Straw, wheat

Wheat forage, wheat hay, wheat straw, wheat grain, soil and water... 

Materials to be Rice (grain, straw), wheat (grain), barley (grain), straw-... 

Sample storage stability Prohexadione-calcium in strawberry, rice grain, rice straw, wheat grain and barley grain is stable at -20 °C for 40, 140, 60, 80 and 100 days, respectively. Approximately 88% of the applied prohexadione-calcium remained in soil when stored at —20 °C after 80 days. 

Wheat straw. Wheat straw ground to 20 mesh was treated with 2% NaOH solution (wt/vol) in 1 2 (solidiliquid) ratio at 121 C for 0.5 h (i.e., 4 g NaOH/100 g wheat straw). Trichoderma reesei QMY-1 was grown on pretreated wheat straw in SSF as well as in LSF under otherwise identical culture conditions. The SSF was carried out with full nutrient concentrations in one set and with one-half nutrient concentrations in the other set to evaluate the possible deleterious effects of elevated osmotic pressure. T reesei QMY-1 produced FP cellulase of 8.6 lU/ml (430 lU/g cellulose or 172 lU/g substrate) in 22 days. This showed that the organism was able to tolerate the high salt concentrations required in the SSF. In contrast, when the nutrients were supplied in one-half concentration, FP cellulase activity dropped to 6.7 lU/ml (335 lU/g cellulose or 134 lU/g substrate). However, the maximum enzyme activity was obtained one week earlier (14 days) than that obtained with full salt concentrations (Table I). 

Isol. from partial acid hydrolysates of gum chagual (Puya spp.) and the hemicelluloses from corn hulls, wheat straw, wheat bran and maritime pine (Pinus pinaster). Amorph. -hlOl (88) (H2O). 

Metals in plant material, mg/kg dw. Wheat straw Wheat grains... 

Rice straw, wheat bran, wheat straw Jamun leaves... 

Straw has a more complicated constitution than wood. Straw contains a relatively large number of cell elements. It contains fiber, vessel elements, the parenchyma cells, and epidermic cells, having high amount of ash and silica. The epidermic cells form the outermost surface cells, which are covered by a very thin layer of wax. This surface layer reduces the moisture absorbance of straw. Wheat straw has higher cellulose, ash, and silica content as compared to that of wood. The wax content of straw is higher than that of wood. Rice straw has been found to possess higher wax content [24]. 

A report on the continuous flash pyrolysis of biomass at atmospheric pressure to produce Hquids iadicates that pyrolysis temperatures must be optimized to maximize Hquid yields (36). It has been found that a sharp maximum ia the Hquid yields vs temperature curves exist and that the yields drop off sharply on both sides of this maximum. Pure ceUulose has been found to have an optimum temperature for Hquids at 500°C, while the wheat straw and wood species tested have optimum temperatures at 600°C and 500°C, respectively. Organic Hquid yields were of the order of 65 wt % of the dry biomass fed, but contained relatively large quantities of organic acids. 

A major source of particulate matter, carbon monoxide, and hydrocarbons is open burning of agricultural residue. Over 2.5 million metric tons of particulate matter per year are added to the atmosphere over the United States from burning rice, grass straw and stubble, wheat straw and stubble. 

AGX are also the dominant hemicelluloses in the cell walls of hgnified supporting tissues of grasses and cereals. They were isolated from sisal, corncobs and the straw from various wheat species [4]. A more recent study on corncob xylans [30] showed the presence of a hnear, water-insoluble polymer... 

Potential resources of xylans are by-products produced in forestry and the pulp and paper industries (forest chips, wood meal and shavings), where GX and AGX comprise 25-35% of the biomass as well as annual crops (straw, stalks, husk, hulls, bran, etc.), which consist of 25-50% AX, AGX, GAX, and CHX [4]. New results were reported for xylans isolated from flax fiber [16,68], abaca fiber [69], wheat straw [70,71], sugar beet pulp [21,72], sugarcane bagasse [73], rice straw [74], wheat bran [35,75], and jute bast fiber [18]. Recently, about 39% hemicelluloses were extracted from vetiver grasses [76]. 

Isolation and Physicochemical Characterisation of Xylose-rich Pectic Polysaccharide from Wheat Straw... 

Key words xylose-rich pectic polysaccharide, pectin, wheat straw, extraction, sugars, lignin, FT-IR, phenolic acids and aldehydes. 

There is growing interest in the use of cereal straws such as wheat straw for animal feed after increasing its digestibility by various methods, or as a raw material for paper and board production. This is particularly important in areas with limited forest resources (1). For all these purposes a good physicochemical characterisation of cereal straw is necessary. 

To date, the structural features of pectic polysaccharides and plant cell walls have been studied extensively using chemical analysis and enzymatic degradation. In addition, research on isolation and physicochemical characterisation of pectin from citrus peels, apple peels, sunflower head residues and sugar beet pulp has been reported (2). However, the pectic polysaccharides extracted from wheat straw have only previously been reported by Przeszlakowska (3). The author extracted 0.44% pectic substances from Author to whom correspondence should be addressed. 

Wheat straw was obtained from Silsoe Research Institute (Silsoe, Bedfordshire, UK), and was dried in a cabinet oven with air circulation at bO C for 16 h. The dried wheat straw was then ground using a Christie Laboratory mill to pass a 60-mesh size screen and stored at 5°C until use. All chemicals were of analytical or regent grade. All experiments were performed in duplicate and yield is given on a dry wheat straw weight basis. 

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