COMPOSITIONAL ANALYSIS OF NEUTRAL DETERGENT, ACID DETERGENT, LIGNIN AND HUMUS FRACTIONS OF MUSHROOM COMPOST

The fibre present in mushroom compost samples was separated by a stand ard method of selective hydrolysis into three components: acid deterge nt fibre (ADF), neutral detergent fibre (NDF) and lignin. Results of d ifferential thermogravimetric (DTG) analysis of these fractions sugges t that with NDF the matrix polysaccharides were detected as a shoulder to the cellulose peak and that structural hemicelluloses pyrolysed be fore the lignin decomposition peak. However, in ADF, only cellulose an d lignin pyrolysis peaks were detected and a hemicellulose decompositi on peak or shoulder was not present. In the lignin there were two pyro lysis peaks which represented residual polysaccharides and lignin. The rmograms of humus which had been separated from the compost by ultraso nic treatment showed that microbial polysaccharides and phenolic compo unds were the main components. Lignin and humus contained high concent rations of nitrogen compared with the other fractions. Comparison of t hermograms of uncomposted wheat straw and straw from compost showed th at straw cell-wall components were altered by fermentation.