Abstract: Soluble polysaccharides such as pectin and carrageenan are extracted from vegetable matter by passing an extraction fluid through a fixed bed of the polysaccharide-containing vegetable material to simultaneously hydrolyze and extract the polysaccharide from the vegetable material and separate the polysaccharide-containing solution from the remaining solid vegetable material. No separate filtration step is required. A filler can optionally be added to the vegetable material to increase the rate of percolation of the extraction fluid through the bed.

Abstract: The photosensitive composition of this invention contains (1) an ethylenically unsaturated component capable of forming a high polymer by addition polymerization or crosslinking, (2) a cyclic cisoid conjugated diene as a photooxidizable component capable of reacting with singlet oxygen to form an endoperoxide, and (3) a photooxygenation sensitizer. A process for preparing a photosensitive element, such as a relief printing plate, embodying a layer of such a composition is described.