Lignin effect

Chang H-m, Sarkanen KV (1973) Species variation in lignins Effect of species on the rate of kraft delignification Tappi 56 132-134... 

Thring, R.W., Chorent, E., Overend, R., 1990. Recovery of a solvolytic lignin effects of spent liquor/acid volume ration, acid concentration and temperature. Biomass 23, 289—305. 

Formation and Elimination of Multiple Bond Functionalities. Reactions that involve the formation and elimination of multiple bond functional groups may significantly effect the color of residual lignin in bleached and unbleached pulps. The ethylenic and carbonyl groups conjugated with phenoHc or quinoid stmctures are possible components of chromophore or leucochromophore systems that contribute to the color of lignin. 

The molecular weight of lignin in the wood, ie, of protolignin, is unknown. In addition to difficulties of isolation and purification, the polymer exhibits strong solvent, ionic, and associative effects in solution. An unequivocal method of measurement has not been developed. The polymer properties of lignin and its derivatives have been discussed (10,16). 

Some hemicelluloses are partiaUy extractable with water, but they are usuaUy extracted with alkaline solutions foUowing removal of Upids and lignin. DeUgnifted plant material is termed, holoceUulose. Neutralization of the alkaline extract effects precipitation of the more linear and less acidic hemicelluloses, termed the hemiceUulose A [63100-39-0] fraction. The more acidic and more branched material, termed hemiceUulose B [63100-40-3], is precipitated with ethanol (70%). HemiceUulose B types type are usuaUy water-soluble after extraction. 

Dietary fiber is a mixture of simple and complex polysaccharides and lignin. In intact plant tissue these components are organized into a complex matrix, which is not completely understood. The physical and chemical interactions that sustain this matrix affect its physicochemical properties and probably its physiological effects. Several of the polysaccharides classified as soluble fiber are soluble only after they have been extracted under fairly rigorous conditions. 

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