The in vitro gas production of untreated and high pressure steam treated sugarcane pith

Abstract

Sugarcane pith is a by-product of the final stage of the processing of sugar cane as it passes through rotary<br><br>sieves to separate fine particle. A technique, which has shown considerable potential as a method for the cost-effective pretreatment<br><br>of lignocellulosic material, is steam explosion. At the end of this process, a substantial proportion of the<br><br>hemicellulose fraction is made water soluble and the lignin fraction is modified. This results in a cellulosic substrate with<br><br>improved enzymatic accessibility and digestibility. It has been shown that energy availability is increased by solubilisation<br><br>of cellulose and hemicellulose and/or by freeing digestible materials from lignin or silica (Hart et al., 1981; Horton et al.,<br><br>1991). By applying the steam explosion process to sugarcane bagasse, Kling et al. (1987) demonstrated that about 60% of<br><br>the hemicellulose fraction was hydrolysed and the susceptibility of cellulose to enzymatic hydrolysis was increased. For<br><br>treatments based on the use of steam-pressure alone high temperatures are needed (t&gt;180°C) which may result in the<br><br>formation of anti-nutritional factors such as 2-furaldehyde (furfural) by secondary dehydration reactions of hemicellulosic<br><br>pentoses and soluble phenolic compounds. Both of these inhibit the activity of rumen microbes and cell-free enzymes. The<br><br>objective of this experiment was to evaluate the effect of high-pressure steam treatment on cumulative gas production (GP)<br><br>profile of sugarcane pith.