SOME CHEMICAL CHANGES INCIDENT TO RIPENING AND STORAGE IN THE GRIMES APPLE

Since 1906, the Pomology Section of the Iowa Station has had under investigation a number of problems dealing with the storage of Iowa apples (1, 7, 10). The investigations have dealt principally with the development and control of Jonathan-spot, soft-scald and internal breakdown as these are affected by the maturity of fruit, cultural conditions, temperature, humidity, aeration and wrap experiments. During the season of 1923, a joint project was outlined with the Chemistry Section of this Station which included a rather complete chemical study of Grimes apples handled under varying conditions before the storage period. It was particularly desirable to know more about the general chemical relationships existing within apples handled under known conditions. The literature dealing with the chemical changes taking place in apples on the tree has been thoroughly reviewed by BIGELOW, GORE and HOWARD (2), also by MAGNESS and DIEHL (8). The present paper gives a rather complete account of certain chemical changes taking place in Grimes apples at the time they were placed in storage, after certain definite periods of delay, and at the time of picking. Further analyses of the fruit after removal from cold storage have been made and are included in this report. These data are of interest in connection with the storage experiments where certain physiological disorders have developed.