Researchers are not sure why, but they suggested that the potential protective effects of the female hormone estrogen and the skin pigment melanin should be investigated as potential reasons.

This paper studied the effects of bagging during the period from young fruit formation to fruit coloration on the contents of pigment, sugar and endogenous hormone in Cara Cara orange flesh.

There was a time when people were afraid of hormone by eating animals, toxins by eating some plants, pigment by drinking some drinks.