A typical 1 cup sliced raw serving of plantain contains 1.9 grams of protein (1.3 g per 100 g), which makes it only a minor source of protein. That covers roughly 4% of the 50 g reference Daily Value, so it adds toward your protein total for the day.
Only about 4% of the calories in plantain come from protein, so it is more of an energy food than a protein food. It is worth eating for other reasons; the protein it adds to a day is incidental.
Among the 71 fruits in the database, plantain ranks 11th by protein per serving, and 660th out of all 796 foods on the site. Set against dried peaches, another fruit entry in the database, a serving carries about 0.5 g more protein (dried peaches has 1.4 g per 1/4 cup).
It is an incomplete protein on its own; pairing it with other plant foods across the day covers the full range of essential amino acids. The serving above is measured by volume at 148 g. The per-100 g figure lets you compare it directly against any other food here, whatever its serving.
Source: USDA FoodData Central #169130 - "Plantains, yellow, raw" (SR Legacy, published 4/1/2019). Values are the published reference figures for that record, not lab measurements for a specific brand or batch.
Quick answers
Plantain protein FAQ
How much protein is in plantain per 100 g?
Plantain has 1.3 g of protein per 100 g. A typical 1 cup sliced raw serving (148 g) provides 1.9 g.
Is plantain a complete protein?
No. Plantain is an incomplete protein on its own; pairing it with other protein sources across the day covers the full range of essential amino acids.
How much of the Daily Value does a serving of plantain cover?
A 1 cup sliced raw serving of plantain contains 1.9 g of protein, about 4% of the 50 g reference Daily Value.
Is plantain a good source of protein?
Plantain is only a minor source of protein, and about 4% of its calories come from protein, which makes it more of an energy food than a protein food. Set against dried peaches, another fruit entry in the database, a serving carries about 0.5 g more protein (dried peaches has 1.4 g per 1/4 cup).