This material still had lignin and hemicelluloses
, a fact that modified the thermal stability of the material; this range also corresponded to the one recorded in this study.
However, most of these fungi degrade lignin at a relatively slow rate and are accompanied by the degradation of cellulose and hemicelluloses
Surrounding the microfibril are the second component, hemicelluloses
(HC), and outside of the hemicelluloses
is the third component, lignin (L).
Due to the crystalline structure of cellulose, the main compound of insoluble fiber, it is possible identify it using X-ray diffraction technique; however, other important compounds like lignin and hemicelluloses
are amorphous and it is not possible to establish a crystalline direction (GHAVAMI; MARINHO, 2005).
The biosorbent contains cellulose, hemicelluloses
and lignin as major constituents, as shown in (Table 1).
Classes of hemicellulose
are named according to the main sugar unit.
Given the numerous evidence suggesting that polysaccharides contained in hemicelluloses
are trapped in lignin, removal of lignin will result in increased hydrolysis of hemicelluloses
(Van Soest, 1994).
Grasses such as corn stover contain hemicelluloses
that are similar to sorghum, primarily consisting of glucuronoarabinoxylan with ferulic acid ester linkages between xylan and lignin .
Hydrothermal treatment is the most commonly used extraction method [14-16], during which high pressure hot water is used to deal with lignocellulosic biomass, thus causing the extraction and dissolution of hemicelluloses
and the generation of low-molecular weight polymers.
Namely, in case of the CALV synthesis, the chemical treatment partially degraded lignin and hemicelluloses
and spaced the fibrils, probably due to sodium hydroxide , which could contribute to the changes in morphology.
The peaks located at 3352.77 [cm.sup.-1] and 3326.24 [cm.sup.-1] in Figures 6(b) and 6(c), respectively, corresponded to the stretching vibrations ofhydroxyl groups (OH) present in the cellulose, hemicelluloses
, and lignin of SB .
Determination of hemicelluloses
, cellulose and lignin contents of dietary fibre and crude fibre of several seed hulls.