Apios americana tubers are protein-dense, with 13–17% protein by dry weight and potato-like starch.
Fat Content
Carbs (Fresh)
Protein (Dry)
Boiled 150 g
- Mild flavor; soft crumb
- Good for mash and salads
- Save a splash of pot liquor
Gentle
Roasted 150 g
- Crisp edges; creamy middle
- Toss with oil near the end
- Finish with herbs and salt
Bold
Stew Or Soup
- Starch thickens broth
- Add late to hold shape
- Pair with beans or dairy
Hearty
American Groundnut Nutrition—Core Facts
This legume forms edible chains of tubers with a nutty, potato-adjacent flavor. Studies describe two standout traits: a higher protein share than common roots and a useful supply of starch for energy. The numbers people quote come from lab work on fresh and dried samples. That’s why you’ll see protein expressed per dry weight in many papers.
Across agronomy references, tubers often land near 13–17% protein on a dry basis, with amino acids present across the board, yet lighter in sulfur amino acids than soy. The carbohydrate fraction sits near one-third of the fresh tuber by weight, mostly as starch. Fat is low, with small amounts of linoleic-rich lipids reported. These points show up consistently in peer-reviewed work and field guides.
| Component | Typical Range | Basis/Notes |
|---|---|---|
| Protein | 13–17% | Dry weight; more protein than potato per gram of dry matter. |
| Carbohydrate | ~36% | Fresh weight; starch-forward energy similar to potato. |
| Dietary Fibre | Moderate | Arabinose-rich fractions noted in lab reports. |
| Fat | ~4–5% | Low overall; linoleic acids dominate the small fat share. |
| Minerals | Calcium & Iron | Reports describe higher calcium and iron than potato. |
| Amino Acids | Broad set | Sulfur amino acids trend lower than in soy. |
Want primary material? The USDA plant guide summarizes dry-basis protein ranges and agronomic context, while a UK team profiled UK-grown tubers and documented amino acids and fibre in a peer-reviewed analysis.
What A Serving Looks Like
A practical plate portion sits near 150–200 g cooked, roughly the size of a medium potato. That serving works as a side with greens and fish, or inside a bean-heavy bowl. Because the tuber belongs to a legume, the taste lands between new potatoes and roasted chestnuts, so it plays nicely with herbs, garlic, and dairy.
Protein per cooked bite won’t match a full cup of lentils, yet the tubers bring more protein than many roots on a dry basis. Pairing with beans or dairy bumps the total and rounds off sulfur amino acids. Salt lightly, use herbs, and add a drizzle of oil after cooking rather than before to keep the crumb tender.
How It Compares To Familiar Staples
Think of this food as a starch with a bit more protein headroom. Potato offers about 2 g of protein per 100 g raw, and sweet potato sits near 1.6 g per 100 g raw. The legume tuber’s lab values show a higher protein share on a dry basis, which helps when you mash it with bean broth or fold it into stews. That blend gives you comfort and better protein balance in the same bowl. For reference values on potato and sweet potato, see USDA-based potato data and USDA-based sweet potato data.
Buying, Storing, And Prepping
Look For Fresh, Firm Chains
Fresh chains hold multiple bead-like tubers. Pick firm pieces with tight skin and skip any with soft spots. If you’re buying from a grower, ask when they were lifted. Fresher lots cook evenly and keep their creamy texture.
Storage That Keeps Texture
Refrigerate in a breathable bag. Field guides mention long refrigerated holding is possible; flavor stays clean and the flesh doesn’t turn watery. Don’t seal them wet. Surface moisture encourages off aromas.
Prep That Respects The Grain
Scrub well. Peel if the skin feels tough, or leave it on for roast dishes where you want bite. Cut pieces to similar size so the batch finishes together. Salt the water for boiling. For roasting, toss with oil and herbs near the end so the edges don’t dry out.
Cooking Methods And Nutrition Give-And-Take
Boiling
Boiling leaves the flavor gentle. Some soluble nutrients move into the water, so save a splash of the cooking liquid for mash. It returns body and starch while keeping the salt level in check.
Roasting
Dry heat sweetens the flavor and crisps the edges. Keep pieces medium in size to avoid a hard shell. Oil late, not early. A quick toss in warm oil after roasting gives gloss without toughening the outside.
Stewing
Stewing locks the starch into the broth. Add chunks in the last third of cooking so they hold shape. Team the tubers with beans or lentils to round out amino acids in the bowl.
| Method | What Changes | Simple Tip |
|---|---|---|
| Boil | Mild taste; soft crumb | Return a ladle of cooking liquid to mash |
| Roast | Crisp edges; creamy center | Toss with oil after roasting for shine |
| Stew | Starch thickens broth | Add in the last third for shape |
Protein Quality And Pairings
Across studies, the amino acid spread looks broad. Sulfur amino acids trend lower than in soy, so a bowl that pairs tubers with beans, dairy, or a little meat fills the gap. That’s classic legume logic: mix foods to level up the profile without chasing grams on a label.
Seeds from this vine pack even more protein than the tubers. Lab work reports figures above 25% for seed meal. Home cooks rarely use seed meal, yet the point stands: this plant produces protein across organs, not just in the tuber chain.
Allergy And Safety Notes
This vine is a latex-bearing species. People with latex allergy react to a range of plants, so proceed with care the first time you try it. Peel, cook well, and start with a small serving. If you’re sensitive, skip it.
Sourcing And Sustainability
Growers in temperate regions raise this vine on trellises and harvest in cool months. Yields differ by site and season because tubers form along strings that can run far from the crown. That spread makes field harvest slow, which is why you’ll find this food at specialty farms and foragers more often than in bulk markets.
Many cooks treat the tuber like new potatoes: boil, roast, or stew, then finish with herbs, butter, or olive oil. The payoff is a side dish with comfort built in and a little more protein headroom than common roots.
Evidence Trail
A USDA species guide summarizes dry-basis protein ranges for tubers, and a UK research group charted amino acids, fibre, and minor lipids in UK-grown samples. Together, those sources give a clear picture for the kitchen: treat it like a starchy side, and pair with legumes or dairy when you want more protein per plate.