient viscosity-reducing enzyme and as a result was selected for the animal studies. In conclusion, penicillin, crude fungal enzyme, and sodium taurocholate additions to a rye-based diet increased, decreased or had no effect on excreta viscosities, respectively, but in all cases increased fat retention. They therefore probably have different mechanisms of action. Key words: Chicks, rye diet, nutrient retention, excreta viscosity, fungal enzyme, penicillin, sodium taurocholate.

Analysis of alkyl‐ and alkenylresorcinols in triticale, wheat and rye

AbstractAlkyl‐ and alkenylresorcinols were extracted with acetone from whole kernels of wheat, rye and various triticales. The resorcinols were ethylated, analysed by GC on a capillary column and further identified by GC‐MS. Alkylresorcinols with chain lengths of C15, C17, C19, C21, C23 and C25 and pairs of isomeric C17, C19, C21, C23 and C25 alkenylresorcinols were quantified in all samples. The content of alk(en)ylresorcinols was highest in rye, intermediate in triticale and lowest in wheat. The relative composition of the resorcinols differed between grains, with a higher content of the C19 alkylresorcinol in rye and of the C21 alkylresorcinol in wheat.Wheat and three lines of triticale were harvested at three stages of maturity after the grain filling period was ended (water content ∼40,30 and 20%). During this period of time the gross chemical composition, water extract viscosity, and content and relative composition of the alk(en)ylresorcinols, were relatively constant.

The Effect of β-Glucanase Supplementation, Stage of Ripeness, and Storage Treatment of Barley in Diets Fed to Broiler Chickens

Carbohydrate composition of ethanol- and water extracts, extract viscosity, and β-glucan content of barley harvested at two stages of ripeness (early yellow ripeness, EYR, and combine ripeness, CR) subjected to two storage treatments have been investigated. The productive value of the barleys supplemented and unsupplemented with β-glucanase has been evaluated in a broiler experiment.Extract viscosity of barley, caused by soluble β-glucans, decreased with later stage of ripeness and by anaerobic storage treatment. The content of β-glucans increased with maturity indicating a lower solubility of the β-glucans. The β-glucan content was reduced by anaerobic storage of the CR barley. Carbohydrate analyses of ethanol-extracts revealed more reducing sugars in EYR barley while sucrose and raffinose was found in higher concentrations in CR barley. During anaerobic storage, sucrose and raffinose disappeared while fructose, galactose, and glucose increased.Anaerobic storage of moist barley and β-glucanase supplementation of the chicken diets improved feed consumption, weight gain, and feed conversion ratios significantly and also increased dry matter content of the excreta and improved cleanliness of the cages. No significant difference in the productive value of the β-glucanase supplemented diets, and those based on anaerobically stored barley was obtained. Enzyme supplementation to the diet in a dry preparation was slightly superior over adding β-glucanase through the drinking water.

Studies of viscosity as the probable factor involved in the improvement of certain barleys for chickens by enzyme supplementation

Synopsis The hypothesis that the sticky droppings and the poor performance of chicks fed on low‐enzyme barleys are due to hemicelluloses and related substances in barley, which in solution in the alimentary tract give rise to a highly viscous state, was tested. It is demonstrated that pectin significantly reduced chick performance and the droppings produced were very sticky. A pectin‐degrading enzyme quickly reduced the viscosity of a solution of pectin and significantly improved the performance of chicks. The effect of feeding a bacterial enzyme preparation on the viscosity of water extracts of the contents of the small intestines of chickens that were fed on a low‐enzyme barley, was studied. It is shown that the viscosities were reduced by the “enzyme”. The viscosities of extracts from chickens that were fed on barley alone were lowered by enzyme preparations that were effective in increasing the performance of chickens. Aqueous extracts of Australian barleys, steamed Irish barley and processed Irish barley were highly viscous, whereas similar extracts of raw Irish barleys had very low viscosities. The viscosities of the former barley extracts were markedly lowered by adding “effective” (i.e. those which improve chick performance) enzyme preparations to them. The “enzymes” gave similar results with a solution of β‐glucan, and it is concluded that the enzyme responsible for lowering the viscosities was endo‐β‐glucanase. A simple method for the determination of endo‐β‐glucanase activity is described. The activities of Irish barleys were high, but the activities of Australian barleys were very low. The enzyme was present in “effective” crude enzyme preparations. It is concluded that the poor nutritional value of low‐enzyme barleys is related to the glucan and β‐glucan components of barley. Under the particular conditions the glucan/β‐glucan components give rise to fairly stable highly viscous conditions in the small intestine.