The Physiology of Growth in Apple Fruits V. Soluble Nitrogen Constituents

Abstract
The ninhydrin-reacting compounds of the apple fruit have been studied during its development on the tree. The compounds present show little variation, but glutamine, conspicuous in very young and in over-mature apples, disappears at intermediate stages. The increase in soluble nitrogenous compounds occurring in over-mature apples left on the tree (Pearson and Robertson 1953) is confirmed qualitatively. An account is given of the chromatographic behaviour of several unidentified ninhydrin-reacting substances found in extracts of apple fruits, leaves, and stems.