Peanuts and peanut butter are whole foods that pack a lot of nutrition into just one serving. In the legume or dried bean family, peanuts are a terrific protein source. But the story gets better and better when you consider the significant amounts of the following nutrients found in a single ounce of peanuts.
The peanut or groundnut (Arachis hypogaea) is a species in the family Fabaceae (commonly known as the bean, pea or legume family).
Because, in botanical terms, “nut” specifically refers to indehiscent fruit, the peanut is not technically a nut, but rather a legume. Peanuts are often served in a similar manner to true nuts in many western cuisines, and are often referred to as a nut in common English.
The peanut was probably first domesticated and cultivated in the valleys of Paraguay. The specific name, hypogaea means “under the earth”; after pollination, the flower stalk elongates, causing it to bend until the ovary touches the ground.
Although the peanut was mainly a garden crop for much of the colonial period of North America, it was mostly used as animal feed stock until the 1930s. In the United States, the US Department of Agriculture initiated a program to encourage agricultural production and human consumption of peanuts in the late 19th and early 20th centuries. George Washington Carver developed hundreds of recipes for peanuts during his tenure in the program.
Health & Nutrition Research
When it comes to eating peanuts, peanut butter, and peanut oil, the research is clear: they benefit our health. Large population studies show that when eaten in small amounts daily, peanuts reduce the risk of many chronic diseases (Sabate, 2006; 2009). Human feeding studies also show that they help manage weight and provide many key nutrients that are important to our diets (Sabate, 2006; 2009).
The myriad of healthy components in peanuts offers natural nutrition to all populations and age groups. You can feel good getting filled up on a crunchy pack of peanuts or a spoonful of peanut butter, knowing that each bite is leading to having a better body and a better diet. Learn more about how peanuts can help your short and long-term health by checking out the disease prevention, weight management, and protective nutrients sections.
Peanut Grading, Shelling and Blanching
At the shelling company buying station, peanuts are sampled and graded by the Federal-State Inspection Service to determine their value. The inspectors establish the meat content, size of pods, kernel size, moisture content, damaged kernels and foreign material. The results of the inspection determine the overall quality and value of each load.
After the peanuts are purchased by the sheller, they are placed in dry storage for eventual sale to processors and manufacturers. At the shelling plant, peanuts are taken from storage and cleaned; dirt, rocks, bits of vines and other debris are removed. If they are to be sold in their shells, the peanuts may also pass through a machine that cuts off any remaining stems on the shells. (About 10% of the peanut crop is sold as in-shell peanuts – usually the Virginia and Valencia types.) To sort for size, the peanuts travel over sizing screens that permit the smaller pods to fall through.
Peanuts to be shelled are placed in slotted drums containing screens of different sizes. Rotating peanuts rub against each other until the shells are opened and the kernels fall out. The kernels are sized on screens that permit the smaller kernels to fall through. The shelled peanuts are cleaned again to remove foreign materials. This is done with density separators, electronic color sorters and by visual inspection to ensure that only the best peanuts reach the market. The peanut kernels are then sized, graded and bagged for market.
From the sheller, peanuts are cleaned again and “blanched” before they are used in most peanut foods. Blanching is simply the removal of the reddish skin covering the kernels. In whole-nut or split-nut dry blanching, the kernels travel through warm air for a period of time to loosen the skins. Then the kernels go through a blanching machine where large rollers rub the surfaces of the kernels until the skins fall off. These kernels are checked with electronic color sorters to ensure that blanching is complete.
Selection & Storage
Peanuts can be available in the markets year around. In the stores, different forms; shelled, unshelled, salted, sweetened etc can be found for purchase. Try to buy unshelled (intact outer shell) nuts instead of processed ones. They generally available in the airtight packs as well as in bulk bins. The pods should feature compact, off white color healthy-looking shell, uniform in size, and feel heavy in hand. They should be free from cracks, mold, and spots and free of rancid smell.
Unshelled groundnuts can be placed in cool dry place for many months, whereas shelled (without the shell) nuts should be placed inside airtight container and kept inside the refrigerator to avoid them turn rancid.
Preparation & Serving Methods
Peanut kernels usually eaten as is, by cracking them with firm pressure between fingers or using clippers, or nutcracker machine. The nuts can also be enjoyed roasted, boiled, salted, or sweetened.
They are nutty, yet pleasantly sweet in taste. Roasting enhances taste, augments antioxidants levels like p-coumaric acid, and helps remove toxic aflatoxin.
Roasted and crushed kernels often sprinkled over salads, desserts, particularly sundaes and other dairy based preparations.
Boiled peanuts possess unique flavor and taste. Boiling, in fact, enriches their nutritional and antioxidants profile.
Peanut butter is a food-paste made of ground-roasted nuts, with or without addition of oil. It is popular throughout the world and commonly used as dip/spread. Peanut-milk is also a popular lactose-free milk like healthy drink.
Peanut “chutney” or paste, made from these nuts, chili peppers, salt, coriander leaves, garlic and mustard seeds, is a popular dip among south Indian, Sri Lanka region.
Peanut oil is another healthy source of edible cooking oil like soy or olive oils. It is widely employed in cooking for its aromatic flavor, especially in many South Indian states, and Sri Lanka.
Peanut allergy is a type of hypersensitivity response in some people to food substances prepared using these nuts. The resultant over-reaction of the immune system may manifest as severe physical symptoms like vomiting, stomach-pain, swelling of lips and throat leading to breathing difficulty, chest congestion, and sometimes death. It is, therefore, advised to avoid any food preparations that contain peanut products in these individuals.
Peanuts are one of the crops that are susceptible to fungal (mold) infection, especially by aspergillus flavus which produces aflatoxin. Aflatoxin is a very powerful and dangerous known carcinogen that may cause liver cirrhosis and cancer. Roasting helps reduce toxin levels in these nuts and thus offers some protection against aflatoxin.