Über den Abbau von Pektinstoffen bei alkalischer Reaktion

Zürich

1960

S. 223-235

2 Abb., 5 Tab., 29 Lit. Ang.

Artikel aus einer ZeitschriftUnselbständiges Werk

200150994

Pectin in contrast to most other polysaccarides suffers a rapid breakdown in alkaline solution whereby glycosidic linkages within the chain molecules are split. This degradation has been studied by viscosity determinations. The alkaline breakdown of pectin increases more rapidly with increasing temperature than the concurrent saponification of the methyl ester groups. Splitting of chain molecules is observed even at low temperature. The degradation is furthermore dependant upon the degree of esterification of pectin; completely deesterified pectate is comparatively alkali stable. The mechanism of the alkaline breakdown is discussed. Upon heating of pectate with alkali, acids are produced by stepwise degradatio from the reducing end groups. The amoung of acids correspondingly increases with decreasing chain length. the high alkali sensitivity of pectins is important in a number of processes where pectin containing plant materials or pectic substances are treated with alkali.