A typical 1 cup serving of apple juice contains 0.2 grams of protein (0.1 g per 100 g), which makes it only a minor source of protein. That covers roughly 0% of the 50 g reference Daily Value, so it adds toward your protein total for the day.
Only about 1% of the calories in apple juice 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, apple juice ranks 69th by protein per serving, and 790th out of all 796 foods on the site. Set against canned pears, another fruit entry in the database, a serving carries about 0.6 g less protein (canned pears has 0.8 g per 1 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 248 g. The per-100 g figure lets you compare it directly against any other food here, whatever its serving.
Juicing strips the fruit's fibre and leaves only trace protein behind.
Source: USDA FoodData Central #173933 - "Apple juice, canned or bottled, unsweetened, without added ascorbic acid" (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
Apple juice protein FAQ
How much protein is in apple juice per 100 g?
Apple juice has 0.1 g of protein per 100 g. A typical 1 cup serving (248 g) provides 0.2 g.
Is apple juice a complete protein?
No. Apple juice 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 apple juice cover?
A 1 cup serving of apple juice contains 0.2 g of protein, about 0% of the 50 g reference Daily Value.
Is apple juice a good source of protein?
Apple juice is only a minor source of protein, and about 1% of its calories come from protein, which makes it more of an energy food than a protein food. Set against canned pears, another fruit entry in the database, a serving carries about 0.6 g less protein (canned pears has 0.8 g per 1 cup).