Morpho-histological characterization and nutritional properties of prickly pear (Opuntia ficusindica L. Mill)

Opuntia ficus indica (L.) is a large genus of succulent shrubs native to Mexico. In 16th century it was introduced into several continents and is now widely grown in the warmer parts of the world. It has been shown that the prickly pear fruit is very rich in vitamins, minerals, amino acids and in sugars. Another important compositional factor of prickly pear is the presence of pigments, such as betalains, which make the fruit and its products particularly attractive. Betalains are vacuolar pigments present in all varieties of reported O. ficusindica. Their main function in the plant is to attract animals for pollen transfer facilitating plant propagation and to protect against UV radiation. Two betalain derivatives are present in cactus-pears: betacyanin, which gives the red-purple colour, and betaxanthin, which gives a yellow-orange colour. These pigments have important antioxidant activities without toxic effects to humans. Given the considerable interest aroused by this species, the aim of our research was to study the morphological and cyto-histological characteristics of the fruit from two different varieties of the prickly pear typical of Sicily (Italy):” Sanguigna” and “Muscaredda” or “Sciannarina”.Some functional compounds of prickly pear such as the betalains, the carotenoids and chlorophyll (a and b) were also quantified. There were no cyto-histological differences between the fruits of the two considered varieties; instead the content of betacyanins and chlorophyll was very different.