Pectins are important structural elements in spruce fibres. Alkaline peroxide bleaching of spruce thermomechanical pulp (TMP) causes degradation and demethylation of pectins, yielding high-charge-density pectic acids. The pectic acids in fibres contribute strongly to the negative fibre charge, and the dissolved pectic acids increase the cationic demand of bleached TMP water. In this study, a me...

An earlier report (5) has described the effect of thiocyanate sprays on sugars and certain other constituents in apples. The present paper is a continuation of the general problem with attention directed to the pectic constituents. In previous work it was noted occasionally that apples spray.ed with thiocyanates were found to keep better in cold storage at 30 to 50 C. than control samples not s...

Pectic substances have generally been thought to be the principal binding agents between plant cells (12). These pectins are considered to be largely pectic acid because the middle lamella stains with ruthenium red (8). Ginzberg (7) considers that protein and metals are also important binding agents between the cells of the root tip of Alaska pea seedlings. There is, however, a need for further...

A pectic fraction, accounting for about 0.3% of the total cell wall polysaccharide, was derived from the hot water extract of an insoluble fraction of the buffer-homogenate of Zea shoots. The pectic polysaccharide fraction was characterized by fragmentation analysis after hydrolysis with acid and Erwinia carotovora pectate lyase. The results suggest that the fraction consists of mostly a linear...