What causes green peas held on the serving line to turn olive green?

The transformation of green peas into an olive green color is primarily a result of the formation of pheophytin. This occurs during the cooking or holding process, especially when vegetables are exposed to acidic conditions or prolonged heat.

Chlorophyll, the pigment responsible for the green color in peas, can break down when exposed to heat or acid. When this breakdown happens, chlorophyll loses its magnesium ion and morphs into pheophytin, which has an olive green hue. This color change is a common occurrence in vegetables and indicates alterations in their cellular structure due to cooking processes.

The other options represent different pigments or compounds. Chlorophyllin, for instance, is a derivative of chlorophyll but is typically bright green and forms under alkaline conditions. Anthoxanthins and flavones are pigments found in some vegetables and fruits but are not responsible for the color change observed in peas. They can cause different hues, such as white or yellow, but do not influence the green to olive green transition seen in peas.