1560s, to remove (a nut, etc.) from a shell, from shell (n.). The meaning to bombard with shells is first attested 1856. To shell out disburse (1801) is a figurative use from the image of extracting nuts. Related: Shelled; shelling.
There are 14 calories in 1 cup, slices (3 oz) of Nopales (Cactus Leaf), raw. You'd need to walk 4 minutes to burn 14 calories. Visit CalorieKing to see calorie count and nutrient data for all portion sizes.
There are approximately one hundred and fourteen known species endemic to Mexico, where the plant is a common ingredient in numerous Mexican cuisine dishes. The nopal pads can be eaten raw or cooked, used in marmalades, soups stews and salads, as well as being used for traditional medicine or as fodder for animals. Farmed nopales are most often of the species Opuntia ficus-indica or Opuntia joconostle although the pads of almost all Opuntia species are edible. The other part of the nopal cactus that is edible is the fruit called the tuna in Spanish, and the prickly pear in English.