Straw alkali-treated

LSF (ii) = 5 g alkali-treated wheat straw (containing 2 g cellulose) in 100 ml medium. 

A sample of 5 g dry ground straw was treated with 200 ml NaOH solution (concentrations of 0.25 and 0.50 mol/l) for 2 h at different temperatures (30 and 55 °C). After the indicated period of treatment, the sample was acidified to pH 5 with glacial acetic acid, concentrated to about 30 ml under reduced pressure, and then filtered. The alkali-soluble hemicelluloses were then precipitated by pouring the concentrated supernatant fluid with four volumes of 95% ethanol (20 °C, 24 h). The precipitates were recovered by filtration, washed with 70% ethanol, and air dried. The scheme for fractionation of hemicelluloses from wheat straw is illustrated in Fig. 3. 

The various forms of powder invented and manufaetured by Mr C.F. Hengst are chiefly eomposed of nitrated straw that has been finely pulped. The straw is treated first with acids and afterwards with alkalies, and the result is a firm fibrous substance which is granulated. It is claimed that this powder is entirely smokeless and flameless, that it does not foul the gun nor heat the barrel, and is at the same time 150 per eent. stronger than... 

For example, when cell walls of maize stem were treated with sodium hydroxide (0.1M) at 20°C for various times to release different amounts of phenolics, a highly significant correlation (r = 0.98) was found between the amount of phenolics released and wall biodegradability (measured by cellulase ) (5). It is of interest to note that alkali treatment of poor quality graminaceous forages (e.g., cereal straw) is used commercially to increase their biodegradability, and thus their feed value for the animal (1). 

As a result of the work cited and the in vitro trial herein reported, it was decided to prepare straw for in vivo trials by treating with 8 grams NaOH and 60 ml. of solution per 100 grams of straw. These levels although not resulting in the highest cellulose digestion in the in vitro experiment, minimized the quantity of alkali and water used with an... 

E. Donefer There was only a slight decrease noted in lignin content when NaOH treated straw was compared with untreated straw. Since our procedure did not involve washing after treatment, the products of the alkali reaction were not removed, and thus the form which the lignin is... 

Forages such as the cereal straws, in which the cellulose is mixed or bound with a high proportion of lignin, may be treated chemically to separate the two components. The treatment processes and their effects are described in detail in Chapter 20. The chemicals used are mainly alkalis (sodium and ammonium hydroxides), and they improve the dry matter digestibility of cereal straws quite dramatically, from 0.4 to 0.5-0.7. 

Take CMC for example, the preparation and processing is as follows. Firstly, the raw materials (such as straw, reed, and cornstalk) are treated with 30 wt% NaOH. Then the alkali cellulose is etherified with monochloroacetic acid. The main reactions are given as follows ... 

Lau and Van Soest and Van Soest et al, have used the measurement of phenolics, released from the walls of cereal straws and maize stover during treatment with alkali, to predict the biodegradability of the treated straws by ruminants. 

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