The extraction of nitrogenous materials from green leaves

Abstract

Extraction of 90-95% of the nitrogenous material from tobacco leaves is accomplished by mincing the leaves, washing, milling 2-3 times in a triple-roller ointment mill and extracting with dilute NaOH at pH 8. The extracts were squeezed through fine cotton cloth (Madapollam). Cen-trifuging for 15 min. at 1500 g. sedimented 30% of the N and this fraction was called chloroplastic, the remainder was considered soluble although it contained microscopic particles. Centrifuging at 8000 g. sedimented the bulk of the N. Regrinding the chloroplastic fraction with the fiber reduced N extraction. Freezing, addition of salts, buffers and compounds preventing precipitation of Ca complexes reduce extractions. An end-runner mill, a domestic meat mincer, a Latapie mincer, a commercial food cutter, and a power driven laboratory agate mortar gave poorer extraction.