It is generally recommended to peel it. It will taste better after peeling, but it can be eaten without peeling. The peel of loofah is not poisonous and has very good medicinal value. However, for the sake of taste, the ribbed loofah is not very tasty, so it is best to peel it and eat it. If you don't peel the skin, the cooked dishes will feel hard or not cooked well. It may be better to use tender loofah without peeling it directly as food. The taste is not that bad and it is more nutritious.
Peel the loofah and put it in water to prevent it from turning black easily. Luffa is one of the vegetables most susceptible to oxidation, and it ages quickly after being peeled and left in the air, so the loofah must be eaten fresh.
When peeling the loofah, be sure to avoid using a peeling knife. You can use a stainless steel spoon or a special peeler to peel the loofah, which can preserve the nutrition of the loofah.