THE CHEMICAL CHANGES IN PEAS AFTER PICKING

Abstract

Definite changes in the chemical composition of shelled peas begin to take place immediately. The most important and striking of these is the decrease in the sucrose content. This partly explains the change in the flavor. The percentage of alcohol-insoluble residue increases, possibly at the expense of sucrose. The changes in the composition of the peas which are presumably related to the respiration are interrupted when the peas become dry. When freshly picked peas are macerated and kept under toluene-water, sucrose and starch decrease, reducing sugars increase, and non-protein N increases. This indicates that sucrase, diastase, and protease are present and active. Even when freshly picked peas are placed at [long dash]20"[degree] C. for 24 hrs. there is marked evidence of change in composition, probably because of rapid changes during the brief period before freezing actually takes place. These experiments show in definite terms the necessity of cooking or canning peas immediately after shelling.