Abstract
Protein nitrogen content was followed in fruits of four apple varieties during cool storage under conditions designed to induce different rates of water loss. Increase in protein nitrogen content during cool storage did not appear to be related to the development of breakdown. High nitrogen level in the fruit, high relative humidity in the storage atmosphere, and advanced maturity at harvest all increased susceptibility to breakdown, but only the first of these factors influenced the protein nitrogen level. An inverse relationship between percentage water loss and breakdown incidence was demonstrated.