Peanuts (Zambia)

Page 1: Peanuts - General
Page 2: Peanut in Zambia
Project page: Nutrito peanut products

1) Peanuts – General


The plant originates from the Andes in South America. During the Inca era, peanuts were considered a heavenly food due to their high nutritional value and were given to the deceased as a burial supplement for their life after death. Already more than 8,000 years ago the peanut plant was cultivated in South America and later also a peanut cream was produced, which was completed with cocoa and honey. At the time of the slave trade, peanuts first reached Africa and then North America. Spanish and Portuguese conquerors brought it to India, Malaysia and the Philippines, from where it spread to China.

Nowadays, China is considered the largest peanut producer, followed by India, Nigeria and the United States. The main producing and exporting countries are the USA, Argentina, Sudan, Senegal and Brazil. China and India produce mainly to cover their own needs.

The plant

Contrary to the obvious assumption based on its name, the peanut is not a nut, but a legume (family Fabaceae). The peanut plant belongs to the subfamily of the Faboideae as do the pea or bean. In English the name comes from the combination of the words “pea” and “nut“. The German name “Erdnuss” (groundnut, “earthnut”) is based on the fact that the fruits of this plant grow in the soil. It has the high fat content, the crunchy consistency and the possibility of raw consumption in common with “real” nuts.

There are different types of peanuts and the most famous are Virgina, Spanish, Valencia and Runner.

The peanut plant grows particularly well in tropical and subtropical areas and prefers warm, sunny regions (ideally approx. 30-34°C for germination, 25-30°C for further growth) with moderate rainfall (approx. 500 mm)). Temperatures above 35°C and waterlogging have a negative effect on the development of the plant. In order to protect the soil and increase the yield, peanuts should be cultivated in three-year crop rotations, for example with maize or small cereals and potatoes or cotton.

The peanut herb, about 50 to 80 centimetres high, forms flowers above ground on the stem. Insects sometimes fertilise the plants, but normally they fertilise themselves. Subsequently, the fruit cots grows down into the soil and form pods, in which usually two seed kernels develop, which are additionally protected by a thin, reddish-brown seed shell. Depending on the species and climatic conditions, ideally about 40 peanuts are formed per plant. As this is an annual plant, new seeds must be planted every year. The complete growth process – from sowing the kernel to the ripe peanut – takes about 100 to 160 days.

Nutrients and health hazards

Peanuts are rich in fibre and protein (23 – 27 %), have a high fat content (approx. 45 – 52 %) and contain a large number of minerals such as potassium, phosphorus, magnesium, calcium, iron and zinc as well as vitamins such as niacin (B3) and vitamin E.

Compared to other food allergies, peanut allergy is particularly common in the population because these legumes contain many allergens.

Under circumstances such as poor growing conditions (e.g. drought), contact with moisture after harvesting or other adverse storage conditions, mould may form on the peanuts (Aspergillus flavus), which may give rise to toxic aflatoxins. These are naturally occurring fungal toxins of which various species are known. In particular, the compound aflatoxin B1 is considered dangerous for humans as it can have a carcinogenic effect.

Use of peanuts

Peanuts can be purchased unpeeled, nevertheless peeled, roasted and salted peanut kernels are more often found in packaging ready for consumption. Roasting counteracts the risk of mould poisoning. Processed products such as peanut butter, peanut flips and peanut oil are popular. Especially in China and India, the latter is used as an edible oil and as a herbal remedy. In addition, peanuts are used in the food industry, for example in cosmetics (e.g. bath and massage oil, face cream, soap), in the chemical industry, in the manufacture of explosives or cat litter and as an oil-containing feed additive for pet food.

The peanut paste “Plumpy’nut” contains peanut butter, sugar, oil and milk powder and was produced specifically for the purpose to treat moderate malnutrition in crisis areas and famine.

Peanut shells are also used, for example in the production of paper, briquettes, shampoo, packaging material and, in rare cases, in biomass power plants.

Peanut Butter – Production

There are various theories about the invention of peanut butter. It was finally patented in 1895 by Dr. John Harvey Kellogg, who was looking for a nutritious food for his toothless patients, but is nowadays best known as a co-inventor of cornflakes.

It is an energy-rich and nutritious food. The consistency of peanut butter is similar to that of butter. Due to legal regulations in Germany the term “butter” is used for products made from milk; therefore peanut butter is often sold under names such as peanut cream or peanut paste. A good peanut butter consists of over 90 % peanuts. In addition, salt, spices, oil, sugar or sweeteners and stabilizers are added. Besides, there is peanut mush / puree, which usually consists of 100% peanuts and contains no additives.

Peanuts with a high oil content are particularly suitable for the production of the popular bread spread. First, the peanuts are dried, pre-cleaned and selected. Then the outer shell (pod) is removed and the peanut kernels are sorted by size. During the subsequent roasting process (continuous or batch, at 160 – 170 °C for 40 – 60 minutes), the water content of the peanuts is reduced to about 1 %. Cooling in cooling boxes or on a conveyor belt is necessary before the red seed skins are removed in the next step, the “blanching” which is done using either water or heat. During the subsequent grinding process, the seeds are heated to about 170°C and often grinded in two different stages to obtain a particularly fine peanut cream. In order to prevent the oil from settling on the surface and the solid components from settling on the bottom, stabilisers (mostly hardened vegetable fats or oils) are added in order to create and maintain a homogeneous mixture. Other ingredients such as salt and sugar are added. The mixture is cooled to about 120°C and filled into glasses. One peanut kernel weighs about 0.5 – 0.6 g. Thus about 400 peanut kernels are needed for a glass of peanut butter (assuming peanut content of 90 %).

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