Peanut meal is the protein-rich byproduct left over after oil is extracted from peanuts. It typically contains around 45% protein, making it one of the more concentrated plant-based protein sources available for animal feed, organic fertilizer, and increasingly, human food products. Most peanut meal is produced at industrial scale from peanut oil operations, and its quality depends largely on how the oil was removed.
How Peanut Meal Is Produced
Peanut meal starts with shelled, roasted peanut kernels. From there, one of two main methods removes the oil. The first is mechanical pressing, where kernels are crushed through a screw press to squeeze out the oil. This leaves behind a partially defatted cake that still contains some residual fat. The second method uses a chemical solvent, typically hexane, to dissolve and pull out nearly all the oil over several hours. Many operations combine both: pressing first to remove the bulk of the oil, then finishing with solvent extraction to get the rest.
The extraction method matters because it determines how much fat remains and how the protein behaves. Solvent-extracted meal is very low in fat (around 1 to 3%) and tends to have different functional properties than mechanically pressed meal, which retains more fat and often more flavor. The solvent extraction process takes longer and costs more, but produces a more shelf-stable product with higher protein concentration by weight.
Nutritional Profile
Peanut meal’s protein content ranges from about 40% to 51%, with an average around 45.6%. The remaining composition includes roughly 8.3% fiber, 5% ash (mineral content), and 2.5% fat in solvent-extracted versions. That protein level puts it in the same league as soybean meal, which is the dominant protein supplement in animal agriculture worldwide.
Peanuts themselves are rich in B vitamins and minerals, and much of that carries over into the meal. Per 100 grams, peanuts provide 75% of the recommended daily intake of niacin, 60% of folate, and 53% of thiamin. On the mineral side, they’re notably high in copper (127% of daily needs), manganese (84%), iron (57%), phosphorus (54%), and magnesium (42%). Potassium is also substantial at 705 mg per 100 grams. These values shift somewhat in defatted meal since removing oil concentrates everything else, but the general mineral and vitamin profile remains strong.
One nutritional limitation worth noting: peanut meal is low in the amino acids lysine and methionine. These are essential amino acids that animals (and humans) can’t produce on their own, so diets built heavily around peanut meal need supplementation to fill those gaps. In poultry nutrition, adding synthetic threonine to peanut meal diets has been shown to produce results identical to soybean meal diets, with matching egg production, feed consumption, and efficiency.
Animal Feed Uses
The primary market for peanut meal is livestock feed, particularly for poultry, swine, and cattle. It serves as a protein supplement mixed into grain-based diets. Research on laying hens has tested inclusion rates of around 4% to 8% of the total diet with good results. At 8% inclusion of high-oleic peanut products, digestibility actually improved without any drop in production performance.
Head-to-head comparisons with soybean meal show peanut meal holds its own. In one study with commercial laying hens, corn-and-peanut-meal diets produced virtually identical results to corn-and-soybean-meal diets across protein levels of 16%, 18.5%, and 21%. Feed consumption was 93.8 grams per hen per day for peanut meal versus 93.7 for soybean meal, with egg production at 92.2 eggs per 100 hens per day for both. The practical difference was negligible.
The main challenges with peanut meal in feed are its amino acid imbalances, lower protein digestibility compared to soybean meal, and the risk of aflatoxin contamination. It also contains anti-nutritional factors like trypsin inhibitors (which interfere with protein digestion) and phytic acid (which binds to minerals and blocks their absorption). Fermentation can dramatically reduce these problems. Studies have shown fermentation cuts trypsin inhibitor content from 0.30% down to 0.03% and phytic acid from 1.43% to 0.35%.
Aflatoxin Risk and Safety Limits
Aflatoxin contamination is the single biggest safety concern with peanut meal. Aflatoxins are toxic compounds produced by mold that commonly grows on peanuts during storage, and they can carry through into the meal. The FDA sets strict action levels for peanut products based on how they’re used. For human food, the limit is 20 parts per billion (ppb). For animal feed, it varies by species and age: immature animals and dairy cattle get the same 20 ppb limit, breeding animals and mature poultry are allowed up to 100 ppb, finishing swine can tolerate up to 200 ppb, and feedlot beef cattle up to 300 ppb.
Fermentation has emerged as an effective way to reduce aflatoxin levels. In one study, the most dangerous form of aflatoxin (B1) dropped from 43.87 micrograms per kilogram to 6.20 after fermentation, well below the international safety threshold of 20 micrograms per kilogram set by the FAO and WHO.
Human Food Applications
While most peanut meal goes to animal feed, food-grade versions are finding their way into human diets. Defatted peanut flour, which is essentially finely milled peanut meal, shows up in baked goods, extruded snacks, meat substitutes, and dairy alternatives. Researchers have also used peanut meal as a primary ingredient in composite snacks, combining it with sorghum and okra to create shelf-stable products.
One of the more novel applications is plant-based meat. Using high-water extrusion, peanut meal proteins can be unfolded and reorganized into fibrous structures that mimic the texture of animal meat. The proteins reform through hydrogen bonds and other molecular interactions, gradually building a layered, meat-like structure. Peanut meal can also be enzymatically broken down into protein hydrolysates, which are used as flavor enhancers or functional ingredients in processed foods.
Use as Organic Fertilizer
Gardeners and organic farmers use peanut meal as a slow-release nitrogen source. Peanut seed meal has an approximate NPK ratio of 3.6-0.7-0.45, meaning it’s relatively high in nitrogen with modest phosphorus and potassium. That makes it well suited for feeding leafy plants and building soil organic matter over time. Peanut shells offer a different profile at 0.8-0.15-0.5, contributing more to soil structure than nutrition. Interestingly, burned peanut shell ash flips the ratio entirely to 0-1.23-6.45, making it a potassium-heavy amendment.
Because peanut meal breaks down gradually through microbial activity in the soil, it feeds plants over weeks rather than delivering a quick hit of nutrients. This makes it popular in organic gardening where synthetic fertilizers aren’t used. It’s typically worked into the top few inches of soil or used as a side dressing around established plants.